Wind Flow Patterns at the University of Arizona Agricultural Centers

Item Type text; Book

Authors Brown, Paul W.; Machibya, Teles; Russell, Bruce

Publisher College of Agriculture, University of Arizona (Tucson, AZ)

Download date 11/10/2021 07:39:41

Link to Item http://hdl.handle.net/10150/310802 WIND FLOW PATTERNS AT THE UNIVERSITY OFARIZONA AGRICULTURAL CENTERS

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Any products, services, or organizations that are mentioned, shown, or indirectly implied in this publication do not imply endorsement by The University of Arizona. WIND FLOW PATTERNS

AT THE UNIVERSITY OF ARIZONA AGRICULTURAL CENTERS

Paul W. Brown Teles Machibya Bruce Russell

June 1995

Technical Bulletin 268

The University of Arizona Agricultural Experiment Station Tucson, Arizona 85721 TABLE OF CONTENTS

Page

Introduction 1

Methods 1

Source of Wind Data 1 Wind Instrumentation and Sensor Exposure 2 Wind Direction Analysis 4 Wind Speed Analysis 5

Results 5

Presentation of Wind Analysis 5

Wind Rose Diagrams 5 Wind Speed Diagrams 7

General Information On Wind 7

Brief Background On Wind 7 Wind Terminology 10 Converting Wind Speed To English Units 11

Wind Flow Patterns: Campus Agricultural Center (Tucson) 12 Wind Flow Patterns:Citrus Agricultural Center (Waddell) 41 Wind Flow Patterns: Marana Agricultural Center 70 Wind Flow patterns: Maricopa Agricultural Center 99 Wind Flow Patterns: Safford Agricultural Center 128 Wind Flow Patterns: Yuma Agricultural Center 157

Mesa Farm 157 Valley Farm 186

Literature Cited 215

iii INTRODUCTION Wind is a meteorological parameter that impacts a wide variety of biospheric processes. A simple listing of items transported by wind - atmospheric pollutants, water vapor, carbon dioxide, other greenhouse gases, heat, pesticides, insects, pathogens, pollen, and soil - clearly shows the important role of wind in the earth's ecosystem. In addition wind also effects human and animal comfort, serves as a source of renewable energy (wind mills /generators) and destroys property and lives throughout the world.

The University of Arizona (UA) College of Agriculture works on a variety of wind -sensitive research projects at its six agricultural centers (ACs). Among the current wind -sensitive projects are tillage studies designed to reduce the production of agricultural dust, migration studies of the sweet potato whitefly (Bemisia tabaci (Gennadius)) and various crop water use studies. Research and farm staff also regularly work with registered and experimental agricultural chemicals and occasionally with genetically altered materials. Knowledge of wind flow patterns can be of value when planning or conducting studies with these materials, or if necessary, when applying for permits to use the materials.

The idea for this publication was initially developed during the winter of 1992/93 when migration of sweet potato whitefly was a major concern of both agricultural producers and UA researchers. In response to these concerns, the authors began to summarize wind direction data collected at ACs where whitefly research was currently in progress. The scope of this effort was subsequently expanded to 1) include wind speed in the analysis and 2) cover all UA ACs. This report summarizes the results of this effort and provides information on the wind flow patterns at each of the six UA ACs as observed by the local automated weather stations operated by the Arizona Meteorological Network (AZMET). Wind flow patterns - both speed and direction - are presented for each hour of the day for each month of the year to provide the end user with maximum flexibility.

METHODS Source of Wind Data Wind data from automated agricultural weather stations operated by the Arizona Meteorological Network (AZMET) were used in this analysis (1). AZMET operates single weather stations at five UA ACs - Citrus (Waddell), Maricopa, Marana, Campus (Tucson) and Safford - and two stations at the Yuma AC. One station at the Yuma AC is located in Yuma Valley and the other station resides on the Yuma Mesa. AZMET weather stations are installed in open areas adjacent to irrigated agricultural land. The surface underneath and in the immediate vicinity ( -100 m2) of the weather station is irrigated turfgrass. The land surrounding AC weather stations is typically allocated to field research plots. At the Yuma and Safford ACs, the stations reside near the farm boundaries and are adjacent to private agricultural land which is placed in production nearly every year. Crop production in the areas adjacent to the AC weather stations is typically some form of row crop with the exception of the Yuma Mesa and Citrus ACs where adjacent areas are in citrus production. Typical crops grown in the immediate vicinity of AC weather stations are:

1 Campus AC Pasture, Cotton, Vegetables Citrus AC Young Citrus* Marana AC Cotton, Small Grains, Vegetables Maricopa AC Cotton, Jojoba, Agave, Vegetables Safford AC Cotton Yuma AC Valley Farm Cotton, Vegetables, Small Grains Mesa Farm Mature and Young Citrus, Alfalfa

* Bare soil prior to planting of small citrus (<2 m height): May 1992

Wind Instrumentation & Sensor Exposure The wind sensors are attached to a tripod tower 3 m above ground level. Horizontal wind speed is measured with cup anemometers and wind direction with wind vanes. Cup anemometers manufactured by Met -One Inc. (model 014A) and R.M. Young Co. (model 03101-5) are employed by AZMET to measure wind speed. Both anemometers use a magnet attached to the cup assembly to generate the sensor output signal. As the cup assembly rotates in response to wind flow, the magnet rotates and either 1) repeatedly opens and closes a switch (Met -One anemometer) or 2) generates a sinusoidal voltage in a wire coil mounted underneath the magnet (R.M. Young anemometer). In the case of the Met -One anemometer, the number of switch closures per unit time is directly proportional to the wind speed. With the R.M. Young anemometer, the frequency of the voltage output signal is directly proportional to wind speed. Regardless of which anemometer is used, the output signal from the anemometer is monitored by a battery powered datalogger (model 21X or CR10) manufactured by Campbell Scientific Inc. (CSI; Logan, UT).

The instrument specifications for the two anemometers differ slightly and are presented in Table 1. These specification differences have little impact on the wind information measured by AZMET, and the two anemometers are used interchangeably at all AZMET station sites. One specification - threshold speed - does impact the accuracy of wind data collected when light wind conditions prevail. The threshold speed is the wind speed necessary to initiate rotation of the anemometer cup assembly. From the specifications listed in Table 1, it is obvious that anemometers used by AZMET do not accurately measure wind speeds below 0.5 m/s. As this publication summarizes hourly mean wind speed data, it is appropriate to extend this lower limit of wind speed accuracy to the 1.0 -1.5 m/s range since during many hours when low wind speed conditions prevail, there will be periods of calm that are not accurately measured.

2 Table 1.Specifications for anemometers used by AZMET

Specification Met -One 014A R.M. Young 03101 -5

Operating Range 0 - 60 m/s 0 - 50 m/s Threshold Speed 0.5 m/s 0.5 m/s Distance Constant 4.6 m 2.4 m Accuracy +/- 1.5 %/0.1 m/s +/ -2.0%

Wind direction is measured at AZMET weather stations using wind vanes manufactured by Met -One Inc. (model 024A) and the R.M. Young Co. (model 03301 -5). Both sensors record wind direction using the same basic principle. The wind vane hub is attached to a rheostat which produces changes in electrical resistance as the wind vane rotates. In both sensors, the rheostat is made part of a simple voltage divider circuit which, when provided with a DC voltage excitation, is engineered to provide an output voltage that is directly proportional to wind direction. The weather station datalogger provides the circuit excitation and monitors the output signal from the vane.

The specifications for the two wind vanes used by AZMET differ slightly and are presented in Table 2. The slight differences in the instruments are not considered significant for the types of wind information measured by AZMET. AZMET therefore uses these vanes interchangeably at all station sites. As indicated in the discussion of anemometer specifications, the threshold speed can impact the accuracy of wind data collected during periods of low wind speed. The threshold speed for a wind vane is the minimum wind speed required to turn the vane. Thus, the accuracy of wind direction data collected during periods of low mean wind speed may be lower than direction data collected when wind speeds are higher.

Table 2.Specifications for wind vanes used by AZMET.

Specification Met -One 024A R.M. Young 03301 -5

Azimuth, Mechanical 0 - 360 deg. 0 - 360 deg. Azimuth, Electrical 0 - 356 deg. 0 - 355 deg. Threshold 0.5 m/s 0.8 m/s Delay Distance < 1.5 m 0.5 m Damping Ratio 0.25 0.2

All wind data used in this analysis were collected using CSI 21X or CR10 dataloggers. The dataloggers were programmed to scan all sensors at 60 s (prior to 1993) or 10 s (1993) time intervals and summarize the data hourly using the CSI wind vector output processing instruction (69 for newer dataloggers or 76 for older dataloggers). The shift from 60 s to 10 s scan intervals was made to provide better information on short-term wind gusts and does not appreciably affect the data summarized in this report.

3 The CSI output processing instructions 69 and 76 provide hourly mean wind speed and the hourly resultant mean wind vector (wind velocity). The procedure used in instructions 69 and 76 are as follows:

1) The output from the anemometer and the wind vane are measured at the frequency dictated by the datalogger scanning interval (60 s or 10 s). Individual wind vectors are then obtained by pairing the wind speed and wind direction for each scan interval.

2) At the end of each hour a resultant mean wind vector is computed using the 60 (60 s scan interval) or 360 (10 s scan interval) wind vectors obtained during the hour. The mean wind speed is then computed by summing the individual scalar wind speeds obtained during the hour and dividing by the number of scans per hour (60 or 360).

NOTE! Hourly resultant wind vectors are computed using actual wind speed, not using the unit vector approach used in some dispersion models.

3) The hourly resultant mean wind vector and the hourly mean wind speed are then stored in the datalogger along with other hourly meteorological data and appropriate time and date markers for later retrieval by telephone or computer.

Wind Direction Analysis The directional component of the resultant hourly mean wind vector was used in the analysis of wind direction at each AC. Approximately six years of wind data were used in the analysis. Table 3 provides the exact starting and ending dates for the data sets used at each AC. The wind vector data were first separated by month of the year, and then within each monthly data set, by hour of day. Each month -by- hour set of direction data was then input into a commercial wind analysis software (Rose; RockWare Inc., Wheat Ridge, CO) to generate wind rose diagrams. Wind rose diagrams are circular graphs that depict the percentage of time the wind is from a particular direction. The Rose software was configured to generate eight "petal" wind rose diagrams. An eight petal wind rose breaks the standard 360 degree compass into eight 45 degree segments (petals) and provides the percentage of time the wind direction resides within each 45 degree segment. Table 4 provides the angular range (in degrees), the directional endpoints and the midpoint direction of each wind rose petal.

Table 3. Beginning and ending dates of data sets used to analyze wind flow at UA ACs. Agricultural Center Beginning Date Ending Date

Yuma (both farms) Jan. 1987 Mar. 1993 Campus Jan. 1987 Mar. 1993 Safford Jan. 1987 May 1993 Maricopa Jan. 1987 Jun. 1993 Citrus May 1987 Aug. 1993 Marana Sep. 1987 Aug. 1993

4 Table 4. Range in terms of degrees and standard compass directions, along with the midpoint direction for the eight petals used in wind rose diagrams.

Angle Range (degrees) Direction Range Midpoint Direction

0 - <45 N - NE NNE 45 - <90 NE - E ENE 90 - <135 E - SE ESE 135 - <180 SE - S SSE 180 - <225 S - SW SSW 225 - <270 SW - W WSW 270 - <315 W - NW WNW 315 - <360 NW - N NNW

Wind Speed Analysis Hourly mean wind speed data collected during the time intervals listed in Table 3 were used in the wind speed analysis. The bulk data set was sorted first by month and then by hour of day to provide 268 month -by -hour data sets. Next, cumulative frequency distributions were developed for each month -by -hour combination by first ranking the wind speed values from low to high. The ranks were then converted to percentage values by dividing by the total number of wind speed observations (highest rank) and then multiplying by 100. Wind speeds associated with the cumulative percentages of 25 %, 50 %, 75% and 100% were extracted from each distribution. Mean wind speed was also computed for each month -by -hour combination by summing the individual hourly mean wind speed values and dividing by the total number of values.

