More Lessons from the Sky Satellite Educators Association

Tracking

Hurricanes

From

Space

More Lessons from the Sky Satellite Educators Association http://SatEd.org

Please see the Acknowledgements section for historical contributions to the development of this lesson plan. This form of "Tracking Hurricanes from Space" lesson plan was published in October 2011 in “More Lessons from the Sky,” a regular feature of the SEA Newsletter, and archived in the SEA Lesson Plan Library. Both the Newsletter and the Library are freely available on-line from the Satellite Educators Association (SEA) at this address: http://SatEd.org.

Content including 2017 hurricanes, Internet links, and updated support materials available from the online Resources page were revised and updated October 2019.

SEA Lesson Plan Library Improvement Program Did you use this lesson plan with students? If so, please share your experience to help us improve the lesson plan for future use. Just click the Feedback link at http://SatEd.org/library/about.htm and complete the short form on-line. Thank you. Teaching Notes

Tracking Hurricanes from Space Interpreting Weather Satellite Data

Invitation Chart the path of hurricanes from satellite images. Analyze the imagery using image processing software to discover tropical cyclone characteristics. Identify the weather patterns of a major storm and predict the direction of the storm and damage possible from tropical cyclones. Apply these skills to current or past severe storms with your research team.

Grade Level: 7-12 Time Requirement: 1-3 class periods Prerequisites: ImageJ skills (optional) Relevant Disciplines: Earth Science, Chemistry, Physics

Student Learning Outcomes By the end of this lesson, students should be able to do the following: • Observe severe storm action from space • Identify weather patterns including clouds types and movement, weather fronts, high and low pressure areas • Differentiate between sustained wind speed in a hurricane and the speed of the storm; associate each with severity of potential damage • Identify and measure the eye of the hurricane; compare the eye size to the overall strength of the cyclone • Use image processing skills to analyze images of the storm as seen by satellite • Predict the path and potential damage of these and other severe storms

Lesson Description This is a teacher-supported, student-centered, team research and analysis project using ImageJ software, tutorial, teamwork, and classroom and Internet resources. The student team will use provided resources to examine Hurricane Katia, a Category 4 storm that followed the Gulfstream without making landfall in the US in 2011. With ImageJ tools, the team will analyze the storm’s characteristics then apply the same techniques to a study of Hurricane Maria, a Category 5 sweeping across Puerto Rico in September 2017. Each team has the opportunity to construct an evidence-based response to a question correlating the area of a hurricane’s eye to the area of the cyclone. (Please note that the Hurricane Katia in this lesson formed in the Atlantic, passed to the northeast of the Caribbean islands as a Category 4, turned northeast and paralleled the US east coast without making landfall in September 2011. Another Hurricane Katia formed in the Gulf of Mexico and made landfall near Veracruz, Mexico as a Category 1 on September 9, 2017. Hurricane names are reused unless retired. Only the names of catastrophic tropical storms causing heavy loss of life and/or property are retired. Katrina is one such example. When students access advisory data from the National Hurricane Center, be sure they do not confuse the two Katias.)

More Lessons from the Sky, © Satellite Educators Association, Inc. Tracking Hurricanes from Space 1 Teaching Notes

Divide the learners into teams and allow them to work through the lesson together as though they were training in analyzing severe storms in preparation for the Your Turn activities. Ensure that each member of a team has a daily responsibility. When the Your Turn section is reached, the team should plan together how best to research and accomplish those tasks, submit the plan for teacher-approval, and implement the plan in a timely manner.

During the activity, students will need to know the latitude and longitude of the storm’s center. Before a storm and throughout a severe storm’s duration, NOAA’s National Hurricane Center (NHC) issues near hourly advisories about the storm that include the data summarized in the tables below. All GOES images of hurricanes in this lesson are date/time stamped making it easier to match the data tables to the imagery. Please note: these tables are available to students in image files that they will view on screen using ImageJ. The student versions of these tables do not include Direction and Speed columns. Refer to the Preparation section about data options when using ImageJ with Hurricane Maria data.

Hurricane Maria Data - 2017 Stack Adv Wind Gust Press Center Center Speed Slice Num Date UTC (mph) Scale (mph) (mb) Lat (N) Lon (W) Direction (mph) 1 1 16-Sep 1500 35 TrpCy 46 1008 12.2 50.5 280 22 6 2 16-Sep 2100 52 TrpSt 63 1002 12.3 52.6 275 20 12 3 17-Sep 0300 52 TrpSt 63 1002 12.5 53.7 280 16 18 4 17-Sep 0900 63 TrpSt 75 994 13.0 54.9 290 15 24 5 17-Sep 1500 63 TrpSt 75 994 13.5 56.2 290 15 30 6 17-Sep 2100 75 Cat 1 92 982 13.8 57.5 285 15 36 7 18-Sep 0300 86 Cat 1 104 979 14.2 58.4 290 13 42 8 18-Sep 0900 92 Cat 1 115 977 14.6 59.5 290 13 48 9 18-Sep 1500 121 Cat 3 150 959 14.7 60.1 285 10 54 10 18-Sep 2100 132 Cat 4 161 95 15.1 60.7 290 9 57 11 19-Sep 0000 161 Cat 5 196 925 15.3 61.1 300 9 60 12 19-Sep 0300 161 Cat 5 196 924 15.5 61.4 300 9 66 13 19-Sep 0900 155 Cat 4 190 934 16.0 62.3 300 9 72 14 19-Sep 1500 161 Cat 5 196 927 16.3 63.1 300 10 78 15 19-Sep 2100 167 Cat 5 201 916 16.8 64.0 300 10 84 16 20-Sep 0300 173 Cat 5 213 909 17.3 64.7 300 10 90 17 20-Sep 0900 155 Cat 4 190 917 17.9 65.6 305 10 96 18 20-Sep 1500 138 Cat 4 167 930 18.4 66.5 305 12 102 19 20-Sep 2100 109 Cat 2 132 957 18.8 67.3 305 12 108 20 21-Sep 0300 109 Cat 2 132 959 19.2 67.9 310 9 114 21 21-Sep 0900 115 Cat 3 138 959 19.6 68.4 315 9 120 22 21-Sep 1500 115 Cat 3 138 960 20.2 69.1 310 9 126 23 21-Sep 2100 121 Cat 3 150 960 20.8 69.8 315 9 132 24 22-Sep 0300 127 Cat 3 155 955 21.0 7.2 320 8 138 25 22-Sep 0900 127 Cat 3 155 959 21.6 7.6 315 7 144 26 22-Sep 1500 127 Cat 3 155 958 22.3 71.0 325 8 150 27 22-Sep 2100 127 Cat 3 155 959 23.3 71.4 335 9 156 28 23-Sep 0300 127 Cat 3 155 954 24.1 71.7 345 9 162 29 23-Sep 0900 121 Cat 3 150 952 24.8 72.0 345 9 168 30 23-Sep 1500 115 Cat 3 144 952 25.5 72.3 340 8 174 31 23-Sep 2100 115 Cat 3 144 952 25.4 72.3 340 8

