SPECIAL SCIENTIFIC REPORT-FISHERIES No

548

Expendable Bathythermograph Data on Subsurface Thermal Structure

in the Eastern North Pacific Ocean

Marine Biological LIBRARYLaboratory DEC 5 1S67

WOODS HOLE, MASS.

SPECIAL SCIENTIFIC REPORT-FISHERIES No. 548

UNITED STATES DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE SERVICE

BUR E AU^OF^COM^WOAT^IslHwiET

UNITED STATES DEPARTMENT OF THE INTERIOR

Stewart L. Udall, Secretary Charles F. Luce, Under Secretary Stanley A. Cain, Assistant Secretary for Fish and Wildlife and Parks

FISH AND WILDLIFE SERVICE, Clarence F. Pautzke, Commissioner

Bureau of Commercial Fisheries, Harold E. Crowther, Director

Expendable Bathythermograph Data on

Subsurface Thermal Structure in the

Eastern North Pacific Ocean By

J. F. T. SAUR and DOROTHY D. STEWART

United States Fish and Wildlife Service Special Scientific Report—Fisheries No. 548

Washington, D.C. August 1967

CONTENTS Page

Introduction 1

Instrumentation 2

Expendable bathythermograph system 2 NSRT (near-surface reference temperature) unit. ... 3 Installations aboard SS CALIFORNIAN 3

Observations 3

Problems with instrumentation 5

Temperature errors 5 Failures 5

Near-surface irregularities in the trace 6

Characteristics of temperature sections b

Further developments 9

Literature cited 10

Tables 11

XBT observations 21

Expendable Bathythermograph Data on Subsurface

Thermal Structure in the

Eastern North Pacific Ocean

J. F. T. SAUR, Oceanographer and DOROTHY D. STEWART, Fishery Biologist

Bureau of Commercial Fisheries Biological Laboratory Stanford, California 94305

ABSTRACT

This report contains reproductions of original temperature-depth traces, two temperature sections, and synoptic weather observations taken between San Fran- cisco and Honolulu in November-December 1965, using an expendable bathythermograph system aboard a merchant ship, A third temperature section derived from closely spaced observations shows the complicated temperature structure with temperature maximums and minimums over a distance of about 45 nautical miles (85 km.) across the outer boundary of the California Current.

INTRODUCTION Subsurface oceanographic observations are sparse in comparison with surface data. It Knowledge of the mechanisms by which the seems feasible to improve greatly the time- environment may affect the abundance and space distribution of subsurface data by two availability of commercial fishes and the ap- methods: the use of anchored and drifting plication of oceanographic and fishery fore- oceanographic buoys and the use of ships of casting will depend upon the collection of opportunity. The latter depends upon instru- oceanographic data well distributed in space ment systems that can obtain the data without and time, both at the surface of the ocean and interfering with the normal operation of the below the surface. Near- surface water tem- ship, particularly without having to decrease peratures collected as a part of the marine the speed or change course. One of the first weather observations are numerous from the systems of this type to be developed is based middle latitudes of the northern hemisphere on the expendable bathythermograph. where shipping is dense. Instrument programs The Bureau of Commercial Fisheries Bio- are underway in the Bureau of Commercial logical Laboratory, Stanford, Calif., with the Fisheries, the Navy Oceanographic Office, cooperation of the Matson Navigation Com- and the Weather Bureau to improve the quality pany, has begun a pilot project to test the of the water temperature observations that feasibility of using an XBT (expendable bathy- are now generally obtained by reading com- thermograph) system manufactured by the mercial grade mercury-in-glass thermom- Sippican Corporation1 aboard a ship of oppor- eters mounted in the ship's sea-water intake tunity. George Hansen of the U.S. Fleet Nu- system in the engineroom and that contain merical Weather Facility, Monterey, Calif,, numerous errors (Saur, 1963; Sette, 1965). added a digitizer- encoder unit to the recorder The cost of obtaining the weather observa- and assisted with the preliminary tests of the tions (including the sea temperatures) aboard system. The system has been placed aboard merchant ships is low compared with the cost the SS CALIFORNIAN to obtain subsurface of oceanographic observations by research temperature data between Honolulu and San vessels. The greatest overhead cost, the Francisco on approximately a biweekly basis. operation of the ship, is already absorbed This project will provide experience to form because the ship has another primary mission. plans for use of ships of opportunity to obtain From the point of view of oceanographic or 1 meteorological observations, a merchant ship The trade name referred to in this publication does is a "ship of opportunity". not imply endorsement of the commercial product. data on an oceanwide basis, and the temperature data will give information on the seasonal changes of the California Current. This report presents the original data taken on round-trip voyage 105 of the SS CALI- FORNIAN in November-December 1965. J. F. T. Saur made this trip to check the per- formance of the XBT system and to train the ship's personnel in its operation. The system was subsequently modified by the manufacturer to overcome deficiencies, some of which were diagnosed during this voyage.