RESULTS Presentation of Wind Analyses The results from the wind direction and wind speed analyses are presented in graphical form in this report. The results from each AC are presented separately and include a brief narrative overview of the results, two topographical maps (1:24000 and 1:250000 scale) depicting the terrain surrounding the AC, wind rose diagrams and wind speed diagrams. The maps are included in each section since local topographical features often influence wind direction in Arizona. The maps, derived from standard United States Geological Survey (USGS) topographical maps, present the major features of the local topography, but eliminate many of the details provided on the USGS maps.

An explanation of the wind rose and wind speed diagrams used in this report is presented in the following sections.

5 Wind Rose Diagrams Important features of the wind rose diagrams used in this report are delineated in Figure 1. The rose diagram is a graphical representation of the standard compass and is oriented such that north is at the top of the diagram, east on the right, west on the left and south at the bottom. The wedge shaped rose petals vary in size in accordance with the percentage of time the wind is from a particular direction. Thus large rose petals reflect a high percentage and small petals a low percentage. The concentric reference circles assist the user in determining the percentage of time the wind is from a particular direction. For example, the first petal to the right of north (petal encompassing north to northeast) in Figure 1 indicates the wind is from this direction about 46% of the time. This compares with the second petal to the right of north (northeast to east petal) which shows the wind is from this direction only 7% of the time.

A final feature of each rose diagram is the presence of a solid straight line that emanates from the center of the diagram. This is call the mean vector ray and represents the vector mean for the wind direction data presented in each wind rose diagram. Users should note that the mean vector ray is a unit vector mean since only direction is used to develop this vector (magnitude of each wind vector used in the computation is assumed equal to one).

Concentric Reference Circles

Rose Petals Percent Labels

Figure 1. Example of wind rose diagram used in this report. Important features of the diagram are labeled.

6 Figure 2 provides an example of the wind rose diagrams provided in this report. To minimize space, twelve rose diagrams are placed on each page, representing either the first or last twelve hours of the day for a particular month. The location, month and hour range of the rose diagrams are provided at the top of each page. The hour of the day is provided just outside of the last concentric reference circle in the upper lefthand corner of each rose diagram. For example, the wind rose diagram located in the upper lefthand corner of Figure 2 summarizes the wind direction data collected at the Marana AC in January for the first hour of the day (hour ending at 1:00 local standard time). Likewise, the rose diagram located in the lower righthand corner summarizes the wind direction data for the Marana AC in January for the twelfth hour of the day (hour ending at noon local standard time). Figure 2 also reveals another feature common to many wind rose diagrams in this report - lack of rose symmetry when any petal exceeds the 50% level (e.g. Hr.1 vs Hr.12). This symmetry problem is inherent to the rose software and could not be eliminated by the authors.

To minimize clutter and maximize the size of each hourly rose diagram, the directional label for the four cardinal points on the compass - north, east, south and west - are not plotted on the rose diagrams. The reader is reminded that the top of the diagram represents north, the bottom south, the right east and the left west.

Wind Speed Diagrams The overall mean wind speed (solid line) and the mean wind speed values with cumulative frequencies of occurrence of 25 %, 50 %, 75% and 100% (dashed lines) are plotted by hour of the day for each month of the year. The wind speed data are presented six to a page with one page containing the data for January through June and a second page containing data for July through December (Figure 3).

A proper interpretation of the data presented from the cumulative frequency distributions (four dashed lines) is as follows:

Bottom dashed line: 25% of the time the mean wind speed is equal to or less than this value. Dashed line second from the bottom: 50% of the time the mean wind speed is equal to or less than this value. This is the median wind speed for each hour. Dashed line third from the bottom: 75% of the time the mean wind speed is equal to or less than this value. Top dashed line: 100% of the time the mean wind speed is this value or less. Note! this represents the maximum hourly mean wind speed observed over the time period presented in Table 3, and is more than likely not the highest mean wind speed ever observed (or experienced) at the particular AC.

General Information On Wind Brief Background On Wind The following paragraphs summarize some important general background information on the subject of wind. Novice users of wind information and new residents of Arizona are encouraged to read this section before examining the final results of this report. Readers with background and experience in meteorology or wind research may wish to skip this section.

7 WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER.

Month: JANUARY Hours:1 to 12

Hr. 4:......

:...... ,...... °

. .: ...... m...... Hr. 7 -so ......

.... 12...... _,..._.._ .. Hr. 11 Hr. . .ó......

......

Figure 2. Example of wind rose graphs used in this report. Each page contains twelve hourly rose diagrams covering either the first or last twelve hours of the day for a particular month. The hour label is located in the upper lefthand corner of each hourly rose diagram.

8 HOURLY WIND SPEED INFORMATION: MARANA AGRICULTURAL CENTER. January to June

January February 14 14 13 13 12 12 11 ! 11 10 10 9 9 8 8 7 \, / . , 7 6 6

5 5 4 r- 4 ti 3 3 2 2

1 1 0' 0 o 3 6 9 12 15 18 21 24 o 3 6 9 12 15 18 21 24 Hour of Day Hour of Day

March April 9 14 3 13 2 12 1 r. 11 0 10 9 t 9 8 8 7 \i, 7 6 ! '/ 6 5 -- 5 4 / \ 4 _¡ 3 w,,_ 3 __.._..``= 2 1 `_ _.._ 1

D 0 0 3 6 9 12 15 18 21 2 o 3 6 9 U 15 18 21 24 Hour of Day Hour of Day

May June 4 14 3 13 2 12 .1 i\ 11 0 'f. ., \ 10 9 9 8 8 .i 7 7 ,\ 6 .Í 6 5 / 5 4 4 . . 3 2 ''-°-- -/f 2 1 ----...,---,Y." 1 0 0 3 o 3 6 9 12 15 18 21 24 Hour of Day Hour of Day

The four dashed lines represent, from bottom to top, hourly mean wind speeds with a cumulative probability of occurrence of 25 %, 50 %, 75 %, and 100% for the period September 1987 through August 1993. The solid line depicts the overall mean wind speed for the hour.

Figure 3. Example of wind speed graphs used in this report. Wind speed data are plotted by hour of day for either the first or last six months of the year.

9 Wind is by definition air in motion. Differences in atmospheric pressure or pressure gradients are the driving force behind wind movement. Pressure gradients can develop due to 1) the presence and /or passage of large scale atmospheric pressure systems, or 2) local differences in the rate at which the lower atmosphere heats and cools. Large scale pressure systems are referred to as "highs" and "lows ", and are familiar to most people through TV weather broadcasts. Other common names for regions of low pressure are troughs, cyclones, hurricanes or depressions. In contrast, areas of high pressure are occasionally referred to as ridges or anticyclones.

Smaller scale, local pressure gradients typically affect wind flow when skies are clear and large scale pressure gradients are weak or nonexistent. The most common of these wind patterns are the sea/land breezes commonly observed along the coasts of large bodies of water (e.g. oceans and very large lakes) and the mountain/valley winds. Both of these local winds result from differential heating and /or cooling of the lower atmosphere.

Arizona rests in a latitude range where high pressure dominates the weather for much of the year. This dominance accounts for the large number of clear, dry days, and produces extended periods where large scale atmospheric pressure gradients are small. This scenario is perfect for the development of local winds. While Arizona does not have any water bodies capable of producing sea/land breeze effects, the state is filled with mountains and valleys and therefore is an ideal location for the development of local mountain/valley wind flows. In general, one can characterize the mountain/valley wind flow regime as one where the wind moves upslope or up- valley during much of the day, and downslope or down -valley during the nighttime hours. A detailed explanation of the physics of the mountain/valley flow regime is beyond the scope of this report. Interested readers may wish to consult a standard climatology text for more details (e.g. 2).

The mountain/valley wind flow pattern exists to some extent in nearly all regions where irrigated agriculture is practiced in Arizona. This is because most agricultural land rests in valleys located in close proximity to mountainous terrain. All six UA ACs reside in such areas, and therefore are subjected to this wind regime during much of the year. The intensity or regularity of the mountain/valley flow varies throughout the year due to seasonal changes in large scale weather patterns (e.g. winter storms, monsoon) and changes in earth -sun geometry (day length, solar angle, solar azimuth).

Wind Terminology The terminology and conventions used to describe wind flow can be confusing and often are misused or misinterpreted. Typically, both the direction and the speed of the wind are measured. When the wind is described both in terms of a speed and a direction, it becomes a vector quantity and is given the term velocity. Thus, a wind velocity might be reported as a wind from the south (180 degrees) at 3 m/s. The term wind velocity is often incorrectly applied to the scalar wind variable known as wind speed. Wind speed is a measure of the local flow of air across a particular measurement point irrespective of direction. In the example presented above, the wind speed would be 3 m/s.

The example in the previous paragraph also highlights another important convention when reporting wind direction. Notice that the velocity is reported as a "wind from the south ". Meteorologists always report winds in terms of the direction from which the wind is blowing. For example, a north wind means the wind is blowing from north to south. Likewise, a west wind indicates wind movement from west to east.

10 Converting Wind Speeds To English Units The metric unit m/s is used when presenting wind speed data in this report. The most common English units for wind speed are miles per hour (mph) and miles per day (mpd). The proper factors to convert wind speed in m/s to units of mph or mpd are as follows:

To convert from m/s to mph: multiply by 2.237 To convert m/s to mpd: multiply by 53.69

11 Wind Flow Patterns: Campus Agricultural Center (Tucson)

The Campus Agricultural Center is located in Pima County on Campbell Avenue just north of the Tucson city limits and south of the Rillito River (Figure 4). The weather station at the AC resides on the west side of Campbell Avenue. Major topographical features located near the AC include the Santa Catalina Mountains to the north and northeast, the Rincon Mountains to the east and the Tucson Mountains to the west (Figure 5).

A typical diurnal pattern of wind speed is observed at the Campus AC with wind speeds reaching minimum levels in the early morning hours and maximum levels in the late afternoon hours. Overall, winds are relatively light at the AC. Mean wind speeds during the peak afternoon periods do not exceed 4 m/s in any month and average less than 3 m/s from August through December. The windiest weather occurs during the spring months of March and May. Extended periods of high wind speed are rare, and hourly mean wind speeds in excess of 10 m/s have been measured only three times in the past six years.

The mountain /valley wind flow in Rillito River bottom produces a very reliable wind flow pattern at the AC. Wind flow is downriver (from the east or southeast) during the late evening and early morning hours and upriver (from the west or northwest) during the afternoon and early evening hours. The transition from downriver to upriver flow typically occurs during the late morning hours during the summer and near noon in the winter. The switch from upriver to downriver flow generally occurs two to three hours after sunset.

12 o .5 1 * kilometers Scale tt MN 1:24,000 GN o .5 1 i miles Elevation in Meters GN MN 0 °02' 12°

= Farm Boundary

1990

Figure 4. Topographical map (1:24,000 scale) showing the location of the weather station (O+) at The University of Arizona Campus Agricultural Center and important features of the surrounding terrain.

13 Mount Kimball 2211

Scale 0 5 10 MN 1:250,000 r 1 r i 1 1 kilometers GN

Elevation in Meters 0 5 10 GN MN II I ! f 1 miles 0 °02' 12°

1990 Figure 5. Topographical map (1:250,000 scale) showing the location of the weather station (C+) at The University of Arizona Campus Agricultural Center and important features of the surrounding terrain.