2 Tracking Hurricanes from Space More Lessons from the Sky, © Satellite Educators Association, Inc.

Teaching Notes

180 32 24-Sep 0300 115 Cat 3 138 942 27.0 72.5 350 9 186 33 24-Sep 0900 109 Cat 2 132 948 27.9 72.7 355 9 192 34 24-Sep 1500 104 Cat 2 127 947 28.7 72.9 350 9 198 35 24-Sep 2100 104 Cat 2 127 941 29.4 73.0 350 9 204 36 25-Sep 0300 92 Cat 1 115 950 30.0 73.0 360 8 210 37 25-Sep 0900 81 Cat 1 98 957 30.6 73.0 355 7 216 38 25-Sep 1500 81 Cat 1 98 963 31.2 72.9 360 7 222 39 25-Sep 2100 81 Cat 1 98 965 31.7 73.1 360 7 228 40 26-Sep 0300 81 Cat 1 98 969 32.3 73.1 360 7 234 41 26-Sep 0900 75 Cat 1 92 970 32.9 73.1 360 7 240 42 26-Sep 1500 75 Cat 1 92 971 33.6 73.1 360 7 246 43 26-Sep 2100 69 TrpSt 86 974 34.1 73.0 360 7 252 44 27-Sep 0300 69 TrpSt 86 975 34.9 72.9 5 7 258 45 27-Sep 0900 69 TrpSt 86 976 35.1 72.9 5 5 264 46 27-Sep 1500 75 Cat 1 86 978 35.6 72.6 15 6 270 47 27-Sep 2100 75 Cat 1 92 979 36.2 72.1 30 7 276 48 28-Sep 0300 75 Cat 1 92 979 36.8 71.5 40 7 282 49 28-Sep 0900 69 TrpSt 86 982 36.8 71.0 60 8 288 50 28-Sep 1500 69 TrpSt 86 982 36.8 69.3 85 13 294 51 28-Sep 2100 63 TrpSt 75 985 36.8 67.8 90 13

If time permits and you would like to have students themselves research the hurricane data online, all of the tropical cyclone advisories are available at this National Hurricane Center site: https://www.nhc.noaa.gov/. Click Archives and select Tropical Cyclone Advisories. Select a year and then a hurricane name.

Additionally, encourage learners to graph changes in sustained wind speed or central pressure using a graphing program such as Microsoft Excel or Vernier’s Graphical Analysis. Students can plot the path of the storms on the included Atlantic Hurricane Tracking Chart or use geographic information system (GIS) software such as ESRI’s ArcGIS Online.

Hurricane Katia Data - 2011 Stack Adv Wind Gust Press Center Center Speed Slice Num Date UTC (mph) (mph) (mb) Lat (N) Lon (W) Direction (mph) 1 12 1-Sep 0300 75 92 987 15.0 44.4 285 20 3 13 1-Sep 0900 75 92 987 15.2 45.9 280 20 5 14 1-Sep 1500 75 92 987 15.5 47.5 280 18 7 15 1-Sep 2100 69 86 990 16.1 49.2 280 18 9 16 2-Sep 0300 69 86 990 16.7 50.6 290 16 11 17 2-Sep 0900 69 86 994 17.0 51.8 295 15 13 18 2-Sep 1500 75 92 991 17.5 52.4 300 14 15 19 2-Sep 2100 75 92 989 18.4 53.5 305 12 17 20 3-Sep 0300 75 92 988 18.5 54.3 305 12 19 21 3-Sep 0900 75 92 988 19.3 55.1 305 10 21 22 3-Sep 1500 75 92 989 19.6 55.8 305 10 23 23 3-Sep 2100 69 86 993 19.9 56.8 300 10 25 24 4-Sep 0300 69 86 992 20.3 57.4 305 10 27 25 4-Sep 0900 69 86 992 21.4 58.5 305 12 29 26 4-Sep 1500 98 121 966 21.9 59.2 305 12 31 27 4-Sep 2100 104 127 965 22.7 60.1 310 12

More Lessons from the Sky, © Satellite Educators Association, Inc. Tracking Hurricanes from Space 3 Teaching Notes

33 28 5-Sep 0300 104 127 965 23.3 61.0 310 13 35 29 5-Sep 0900 98 121 972 23.9 62.0 305 12 37 30 5-Sep 1500 109 132 965 24.6 63.3 310 13 39 31 5-Sep 2100 115 138 959 25.2 63.9 310 12 41 32 6-Sep 0300 132 161 946 25.8 64.4 315 10 43 33 6-Sep 0900 127 155 950 26.5 65.1 315 10 45 34 6-Sep 1500 121 150 954 27.0 65.9 310 9 47 35 6-Sep 2100 104 127 963 27.6 66.7 320 9 49 36 7-Sep 0300 104 127 963 28.1 67.2 315 9 51 37 7-Sep 0900 92 115 973 28.7 67.9 315 10 53 38 7-Sep 1500 86 103 976 29.2 68.8 315 10 55 39 7-Sep 2100 81 98 982 29.9 69.7 320 10 57 40 8-Sep 0300 81 98 982 30.8 70.0 340 13 59 41 8-Sep 0900 92 115 970 32.0 70.2 350 14 61 42 8-Sep 1500 92 115 970 33.6 70.1 5 16 63 43 8-Sep 2100 86 104 973 34.9 69.6 25 17 65 44 9-Sep 0300 86 104 973 36.3 68.8 35 21 67 45 9-Sep 0900 86 104 967 37.6 67.5 50 24 69 46 9-Sep 1500 86 104 968 39.3 65.8 50 29 71 47 9-Sep 2100 86 104 970 40.6 62.7 60 38

The single most destructive tropical cyclone to land in the U.S. is Hurricane Katrina (2005). As such, abundant remote-sensing data available from multiple satellites and sensors has been analyzed offering significant insight to hurricane structure and behavior. Included in the Resources section below are a number of sources of information and video clips about Katrina. The teacher is invited to explore these sources and modify the lesson to include them as needed for your specific curriculum.

Important Terms Dry line Hurricane Tropical cyclone Eyewall Hurricane eye Tropical storm Geosynchronous Infra-red Typhoon Gulf Stream Landfall Universal Time Coordinate

Assessment Suggestions The actual mode of assessment will depend on your classroom situation, the needs of your students, and your overall curriculum. Some suggestions follow: • Participation and teamwork • Individual answers to questions • Quality of team’s report on predicted storm path and potential damage including supporting evidence • Proficiency with thresholding and measurement using ImageJ • Completion and quality of assigned Your Turn activities

Next Generation Science Standards The Next Generation Science Standards sets below are relevant to this lesson. Each set includes a disciplinary core idea (DCI), science and engineering practice (SEP),

4 Tracking Hurricanes from Space More Lessons from the Sky, © Satellite Educators Association, Inc.

Teaching Notes crosscutting concept (CC), tied together by a Performance Expectation (PE).

Grades 6-8: Waves and Their Applications in Technologies for Information Transfer PE- MS-PS4-3 - Integrate qualitative scientific and technical information to support the claim that digitized signals are a more reliable way to encode and transmit information than analog signals. DCI- MS-PS4.C - Digitized signals are a more reliable way to encode and transmit information. SEP- Integrate qualitative scientific and technical information in written text with that contained in media and visual displays to clarify claims and findings. CC- Technologies extend the measurement, exploration, modeling, and computational capacity of scientific investigations.