INSTRUMENTATION

Expendable Bathythermograph System The permanent shipboard components of the XBT system are the launcher (fig. 1) and the recorder (fig. 2) along with the connecting Figure 2. Reading the paper tape punched by the reper- electric cables. These components are small — forator on top of the electronic rack which holds the enough and light enough to be easily moved recorder and digitizer encoder unit. from ship to ship. In figure 2, the recorder is shown mounted in a rack with a digitizer- encoder unit. A reperforator unit, which punches digitized data on a five-channel paper tape, is mounted on the top of the rack. Once permanent mounts for the rack have been fixed aboard a ship, the rack can be carried on board by two persons, secured, and checked out in 1 to 2 hours. The expendable component of the system is a canister that contains the expendable probe and wire (fig. 3). The sensing element is a rapid-response thermistor wafer which is mounted in the nose of the probe in a manner that allows the water

Figure 3. — Disassembled canister. The shipboard end of the fine wire pays off the spool (top center) in the canister (center) while the end connected to the thermistor pays from another spool inside the probe (lower right) through the finned end. Water enters the tube at the tip of the weighted nose of the probe, flows past the thermistor and out through the same orifice as the wire. The cap (left center), removed before loading into the launching tube, provides rubber cushioning to protect the thermistor during shipment and handling. The pin (right center), inserted through the holes in the the Figure 1. — Placing an expendable thermograph canister canister and the hole in one fin of the probe, locks in the loading breech of the launcher. The arrow is probe in the canister. When the pin is pulled, the probe pointed at the lower end of the discharge tube. is released and slides out of the launch tube by gravity. to flow past it as the probe drops through the water. This sensor is connected to the recorder through a hard-wire link. The wire is com- posed of three insulated conductors (Model T-3 probe), but it is very fine and has a breaking strength of about 8 oz. (227 g.). As the ship proceeds on course, a dual spooling system allows the wire to pay out freely from the canister in the launcher aboard ship while simultaneously the wire is payed out freely from the tail end of the ballistically shaped and finned probe as it falls vertically through the water. The temperature is recorded on the analog recorder which has a modified balanc- ing bridge circuit. The probe has a calibrated rate of descent so that the depth is determined by the time interval from entry into the water. The recorder operates automatically. The Figure 4. — Position of launcher in relation to hull near recording cycle starts when the probe enters vessel stern. For the purpose of the photograph the the water. After a period of recording the launcher was moved to its alternate mount on the star- temperature-depth analog trace, the cycle board side at a location comparable to the portside stops and the recorder returns to a standby mount used during the trip. The deck is between 25 and condition. 30 ft. (8 - 9 m.) above the waterline.

The specifications of the system are as of ±0.15° C. over a total range of -2° C. to follows: 40° C; it uses four 12-degree overlapping scales. Temperature: Installations Aboard SS CALIFORNIAN Range: 28° to 95° F. (-2° . 35° C.) Aboard the SS CALIFORNIAN the launcher Accuracy: +0.36° F. (±0.2° C.) for the XBT system is mounted on the port rail of the main deck about 25 ft. (7.5 m.) Response time: 0.1 sec. from the stern. This is slightly aft of the point Depth: where the hull of the vessel begins to curve inward toward the stern so that the wire trails Range: to 1,500 ft. aft with little danger of contact against the (0 - 460 m.) side of the ship (fig. 4). The probe enters the Accuracy: ±15 ft. (4.6 m.) or 2 water a few feet ahead of the wake. The XBT percent of depth, recorder and the NSRT indicator are installed whichever is greater one deck below the launcher in an area adjacent to the boatswain's locker. The distance from Time for deploy- the XBT launcher to the recorder is about 45 ment: 90 sec. ft. (14 m.). The distance from the NSRT sensor Ship's speed: to 30 knots (0 - 15m. in the engineroom to the indicator aft is about per second) 200 ft. (60 m.). The intake for the sea-water line in which the NSRT sensor is mounted is NSRT (Near-Surface Reference about 25 to 28 ft. (7-8 m.) below the surface, Temperature) Unit depending upon vessel loading.