14 HOURLY WIND SPEED INFORMATION: CAMPUS AGRICULTURAL CENTER. January to June

January February

1 1 0 .'+ `.5,:

8 ° i

7 7 \ .i 6 6

5 5 4 \ 4 3 .. \ 2 .. "._. t-' .. .__ .. ,`,,.,_., 1 - ._.._ ._ ._.._.._.._ ..-... _._ ---_. /_ 0 0 3 6 9 12 15 18 21 2 Hour of Day Hour of Day

March April 12 2

11 1

10 0

9 9

8 8

7 7 ' . '''' 6 6 , 5 i:

4 4 5. \ 3

2 - r 2 ._.. .._.._ _' .., : ._.._.. -_..___.r.._.._.._.._ _.._.._... o ` o 3 6 9 12 15 18 21 24 0 3 6 9 12 15 18 21 2

. r Hour of Day Hour of Day

May June h 2

1 1

0 0

9 9

8 i" 8 7 / 7 i _ ' 6 f \ / 6 r' 5 5

3 -- \` 2 2 '_. ¡,/-'\ ..-.._...... _ , ._..._.._ ,...-` 1 '\.._.._.. -' -"-'----'-,' Ó o_ _ _ ._ ._ _. .. 21 Hour of Day Hour of Day

The four dashed lines represent, from bottom to top, hourly mean wind speeds with a cumulative probability of occurrence of 25 %, 50 %, 75 %, and 100% for the period January 1987 through March 1993. The solid line depicts the overall mean wind speed for the hour.

15 HOURLY WIND SPEED INFORMATION: CAMPUS AGRICULTURAL CENTER. July to December

July August h z

1 1

0 o

9 9 .' 8 i. 8 it ...... 7 6 f ` 6 / . .., . 5 i 5 ..-. 4

2 2 -. _.,- +...' _---i,'_' /. ` '_' -. 1 ..._ ._..-...... _..-.._. ,°- 1 - ._.. '----° 0 . 0 0 3 6 9 12,15 18 21 2 Hour of Day Hour of Day

September October 12 Z

11 11

10 0

9 9 8 / E 7 1...... 7 ...... 6 6 .. 5 b 5 - 4

3 3

1 1 __--.' ..._..-..-.._.._.._...... _..._»_... 0 0 o 3 6 9 12 15 18 21 24 0 3 6 9 12 15 18 21 2+ Hour of Day Hour of Day

November December

..4 12

.1 11

o 10

9 -... ¡ 9 8 . 8 . ... 7 7 6 / 6 5 5

4 4

3 ,J '\ 3 ,' .. .. 2 ..._.._..-.._.._...... -.- ._.... 1 0 0 o 3 6 9 12 15 18 21 Hour of Day Hour of Day

16 WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER. Month: JANUARY Hours:1 to 12

Hr. 2 50...... , Hr...... 55...... ,

...... ,., Hr. 10 ...... WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER. Month: JANUARY Hours: 13 to 24

Hr. 13.,...... SD...... Hr. 14 93...... Hr. 15

......

...... 50......

...50... . Hr. 22..,...... ,

18 WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER.

Month: FEBRUARY Hours:1 to 12

...... 50...... ,..

Hr. 10...... 50... Hr. 11 ...... ,...... ,.

...... 50......

19 WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER. Month: FEBRUARY Hours: 13 to 24

Hr. 14 50...... Hr. 15 50......

50,......

Hr. 17 ...... SD.,...... ,,..

Hr. 21

......

50,.,,,..,., 51)......

Hr. 23..:...... 50...... ,...... ,. Hr. 24...... 50...... ,,

50 90 00 ED 10

.....50..... 20 WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER. Month: MARCH Hours:1 to 12

Hr. 2 5°.,...... ,

...... SD..,......

. .... Hr. 12......

21 WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER. Month: MARCH Hours: 13 to 24

...... 50......

Hr. 19 50..... Hr.20 ...... 5°...... Hr. 21 ...... 50......

...... 50......

Hr. 24...... 50...... ,

22 WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER. Month: APRIL Hours:1 to 12

Hr. 1 ,.50...... Hr. 2 so......

Hr.

50 9b 30. 20 lü

so...... 50......

50...... Hr. 10 Hr. 11...... 50.... Hr. 12 ...... 50

....50...... WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER. Month: APRIL Hours: 13 to 24

Hr. 13 5°. Hr. 14 50 Hr. 15...... 5°......

...,,......

SD.....,,..,

Hr. 16 ...... 50...... Hr. 18...... 5°.,......

24 WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER.

Month: MAY Hours:1 to 12

.,...,..,,,. .: y......

Hr. 11 ......

25 WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER. Month: MAY Hours: 13 to 24

Hr. 15 ...... 5°......

5,......

Hr. 16...... "... Hr. 18...... "......

50 i{3 0F} 30 %3 5t1 50

......

Hr. 21...... 51'...... WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER. Month: JUNE Hours:1 to 12

. ..5°...... Hr. 12......

50 18

27 WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER. Month: JUNE Hours: 13 to 24

...... ,

Hr. 19 5°...... , Hr.20 50...... ,. qo......

EO 30 50 50 9

90...... _

5......

50...... Hr. 22 ...... ,.,..,...

28 WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER.

Month: JULY Hours:1 to 12

Hr. 1 5, .. r. .,...,.....,

29 WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER. Month: JULY Hours: 13 to 24

......

so......

Hr. 17 ...... 5°.,...... Hr. 18 ...... 5C......

5n...... 50......

Hr. 20 5°......

...... ,, Hr. 24 ....

30 WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER.

Month: AUGUST Hours:1 to 12

Hr. 8..,,...... sp.....,....,

31 WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER. Month: AUGUST Hours: 13 to 24

.....5° Hr. 14 ...... Hr. 15 ,.,...... 5°.....

...... ,

Hr.17 ...... 5...... ,.

32 WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER. Month: SEPTEMBER Hours:1 to 12

Hr.

...... 50...... ,..... Hr. 11 Hr. 12 ...... 50...... ,

50 90 30

,..gp......

33 WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER. Month: SEPTEMBER Hours: 13 to 24

34 WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER. Month: OCTOBER Hours:1 to 12

Hr. 1 ...... 50

Hr.

50 40 30.,...,

qo......

5,...... ,...50...,...,.

Hr. 10 ...... 5°...,.,.,. Hr. 11 5o......

35 WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER. Month: OCTOBER Hours: 13 to 24

Hr. 13 5°......

,....,. p,....,,....,.

Hr. 16...... p...... Hr. 17 ...... ,...... ,...,,

...... Hr. 19 ....

Hr. 22 ...... 50......

36 WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER. Month: NOVEMBER Hours:1 to 12

Hr. 7 5ó

sò -143 zá

Hr. 12:...... "...

37 WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER. Month: NOVEMBER Hours: 13 to 24

:,,..

50..,..... Hr. 19 50.... Hr. 21

3D 40 50 50 10 3 . ..2D -` :..:.: 5

. gp......

38 WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER. Month: DECEMBER Hours:1 to 12

... Hr. 5 50......

...... 50...... Hr...... 50......

..,10...... :'

só 99 . 30 EP. ig.a

...... SFI,......

Hr. 10 ...... Hr. 12 55......

50...... WIND ROSE DIAGRAMS: CAMPUS AGRICULTURAL CENTER. Month: DECEMBER Hours: 13 to 24

Hr. 13 50

30...

so,.,.....,. Hr. 19 so ......

.,,,,,,.3p...,...

,.,,,.,.

..,..,90,.,,...,., ,,..50...,.,...,

50. ..50 ...... 50...... ,., Hr. 22 Hr. 23 ...... Hr. 24 90......

50 i3 30 20 10 _.=,:,:. 50 10' 30 2

...., g0..,..

...... ,.50,.....,...... ,.5a,.... 40 Wind Flow Patterns: Citrus Agricultural Center (Waddell)

The UA Citrus Agricultural Center is located in Maricopa County about 40 km northwest of downtown Phoenix. The AC rests on the western edge of the Agua Fria River valley just east of the White Tank Mountains and about 21 km north of Interstate Highway 10 (Figures 6 & 7). Nearby topographical features include the White Tank Mountains to the west and the Agua Fria River to the east (Figure 7).

Wind speeds at the AC are quite low, especially during the winter months. Peak wind speeds typically occur during the warmest part of the day while the lowest wind speeds occur around sunrise. Daytime wind speeds average less than 3.5 m/s and 2.5 m/s during the summer and winter months, respectively while wind speeds at sunrise average less than 1.5 m/s throughout the year. Mean wind speed is highest during the months of May and June, and lowest in December. Hourly mean wind speeds in excess of 10 m/s are rare and have occurred in only three months - April, November and December - during the six - year period of this evaluation.

Prevailing winds tend to be downslope (from the southwest, west or northwest) during the nighttime hours, upslope (from east toward White Tank Mountains) during the mid to late morning hours and upriver (from southwest, south or southeast; Agua Fria River) during the rest of the daylight period. The intensity of this prevailing wind pattern varies with time of year. Nighttime downslope winds occur with greater regularity during the winter months while the upslope and upriver winds are more regular during the warmer months.

41 o .5

1 kilometers * Scale MN 1:24,000 GN o .5 miles 1 GN MN 0 °48' 12'h° Elevation in Meters = Farm Boundary

1990 Figure 6. Topographical map (1:24,000 scale) showing the location of the weather station (0) at The University of Arizona Citrus Agricultural Center and important features of the surrounding terrain.

42 Bell Road

eió

l " 732

Sun 1 City

Beacon 1225 ei Q. Luke AFB ` I

Perryville Prison l-10 Goodyear Avondale

Scale 0 5 10 MN GN 1:250,000 I I 1 I 1 I kilometers

GN MN Elevation in Meters 0 5 10 0°48' 12'%° miles

1990

Figure 7. Topographical map (1:250,000 scale) showing the location of the weather station (C+) at The University of Arizona Citrus Agricultural Center and important features of the surrounding terrain.

43 HOURLY WIND SPEED INFORMATION: CITRUS AGRICULTURAL CENTER. January to June

January February R 14

3 13 a 12 1 11

3 10

7 9 3 r %, ,, 8 7 í í/: ...' . 6 5 i.....S Y 4 S 3 . : .._...._...,_ .-.._.._... 2

S ` 0 o - - - - 21 o 3 6 9 12 15 18 21 Hour of Day Hour of Day

March April 14 14 13 13 12 12 11 11 m 10 10 9 i 5 9 8 ti7 g ./ 7 6 5 4 3 2

1 0 o 3 6 9 12 15 18 21 24 3 6 9 12 15 18 21 Hour of Day Hour of Day

May June 14 14 13 13 12 12 11 11 10 10 9 9 8 8 7 7 ,I J 6 6 5 5 4 4 3 3 2 .::;;% 2 1 ::-- 1 0 0 o 3 6 9 12 15 18 21 24 o 3 6 9 12 15 18 21 24 Hour of Day Hour of Day

The four dashed lines represent, from bottom to top, hourly mean wind speeds with a cumulative probability of occurrence of 25 %, 50%, 75 %, and 100 % for the period May 1987 through August 1993. The solid line depicts the overall mean wind speed for the hour.

44 HOURLY WIND SPEED INFORMATION: CITRUS AGRICULTURAL CENTER. July to December

July August 4 14 3 13 2 12 1 11 0 10 9 9 8 8 7 V 7 i \ i .- . . 6 .Yí, f'- 6 5 Í í 5 ì .... - -_M. 4 , ..¡-_..._... 3 - .. 2 1

1 0 o 3 6 9 12 15 18 21 24 Hour of Day Hour of Day

September October 14 14 13 13 12 12 11 11 10 10 9 9 8 A 8 `, 7 7 6 s 6 5 5 4 4 3 3 2 2 1 1 0 0 o 3 6 9 12 15 18 21 24 o 3 6 9 12 15 18 21 24 Hour of Day Hour of Day

November December 14 .4 13 3 12 .2

11 1 10 0 t.