Grades 6-8: Earth's Systems PE- MS-ESS2-5 - Collect data to provide evidence for how the motions and complex interactions of air masses result in changes in weather conditions. DCI- MS-ESS2.C - The complex patterns of the changes and the movement of water in the atmosphere, determined by winds, landforms, and ocean temperatures and currents, are major determinants of local weather patterns. SEP- Collect data to produce data to serve as the basis for evidence to answer scientific questions or test design solutions under a range of conditions. CC- Cause and effect relationships may be used to predict phenomena in natural systems.

Grades 6-8: Earth and Human Activity PE- MS-ESS3-2 – Analyze and interpret data on natural hazards to forecast future catastrophic events and inform the development of technologies to mitigate their effects. DCI- MS-ESS3.B - Mapping the history of natural hazards in a region, combined with an understanding of related geologic forces, can help forecast the locations and likelihoods of future events. SEP- Analyze and interpret data to determine similarities and differences in findings. CC- Graphs, charts, and images can be used to identify patterns in data.

Grades 9-12: Waves and Their Applications in Technologies for Information Transfer PE- HS-PS4-2 - Evaluate questions about the advantages of using digital transmission and storage of information. DCI- HS-PS4.A - Information can be digitized; in this form it can be stored reliably in computer memory and sent over long distances as a series of wave pulses. SEP- Use mathematical representations of phenomena or design solutions to describe and/or support claims and/or explanations. CC- Modern civilization depends on major technological systems.

Grades 9-12: Earth's Systems PE- HS-ESS2-2 – Analyze geosciences data to make the claim that one change to Earth’s surface can create feedbacks that cause change to other Earth systems. DCI- HS-ESS2.D - The foundation for Earth's global climate systems is the electromagnetic radiation from the sun, as well as its reflection, absorption, storage, and redistribution among the atmosphere, ocean, and land systems

More Lessons from the Sky, © Satellite Educators Association, Inc. Tracking Hurricanes from Space 5 Teaching Notes

and this energy's re-radiation into space. SEP- Analyze data using tools, technologies, and/or models (e.g., computational, mathematical) in order to make valid and reliable scientific claims or determine an optimal design solution. CC- Empirical evidence is required to differentiate between cause and correlation and make claims about specific causes and effects.

Grades 9-12: Earth and Human Activity PE- HS-ESS3-1 - Construct an explanation based on evidence for how the availability of natural resources, occurrence of natural hazards, and changes in climate have influenced human activity. DCI- HS-ESS3.B - Natural hazards and other geologic events have shaped the course of human history; they have significantly altered the sizes of human populations and have driven human migrations. SEP- Construct an explanation based on valid and reliable evidence obtained from a variety of sources (including students’ own investigations, models, theories, simulations, peer review) and the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future. CC- Change and rates of change can be quantified and modeled over very short or very long periods of time. Some system changes are irreversible.

Preparation An Internet enabled computer with an acceptable browser is needed for this activity. Organize learners into teams of no more than four to a computer.

ImageJ is available from https://imagej.nih.gov/ij/ free of charge. Of the several download choices, the easiest to install is the one bundled with Java in either 32- or 64- bit versions. The bundled Java installs automatically and runs only with ImageJ. It does not interfere with any other programs or plug-ins (including Java) already installed on your computer. NOTE: In Windows Vista and later versions, security protocols prevent ImageJ updates when installed in the default Program Files folder. Installation in any other convenient place except the Program Files is recommended.

The Student Activity tutorial requires the use of six image and text files prepared specifically for this lesson and described elsewhere in these Teaching Notes. The files are available on this lesson's online Resources page found at this address: http://SatEd.org/library/Resources.htm

Download Resources.zip. Resources.zip is a compressed archive containing all image and data files needed for this lesson except the Hurricane Maria files. Open Resources.zip (21.6 MB) and extract the Resources folder in an appropriate location on your computer. Use a classroom-friendly method of placing the Resources folder on each student computer (usually download and extract on each or copy and paste).

Why are the Maria files available separately? Maria-296.zip (55.0 MB) contains Maria_Stack_HUIR-296.gif and Maria_Data-296.txt. The stack consists of 296 frames or images of Hurricane Maria in timed sequence where each frame is separated by 1 hour. Depending on the age and configuration of the student computers, this large stack

6 Tracking Hurricanes from Space More Lessons from the Sky, © Satellite Educators Association, Inc.

Teaching Notes may require more memory than the computer has available. In addition, ImageJ has a memory control. When installed, it automatically identifies a set amount of the computer’s available memory to use for viewing and processing imagery.

If an ImageJ “Out of memory” error message is displayed, the first step is increase ImageJ’s memory allocation. Use File > Options > Memory & Threads; increase the number in the Maximum memory field; uncheck Keep multiple undo buffers; and check Run garbage collector on status bar check. Click OK. (Note: This setting changes the way ImageJ behaves. It makes no changes to your computer.) If the maximum amount of available memory has already been allocated to ImageJ and there is still a problem, download Maria-150.zip (27.8 MB). This stack has about half as many slices with a 2-hour separation between images. Although not recommended, you can download and use Maria-38.zip (6.8 MB) if necessary. This stack contains only 38 slices and shows Maria when closest to Puerto Rico only. You may need to experiment before the lesson to determine which stack is best for your situation.

These Teaching Notes are provided in portable document format (.pdf). An acceptable PDF reader such as Adobe Reader or equivalent is needed for viewing or printing the files. The Student Activity pages are provided in Microsoft Word document (.docx) format allowing the teacher to more easily adapt these pages to the specific needs of the students, the curriculum, and classroom.

The Student Activity pages should be duplicated and distributed one set per learner or team. The Student Answer Sheet should be duplicated and distributed one per learner. The original PDF file for the hurricane tracking chart is included and may be duplicated and distributed for use if needed.

Background A hurricane is a tropical cyclone, a severe storm system beginning as a tropical depression, becoming a tropical storm and then a hurricane as maximum sustained wind speed increases. These cyclones are called hurricanes in the Atlantic and Eastern Pacific Oceans, typhoons in the Western Pacific. Tropical cyclones typically form in the tropical zones of the oceans at least 500km (300 miles) from the equator. Western Pacific tropical cyclones form north and south of the equator, while Eastern Atlantic tropical cyclones are almost exclusively on the north side. Numerous subtropical cyclones have been recorded in the South Atlantic, but only two tropical cyclones. Tropical Storm Anita drenched southern Brazil and Uruguay in 2010, and Hurricane Catarina reached Catageory 2 in 2004 strength when it made landfall in Brazil. Some hurricanes form in the Eastern Pacific affecting Southern Mexico and Baja California and sending storm surges and rain to the southwestern United States. Most hurricanes affecting the United States form near the Tropic of Cancer in the Atlantic Ocean and move westward toward the Caribbean Sea or northward to the U.S. eastern seaboard.

Hurricanes form over warm ocean water that is at least 26.5C (79.7F) to a depth of at least 50 meters (164 feet). Since the global average sea surface temperature is 16.1C (60.9F), tropical cyclones are generally seasonal, occurring when the water is warm enough. The National Weather Service marks June 1 to November 30 as the official North Atlantic hurricane season.