An NSRT unit is also being tested for accuracy and reliability during this project. The OBSERVATIONS device is intended for use on merchant ships so that sea temperatures will not be read from The locations of the observations on the mercury-in-glass thermometers in the intake outbound leg from San Francisco to Honolulu system. The system consists of a thermistor are shown in figure 5. Numbers are not con- probe installed in the ship's sea-water intake secutive because all probe releases were num- and a remote temperature-indicating meter. bered serially whether they were successful On the SS CALIFORNIAN the meter was in- drops or failures. The XBT drops on the out- stalled near the XBT recorder so that the bound leg were made by the senior author, and temperatures could be used as a subsurface uneven spacing occurred while he was becom- (26 - 30 ft. or 8 - 9 m.) check against the ing familiar with the system and establishing XBT temperatures. Usually the meter would a routine convenient for ship's personnel. be installed on the bridge where the weather Licensed officers of the SS CALIFORNIAN report is logged. The NSRT has an accuracy made most of the observations on the return 4 0* N

12 30* 16 17

• 20 22 23 • 24 27

• 28 29 ^•J2

2 0' ts-

160° 150° 140' 130° 120" W.

Figure 5.~Location of observations, SS CALIFORNIAN Voyage 105. Outbound from San Francisco to Honolulu.

leg from Honolulu to San Francisco. The loca- Monterey, Calif., has supported this project, tions are shown in figure 6. At locations 55 to and the observations were transmitted by radio 62 probes were dropped at closely spaced (in BATHY report form) to that activity for intervals by the senior author in the western use in its oceanographic services. boundary of the California Current. Selected portions of synoptic weather obser- The individual traces for the drops where vations logged by ships' personnel for the U.S. good records were obtained are shown following Weather Bureau are given in tables 1 and 2. table 13 and are identified by the observation Tables 3 through 13 give the weather codes number. Date, time, location, and NSRT tem- used in logging the weather observations perature are shown also with each trace. (reproduced from the International Code for Surface temperature and surface salinity are Radio Weather Reports from Ships, U.S. Dept. given when observed. of Commerce, Weather Bur., Wash., D.C., The U.S. Fleet Numerical Weather Facility, 1960). 40 N.