9 9 -t 8 8 Í i 7 r . i..i. 6 i 5 4 4 3 3 2 2 -'---.--.-, !"-". _. ---'.-..-..___.._.._.. ..-. _. ,.....- 1 _ - 0 0 o 3 6 9 12 15 18 21 24 0 3 6 9 12 15 18 21 24 Hour of Day Hour of Day

The four dashed lines represent, from bottom to top, hourly mean wind speeds with a cumulative probability of occurrence of 25 %, 50 %, 75 %, and 100% for the period May 1987 through August 1993. The solid line depicts the overall mean wind speed for the hour.

45 WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: JANUARY Hours:1 to 12

50 90 30 Zü t xi} 30 .10 5t] 50 90 30 n 1 WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: JANUARY Hours: 13 to 24

Hr. 13 ...... Sa...... Hr. 14 5u......

......

Hr. 18...... 9'...... ,,, WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: FEBRUARY Hours:1 to 12

... so......

Hr. 10......

SÓ 9á 36 29 1.k 3.,,..9 50 50: Ep',,1p WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: FEBRUARY Hours: 13 to 24

49 WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER.

Month: MARCH Hours:1 to 12

50 WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: MARCH Hours: 13 to 24

.50...... Hr. 13 ...... Hr. 14 ...... 93...... Hr. 15...... 50

so ...... , Hr. 22..:...

51 WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: APRIL Hours:1 to 12

......

Hr. 11...... 50......

`......

50 9Q 30 2D w 50 50 9D 30 20 1

52 WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: APRIL Hours: 13 to 24

Hr. 15 ...... 5°......

30 q0 50 50 90 30 20 3D 55

...... 50 ......

Hr. 16...... 50.,......

50 9D

.....,...,...... ,

Hr. 21

......

5,......

Hr. 24......

`-_..,...... ,, ,

53 WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: MAY Hours:1 to 12

,.,..,..,,.:

...... "...... ,...,, ... Hr. 10..:...... 50...... ,.,... Hr. 12..

54 WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: MAY Hours: 13 to 24 WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: JUNE Hours:1 to 12

Hr. 7

50 91) 30 Zdl°ifl 20 30 'H! 5D

Hr. 10...... 50...... ,.

56 WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: JUNE Hours: 13 to 24

Hr.14 ...... ,. Hr. 15 ...... ,..

913......

Hr. 16 ...... 5°.

57 WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: JULY Hours:1 to 12

58 WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: JULY Hours: 13 to 24

5 WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: AUGUST Hours:1 to 12

50 9D 30 '.°. iD 80 30.....90 50 50

Hr.8 ic......

50 9D 30 = = 10 PA^^30 9050 50 9D 30 E 1 -

.....53...... 60 WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: AUGUST Hours: 13 to 24

Hr. 13...... Hr. 14

,...... ,,..,.....

....SO.,...... Hr. 17 ...... 5°,...... Hr. 18......

50......

Hr. 20 5fj...... Hr. 21 50......

50 WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: SEPTEMBER Hours:1 to 12

Hr. 1

Hr. 4 Hr. 5 5° Hr. 6 50

Hr. 9 5,

50 50

Hr. 10 " Hr. 11,, Hr. 12 5°

5, 50 ,,,,,,,, . 62 WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: SEPTEMBER Hours: 13 to 24

Hr. 14 so Hr. 15 5°...... ,,.

5,9,.,,,...,.. 5p...... , .."...... Hr. 16...... Hr. 18 :......

50 94 -3030 30 °ai 50

...... 5D ......

Hr. 21 ...... sp...... ,

....50......

...... 54...... ,. Hr. 24 .

lí] ED 3D 94 50 50 e4 .3U 93 50 WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: OCTOBER Hours:1 to 12 WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: OCTOBER Hours: 13 to 24

...... 5° .. Hr. 16 Hr. 17 ...... 5°

50 9D... 30 20 .. ..lp 90 50 50 1E1 30

yo...... "...,, 50...... ,,...... ,......

so Hr. 19 ...... 50.. Hr. 20 Hr. 21 ...... 50...... qo,..,.,..,

20 30 '0 50

...... Sp...... r 50...... ,..... Hr.23 Hr. 24...... so...... , WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: NOVEMBER Hours:1 to 12

66 WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: NOVEMBER Hours: 13 to 24

Hr. 13 50 Hr. 14 5°...,...... ,

50 90 30 20 10 9(3 50 50. gU 30 20 1

,30......

......

...... 50., Hr. 17 50 Hr. 18...... 5°...... ,

......

50 1E) 3 10 50

......

50 Hr. 19 ...... 50..,...... Hr. 20 Hr. 21 ...... 50...... ,.

.... 50...... ,.. . WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: DECEMBER Hours:1 to 12

...... D......

Hr.

30 90 50 50 9E1 ,i0 00 3I1. ..%i 50 .. . _ ^. - -

...... qp......

50......

.,...SD...... 50...... Hr. 11..:....".. Hr. 12 ..:...

50 90

68 WIND ROSE DIAGRAMS: CITRUS AGRICULTURAL CENTER. Month: DECEMBER Hours: 13 to 24

Hr. 13 5°..

Hr. 16 ...... 5°...... ,,, Hr. 18 ......

. . . 50 1D 30 20 30 9!i 5t1 50 9...... EÇ9D 1: E 33) 9(ì 5t] 50 9D 3 50

Hr. 21

4a.,......

50......

...... 5o...... ,....., Hr. 24......

3 io Sñ 50 _ .. 2ó 30 aó 5v

go ......

69 Wind Flow Patterns: Marana Agricultural Center

The Marana Agricultural Center is located in Pima County just northeast the intersection of Trico -Marana Road and Sanders Road near the town of Marana (Figure 8). The Center is located about 5 km east of the Santa Cruz River (Figure 9). Major nearby topographical features include the Tortolita Mountains to the east -northeast, the Tucson Mountains to the south and the Silverbell Mountains to the southwest.

Wind speeds at the Marana Agricultural Center generally average 2 m/s or less during the late evening and early morning hours, and 3 to 4 m/s during the late afternoon. High wind speeds are not common at any time of the year, and sustained (hourly mean) wind speeds in excess of 10 m/s are rare. The double peak that is prevalent in most of the monthly plots of wind speed is a unique feature that is not observed at the other UA ACs. The first peak occurs during the early to mid -morning period when the direction of flow is from the southeast (downriver). The second peak occurs during the late afternoon hours when the wind is blowing upriver from the northwest. The slower wind speeds that occur between the two maxima coincide with the period when the wind is switching from downriver to upriver flow. The double peak wind flow is most distinct during the spring, early summer and fall months. The pattern nearly disappears during the coldest months and during the monsoon months.

As indicated above the Marana Agricultural Center experiences a distinct diurnal shift in wind direction. During the nighttime hours and the first few hours after sunrise, wind flow is consistently downriver from the southeast. The wind flow switches and flows upriver from the west or northwest during the afternoon hours. The hours between episodes of upriver and downriver flow - mid to late morning and two to three hours after sunset - have variable wind direction and generally lower wind speeds.

70 o .5 1 kilometers I MN GN Scale 1:24,000 o .5 t miles GN MN 0 °06' 12°

Elevation in Meters = Farm Boundary

1990

Figure 8. Topographical map (1:24,000 scale) showing the location of the weather station (C.) at The University of Arizona Marana Agricultural Center and important features of the surrounding terrain.

71 Picacho Peak 1031

Scale 0 5 10 * 1:250,000 MN i 1ii 1 I 1 kilometers GN

Elevation in Meters GN MN 0 5 10 0 °06' 12° I I l l II I miles

1990

Figure 9. Topographical map (1:250,000 scale) showing the location of the weather station (O+) at The University of Arizona Marana Agricultural Center and important features of the surrounding terrain.

72 HOURLY WIND SPEED INFORMATION: MARANA AGRICULTURAL CENTER. January to June

January February 14 4 13 3

12 2 11 i 1 10 0 9 .,: 8 8 ",f 7 \ 7 6 6

5 5 4 4

3 2 ,.. - 1 1 ._.,_ ...... --+-..,--- 0 0 o 3 6 9 12 15 18 21 24 0 3 6 9 12 15 18 21 ?+ Hour of Day Hour of Day

March April 4 3 3 2 2

J. 1 0 0 '1 .a\ 9 ^ ' 9 j ' $ . -.. 8 /, 7 ' 7 r. ' ,'.- 1, 6 í ^, 6 ,.^-, 5 -! r . J--' ` /. 3 4 - -,...^.r -.. 2 ,- _ 2 .-,. 1 1 . _ 0 `--- 0- _- 21 ------' Hour of Day Hour of Day

May June A 4 3 A 3 2 2 .1 í\ 1 r----._ .0 . ' 0 . ,, , P. 9 i -t 9 % ti .. í _.. 8 +/ ' . -" `. , 7 í' It 6 I I 6 '`-J .. , . . -,.s. $ ` \../ :. .,f' - 3 Ç' , --^'" ..^... . ,,\`i...+ 2 -'v'r 2 ---- .'.'- ` _.__ ,,. 1 -, . 0 0_ _- . 0 3 6 9 12 . 15 18 21 Zr 6 12 15 IS Hour of Day Hour of Day

73 HOURLY WIND SPEED INFORMATION: MARANA AGRICULTURAL CENTER. July to December

July August A 14

3 13

2 12

.1 11 .0 \ %ì ;1 10 ' ti t 9 8 r'' 8 7 \ l 7 V 6 6 5 5 4 ..,-.. -_ 4 _. 3 ._. 2 .._.._..-.- ._. _.._... _.. 1 _. 1

0 00 3T T 6 9 12 15 18 . 21 24 o 3 6 9 12 15 18 21 Hour of Day Hour of Day

September October 14 .a 13 3 12 2 11 u 30 0 9 9

8 8 7 7 1\. ..--- - /;r,, 6 6 \ 5 5 ` 4 4 3 2 ..._.---° "I ^ , _. ...__._.. `'f- ...i---' \ - 1 0 3 6 9 12 15 18 21 24 0 3 6 9 12 15 18 21 2' Hour of Day Hour of Day

November December A li

3 13

2 12

.1 11 0 s\ LO 9 ì v,/ /`. . 9 8 ;l '1 8 " '! .,i 7 / . 7 P, ..l A 6 /' ', í \ : S ` í

4 /^ 4 -,. . " 3 \ ._.._..-__.% i 1 .__., __ ., r 0 0 0 3 6 9 12 15 18 21 24 0 3 6 9 12 15 18 21 2, Hour of Day Hour of Day

Month: JANUARY Hours:1 to 12

......

...,...... Hr. 9 5°......

...,,,..50......

Hr. 10 "...... 50......

...... 90 ......

...... 30......

50 90

...,.. 90.,.,...,.

75 WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: JANUARY Hours: 13 to 24

Hr. 2 Hr.24...... 5D.. ,.....,

...,..Sa...... So.,..,... 76 WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: FEBRUARY Hours:1 to 12

77 WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: FEBRUARY Hours: 13 to 24

......

Hr. 17 " Hr. 18...... " ......

......

...... 50...... Hr. 21 ....

, ^96 30....@9 ° ID @F7...... 3p..913 5D 50 9D 30 ..,,..®:r,,...

Hr. 22...... 5a..

78 WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: MARCH Hours:1 to 12

all..,..,.,,.

Hr. 10.:...... 5°...... ,...,,

79 WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: MARCH Hours: 13 to 24

80 WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: APRIL Hours:1 to 12

81 WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: APRIL Hours: 13 to 24

Hr. 13 50...... , ...... 90...... ,

...... ,

50......

...... 50.,...... , Hr. 16...... 50.,...... Hr. 18 .

90.,......

......

. . 50.,...... Hr. 22...... 50.. Hr. 23..:...... SD...... Hr. 24..:...... ,,,.,..,.....,.,, WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: MAY Hours:1 to 12

so so

83 WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: MAY Hours: 13 to 24

Hr. 13 ...... Hr. 14 Hr. 15

...... 50....,...... 50...... Hr. 16 Hr. 17 Hr. 18 50...... ,,

......

...... Hr. 21 50 ......

.....