More Lessons from the Sky, © Satellite Educators Association, Inc. Tracking Hurricanes from Space 7 Teaching Notes

As warm water evaporates, the warm moistened air above it rises. This vertical wind must rise slowly for the cyclone to form. Strong upward air movement can dry out the mid-levels of the troposphere thus stopping the storm development. (Refer to https://www.weather.gov/jetstream/layers for a description of the troposphere and other atmospheric layers.) Slowly rising, warm, moistened air begins to circle drawing more energy from the warmer-than-usual water. Eventually, nearly horizontal bands of rain form like arms of a spiral around a characteristically low-pressure center spawning numerous thunderstorms, strong winds, and heavy rains. The eye of the hurricane is formed when cooler air is drawn down through the center of the spiraling cyclone. The eyewall consists of rapidly rising, moist air moving horizontally as much as vertically. In the eye, horizontal movement of air is significantly reduced leaving relatively calm and clear air. These characteristics are unique to tropical cyclones and unlike severe frontal storms in non-tropical regions of the world.

The sustained wind speeds of a hurricane are severe. Wind speeds at sea are described by the Beaufort Wind Scale developed in 1805 by Sir Francis Beaufort of England. Today’s hurricanes are classified using the Saffir-Simpson scale that considers wind speed and several other factors to divide hurricanes into 5 categories.

Category Sustained Wind Speed Damage 1 119-153 km/hr (74-95 mph, 64-82 kt) Some 2 154-177 km/hr (96-110 mph, 83-95 kt) Extensive 3 178-209 km/hr (111-130 mph, 96-113 kt) Devastating 4 210-249 km/hr (131-155 mph, 114-135 kt) Catastrophic 5 >249 km/hr (>155 mph, >135 kt) Catastrophic

It was developed in 1971 by civil engineer Herbert Saffir and meteorologist Bob Simpson, then director of the National Hurricane Center. Summarized in the table above, a more detailed description of the Saffir-Simpson scale can be downloaded as a pdf file at this web site: https://www.nhc.noaa.gov/aboutsshws.php.

The damage caused by a hurricane can include that caused by high winds, heavy rains, storm surge on coastal areas, and flooding. Certainly, a Category 5 hurricane will cause more damage than a Category 2 because of higher wind speed. But sustained wind speed is not the only damage factor. The speed at which the storm system moves over the ocean and land determines whether the rainfall and high winds are experienced for a several hours or several days. When a storm with slower wind speeds slows or stalls without losing sustained wind speed, the damage and danger to life can be far more extensive than a more severe storm moving quickly through the area. Hurricane Katrina in 2005 is an example of a tropical cyclone that was both a Category 5 and moving slowly over New Orleans. Hurricane Maria was a Category 5 moving at a slower ground speed as it swept across Puerto Rico in 2017. The damage and death toll from both storms was catastrophic.

According to the NOAA’s National Climatic Data Center (NCDC), the number of severe storms causing significant amounts of damage has increased since 1980. From 1980 to October 2016, there have been 35 “billion dollar storms.” That is, 35 hurricanes and tropical storms that each caused at least one billion dollars in damage values adjusted for inflation). Eight of the top ten of those occurred since 2004. A total of thirteen surpassed the 10-billion dollar mark, and ten of those occurred since 2004. Four

8 Tracking Hurricanes from Space More Lessons from the Sky, © Satellite Educators Association, Inc.

Teaching Notes hurricanes and a tropical storm rank in the $10-$20 billion range: Hugo in 1989, TS Allison in 2001, Francis in 2004, Irene in 2011, and Matthew in 2016. Four hurricanes rank in the $20-$30 billion club: Ivan and Charley in 2004, Rita and Wilma in 2005. Three claim the $30-$100 billion range: Andrew in 1992, Ike in 2008, and Sandy in 2012. According to the NCDC, one lone hurricane holds the record for $160 billion in damage and that is Katrina in 2005. The damage costs for 2017 Hurricanes Harvey (Texas), Irma (Florida), and Maria (Puerto Rico) were not yet tabulated as of this writing.

One wonders about the causes of the seeming increase in intensity and frequency of severe storms directly affecting the United States. The answers, of course, involve complex mixtures of political and social issues as well as the underlying natural causes. Is global climate change part of this equation? Can preparatory steps be taken to lessen the damage and loss of life in the future?

To better understand these natural phenomena, satellites with remote sensors have been placed in orbit to help us observe, measure, and monitor patterns of change in the Earth’s atmosphere and oceans. Analyzing imagery from NOAA’s geosynchronous Earth orbiting satellites (GOES) can provide us with knowledge of characteristics and behavior of tropical cyclone storm systems thus allowing improved forecasting and preparation for such storms.

The word hurricane is from the Spanish huracán which derives from the Taino huracan or tempest. Christopher Columbus encountered the Taino people in the region often referred to today as the West Indies and discovered huracan when a severe storm sank several of his ships.

Today hurricanes are named according to a predetermined schedule established by the National Hurricane Operations Center. Names are given to storms in alphabetical order. The first storm of the season has a name beginning with A, the second storm a name beginning with B, and so on. Tropical cyclones in other parts of the world are named by other countries. However, as of this writing, pre-planning and international agreement have produced names for tropical cyclones through at least the year 2021.

Acknowledgements This lesson was inspired by several prior versions of the same basic plan. The first is “The Storm That Ate South Carolina” appearing in The IPT Sourcebook, Classroom Activities and Reference Materials, Version 2.1, developed by the Image Processing for Teaching Project at the Lunar and Planetary Laboratory of the University of Arizona and distributed by the Center for Image Processing in Education in Tucson, Arizona. It was supported in part by a grant from the National Science Foundation and is copyrighted by the Arizona Board of Regents.

The second is an on-line version developed for the Exploring the Environment project by the Center for Educational Technologies at Wheeling Jesuit University as part of NASA’s Classroom of the Future. It is copyrighted 2004, 2005, 2011 by Wheeling Jesuit University.

The method for measuring the eye of the hurricane is from “Hurricanes – How Strong Are They?” by Helen E. Martin. It is one of more than fifty satellite-based lessons

More Lessons from the Sky, © Satellite Educators Association, Inc. Tracking Hurricanes from Space 9 Teaching Notes compiled by Satellite Educators Association, Inc. and published in Lessons from the Sky, © 1995 by Amereon, Ltd.

This version of the lesson, supplemental materials, and this edition of Teaching Notes were developed by J.P. Arvedson for the Satellite Educators Association as part of More Lessons from the Sky, a regular feature of the on-line Satellite Educators Association Newsletter. More information about the Satellite Educators Association, its annual Satellites & Education Conference for teachers, its international student environmental research collaborative, and free access to the online Newsletter can be found at http://SatEd.org. All More Lessons from the Sky lesson plans are archived in the online SEA Lesson Plan Library available at http://sated.org/library/about.htm.

Regardless of the form in which this lesson is distributed to others, full credit must be given to all authors and publishers.