30*

20' due to insulation defects in the wire link. If CHARACTERISTICS OF TEMPERATURE the wire breaks in the water, the electrical SECTIONS short causes the pen to move to the high- temperature side of the recorder and remain The temperature section derived from the there. In 71 releases, two failures appearedto observations on the outbound leg is shown in result from insulation defects and six from figure 7 and that for the inbound leg in figure 8. wire breaks. The isotherms for every 2° F. show the gross features of the temperature structure. The pronounced mixed layer is evident across the NEAR-SURFACE IRREGULARITIES entire section, but it becomes progressively IN THE TRACE shoaler from about long. 140° W. toward the California coast. Similarly the isotherms rise The rated response time of the thermistor more rapidly in the eastern half of the sec- sensor is about 0.1 sec. Thus, it takes 0.3 tions. Both features are evidence of more sec. for the thermistor to respond to 95 per- rapidly moving southward flow, normal to the cent of a step change in temperature and section, in the eastern part which is occupied during this time the probe descends about 9 by the California Current. to 10 ft. (3 m.). When the cycle starts as the On the outbound section (fig. 7), the iso- probe enters the water, the thermistor is therms show a steep rise at mid-depths at responding to change from its ambient tem- observation 22. This feature is worth noting perature in the launcher to water temperature. because a similar rise in the isotherms occurs For most of the observations a small curve at observation 39 on the return section (fig. 8). appears in the trace between the surface and Although the gradients were small at these 10 ft. (3 m.), which is a result of the therm- depths and a slight temperature error could istor response time. No attempt should be cause such a feature, it seems that this made to utilize the record of temperature for temperature ridge may well be a real feature. depths less than 10 ft. (3 m.) . Time series sections, such as those planned In 12 observations included in this report, for this pilot project, should reveal much the temperature trace exhibited a gradient information on features like this which here- from the surface to a depth of 20 ft. (6 m.) or tofore might well have been viewed with sus- greater which was not believed to be valid. picion as instrumental or observational error. This conclusion was reached for several Because a temperature inversion appeared reasons. A large storm had moved through at observation 55, a special series of closely the area preceding the voyage, and the weather spaced observations was begun. The tempera- remained windy with cooling at the surface, ture structure from the closely spaced XBT which would create a well-mixed layer. Ex- observations over a distance of about 45 cellent agreement between the bucket (surface) nautical miles (85 km.) reveals a complex temperature and the NSRT temperature (8 - structure of maximums and minimums (fig. 9). 9 m. below the surface) verified the isothermal Robert P. Brown of the BCF Tuna Re- condition in the surface layer. Thus, the near- sources Laboratory, La Jolla, Calif., has surface gradient appearing in the trace was previously noted (unpublished data and per- judged to be instrumental. In tests made by sonal communication) that similar complicated the manufacturer in probes of the same model vertical temperature structure was observed (T-3), a few also failed to have the proper about 500 nautical miles (930 km.) west of response. Since the evidence is not conclusive Los Angeles. He found this structure was that the apparently erratic trace was due to associated with the boundary between the the instrument system, the traces are shown outer edge of the California Current and the as they were recorded, but the doubtful portion Eastern North Pacific Central Water Mass. (according to our judgment) has beenhachured Roden (1964) has also described the occur- to draw attention to it. These doubtful gradients rence of temperature maximums in mechani- occurred at observations 8, 9, 10, 11, 12, 15, cal bathythermograph observations from the 17, 28, 29, 31, 52, and 64. We feel that the Northeast Pacific Ocean. It appears that such trace for these observations should be vertical structure is characteristic of the outer through the hachured portion to connect with boundary of the California Current for dis- the vertical line just below the hachured layer, tances of at least several hundred miles portraying an isothermal water layer. parallel to the California coast. OBS. NO. 32 31 29 28 27 24 23 22 20 17 16 15 12 II 10 9 8 7 5 4

NSRT (0 <0 yr i74 72 6 8

500

1,000 -

1,500 1,600'- TEMP. OBS. NO. 34 35 36 37 38 39 40 42 43 44 46 48 50 52 53 54 55 63 64 66 67 68 69 NSRT

500

ID Ul U-

0. QUJ 1.000-

1,500

1.500" TEMP.

500 1,000 1,500 2,000 GREAT CIRCLE DISTANCE FROM MAKAPUU PT. (NAUTICAL MILES)

Figure 8. —Temperature-depth section derived from observations taken during the inbound leg (Nov. 28 to Dec. 3, 1965), omitting observations 56-62 giving details of boundary region shown in figure 9. Mixed layer depth is designated by MLD. The near surface reference temperature (NSRT) is in degrees Fahrenheit. Shaded area is the sea floor. Ob- servation 69 (see trace) may have hit rising continental slope at 1,070 ft. (326 m.), indicated by the black dot. 650'- TEMP,

1,5 00- TEMP

DISTANCE H 10 nautical miles *\

Figure 9. — Complex temperature structure over a distance of about 45 nautical miles (85 km.) in the western boundary of the California Current.