50 ,,,.90 ,tp...,30 50 96,^30^. 0D 3D 90 50 3D - - V® b

..,..90.,..,.,

...... ,50......

50 Hr. 22 Hr. 24...... 50...... ,.,...,,

84 WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: JUNE Hours:1 to 12

Hr. 9 5°

,...... 3D ......

5Ó9ß 3Ó

Hr. 12...... 50......

,.50 ...... 5a

85 WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: JUNE Hours: 13 to 24

sp......

Hr. 18 ...... 50...... ,

;...... 90......

,.. 5D,.,.,..,,...... 50...... Hr. 19 5°...... , Hr.20 50...... Hr. 21 ......

go ,:

Hr. 22 ...... ". Hr. 23...... ,... Hr. 24 ...... "......

86 WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: JULY Hours:1 to 12

Hr. 2 513......

50 10 30 20 19 as 50 10

87 WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: JULY Hours: 13 to 24

50 sp...... Hr. 13 Hr. 14 Hr. 15...... Sp...... ,,,

..,.,Sp, ,...... , ...... Hr. 16 Sp., Hr. 17 50 Hr. 18 ...... 9'...... ,..,... ,...... go.....,..

3Í1 90 5fl

...... gyp......

......

Hr. 20 ...... 50...... Hr. 21 ...... so......

i0 PA 30 90 50 50 9p .30....: °®s ED 30 90 50 50 WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: AUGUST Hours:1 to 12

Hr. 2 613...... ,

io......

....SD...... ,, ..50......

...... 50...... ,.,.,, ...... "...... Hr. 10...... o...... Hr. 11 ..... Hr. 12...... yo,......

,...50, WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: AUGUST Hours: 13 to 24 WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: SEPTEMBER Hours:1 to 12

91 WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: SEPTEMBER Hours: 13 to 24

Hr. 13 ...... Hr. 14 .... Hr. 15

Hr. 17

So...,...... 50...... ,., Hr. 24 .... WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: OCTOBER Hours:1 to 12 WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: OCTOBER Hours: 13 to 24

...... Hr. 17 5,....

so.... Hr.20 50...... Hr. 21 50......

...... Hr. 22 50...... ,

50 90 30 29 lü

.....5p...... WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: NOVEMBER Hours:1 to 12

so so

Hr. 8 50...... ,..,,

50...... 5......

...... 50.... Hr. 10 .... Hr. 11 5° Hr. 12 ...... 5°......

_ ......

,..,gp..,.,,, WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: NOVEMBER Hours: 13 to 24

96 WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: DECEMBER Hours:1 to 12

..... ,.

50......

Hr. 11 ...... 5°...... Hr. 12...... 5°..

97 WIND ROSE DIAGRAMS: MARANA AGRICULTURAL CENTER. Month: DECEMBER Hours: 13 to 24

Hr. 18 50......

50 90 30

...... ,.,,..50...,,,...,,... 50...... Hr. 20...... 50...... ,....., Hr. 21 ...... ,,...:

50 5ß......

23 Hr.24...... ,....50.,......

...... 50...... ,,. 98 Wind Flow Patterns: Maricopa Agricultural Center

The Maricopa Agricultural Center is located in western Pinal County approximately 5 km east of the town of Maricopa and 30 km northwest of Casa Grande (Figure 11). The AC is located in the flood plain of the Santa Cruz River and the normally dry river and its attendant levies run through the AC (Figure 10). Major topographical features surrounding the AC include the Gila River to the north, the Sacaton Mountains and Sacaton Butte to the east -southeast, and the Sierra Estrella Mountains to the northwest (Figure 11).

Wind speed at the Maricopa AC follows the typical diurnal pattern and reaches minimal levels during the evening and early morning hours, and maximum values during the late afternoon. Mean wind speeds typically are light and average less than 2 m/s during the early morning hours and less than 4 m/s hours during the peak afternoon periods. Winds are particularly light during the months of July through December. The windiest months occur during the spring and the windiest month is typically May. The rather open and flat terrain surrounding the Maricopa AC allows for high wind speeds on occasion. Sustained wind speeds in excess of 10 m/s have been observed in all months except September.

Wind direction is typically downriver (from the southwest, south or southeast) during the nighttime hours and either upriver (from north) or upslope (from west or southwest) toward the Sacaton Mountains during the afternoon. The upriver afternoon flow pattern is more prevalent during the winter months while the upslope afternoon pattern is common during the warmer months. The transition from downriver to upriver /upslope flow occurs late in the morning while the reciprocal transition occurs about two hours after sunset.

99 ......

o .5 1 kilometers * Scale MN GN 1:24,000 o .5 miles GN MN 0 °31' 12%:° Elevation in Meters = Farm Boundary

1990

Figure 10. Topographical map (1:24,000 scale) showing the location of the weather station (0) at The University of Arizona Maricopa Agricultural Center and important features of the surrounding terrain.

100 Scale * 0 5 10 MN 1:250,000 GN l 1 1 1 1 1 1 kilometers

MN Elevation in Meters GN 0 5 10 0 °31' 121°

1 miles

1990

Figure 11. Topographical map (1:250,000 scale) showing the location of the weather station (O+) at The University of Arizona Maricopa Agricultural Center and important features of the surrounding terrain.

101 HOURLY WIND SPEED INFORMATION: MARICOPA AGRICULTURAL CENTER. January to June

January February 14 14 13 13 12 12 11 11 10 A / > 10 i J\ 9 . , ` 9 8 8 7 7 r 6 6 5 5 4 4 3 3 2 - _ 2 iw '._-^ -.."!._..-.. - ._.._ _ 1 1 _:.-- -°---». 0 0' o 3 6 9 12 15 18 21 24 0 3 6 9 12 15 18 21 24 Hour of Day Hour of Day

March April 14 V 13 3 12 2 11 í\ 1 i t, 10 0 \ 9 9 /-.....\ % 8 8 7 7 r,

6 6 + 5 5 4 4 3 ?- _.._... 2 2 ; __ _- :___.. .._»_.- 1 1 _ ...._.

0 D o 3 6 9 12 15 18 21 24 Hour of Day Hour of Day

May June 14 14 13 13 12 12 11 11

10 LO - 9 9 Í 8 Y 8 A .` _ './1. 7 7 \ 6 6 J % v 5 5 4 4 -`.'.. 3 3 ..f .._.._.._..__.._. -...._._ -,---'..--._..-..-. ,... _... 2 2 ...-._.°..- -,-.....- -..> ,.... , 1 0 0 o 3 6 9 12 15 18 21 24 3 6 9 12 15 18 21 Hour of Day Hour of Day

The four dashed lines represent, from bottom to top, hourly mean wind speeds with a cumulative probability of occurrence of 25 %, 50 %, 75 %, and 100% for the period January 1987 through June 1993. The solid line depicts the overall mean wind speed for the hour.

102 HOURLY WIND SPEED INFORMATION: MARICOPA AGRICULTURAL CENTER. July to December

July August 14 14 13 13 12 12 11 11 10 \ 10 9 9 8 8 7 7 i 6 s'j 6 5 5 t 4 4 3 3 . . .. 2 2 .._.._.._.. i 1 1 0 0 o 3 6 9 12 15 18 21 24 o 3 6 9 12 15 18 21 Hour of Day Hour of Day

September October 4 .4

3 .3 2 2 1 .1

0 .0 .._ 9 /. 9 r 8 F s.,.. t - 8 . _ . .s.. , `... 't 7 ' `.' í: 6 6 s: 5 5 4 4

3 . _...._ . 3

" a`.'.-.C .._-'----.'""---...7.7-::::..------..--... 1 ._......

1 _ 0 0 3 6 9 12 15 18 21 2, Hour of Day Hour of Day

November December

14 .4 13 3 12 2 11 .1 %.,

10 .0 9 9 / , 8 8 7 7 , \s 6 5 4 4 3 3 ..._.- 2

1 1 ._...._..__ ...-r 0 0 o 3 6 9 12 15 18 21 24 0 3 6 9 12 15 18 21 2, Hour of Day Hour of Day

The four dashed lines represent, from bottom to top, hourly mean wind speeds with a cumulative probability of occurrence of 25 %, 50 %, 75 %, and 100% for the period January 1987 through June 1993. The solid line depicts the overall mean wind speed for the hour.

103 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER.

Month: JANUARY Hours:1 to 12

90 50 50. .gU 30 09 1®AA®.: 3D....90....50 50 90 30 @D ® .: 20 30 90 59

104 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER. Month: JANUARY Hours: 13 to 24

...... 50...... Hr. 15...... 90......

50 50 94 ,30 3D H3 5b 50 9B 30 0a 30 90 5b .. *r .®' 0 "° °"

.,,..,.,,....,

.....qp.....,.

Hr. 18...... 5°...... ,,,

50 9ß 30 EO ,^ -_ fl PD 50 50 9ß

105 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER.

Month: FEBRUARY Hours:1 to 12

20 3l] 90 0 50 94 06 30 90 50 50 94 30 20 30 90 50

,90...... 106 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER. Month: FEBRUARY Hours: 13 to 24

50...... so......

Hr. 16 ...... 50...... ,.. Hr. 17 ...... SO...... Hr. 18...... Sp...... ,...,

., ,

. 1 : 50 0E1,...3I1 90 50 50 9ß 90 5D 50 . _ 2ß 50 10 . - 3p iß 0ß.....3i1 10 30. : 3D 9p - - _ ,®.

,r...... yp......

......

Hr. 19 ...... 50...... ,,.,, Hr. 21 ...... 50...... ,.,,

,...... 90....,.. ...,....,,, ...... :

......

,....so......

.. Hr. 23 ...... 50 Hr. 24 ...... 50...... 50......

®D 3D 9D 50 50 90 30 ED 1

107 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER. Month: MARCH Hours:1 to 12

......

5,......

Hr. 10...... 5°.. Hr. 11......

cEl 3D 90 50 Sd 9Q 30 ® 3D qHi 50

144.-'.

108 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER. Month: MARCH Hours: 13 to 24

... q3......

......

Hr. 17 su Hr. 18......

109 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER. Month: APRIL

......

,,... s,......

Hr. 12...... ,.....

5..,...... 13 110 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER. Month: APRIL Hours: 13 to 24

111 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER. Month: MAY Hours:1 to 12

iD 0D 3D 90 5D 50 90 30 Zfl 113 3D 50

iD 00 30 913 50 SD 9ß 30 2D D RD 3D .413 5D 50

Hr.

...... - . . . d . . . iD FD 3D.....9;! 5D 50 9D 30 DD ,,..i{3 0D 3D '.....5D 50 94 30 DD°ID® 30 11:3 50

......

Hr. 10 Hr. 11 ...... 5°

50 9D 30,....Z9. .a D ¢D 3D 90 50 50 9D 30

30 .

112 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER. Month: MAY Hours: 13 to 24

50 Hr. 14 Hr. 15..,...... so......

......

Hr. 16 ...... 50.

0D 3D 90.....50 50

: ....

50...... so......

Hr. 20 ...... 50...... Hr. 21...... 50......

,...... ,.

,..,,,..., 50...... 50 Hr. 23...... ,. Hr. 24...... 50...... ,...,, p...... ,

p...... :

5p ?D 30 90 50 50 90 30.. 90 50

.:.:

,,.,Sp.....

113 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER. Month: JUNE Hours:1 to 12

..°... : :_..

5D 50 40 30 i i{i @Fl 30 40 50 50 46 30 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER. Month: JUNE Hours: 13 to 24

alp......

......

5ó Hr. 19 Hr. 20 5° Hr. 21...... 50...... ,.

`,.,...,..gp..,..,,

115 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER. Month: JULY Hours:1 to 12

so......

Hr. 10...... 5° Hr. 11 ...... "...... :

50 90 .30 2E1.....3Ú 9b 513 50.. 2fJ 3D 90 50 50 90 313 ¢9

116 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER. Month: JULY Hours: 13 to 24

117 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER.