All imagery used in the "Tracking Hurricanes from Space" lesson are provided courtesy the National Oceanic and Atmospheric Administration and the National Aeronautics and Space Administration. The originals are in the public domain and cannot be copyrighted. Images for the following files were retrieved online in mid-September 2011 and 2017 and processed by J.P. Arvedson for use in this lesson:

o Each frame of the Katia_Stack_HUIR.gif file is courtesy of NOAA. The animation was created by stacking a sequence of individual images using ImageJ. Each was downloaded from the NOAA's GOES image server after searching for INFRA- RED images of the HURRICANE SECTOR from the GOES-EAST ARCHIVE. The images were then read into ImageJ, stacked for animation, and saved as an animated GIF.

o The Dry_Line.gif image is courtesy of NOAA and was downloaded from NOAA’s GOES image server. It was downloaded as ECIR112610015.gif and the name changed to Dry_Line.gif for learners' convenience. With the launch of the newer GOES-R/S series satellites, the GOES image server has been replaced by the GOES Image Viewer. It provides five times the data three times more often.

o The Emilia.png image is courtesy of NOAA’s Environmental Visualization Laboratory program. The image was developed by, housed in, and retrieved from https://www.nnvl.noaa.gov/. It was listed as "Busy East Pacific Hurricane Season.” The image showing three storm systems was captured in real time on July 12, 2012.

o The Hurricane Maria stacks Maria_Stack_HUIR.gif (all three versions) were assembled using ImageJ from single images downloaded from NOAA’s GOES server. Each image shows the GOES infrared channel data and is cropped to the hurricane sector. The images were stacked, animated, and saved using ImageJ.

o Katia_Data.txt and Maria_Data.txt (all three versions) were compiled from advisories archived by the NOAA’s National Hurricane Center.

o The hurricane tracking chart, Track_Chart.tif, is courtesy of NOAA’s National Hurricane Center. It downloads as a portable document file (PDF). For use with

10 Tracking Hurricanes from Space More Lessons from the Sky, © Satellite Educators Association, Inc.

Teaching Notes

ImageJ, the pdf image file was converted to uncompressed tagged image format file (tif). Other versions of the tracking chart are available. Source: https://www.nhc.noaa.gov/AT_Track_chart2.pdf

Please note: The GOES-East Archive from which GOES-East images were obtained to produce Katia_Stack_HUIR.gif, Dry_Line.gif, and Maria_Stack_Huir.gif was phased out when GOES-16 became operational in 2017. GOES imagery is available from the new GOES Image Viewer at https://www.star.nesdis.noaa.gov/GOES/index.php.

Resources Note: All of these URLs were current and active as of this writing. If any are unreachable as printed, the use of online search engines such as DuckDuckGo, Google, Ask, and Bing is suggested to find current links.

_____. Atlantic Hurricane Tracking Chart, National Hurricane Center, National Weather Service, National Oceanic and Atmospheric Administration. Retrieved October 10, 2019 from https://www.nhc.noaa.gov/AT_Track_chart2.pdf Downloadable and printable Atlantic hurricane tracking chart.

_____. Jet Stream Max: Ocean Circulations. National Weather Service, National Oceanic and Atmospheric Administration. Retrieved October 10, 2019 from https://www.weather.gov/jetstream/circulation Interactive map of major ocean surface currents.

_____. Aquarius Ocean Circulation. National Aeronautics and Space Administration. You Tube. Retrieved October 10, 2019 from https://www.youtube.com/watch?v=vP4QTyVQTUo Two minute video animation with narration about global ocean currents measured by sensors on the Aquarius satellite.

_____. Beaufort wind scale, Storm Prediction Center, National Weather Service, National Oceanic and Atmospheric Administration. Retrieved October 10, 2019 from https://www.spc.noaa.gov/faq/tornado/beaufort.html Full description of Beaufort Wind Scale.

_____. Billion-Dollar Weather and Climate Disasters: Table of Events, National Centers for Environmental Information, National Oceanic and Atmospheric Administration. Retrieved October 10, 2019 from https://www.ncdc.noaa.gov/billions/events/US/1980-2017

_____. Dry line: A moisture boundary, Online Meteorology Guides, Department of Atmospheric Sciences, University of Illinois at Urbana-Champaign, 1999. Retrieved October 10, 2019 from http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/af/frnts/dfdef.rxml

_____. Explore the World in Real-Time. Imagery and Data, Satellite and Information Service, National Oceanic and Atmospheric Administration. Retrieved October 10, 2019 from https://www.nesdis.noaa.gov/content/imagery-and-data

_____. NOAA Geostationary Satellite Server, National Oceanic and Atmospheric

More Lessons from the Sky, © Satellite Educators Association, Inc. Tracking Hurricanes from Space 11 Teaching Notes

Administration. Retrieved October 10, 2019 from https://www.goes.noaa.gov Source of GOES-East imagery used in this lesson. Beginning in 2017, this server will be slowly phased out in favor of the newer GOES Image Viewer which offers imagery from the newer GOES-R/S series.

_____. GOES Image Viewer. National Environmental Satellite, Data, and Information Service, National Oceanic and Atmospheric Administration. Retrieved October 10, 2019 from https://www.star.nesdis.noaa.gov/GOES/index.php

_____. Glossary, National Weather Service. National Oceanic and Atmospheric Administration, 2009. Retrieved October 10, 2019 from http://www.weather.gov/glossary/index.php?letter=d Definition of dry line.

_____. How does a hurricane form? NASA/NOAA SciJinks, National Aeronautics and Space Administration. Retrieved October 10, 2019 from https://scijinks.gov/hurricane/

_____. Hurricane Katia Advisory Archive, National Hurricane Center, National Weather Service, National Oceanic and Atmospheric Administration, 2011. Retrieved October 10, 2019 from https://www.nhc.noaa.gov Follow Archives links to Tropical Cyclone Advisories, 2011, Hurricane Katia, desired advisory type, date time.

_____. Layers of the Atmosphere. JetStream – Online School for Weather, National Weather Service, National Oceanic and Atmospheric Administration. Retrieved October 10, 2019 from https://www.weather.gov/jetstream/layers Includes easy to use graphics for understanding the troposphere.

_____. Severe weather: Hurricanes! Exploring the Environment module & activities, October 10, 2019 from http://www.cotf.edu/ete/modules/sevweath/sevweath.html

_____. The Saffir-Simpson Hurricane Wind Scale, National Hurricane Center, National Weather Service, National Oceanic and Atmospheric Administration, 2010. Retrieved October 10, 2019 from https://www.nhc.noaa.gov/aboutsshws.php

_____. The storm that ate South Carolina. The IPT Sourcebook: Classroom Activities and Reference Material, Center for Image Processing in Education. The Image Processing for Teaching Project, Lunar and Planetary Laboratory, University of Arizona, 2000. Developed in part with a grant from the National Science Foundation.

_____. Tropical Cyclone Names, National Hurricane Center, National Weather Service, National Oceanic and Atmospheric Administration, 2011. Retrieved October 10, 2019 from https://www.nhc.noaa.gov/aboutnames.shtml

Allen, Jesse, Chelle Gentemann, Frank Wentz, Michael Carlowicz. Atlantic heat source for Hurricane Irene, NASA Earth Observatory, August 25, 2011. Retrieved October 10, 2019 from https://earthobservatory.nasa.gov/IOTD/view.php?id=51853 Graduated-color satellite image clearly showing source of heat energy for hurricane formation in North Atlantic Ocean and explanation of the process related to

12 Tracking Hurricanes from Space More Lessons from the Sky, © Satellite Educators Association, Inc.

Teaching Notes

Hurricane Irene.