FURTHER DEVELOPMENTS was removed from the ship for one trip to repair the digitizer. Subsequent to the shakedown cruise, the On the basis of preliminary analyses of Sippican Corporation recalled the XBT system these traces, the modified system is more for re-engineering. The model T-4 probe was reliable than that used on voyage 105. The developed to improve the wire insulation and defects causing the near-surface irregularities to assure better response of the thermistor appear to have been remedied, so that the at the time of water- entry. traces in almost every instance show rapid The modified XBT system was installed response of the system when the probe enters aboard the SS CALIFORNIAN on June 1. By the water. early November 1966 the ship had completed The percentage of total failures has been nine round trips. During this period observa- 8 percent as compared with 11 percent on tions were taken for 10 sections; 1 outbound voyage 105. A few of these failures may be and 8 inbound sections between San Francisco attributed to poor insulation on the wire of and Honolulu and 1 special outbound section the T-4 probes. Most failures occurred be- from Los Angeles to Honolulu. The system cause the recorder did not trip and go through SAUR, J. F. T. the cycle; a problem not encountered during 1963. A study of the quality of sea water the shakedown on voyage 105. Minor modifi- temperature reported in logs of ships' cations still need to be made on the present weather observations. J. Appl. system; however, the observations from the Meteorol. 2(3): 417-425. cruises made since June 1, 1966, demonstrate SETTE, O. E. the capability of this unit to produce high 1965. Computer preparation of surface sea quality data. temperature observations for analysis and charting. Proceedings of the ONR- NSIA Symposium on Automatic Collec- LITERATURE CITED tion, Processing and Analysis of Oceanographic Data, University of Cali- fornia, San Diego, December 11-12, RODEN, GUNNAR I. 1964. Published for ONR and NSIA by 1964. Shallow temperature inversions m Lockheed- California Company, October the Pacific Ocean. J. Geophys. Res. 12, 1965: 59-60. 69(14): 2899-2914.

10 Table 1. Synoptic weather observations, SS CALIFORNIAN Voyage 105. Outbound from San Francisco to Honolulu

0) p Table 3. Direction of wind or waves (in 10 ' s of degrees, from which wind is blowing or from which waves come)

Symbol dd— True direction, in 10's of degrees, FROM which wind is blowing (00-86)

Symbol duda—Direction, in 10's oj degrees, FROM which waves come

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~~13 sse * s Table 6. Past weather~~

~~Symbol W—Past weather~~

~~Code Description figures~~

~~Cloud covering }{ or less of the sky through- out period. Cloud covering more than \i of sky during~~

part of period, and less than >/2 during part of period. Cloud covering more than % of sky through out period. Sandstorm or duststorm or blowing snow. Fog or ice fog or thick haze. Drizzle. Rain. Snow or rain and snow mixed or ice pellets. Shower(s). Thunderstorm (s) with or without precipitation

~~Notes~~

1. In 0000, 0600, 1200 and 1800 G. C. T. reports "Past Weather" covers the preceding 6-hour period while in 0300, 0900, 1500, and 2100 G. C. T. reports, "W" covers the preceding 3-hour period. 2. The code figure for "W" is selected in order that "W" and "ww" together give as complete a description as possible of the weather in the time interval concerned. For example, if the type of weather undergoes a complete change during the time interval concerned, the code figure selected for "W" will describe the weather prevailing before the type of weather indicated by "ww" began. If however more than one code figure may be given to W with regard to past weather, the higher code figure is reported.

~~Table 7. Cloud amount: total cloud, low cloud~~

~~Symbol N—Fraction of the celestial dome covered by clouds~~

~~Symbol N^—Fraction of celestial dome covered by type of cloud reported jor CL (or Cm if no CL cloud present)~~

~~Symbol N,—Fraction of the celestial dome covered by the cloud layer reported by Symbol C~~

~~Code figures Table 8. Type of low clouds~~

~~Symbol CL—Clouds of types Stratocumulus, Stratus, Cumulus, and Cumulonimbus~~

~~Code fig- Technical language specifications Plain language specifications ures~~