Month: AUGUST Hours:1 to 12

118 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER. Month: AUGUST Hours: 13 to 24

Hr. 13 Hr. 14 Hr. 15 ......

119 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER. Month: SEPTEMBER Hours:1 to 12

.,....,50,.,,.....,

...... 50...... Hr. 10..... Hr. 12...... ,

.. ,50...... 120 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER. Month: SEPTEMBER Hours: 13 to 24

...... Hr. 13 ...... so. Hr. 14 5° Hr. 15

so 20 ...... 30 413

121 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER.

Month: OCTOBER Hours:1 to 12

Hr. 2 Hr. 3...... 5°.,,..,... WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER. Month: OCTOBER Hours: 13 to 24

Hr. 17 5a

,.,.;..

. . - . 313 PD 30 50 50 9ß 30 30 0iF 30 90- 50 50 90 30 20. 30 90 50 p®..r l'':

123 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER. Month: NOVEMBER Hours:1 to 12

Hr. 3 ...... ,

lá e :;::'1fl ® 30 9b 5{7 50 ID 30 2{ 2t....BD 3p ID 5D

5...... i ? í - .. _ c..,.....F:.....

,.....,g...... ,-

......

, ,5°,., .,.,. Hr. 12 ...... , ......

50 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER. Month: NOVEMBER Hours: 13 to 24

125 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER. Month: DECEMBER Hours:1 to 12

Hr. 3 50

126 WIND ROSE DIAGRAMS: MARICOPA AGRICULTURAL CENTER. Month: DECEMBER Hours: 13 to 24

Hr. 15 5ß......

HD 3D ! 5ß 50 9ß 36 ..lar' o PD 36 90 50

...... , ,...... - ...... yp.....,

....50......

so...... 50 Hr. 16 Hr. 17 Hr. 18 ...... so......

......

Hr. 19 50......

127 Wind Flow Patterns: Safford Agricultural Center

The Safford Agricultural Center is located southeast of the intersection of Montierth and Lone Star Roads in Graham County (Figure 12). The Center rests approximately 5 km southeast of Safford and 4 km south of the Gila River (Figure 13). Significant nearby topographical features include the Pinaleno Mountains and Mount Graham to the southwest and Weber Peak and Turtle Mountain to the northeast.

Wind speed at the Safford Agricultural Center follows a typical diurnal pattern with wind speed reaching minimum levels during the early morning hours or just before sunrise and maximum levels late in the afternoon. The intensity of this diurnal pattern varies with month of the year. The pattern is relatively strong during the spring and early summer months, then weakens during the late summer, fall and winter. April and May -the two windiest months - commonly have afternoon wind speeds in excess of 5 m/s. In contrast, peak afternoon wind speeds average less than 3 m/s during each of the last five months of the year (August - December). Sustained wind speeds in excess of 10 m/s are not common at the AC; however, mean hourly wind speeds in excess of 13 m/s have been observed on occasion during the spring months.

The direction of wind flow varies with time of day and typically flows in the downriver direction (from southeast) during the nighttime and early morning hours. The daytime direction is somewhat less reliable, but still is commonly from the northwest or upriver during the afternoon hours. The upriver afternoon flow is most prevalent during the spring months, but exists with considerable regularity during the summer and fall. The upriver afternoon flow pattern weakens considerably during the cold, winter months.

As is typical of any location with a distinct diurnal wind direction pattern, there are transition periods between the periods of upriver and downriver flow which show little if any pattern of wind direction. The time of day for these transition periods shifts with the time of the year due to differences in daylength, solar angle and solar azimuth. For Safford, the switch from upriver to downriver flow in the evening occurs two to three hours after sunset. The reciprocal daytime switch from downriver to upriver flow occurs between 10:00 and 12:00 Mountain Standard Time.

128 - 890

Lone Star Road

9p2 re-

9p5

o .5 kilometers Scale MN 1:24,000 GN 0 .5 1 1 miles GN MN 0 °45' 11'h° Elevation in Meters = Farm Boundary

1990 Figure 12. Topographical map (1:24,000 scale) showing the location of the weather station (C+) at The University of Arizona Safford Agricultural Center and important features of the surrounding terrain.

129 Mount J L Graham 3267

0 5 10 Scale MN j 1 I it 1 1 1:250,000 kilometers GN

GN MN 10 Elevation in Meters 0 5 0 °45' 1154° I 1 I I I I 1 miles

1990 Figure 13. Topographical map (1:250,000 scale) showing the location of the weather station (O+) at The University of Arizona Safford Agricultural Center and important features of the surrounding terrain.

130 HOURLY WIND SPEED INFORMATION: SAFFORD AGRICULTURAL CENTER. January to June

January February 4 3 3 2 2 . - 1 1 1 s, 0 t ' ,../ o / ,.\ 9 í % .. 9 1 . . ' L. ..._... --- \ 8 7 Í 7 6 6

5 5 -.._'- _ - 4 4 .% .--_ ,_ 3 . -..- _____ 2 '-_ ._.- ._.._.._ ' -..-_.._.._. ..._.. __.._..-.._..--_.._^_. 1

1 0 9 12 15 Hour of Day Hour of Day

March April 4 14 3 ¡, 13 2 ,t ,'' 12 1 i 't' 11 0 i - ° 10 g ' 'l 't E 9 .` . TJ 8 d 7 .... h 7 6 6 5 ! q 5 q

3 _... .. 3 _ ..`...-. 2 .._..: ,._.._ ' '`. - .. 2 1 1 0 o 3 6 9 12 15 18 21 Hour of Day Hour of Day

May June .4 .4 3 /.. 3 2 2 %, .1 i í/ 1 .. .0 i \.i J .0 9 " k 9 .. 8 t i'. .

7 7 ' i 6 6 / 5 q _s,..,, ._.._ /... ,,, .. 2 zs.....,' . -.. - --_r. _.._..

0 0 0 3 6 9 12 15 18 21 2, Hour of Day Hour of Day

131 HOURLY WIND SPEED INFORMATION: SAFFORD AGRICULTURAL CENTER. July to December

July August 14 .9 13 3 12 2 11 1 10 0

9 9 A 8 j I / 1 ' 8 7 /' ,i 7 i \ \. y' 6 6 = . + 5

4 4 3

2 2 _ ._..-.._.._.._' -._.._ .._. ' _.._..-... 1 1 "- -.._.. _e 0 0 3 6 9 12 15 18 21 24 21 Hour of Day Hour of Day

September October

3 2

1 0 9 8' 7 ì\ , .._ ... .` 6- .._.._ . .... _ _.. . 5

4 ._. - ._.._.... 3 -_ ... Z -._.._. ._ ,.._..--' '--- 1 .....9 _:--..-'_.._

J 0 3 6 9 12 15-.18 21 2d 9 12 15 18 21 24 Hour of Day Hour of Day

November December 14 .3 13 2 12 1 %1 11 0 f 10 9 s ° 9 ti s: 8 7 7 6

5 5 4 - - ._.._.._.._. 4 3 / \ 3 ^.."e--r -.._.._ -°-..._.._._... 2 1 .. ' - 1 0 0 24 o 3 6 9 12 15 18 21 24 Hour of Day Hour of Day

132 WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: JANUARY Hours:1 to 12

50..., Hr. 1

50 90 30 Z0

.,.

Hr. 12...... 50...... ,.,...

50...... 133 WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: JANUARY Hours: 13 to 24

Hr. 13 ... Hr. 15 ...... ,...... ,

.....30......

.18......

...... 50...,...... sp,.,,,....

Hr. 16 ...... 5°...... Hr. 17 ...... sp...... Hr. 18 ...... 5°.,...... ,..,.,.

Hr. 22 ...... 5°

50- ...9D 30...9.....lp. m -::::-,: 50 50 9D WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: FEBRUARY Hours:1 to 12

Hr. 2 50...... Hr.3 _...... Sa......

50 90 30 00

,...... 50...... Hr. 8 50......

5,......

Hr. 10 ...... 513 Hr. 12...... 50...... ,

50 40.

, ...... SD...... 50.. .

135 WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: FEBRUARY Hours: 13 to 24

136 WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: MARCH Hours:1 to 12

...... Hr. 5 ......

...

Hr. 7 so

SO...'gp..,,,3Ò E9 16 .,,..es-__.:_:_..: 50 90 30

...... 90......

,....Sp...... ,......

50 5,...... Hr. 11 Hr. 12...... "...... ,

137 WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: MARCH Hours: 13 to 24

Hr. 15 ...... 5a......

90......

138 WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: APRIL Hours:1 to 12 WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: APRIL Hours: 13 to 24

140 WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: MAY Hours:1 to 12

141 WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: MAY Hours: 13 to 24

Hr. 13 Hr. 14

Hr. 16 50 Hr. 17 Hr. 18

....

;,,,,'

ep 30 i i 50 1 113 eP 90 50 58

Hr. 19 5° Hr. 20 50 Hr. 21

142 WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: JUNE Hours:1 to 12

Hr. 7 .so...... Hr. 9 50...... ,

50 11 50

143 WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: JUNE Hours: 13 to 24

Hr. 20 Hr. 21 so

......

Hr. 22...... Hr.23 9'......

`:...... ,

144 WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: JULY Hours:1 to 12

Hr. 5 9'

.,......

...... so...... 50...... Hr. 7 50...... Hr. 8 :.....,.,,go..,..,.., ......

145 WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: JULY Hours: 13 to 24

......

50......

Hr. 24 ...... 50...... WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: AUGUST Hours:1 to 12

Hr. 1 ...... 50...... Hr. 2 50...... Hr. 3 50...... ,,

50 9D 50

Hr. 5 ......

..... 50,.,.,..,......

Hr.8 s° Hr.9 ...... WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: AUGUST Hours: 13 to 24

.....w ...... Hr. 14 Hr. 15,...... ,...... 50......

90. ...50

...... -:...... ,.

so,..,......

50 Hr. 17 Hr. 18 ..

...q...... ,,,r

50 9p

Hr. 20

<.....

...... ,.

Hr. 22 ...... 50

148 WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: SEPTEMBER Hours:1 to 12

Hr. 2 50 WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: SEPTEMBER Hours: 13 to 24

Hr. 14 ..., ...,.... Hr. 15...... 50...... ,

DD...... 50.....,..,, Hr.19 Hr.20 50 Hr. 21 50...... WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER.

Month: OCTOBER Hours:1 to 12

151 WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: OCTOBER Hours: 13 to 24

Hr. 13 50.. Hr.14 50

Sp.....,,.. so,.,,,...... ,.

Hr. 16 50 Hr. 18 ...... 50.,....,.,,..,.

...... go...... ,,

90.,...... 10 ......

,..,.,50,.,.,..,,. .,..,.,.,50,.,.,......

Hr.20 5°...... ,.., Hr.21 ....,...... SO...... ,.,...

AO......

.... so.. ..., ....Sp...... 50...... Hr. 22 so Hr. 23 Hr. 24...... 50......

50, 90 30 Z9 1®sr.i `q 50 50 90 30 WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: NOVEMBER Hours:1 to 12

...... 50......

50 .. ..5°...... Hr. 10...... 50...... Hr. 11...... Hr. 12...... WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: NOVEMBER Hours: 13 to 24

Hr. 13 so Hr. 14 Hr. 15 so

,31)

50 Hr. 16 , Hr. 17 Hr. 18 5°

.'. . . - .. , . ..

50 Hr. 19 Hr. 20 50 Hr. 21 SO

. 10

Hr. 22 5° Hr. 24 50 ......

' ...... 50 ...... 154 WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: DECEMBER Hours:1 to 12

Hr. 3 50

Hr. 5 o

Hr. 10...... 513. Hr. 11 5° WIND ROSE DIAGRAMS: SAFFORD AGRICULTURAL CENTER. Month: DECEMBER Hours: 13 to 24

Hr. 14 50

...... Hr. 16 5° ,...... Hr. 18 50

. ...50...... Hr. 21 50......