Chesters, Dennis (scientist), Greg Shirah, Alex Kekesi (animators). Hurricane Katrina GOES clouds. NASA Scientific Visualization Studio, Goddard Space Flight Center. Sep. 14, 2005. Retrieved October 10, 2019 from https://svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=3251

Dolce, Chris. “Record Number of Billion-Dollar U.S. Disasters,” The Xtreme Weather. Retrieved October 10, 2019 from http://new.thextremeweather.com/record- number-of-billion-dollar-us-disasters/

Gyory, Joanna, Arthur J. Mariano, Edward H. Ryan. The gulf stream, Ocean Surface Currents, Rosenstiel School of Marine and Atmospheric Science, University of Miami. Retrieved October 10, 2019 from http://oceancurrents.rsmas.miami.edu/atlantic/gulf-stream.html

Martin, Helen. Hurricanes – How strong are they? Lessons from the Sky Satellites and Education A Resource Guide, Mattituck, New York: Amereon, LTD, 1995. More than 50 lesson plans compiled by The Satellites Educators Association, Inc.

National Research Council. A Framework for K-12 Science Education, Washington, DC: The National Academies Press, 2012. Retrieved October 10, 2019 from https://www.nap.edu/catalog/13165/a-framework-for-k-12-science-education- practices-crosscutting-concepts

National Research Council. The Next Generation Science Standards, Next Generation Science Standards For States, By States, Washington, DC: The National Academies Press, 2013. Retrieved October 10, 2019 from https://www.nap.edu/catalog/18290/next-generation-science-standards-for- states-by-states

Perkins, de La Beaujardiere, and Shirah. Winds of hurricane Katrina, Earth Observatory, NASA, 2006. Retrieved October 10, 2019 from https://earthobservatory.nasa.gov/IOTD/view.php?id=6882 Includes an animation of Hurricane Katrina winds predicted by the model.

Rasband, Wayne. ImageJ: Image processing and analysis in Java. National Institute of Health. Retrieved October 10, 2019 from https://imagej.nih.gov/ij/

Schiele, Edwin. Ocean Conveyor Belt Impact, Ocean Motion and Surface Currents. National Aeronautics and Space Administration. Retrieved October 10, 2019 from http://oceanmotion.org/html/impact/conveyor.htm Explanation of major ocean currents and the need to study them.

Shirah, Greg, Alex Kekesi (animators). Katrina Retrospective: 5 Years After the Storm, April 24, 2010. Goddard Media Studios, National Aeronautics and Space Administration. Retrieved October 10, 2019 from https://svs.gsfc.nasa.gov/10633. Narrated review of Katrina using multiple environmental satellites to analyze and observe the storm.

More Lessons from the Sky, © Satellite Educators Association, Inc. Tracking Hurricanes from Space 13 Teaching Notes

World Meteorological Organization. Regional Association IV (North America, Cnetral America and the Caribbean) Hurricane Operational Plan. Tropical Cyclone Programme, Report No. TCP-30, 2016 edition. Retrieved October 10, 2019 from https://www.wmo.int/pages/prog/www/tcp/documents/HURRICANEOPERATION ALPLAN-2016_en.pdf

Answers to Questions in Student Activity 1. From this information, briefly explain in your own words how a geosynchronous orbit works. Answers will vary. Geosynchronous satellites orbit at an altitude of about 35,900 kilometers (22,300 miles) where their orbital rotation matches the Earth's rotation.

2. At what local time was the first satellite image of this stack captured? The first satellite image was taken on August 31, 2011 at 10:15 PM (EST), 9:15 PM (CST), 8:15 PM (MST), or 7:15 PM (PST). You may need to adjust for Daylight Savings Time.

3. At what local time was the last satellite image of this stack captured? The last satellite image was taken on September 9, 2011 at 6:15 PM (EST), 5:15 PM (CST), 4:15 PM (MST), or 3:15 PM (PST). You may need to adjust for Daylight Savings Time.

4. How do the land areas change in brightness over time? Land areas show a significant change in brightness over time.

5. How do oceans change in brightness over time? Oceans show very little change in brightness over time.

6. In general, do the clouds appear darker or lighter than Earth’s surface? Clouds appear lighter than the Earth’s surface.

7. From your personal experience, are clouds usually cooler or warmer than Earth’s surface? Clouds are generally cooler than the Earth’s surface.

8. In these images, cold appears _____ and warm areas appear _____. In these images cold appears lighter and warm appears darker.

9. With this rule in mind, how can you tell which images were captured when the sun was shining on North America? The sun is shining when the land appears darker (warmer).

10. Do the oceans change brightness as much as land areas do? Why do you think this happens? Answers will vary. Oceans do not change brightness as much as land areas because they do not gain or lose heat as quickly. (The specific heat of ocean water is greater than that of land.)

11. “Land heats up and cools down _____ and water heats up and cools down _____. Lands heats up and cools down quickly and water heats up and cools down slowly.

12. Look at the spiraling cloud pattern on the right side of the image window. What is the relative temperature of the ocean near this spiral? Answers will vary. Generally, the relative temperature of the ocean surface near the cyclone is much warmer than the clouds

14 Tracking Hurricanes from Space More Lessons from the Sky, © Satellite Educators Association, Inc.

Teaching Notes

and is about the same as the average temperature of the land.

13. In general, do you see more clouds over the land or over the oceans? Why do you think this is true? Answers will vary as this may not be as apparent in this stack of Katia imagery. In general, there are more clouds over oceans because there is a steady supply of both heat and moisture.

14. In general, in which direction do the cloud patterns move in each zone – east to west, or west to east? In general, the clouds in the bottom of the images seems to be moving from east to west while the clouds in the top of the image seem to be moving from west to east.

15. Check out the swirling cloud patterns that look like suds going down the drain – what do you think they are? Answers will vary. The swirling patterns are tropical cyclone systems (“storm systems”) – the one on the right is a hurricane, the one over Louisiana is a tropical storm.

16. In which direction do these features rotate – clockwise or counterclockwise? These systems rotate counterclockwise (in the Northern Hemisphere).

17. Large, clear areas are associated with _____ pressure systems and cloudy areas are associated with _____ pressure systems. Large, clear areas are associated with high pressure and cloudy areas are associated with low pressure.

18. Which type of pressure system seemed to cover the southeastern states during the first 24 hours of the stack of images? How can you tell? The system around the southeastern states is a high pressure system because it is relatively cloudless.

19. Using this pattern, Katia is the _____ Atlantic hurricane of the season. Katia is the 11th hurricane of the season.

20. What would be an appropriate name for the next hurricane of the season after Katia? Any male name beginning with “L” would be appropriate such as Lawrence, Leonard, or Louis. 21. What kind of pressure system is this storm – high or low? Storms are low pressure systems.

22. Describe what happens to Maria – both the eye and the clouds – when it passes over land. Why do you think this occurs? The eye and clouds dissipate over land since the major source of heat energy driving the storm, the ocean, is no longer present.