No Cl clouds. No Cumulus, Cumulonimbus, Strato- cumulus or Stratus. Cumulus humilis, or Cumulus Cumulus with little vertical extent fractus other than of bad and seemingly flattened, or ragged weather, or both. Cumulus other than of bad weather, or both. Cumulus mediocris or congestus, Cumulus of moderate or strong verti- with or without Cumulus of cal extent generally with protuber- species fractus or humilis, or ances in the form of domes or Stratocumulus; all having their towers, either accompanied or not bases at the same level. by other Cumulus or by Strato- cumulus; all having their bases at the same level. Cumulonimbus calvus, with or Cumulonimbus the summits of which, without Cumulus, Stratocumu- at least partially, lack sharp out- lus or Stratus. lines, but are neither clearly fibrous (cirriform), nor in the form of an anvil; Cumulus, Stratocumulus or Stratus may be present. Stratocumulus cumulogenitus Stratocumulus formed by the spreading out of Cumulus; Cumulus may also be present. Stratocumulus other than Strato- Stratocumulus not resulting from the cumulus cumulogenitus. spreading out of Cumulus. Stratus nebulosus or Stratus frac- Stratus in a more or less continuous tus other than of bad weather, sheet or layer, or in ragged shreds or both. or both, but no Stratus fractus of bad weather. Stratus fractus or Cumulus frac- Stratus fractus of bad weather or tus of bad weather or both Cumulus fractus of bad weather (pannus) usually below Alto- or both (pannus) usually below stratus or Nimbostratus. Altostratus or Nimbostratus. Cumulus and Stratocumulus, Cumulus and Stratocumulus, other other than Stratocumulus cu- than those formed from the spread- mulogenitus, with bases at dif- ing out of Cumulus; the base of ferent levels. Cumulus is at a different level than that of the Stratocumulus. Cumulonimbus capillatus (often Cumulonimbus, the upper part of with an anvil), with or without which is clearly fibrous (cirriform) Cumulonimbus calvus, Cumu- often in the form of an anvil; either lus, Stratocumulus, Stratus or accompanied, or not by Cumulo- pannus. nimbus without anvil or fibrous upper part, by Cumulus, Strato- cumulus, Stratus, or pannus. Clouds C L not visible owing to No Cumulus, Cumulonimbus, Strato- darkness, fog, blowing dust or cumulus or Stratus visible owing to sand, or other similar phe- darkness, fog, blowing dust or nomena. sand, or other similar phenomena.

~~Note: "Bad Weather" denotes the conditions which generally exist during precipitation and a short time before and after.~~

~~16 Table 9. Height of low clouds~~

~~Symbol h—Height above sea of base of the cloud~~

~~Code figures .~~

~~Table 10. Type of middle clouds~~

~~Symbol fM— Clouds of types Altocumulus, Altostratus, and Nimbostratus~~

~~Code fig- Technical language specifications Plain language specifications ures~~

No Cm clouds No Altocumulus, Altostratus or Nim- bostratus. Altostratus translucidus. Altostratus, the greater part of which is semitransparent; through this part the sun or moon may be weakly visible as through ground glass. Altostratus opacus or Nimbo- Altostratus, the greater part of which stratus. is sufficiently dense to hide the sun (or moon), or Nimbostratus. Altocumulus translucidus at a Altocumulus, the greater part of which single level. is semitransparent; the various elements of the cloud change only slowly and are all at a single level. Patches of Altocumulus translu- Patches (often in the form of almonds cidus (often lenticular), contin- or fishes) of Altocumulus, the uously changing and occurring greater part of which is semitrans- at one or more levels. parent; the clouds occur at one or more levels and the elements are continually changing in appearance. Altocumulus translucidus in Semitransparent Altocumulus in bands, or one or more layers bands or Altocumulus in one or of Altocumulus translucidus or more fairly continuous layers (semi- opacus progressively invading transparent or opaque) progres- the sky; these Altocumulus sively invading the sky; these Alto- clouds generally thicken as a cumulus clouds generally thicken whole. as a whole. Altocumulus cumulogenitus (or Altocumulus resulting from the cumulonimbogenitus) spreading out of Cumulus (or Cu- mulonimbus). Altocumulus translucidus or Altocumulus in two or more layers opacus in 2 or more layers, or usually opaque in places and not Altocumulus opacus in a single progressively invading the sky; or layer, not progressively invad- opaque layer of Altocumulus not ing the sky, or Altocumulus progressively invading the sky; or with Altostratus or Nimbo- Altocumulus together with Alto- stratus. stratus or Nimbostratus. Altocumulus castellanus or floc- Altocumulus with sproutings in the cus. form of small towers or battlements, or Altocumulus having the appearance of cumuliform tufts. 9 Altocumulus of a chaotic sky, Altocumulus of a chaotic sky gen-

. generally at several levels. erally at several levels. X Clouds Cm not visible owing to No Altocumulus, Altostratus or Nim- darkness, fog, blowing dust or bostratus visible owing to darkness, sand, or other similar phe- fog, blowing dust or sand, or other nomena, or because of a con- similar phenomena, or more often tinuous layer of lower clouds. because of the presence of a continuous layer of lower clouds.