.:...... 30.....

IG......

Hr. 24...... 50...... Wind Flow Patterns: Yuma Agricultural Center Yuma Mesa Farm

The Mesa Farm at the Yuma Agricultural Center is located on the western side of the Yuma Mesa approximately 5 km south of Yuma at the intersection of Avenue A and 15th Street (Figure 14). The edge of the mesa rests within 1 km of the farm to the north and about 2 km from the farm on the west. Major nearby topographical features include Yuma Valley and the Colorado River to the west and north and the Gila Mountains to the east (Figure 15).

Wind speeds at the Yuma Mesa AC are lower than at any other UA AC due to the large expanses of nearby citrus production. Trees serve to reduce wind speeds through 1) blocking and diversion effects and 2) increased aerodynamic roughness. Although Mesa Farm winds are light, the wind does follow the typical diurnal pattern of light winds during the nighttime and early morning hours and higher wind speeds during the afternoon hours. Peak afternoon wind speeds typically average less than 3 m/s.

The windiest weather typically occurs during the spring months of March, April and May. The fall months of September, October and November produce the lowest wind speeds. Extended periods of sustained high wind speeds are not common, and no hourly mean wind speeds in excess of 10 m/s have been observed at the farm during the past six years.

Northerly winds dominate the flow pattern at the Mesa Farm during the winter months. Evening and early morning winds tend to blow from the north and northeast while daytime winds blow from the north and northwest. The slight shift from a more easterly flow (from higher elevations) at night to a more westerly flow (from lower elevations) during the day shows that elevation does play a slight role in the winter flow patterns.

An east -west flow pattern develops during the spring months and continues until winter. Winds flow from the east or southeast toward lower elevation and the valley at night, then reverse and flow from the west and southwest (upslope or upriver) during the afternoon hours. A true east -west flow regime is more common during the spring and fall months while a southeast (night) /southwest (day) flow regime is more common during the summer months.

157 o .5 1 kilometers *. MN Scale GN 1:24,000 o .5 1 1 mites GN MN 1°15' 13° Elevation in Meters = Farm Boundary

1990

Figure 14. Topographical map (1:24,000 scale) showing the location of (+O) and the terrain surrounding the weather station at the Mesa Farm of The Yuma Agricultural Center.

158 Pilot Knob 268 `... J Gita Rivo

MEXICO

ARIZONA

MEXICO

Scale 0 5 10 * I MN 1:250,000 1 1 1 1 i 1 1 kilometers GN

Elevation in Meters GN MN 5 10 0 1 °15' 13° 1 I 1 I- I 1 miles

1990

Figure 15. Topographical map (1:250,000 scale) showing the location of (O+) and the terrain surrounding the weather station at the Mesa Farm of The Yuma Agricultural Center.

159 HOURLY WIND SPEED INFORMATION: YUMA MESA AGRICULTURAL CENTER. January to June

January February LU 10

9 9

8 8 r t 7 7 -T' '' ,r"<; 6 \...... 5 \,..."'"-..1 w. 5

3 3 "^---'¡ ._ . . 1" ...... _.. 2 ..\,...7__....., 1 1 1_,.. ._ ..._.+--°..»- .. ..._.._.._. _.._._..'. '.._.._.._.._... 0 0 0 3 6 9 12 15 18 21 24 3 6 9 12 15 18 2 24 Hour of Day Hour of Day

March April LU 10

9 9

8 -- \ / 8 . `,..... 7 7 i'''\ Jri á \ 6 t'l 6 ,'>, ...... r , ` ^ .. 5 5 Y `.... ) 4 4

3 y... ._._..__.` 2 ^ y. ; .. 2 w ._ ....._.._. _ .._. ..` ...._..: / . ._.._.._..._.»' 1°.omue._.._.....r ......

0 0 0 3 6 9 12 15 iR 21 2e 3 6 9 12 15 18 21 24 Hour of Day Hour of Day

May June LU U

9 9

8 ^ Z '.`, 8 ,l 7

6 % 6 .... 5 5 _. s.: ,\. 4 4 ` v

3 .1----'------".'-----''^ .-..,... , / ` Z ...... _.._.._ .....__._ ..,_. _.. 1 .,..._..'-- 9 21 O 3 6 9 12 15 16 21 24 Hour of Day Hour of Day

160 HOURLY WIND SPEED INFORMATION: YUMA MESA AGRICULTURAL CENTER. July to December

July August u

9 9

8 8

7 / 7

6 6 + \ . . . 5 \ i ' /- , 4 4 - ._.._.._.».._.._. - 3 /.

,,,,_.-. 2 ... .._-^ . .. 2 ...._.._.._.._.._% ._...-.._.//. '___..w. 0 0 3 6 9 12 15 18 21 2 Hour of Day Hour of Day

September October lo u

9 9

8 8

Vl 7 7 8 6 6 ,\ .

5 5 .Ns 1 N 4 4 ¡ `..

3 3

..., 2 2 .._.._. . 1 ..._._. ;" __...... _..._.._.._.._..-». .__.._.._.._. o 0 o 3 6 9 12 15 18 21 24 Hour of Day Hour of Day

November December lo u

9 9

r.. 8 8

7 7 .. r 6 6 \. I \ 4 5 5 \ ! ' 4 í! " 4 ,s

3 3 _.._. 2 /55 -.._-- , ... ° 1 l - ..._.._..... 0 °0 3 6 9 12 15 18 21 24 Hour of Day Hour of Day

161 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: JANUARY Hours:1 to 12

Hr. ..,.50.. Hr. 2 Hr. 3 ....,....,.5a

30 90 So So 90 30 ZU 30 90 50 So 90 30 6fl 2 r° _, .°` 3U 90 513 ®,.

Hr. 5 ...... J......

,......

.. so...... 50...... 50...... ,.

So Hr. 7 Hr. 8 so...... Hr. 9 SO

....., go...... :.....,.., .....,.,,,,;; ...... '

50 90 30 00

50...... ,...... 50...... WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: JANUARY Hours: 13 to 24

Hr. 15 ..

= 2,0 io 51:1 sb 1¢ 30 20 ID .Db 3ñ 4113 sb sá ID aó ItAio oO. 3o go al = di®

50 ,...... ,...,.

sD...... Hr. 21 ......

2D 3D 1H3 5D 50 96 30 2D WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: FEBRUARY Hours:1 to 12

Hr. 4 5p......

50 00 3I3 90

' Hr. 7 50...... , Hr. 8 Hr...... 50......

...... 430......

50 9E1 30 Z9""'lp..: 30 0 50 50 9p 30 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: FEBRUARY Hours: 13 to 24

Hr. 15

9ß ®: Eß 30 $3 50 50 Z9g. . 90 30 90. 50 50 9ß 30 Z9 ®

".,...... ,.

50..... Hr. 16 ...... 50.,...... Hr. 17 Hr. 18 ...... 5p.,...... ,....,.....,.,,:

PD 90 50 50 96 50 95 30. . 30

. Hr. 19 50...... ,.

...,50, .,,.... 165 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER.

Month: MARCH Hours:1 to 12

,..,.....50...... ,.....

.... ga......

50 ....,,.,,...... Hr. 10 59....,......

50 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: MARCH Hours: 13 to 24

Br 13 ''-'^o--`` Hr. 14 *m--`` Hr. 15'~--"--`` qj «`

,a--``` ,m-`^``` Hr. 16| "--``' Hr. 17 Hr.10' . _~,^m-'.,'

--sn-'. `--m°--' Hr. 19''^'-'"--`` Hr.2O''--so--``` Hr. 21 ''-'^a--`` '' .-. -`/ '-30-` WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: APRIL Hours:1 to 12

Hr.3 50......

50 90

Hr. 7 50......

50 313 E0

.,,qp......

......

Hr. 10 ...... Hr. 11 ...... ,...... 50... Hr. 12 ...... 5ó...... ,.,...,...... ,..,

168 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: APRIL Hours: 13 to 24

Hr. 16 50...... Hr. 17 50...... , ...... 90.....,

90...... 50...... , . . ,.....

Hr. 19 ...... 50 Hr. 21 ...... 50...... ,

- 113 3I1 90 50 50 90 30 :,:_,. v 111 00 30 90 50 50 9p,..3 : .: v 10 ¢D 30

.-. 30 ...... ':

.... 90......

.....50...... ,

Hr. 22 ...... 5°

169 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER.

Month: MAY Hours:1 to 12

170 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: MAY Hours: 13 to 24

171 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: JUNE Hours:1 to 12 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: JUNE Hours: 13 to 24

so......

Hr. 18 ...... 9,...... ,,, ...... io......

iQ 00 30 90 50 50 9Q ' 113 30 90 ALi"'.._ 00 50

yD......

..,....so......

50...... ,.... Hr.20 Hr. 21 ...... 50...... ,.....,

Hr. 24 ...... 5°...,. ..

50 90 3D 30 133....SÚ

......

173 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: JULY Hours:1 to 12

51,......

Hr. 11 .....:...... 5C...... , ,,....,....

50 90 30 2D 50 ithe. 50 9f} 30 E0 2: t

. - - ...,

174 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: JULY Hours: 13 to 24

Sp 94 30 50 .®;. D 2ß 30 90 5D SD 9!Y

175 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: AUGUST Hours:1 to 12

,..

50..... Hr. 11..:......

176 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: AUGUST Hours: 13 to 24

..c

,......

Hr. 18...... '°...... ,. o ......

.... 50 90 30 ail 11 i{3 FD 30 40 50 50 9ß 30

177 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: SEPTEMBER Hours:1 to 12

178 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: SEPTEMBER Hours: 13 to 24

Hr. 16 ...... 5°.

..::.: PA`:...... 50 . 0 EQ 30 90 5t1 50,,9Q /.

.....ar.n....,..

yQ......

...... 50......

Hr. 19...... 50 . Hr. 20 ...... 50 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: OCTOBER Hours:1 to 12

Hr.3 :

Hr. 4 Hr. 5 50 Hr. 6

Hr. 7 Hr. 8 5° ...... 10 ......

5J ......

180 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: OCTOBER Hours: 13 to 24

Hr. 13 5, 3..'.'.,

3......

50 9D 3D Zühit ED 3D 9!3 51l 50 9D 3b Z9 ED 3D 90

...... , ... 55 Hr. 16......

50......

..... 50,......

Hr. 19 50 Hr. 21 ...... 5fJ

50 9D' Z_0 ED 3D 90 5D 50 90 3ti 50

......

...... 90...... 50 ..... Hr. 22 ..:...... 50...... Hr. 24 ...... sa ...... : ...... " ......

181 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: NOVEMBER Hours:1 to 12

...... 50 ...... 50...... Hr. 10 ...... 50 Hr. 11 5° Hr. 12......

50 90 a0 Zfl 3b

182 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: NOVEMBER Hours: 13 to 24

50 Hr. 20 50. ,..

183 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: DECEMBER Hours:1 to 12

Hr. 50 Hr. 2

90......

30 ...

50 96 30... ,. 00... =' 3U 90 50 50 90

d....,...'

.30......

......

50 Hr. 7 Hr. 8 50...... ,.... Hr. 9 50

...... 90...... 10......

50 9D 30 WIND ROSE DIAGRAMS: YUMA MESA AGRICULTURAL CENTER. Month: DECEMBER Hours: 13 to 24

t 0 PD 30 51) 50 94 3D..... PD . Ob.. 30 9D 5D 50^ ^, 96 30 00 ® 3D 9D 50

,...... 50...... ,...... rp...... ,. ..,,...... , .,...... ,... Hr. 17 Hr. 18 ......

3D D ....50 50 94 30 PD tltl : 06 3D 90 50 5D 90 30

.....50...... Hr. 24 ...... 50......