23. What happens to the eye just before landfall – the point when it reaches the shore? Does the storm appear to get stronger or weaker? The eye becomes smaller and darker just before landfall – a sign the storm is strengthening.

24. Explain which current(s) is affecting Katia’s behavior and why. Katia forms along the North Equatorial Current in the Atlantic Ocean. The storm turns northward and follows the Gulf Stream. These are both warm water currents, so the storm system continues to gain energy and intensify.

Data in this chart will vary. This is just a sample:

More Lessons from the Sky, © Satellite Educators Association, Inc. Tracking Hurricanes from Space 15 Teaching Notes

Hurricane Katia Data Slice No. Date UTC Lat (N) Lon (W) 31 4 Sep 11 2115Z 23 60 59 8 Sep 11 0915Z 32 70

25. How far in kilometers did Katia’s eye move between these two images? Answers will vary. For example, plotting the locations from the table above on the Atlantic Hurricane Tracking Chart and then measuring the distance using ImageJ produces a distance measurement of 1591.19 kilometers.

26. How many hours passed between these images? Answers will vary. In the example from Answer 25 above, the time interval is 84 hours.

27. Calculate Katia’s average speed in kilometers per hour. 1591.19 km Answers will vary. From the example in #25-26 above, = 18.9 km/hr (or 11.7 miles/hr). 84 hours

28. Describe something in your experience that travels at about the same speed as a hurricane. Answers will vary. Answers could include such examples as a horse, a cyclist, or an automobile being driven slowly through a school zone.

29. In what ways are satellites valuable in weather forecasting? Answers will vary. Satellites give us a larger perspective of changing weather patterns as seen from space on a global scale. When successive images are animated, development of storms can be seen as cloud patterns change.

16 Tracking Hurricanes from Space More Lessons from the Sky, © Satellite Educators Association, Inc.

Student Activity

Tracking Hurricanes from Space Interpreting Weather Satellite Data

Introduction

In the past, meteorologists based their weather predictions on information gathered by a worldwide network of observers on land and at sea. Even with reports from hundreds of stations every few hours, it was hard to see the large- scale patterns that make weather prediction possible.

Today, satellites allow meteorologists to see the weather over the entire planet. In this activity, you will examine a series of satellite images of North America. You will study weather patterns and follow several major storms including the first Category 5 hurricane to make landfall in Puerto Rico in 90 years.

You will work with your investigative team to examine the behavior and characteristics of tropical cyclones in order to predict the path and probable behavior of future severe storms.

A look at Katia

 Ensure a working copy of ImageJ is installed on your computer, the computer is Internet enabled, and you have a copy of the Resources folder available. The Resources folder contains all the data files for this lesson.

 Launch ImageJ.

 On the ImageJ menu bar, click File > Open > GIF, navigate to the Resources folder for this lesson, highlight Katia_Stack_HUIR.gif and click Open.

 You should be looking at a stack of images. There are three ways to view the images. ✓ You can press the > key or the → key to advance one frame; the < key or the  key to reverse one frame. ✓ You can click the arrow buttons at each end of the horizontal scroll bar found at the bottom of the image window: right arrow advances one frame, left arrow reverses one frame. ✓ You can drag the slider in the scroll bar and move it right (forward) or left (reverse).

More Lessons from the Sky, © Satellite Educators Association, Inc. Tracking Hurricanes from Space 17 Student Activity

 ImageJ can also animate the stack and allows you to adjust the animation speed (frame rate or number of frames per second). Click Image > Stacks > Animation > Animation Options; set Speed to 3 fps; click OK. If the animation does not start automatically, press the back slash key \ to start or stop the animation at any time. Alternatively, you can start the animation by clicking the Play button in the lower left corner of the image window.

 Continue to adjust the speed and animate the stack until you can easily observe changing patterns in the image sequence.

You may notice something strange about these images. Except for the changing clouds, nothing moves. As the earth rotates, some satellites orbit the planet at a speed of more than 11,000 kilometers (almost 6900 mi) per hour at an altitude of almost 38,000 km (more than 22,000 mi). To an observer on the ground, the satellite would appear to remain stationary over the same surface location. The effect in the image is that North America appears to be standing still. This satellite is in a geosynchronous orbit.

1. From this information, briefly explain in your own words how a geosynchronous orbit works.

18 Tracking Hurricanes from Space More Lessons from the Sky, © Satellite Educators Association, Inc.

Student Activity

Looking for patterns

 Watch the cloud patterns form, move, and disappear. Look for evidence of where and when the clouds first appear.

The information bar at the bottom of each frame shows the image is infrared, has a resolution of 8 km (about 5 mi) – that is, each pixel represents 8 km on the ground – and the date and time when the image was captured. The times are shown in 24-hour format, so anything over 12 hours is between noon and midnight. For example, the image with 9 1 2011 1915Z in the information bar was captured on September 1, 2011 at 1915Z. The Z (“Zulu” in the phonetic alphabet) means UTC or Universal Time Coordinate. UTC is the name of the time zone at the Prime Meridian (0 longitude). On a 12-hour clock, 1915Z would be 7:15 pm UTC.

 Stop the stack animation and go to the first frame.

To convert between UTC and your local time, add or subtract an hour for every time zone difference between your location and the Prime Meridian. For example, to convert from UTC to Pacific Time (PST), subtract 8 hours from UTC. During Daylight Savings, subtract 7 hours to convert from UTC to PDT.

2. At what local time was the first satellite image in this stack captured?

3. At what local time was the last satellite image in this stack captured?

 Animate the stack again and look at the areas where there are no clouds, both over land and over the oceans.

4. How do the land areas change in brightness over time?

5. How do the oceans change in brightness over time?

6. In general, do the clouds appear darker or lighter than Earth’s surface?

Remember, the IR in the lower left corner of the image indicates this is an infrared image. The infrared camera capturing this image does not see visible colors the way your eyes do. It senses infrared radiation interpreted as temperature. In an infrared image, the whiter the gray tone, the colder the temperature; darker means warmer.

7. From your personal experience, are clouds usually cooler or warmer than Earth’s surface?

8. Complete the following sentence by filling in the blanks with either darker or lighter: “In

More Lessons from the Sky, © Satellite Educators Association, Inc. Tracking Hurricanes from Space 19 Student Activity

these images, cold appears _____ and warm areas appear _____.”

9. With this rule in mind, how can you tell which images were captured when the sun was shining on North America?

10. Do the oceans change brightness as much as land areas do? Why do you think this happens?

11. Complete this sentence by filling in the blanks with either quickly or slowly: “Land heats up and cools down _____ and water heats up and cools down _____.”

12. Look at the spiraling cloud pattern on the right side of the image window. What is the relative temperature of the ocean near this spiral? (HINT: Compare relative temperature of the ocean to those of land and clouds by considering the graytone brightness in the image.)

13. In general, do you see more clouds over the land or over the oceans? Why do you think this is true?

Look carefully at the cloud patterns changing throughout the animation.

14. In general, in which direction do the cloud patterns move in each zone – east to west, or west to east?

Storms on the horizon

15. Check out the swirling cloud patterns that look like suds going down the drain—what do you think they are?

16. In which direction do these features rotate—clockwise or counterclockwise?

 Click File > Open; navigate to the Resources folder, highlight Dry_Line.gif; click Open.