~~18 Table 11. Type of high clouds — Symbol Cu Clouds of types Cirrus, Cirrostratus , and Cirrocumulus~~

~~Code fig- Technical language specifications Plain language specifications ures~~

No Ch clouds. No Cirrus, Cirrostratus or Cirrocu- mulus. Cirrus fibratus, sometimes un- Cirrus in the form of filaments, cinus, not progressively invad- strands or hooks, not progressively ing the sky. invading the sky. Cirrus spissatus, in patches or en- Dense Cirrus in patches or entangled tangled sheaves, which usually sheaves which usually do not in- do not increase and sometimes crease and sometimes seem to be seem to be the remains of the the remains of the upper parts of upper part of a Cumulonimbus; Cumulonimbus; or Cirrus with or Cirrus castellanus or floccus. sproutings in the form of small tur- rets or battlements or Cirrus having the appearance of cumuliform tufts. Cirrus spissatus cumulonimbo- Dense Cirrus often in the form of an genitus. anvil, being the remains of the upper parts of Cumulonimbus. Cirrus uncinus, or fibratus, or Cirrus in the form of hooks or fila- both, progressively invading ments or both, progressively invad- the sky; they generally thicken ing the sky; they generally become as a whole. denser as a whole. Cirrus, often in bands, and Cirro- Cirrus, often in bands converging to- stratus, or Cirrostratus alone, wards 1 point or 2 opposite points progressively invading the sky; of the horizon and Cirrostratus, or they generally thicken as a Cirrostratus alone; in either case whole, but the continuous veil they are progressively invading the does not reach 45° above the sky, and generally growing denser horizon. as a whole, but the continuous veil does not reach 45° above the horizon. Cirrus, often in bands, and Cirro- Cirrus, often in bands converging to- stratus, or Cirrostratus alone, wards 1 point or 2 opposite points progressively invading the sky; of the horizon, and Cirrostratus, or they generally thicken as a Cirrostratus alone; in either case whole, but the continuous veil they are progressively invading the extends more than 45° above sky, and generally growing denser the horizon, without the sky as a whole; the continuous veil ex- being totally covered. tends more than 45° above the horizon, without the sky being completely covered. Cirrostratus covering the whole Veil of Cirrostratus covering the sky. celestial dome. Cirrostratus not progressively in- Cirrostratus not progressively invad- vading the sky, and not entirely ing the sky, and not completely covering it. covering the celestial dome. Cirrocumulus alone, or Cirrocu- Cirrocumulus alone, or Cirrocumulus mulus predominant among the accompanied by Cirrus or Cirro- cirriform clouds. stratus or both, but Cirrocumulus is predominant. Clouds Ch not visible owing to No Cirrus, Cirrostratus or Cirrocumu- darkness, fog, blowing dust or lus visible owing to darkness, fog, sand or other similar phenom- blowing dust or sand, or other ena, or because of a continuous similar phenomena, or more often layer of lower clouds. because of the presence of a continuous layer of lower clouds.