185 Wind Flow Patterns: Yuma Agricultural Center Yuma Valley Farm

The Valley Farm at the Yuma Agricultural Center is located about 8 km west of Yuma at the intersection of 8th Street and Somerton Avenue (Figure 16). The farm resides in the Colorado River bottom 1.5 km east of the river. Significant nearby topographical features include the Yuma Mesa and Gila Mountains to the east, the Cargo Muchacho Mountains to the north and the Chocolate Mountains to the northeast (Figure 17).

Wind speed at the Valley Farm follows the general diurnal pattern with relatively light winds in the nighttime and early morning hours and higher winds during the middle or late afternoon hours. A unique wind flow feature at the Valley Farm appears during the fall and winter months when wind speeds reach their daily minima during the late evening hours. The winds then tend to increase slowly during the rest of the evening and early morning hours. This pattern disappears during the summer months and follows the more normal pattern of declining throughout the night to minimum values at sunrise.

The cooler winter months - November through March - tend to have the highest average winds while June, September and October bring the lightest winds. Periods of extremely windy weather do occur with some regularity in the Yuma Valley. Hourly mean wind speeds in excess of 10 m/s have been observed in every month except June, July and December.

Wind flow tends to move downriver (from north) during much of the day during the winter months of November through February. This downriver pattern is most prevalent during the first twelve hours of the day. Flow from the northwest and west becomes more common during the late afternoon and evening hours.

The spring and summer months bring a less distinct downriver flow pattern during the evening and morning hours. The mean vectors continue to show flow from the north, northwest or northeast; but flows from other directions become more common. The flow pattern in the afternoon also shifts to one of upriver or upslope flow. The upriver / upslope flow regime becomes very reliable during the hot summer months of May through August, then fades in intensity in the fall months of October and November.

186 o .5 1 * kilometers MN Scale GN 1:24,000 o .5 I miles GN MN 1°15' 13°

Elevation in Meters = Farm Boundary

laso

Figure 16. Topographical map (1:24,000 scale) showing the location of (0) and the terrain surrounding the weather station at the Valley Farm of The Yuma Agricultural Center.

187 * Scale 0 5 10 MN 1:250,000 i 1 1 1 1 1 1 kilometers GN

MN Elevation in Meters GN 0 5 10 1 °15' 13°

1 I I I I miles

1990

Figure 17. Topographical map (1:250,000 scale) showing the location of (+O) and the terrain surrounding the weather station at the Valley Farm of The Yuma Agricultural Center.

188 HOURLY WIND SPEED INFORMATION: YUMA VALLEY AGRICULTURAL CENTER. January to June

January February 4 I.4

3 13 2 '`1 L2 1 -_ % 11 %. ' LO ./ ,\,., / 9 1\ \ :t%: - . .. _.._ . 8

7 7 ,'% 6 6 ...... -.....". v/. 3 `,\ .- 3 _ 2 - - "`. `..- 2 .._.._.. _._ ._... 1 .,--.._------__ --_ . _ . -

0 0 9 12 15 18 21 Hour of Day Hour of Day

March April 14 4 13 3 12 2

11 1 _ 10 0 \ . , . '\ 9 9 %" 8 8 f' 7 7 6 6 5 5 ._.._.._.._... 4 /. . _.._.._..__.._- 3 %.- _ 2 2 ------`"- _.._. _ 1 1 .... 0 0 o 3 6 9 12 15 18 21 24 0 3 6 9 12 15 18 21 2 Hour of Day Hour of Day

May June 4 4 3 í\ 3 . s. 2 2 1 % f 1 0 -. 0 9 \ % /% 9 .`' .... 8 ,\. .. i 7 ' 7 ^\....\ 6 6 '\.,- 5 5 4 - _.._.-- .,_, -' .-._.._. _ -^_-_..- 3 _. = - -._----~ - 2 1, . __.._.-. ' . 1 = _4' /,... -/- ._. ...- 0 0 3 6 9 12 15 18 21 22 0 3 6 9 12 15 18 21 2 Hour of Day Hour of Day

189 HOURLY WIND SPEED INFORMATION: YUMA VALLEY AGRICULTURAL CENTER. July to December

July August 4 4

3 7 d 2 2

1 1 / 1

0 . `. 9 \ " , ,%' . .. 8 %, _. ... _.. ' tt 7 i \ 7 6 ...`¡ . 6 5 5 ..._. 4 . 3 -/ - ' ... .. ,.v _._'. 1 ..-:_/e . .. 0 Hour of Day Hour of Day

September October 14 4

13 3 12 2 .. 11

10 0 % ,\ t. 9 9 í `.. . 8 8 I 7 . 7 \ 6 6

5 5 4 4 3 3 2 2 1 1 ..._..___.._._...... _. _._.....+ o 0 o 3 6 9 12 15 18 21 24 Hour of Day Hour of Day

November December 4 l4

3 13

2 12

1 11 ., 0 LO `'.`>.._..1..._.._.i .. 9 ._... 9 `- . 8 " l 8 .,,!. 7 t 7 ' 6 6 -- 5 í 4 % ',.., 4 ._. 3 í í, - ``\.. 3 - ._..!//" i 2 sjM .._..i _._.._. \ _' _ ._.__.. .._. .:::.:.._.._.. 1 ..._._-'-.._. .___.._..

0- _ 9 12 13 21 - - -- -. -- - Hour of Day Hour of Day

190 WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: JANUARY Hours: 1 to 12

:.... . 50 9ß..1e30 Z9.....14 tl.? 30 90....59 50 91) 30 29.....lÙ :'v ....2f1 30 90 50 50 94 30 29 lß

191 WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: JANUARY Hours: 13 to 24

192 N

......

... ..

,...,

...... ti

ti WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: FEBRUARY Hours: 13 to 24

9D 50 96 30 29 1®9 ZD 3D 93 50 50 90 30 00 ' ZD 3D 9<3 59 50 30 29 nr 9ÉY....3Ó . . _ . . . - . . _ . . _ - . . .- : .,.®d ,.: d".:,. - _ _.®®"...

... 90....

.....50...... 50...... Hr. 22 Hr. 23 50 .

0.9... 55 1dI 3D...9D 59 50 9D 2D 30 99... 50 50 9D 30 2D D 40 3029e' _ _ '. ®aster" - - "I&'.

194 WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: MARCH Hours:1 to 12

Hr. 1 Hr. 2

3ß 9 0 5p 50 9ß Ma 2f1 3D....9[1 50 SD 9ß 30 5 ......

...... ,..,,.. ,

Hr. 4 Hr. 5 51,......

50 9ß 30 ®! Dß 3ß 90 50 50 9ß í31 30 90 50 3 a : .

qp......

...... , SD...... Hr. 10 .... Hr. 12 ...... 5D ...... ".....

- : ' ..,; : ,,:. . , . : .... Q: 90 90 50 50 913. 50 50 9ß 30 29... .: 2ß 30 50 50 30 Ze' 20.....3ti...90 `, "'ç... ":.. _ ,..:.,'' : i

7[}

...... 50 ...... '.... ,so ...... WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: MARCH Hours: 13 to 24

Hr. 13 50...... Hr. 15 _....,...... 50...... ,. lo

50. .°' W3 50 50 11) 30 30 90. .50

®,._;':...... ::,..,,,,:' . '. ..

...... ,..,... ,..

Hr. 17 ...... GO.,...... ,,, Hr. 18...... 50...... `

Hr. 21 50......

. fi ED 30 90 50 . ... D H9 30.. gp rA WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: APRIL Hours:1 to 12

Hr. 8

90 50 50 9D 30 ,."T._Á 3D 90 50 50.... 9D

GO...... ,. Hr. 10...... 5°...... ,..,,, Hr. 11 ...... 50

50 3b 90 5S1 50 90 ED 3D 90 50 50 10 3D

....,90 ...... ,, WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: APRIL Hours: 13 to 24

Hr. 13 50.. Hr. 14 '° Hr. 15 ...... ,,

50 9ß 30 89' v i0 OEl 30 90 50 50 9ß 30

.30. ''''

.. ,50 ......

Hr. 16...... SO...... ,.

.....30......

...., ;::...... :. 50 ^ 9ß 30 i0 00 3ß 9[i 50 SÓ 9ß 10 E0 30 9Ì1 50 50 9ß 3 0E7 30

®. .

p...

...... 50

,....,.....,...., ...... 50.,..,.." .,.....50...... Hr. 22..:...... ,.50 Hr. 23 .. , ...... :

198 WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: MAY Hours:1 to 12

Hr. 6

EO at 90 5D 50^^^90 30 E11 3D 90 5t1 50 10 30

Hr. 7 Hr. 8 Hr

50 &''90 30 00 30 90 50 50 90 30 EO 30 90 50 50 90 3

.,......

,.., 50...... ,

50...... ,., Hr. 10 .. Hr 12

50 WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: MAY Hours: 13 to 24

Hr. 13 ...... 50...... ,

50 10 30

...... -:

4g......

Hr. 16 ...... 5p...... Hr. 17 ...... 50...... lo....,..,

50 90 30 00,.; i{3 PD 30 90 50 50 90

Hr. 22 ...... 5p......

200 WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: JUNE Hours:1 to 12

201 WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: JUNE Hours: 13 to 24

Hr. 13 5° Hr. 14 50......

so...... so......

... Hr. 17 5U Hr. 18 ...... 5°......

202 WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: JULY Hours:1 to 12

Hr. 2 513......

2F) 3b 90 5 59 91-1 30 00.

......

Hr. 10.,.,...... SD...... > °...... 4u......

313......

50 913 30 0 913 3D 90

203 WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: JULY Hours: 13 to 24

204 WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: AUGUST Hours:1 to 12

Hr. 4 Hr.

s0 95. lp ti u 30 90 50 50,9D

10...... 50,...... 50...... Hr. 7 50.. Hr. 8 50 Hr. 9 50...

59 13 30 efl

205 WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: AUGUST Hours: 13 to 24

Hr. 15 50

50 99

Hr. 16 Hr. 17 w Hr. 18 io

"' J13 63 30 10 50

Hr. 21 5°

Hr. 22 93 Hr. 23 513

50 19 2b 30 10 50 WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: SEPTEMBER Hours:1 to 12

30 90 50 Sü 99... .30 20 lb WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: SEPTEMBER Hours: 13 to 24

so Hr. 13 Hr. 14 513....,...

5G1 90 30 20 31) 113 5n 50 30 ID 5D

...... Hr. 16 50...... ,,.

so...... Hr. 23 50......

`:.....,...... ,., WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: OCTOBER Hours:1 to 12

...... 5°...... , Hr. 12 .... WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: OCTOBER Hours: 13 to 24

50......

Hr. 17 ...... 5°......

210 WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: NOVEMBER Hours:l to 12

Hr.l ---50-- Bz.3 '_--

.113 ED 3D 1D 5D 50 10 30 ED 0

Hr. 0~.-'ro--

`^-.`r-'' ...... ,...... Bz. 8 ---'50--' Hr. 9''-'+"--``

211 WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: NOVEMBER Hours: 13 to 24

Hr. 13 5D......

., ,...... : .... _

it. c'0 90.,59 50 9D 30 : : iD ED 3D 40 50 9D 3D"@9 i{3 2D"...30 90 ITt:.

30...... ,.....,... ..

su...... f Hr. 23 ...... ,5,... WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER.

Month: DECEMBER Hours:1 to 12

Hr. 2

Hr. 10 Hr. 11 9'

55H IQ. 30 Z.6 .1

213 WIND ROSE DIAGRAMS: YUMA VALLEY AGRICULTURAL CENTER. Month: DECEMBER Hours: 13 to 24

:..,...3t,......

10......

. 5a,..., ,..... 50......

93 ...... Hr.20 Hr. 21 ......

214 LITERATURE CITED

1. Brown, P.W. 1989. AZMET: Accessing the Arizona Meteorological Network By Computer. Arizona Cooperative Extension publication 187033. The University of Arizona, College of Agriculture. 26 p.

2. Crowe, P.R. 1971. Concepts in Climatology. Longman Ltd. Manchester, England. 589 p.

215