~~19 Table 12. Period of waves~~

~~Symbol Pu—Period of waves~~

~~Code~~

~~3 3 o~~

~~o w a ciii o z~~

~~a. aui 30 3 30 o 30 40 50 60 70 80 90° F.~~

~~UJ u.O a (U~~

~~0. Ula 30 30 n~~

~~UJ oU. av> HI ax.~~

~~oui 30 40 50 60 70 80 90° FT~~

~~O 111~~

~~a. otu 30 40 50 60 70 80 90° F~~

~~-J- I~~

~~I TRACE TEMPERATURE, I ?;~~

~~K o~~

~~UJ Ui u. ou. aV) UI Q~~

~~X t- 0. oU) 30 40 50 60 70 80 90° F~~

~~i 30 40 50 60 70 80 90° F.~~

~~-J- I~~

~~/ t~~

~~10- t~~

~~I CALIFORNIAN Voyage No. 105~~

~~XBT Observation No. 24~~

~~November 26, 1965; 0515 G.c.t. 25°31' N., 151°05' W.~~

~~12- NSRT Temp. 23.0° C. (73.40° F.)~~

~~Near Surface Salinity 35.177»o~~

~~13-~~

~~14-~~

~~15-~~

~~36 30 40 50 60 70 80 90° F. o~~

~~oV) ao_~~

~~a. oui 38 30 40 50 60 70 80 90° F n~~

~~H 7 id U~~

~~W O UJ (E Q~~

~~a. oui 30 40 50 60 70 80 90° p~~

~~-1 - I~~

~~5 —~~

~~UJ u. O 8 — w a Ml a~~

~~t CALIFORNIAN Voyage No. 105 a. I XBT Observation No. 31 oin November 27, 1965; 0137 G.c.t.~~

~~22°20' N. , 156°09' W.~~

~~12- NSRT Temp. 24.85° C. (76.73° F.)~~

~~40 30 40 ft 30 40 50 60 70 80 90° F~~

~~Small perturbations in mixed layer caused by gain too high on amplifier.~~

~~UJ f (U / I Z~~

~~O I tc a 9.~~

~~/. J~~

~~CALIFORNIAN Voyage No. 105~~

~~XBT Observation No. 34 aui November 28, 1965; 0820 G.c.t.~~

~~21°23' N., 157°27' W. NSRT Temp. 24.62° C. (76.32° F.) /~~

~~/ 13-~~

~~14- &~~

~~15-~~

~~42 30 40 50 60 70 80 90° F~~

~~o l~~

~~u UJ u. ou. w a UJ a~~

~~i- o. 30 n~~

~~_j o atn ui o~~

~~x i- a. oUJ 30 A 30~~

~~ou. aV) u IE Q Z X~~

~~0. aIll 30 30 40~~

~~o Ui K O z 3~~

~~X »- Q. QUI 30 40 50 60 70 80 90° P o 3 o 30 Q 30 40 50 60 70 80 90° F n~~

~~H 7 Id Id~~

~~w Q UJ~~

~~X I- a. oUJ 30 40 50 60 70 SO 90° F~~

~~T t~~

~~+ rr K 7 III~~

~~10-~~

~~CALIFORNIAN Voyage No. 105~~

~~XBT Observation No. 48~~

~~December 1, 1965; 0250 G.c.t. 31°07' N., 140°37' W. 12- NSRT Temp. 20.10° C. (68.18° F.)~~

~~13-~~

~~14-~~

~~15-~~

~~53 30 40 50 60 70 80 90" F~~

~~UJ UJ 1 w a a x z 10-~~

~~CALIFORNIAN Voyage No. 105 a. XBT Observation No. 50 Ui o December 1, 1965; 0715 G.c.t.~~

~~31°37' N., 139°32' W.~~

~~NSRT Temp. 19.60° C. (67.28° F.)~~

~~Near Surface Salinity 34.967..~~

~~13-~~

~~14-~~

~~13-~~

~~54 30 4~~

~~a 111 o~~

~~a. oHi • 30 40 50 60 70 80 90 F. n • 30 40 50 60 70 80 90 F. n 30 A 3 30 40 50 60 70 80 90 • F n~~

~~a 111 Q~~

~~a. aUJ 30 40 50 60 70 80 90 • K~~

~~V)Q Ul (EQ~~

~~X I- Q. oUJ 30~~

~~Ui UJ u.~~

~~w a a~~

~~Ua. a 30 30 n~~

~~UJ UJ~~

~~avt UJ (E O~~

~~O. Ulo 3~~

~~a(A ui a~~

~~0. 30~~

~~UJ UJ~~

~~V)o 111 a z 3 x x H ua. o 30 40 50 60 70 80 90° F.~~

~~1 30~~

~~u UJ u. ou. W O a~~

~~MBL WHOI Libra~~

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