In this image, as Katia becomes a Category 1 hurricane with sustained winds of 121 km (75 mi) per hour, Tropical Storm Lee covers much of Louisiana, Mississippi, and Alabama with a sustained wind speed of 80 km (50 mi) per hour. Notice the band of clouds that forms along a diagonal line from the Oklahoma panhandle to the Great Lakes. This is called a Dry Line – a nonfrontal boundary between a hot, dry air mass from the southwest and a warm, moist air mass from the southeast. Clouds form in this region when dry air cools as it flows down the eastern side of the Rocky Mountains. It flows under and lifts the warm moist air from the Gulf of Mexico. As the warm air rises, it expands and cools until water vapor condenses and clouds form.

Most things in the natural world have a tendency to move from an area where

20 Tracking Hurricanes from Space More Lessons from the Sky, © Satellite Educators Association, Inc.

Student Activity there is more of it (such as high air pressure) to an area where there is less of it (such as low air pressure). Broadcast weather reports often refer to high and low pressure areas in the atmosphere. High pressure systems contain cool, dry, denser, sinking air, whereas low pressure systems contain warm, moist, less dense, rising air.

17. Look again at areas in the images that do not have clouds. Complete the following sentence using the words low and high: “Large, clear areas are associated with ____ pressure systems and cloudy areas are associated with _____ pressure systems.”

18. Which type of pressure system seemed to cover the southeastern states during the first 24 hours of the Katia animation? How can you tell?

 Close Dry_Line.gif.

 Click File > Open, navigate to Emilia.png, click Open.

This is a GOES West image of the North Pacific Ocean on July 12, 2012 at 1800Z. This is a real-time image, not a composite. Notice the three storm systems. NOAA Environmental Visualization Laboratory labeled the systems when the image was prepared for posting. Notice Tropical Storm Fabio has formed in the East Pacific. This is the sixth named storm of the 2012 Eastern Pacific Hurricane Season. Hurricane Emilia is entering an area of cooler sea surface temperatures and will begin to weaken. The remnants of Hurricane Daniel can be seen to the west of Hawaii.

During a hurricane season, the Pacific hurricanes are named in alphabetical order, and alternate between men’s and women’s names. For instance, the first hurricane of the season might be Annie, the second Barney, the third Carolyn, the fourth Douglas, and so on. Atlantic hurricanes are named the same way.

19. Using this pattern, Katia is the _____ Atlantic hurricane of the season. (Which number?)

20. What would be an appropriate name for the next hurricane of the season after Katia?

 Close Emilia.png.

 Click File > Open > GIF; navigate to Maria_Stack-38.gif; click Open.

21. What kind of pressure system is this storm—high or low?

Look at the small dark hole that forms at the center of Maria. This is the eye of the hurricane. The eye is where cold air is being pulled down into the heart of

More Lessons from the Sky, © Satellite Educators Association, Inc. Tracking Hurricanes from Space 21 Student Activity the hurricane to feed the powerful winds of the eye wall—the ring of clouds surrounding the eye. Since there is cold sinking air in the eye, the air is clear there. The dark color seen in the eye is the ocean’s surface.

 Animate the stack. Adjust the animation speed as desired. Observe the complete stack animation several times.

22. Describe what happens to Maria—both the eye and the clouds—when it passes over land. Why do you think this occurs?

23. What happens to the eye just before landfall—the point when it reaches the shore? Does the storm appear to get stronger or weaker?

 Close Maria_Stack-38.gif.

 If needed, refer to a world globe, atlas, or one of the following online maps that shows ocean currents to help answer the following question: https://www.weather.gov/jetstream/circulation

24. Explain which current(s) is affecting Katia’s behavior and why.

How fast is Katia going?

There will be several steps to determining the average speed with which Hurricane Katia moves over the ocean.

Katia_Stack_HUIR.gif should still be open. First, you will choose any two frames of the animated stack, as far apart in time as possible, that clearly show Katia’s eye. Using the table on your answer sheet, record the slice number, date, and time of each of those two images. The slice number is the first number in the image information bar in the image window. In the example below, the slice number is 37 of 72.

 Open Katia_Data.txt. (File > Open > Katia_Data.txt)

You may need to move between several image windows that are all open at the same time on your screen. Remember, only the active window will respond to ImageJ commands. In ImageJ there are two ways to activate a window:

Student Activity

 Click once on an image window to make it the active window. OR…  On the ImageJ menu bar, click Window and select the name of the image window you wish to make active.

To measure the distance in kilometers (or miles) there must be a distance reference for setting the measurement scale in ImageJ. You can use the distance scale on the tracking chart if at least two positions of Hurricane Katia are accurately marked on the chart. To mark the chart, you will need to know the latitude and longitude of the storm’s center on at least two different occasions. The pixels in the Katia stack images are not calibrated to latitude and longitude, but they are stamped by NOAA with date and time. NOAA’s National Hurricane Center issues hourly advisories before and during each severe storm. The advisories are archived and available online for historical reference. Some of the advisory data for Hurricane Katia have been summarized in the table in Katia_Data.txt image window.

Look up the latitude and longitude of the center of the storm (eye) for each of the two images for which you recorded slice number, date and time in the table on your answer sheet. Record these latitudes and longitudes in the same table.

 Close Katia_Data.txt.

 Open Track_Chart.tif.

You will use ImageJ to mark the Katia locations you selected on the tracking chart with “Katia,” date and time on your hurricane tracking chart.

 Click Edit > Options > Colors. Using the drop down arrows, set Foreground color to black, Background color to white, Selection color to red. Click OK.

 Double-click the Paintbrush Tool button. In the Paintbrush Tool dialogue, change Brush Width to 3 pixels. Click Close.

 Click the Paintbrush Tool button again once. Place the cursor on the tracking chart at the desired latitude and longitude and left-click once. If the dot is in the wrong position, press Ctrl-z or click Edit > Undo. Reposition the cursor and try again. When the dot is in the correct spot, move the cursor to the second location and click once.

 If both dots are in the correct positions, click the Scrolling Tool button to deactivate the Paintbrush.

If the hurricane changes direction, feel free to add more location points on your tracking chart. Now, you will label each mark with the hurricane’s name (Katia), the date (ddMMMyy format), and the UTC time in 24 hour format.

 Double-click the Text Tool button. In the Fonts dialogue, use the slider or type in the field to change the font size to 18. Close the Font dialogue window.

 Click the Text Tool button again once. On the tracking chart image, click and drag down and left to form a text insertion box. Release the mouse button, then click and hold in the text insertion box to drag it to a location next to the first dot you marked on your chart image and release.

 Type the hurricane name (Katia) and press Enter (or Return). Type the date in ddMMMyy format (such as 09AUG10 for August 9, 2010); press Enter (or Return). Type the UTC time in 24 hour format (such as 0315Z for 3:15 AM). To set the text box and make it a permanent part of the image, press Ctrl-D on the keyboard.

 Repeat the last two steps to label the second point on your chart.

 Click the Scrolling Tool button to deactivate the Text Tool.

Find the distance scale in the upper right corner of your tracking chart. Zoom- in, if desired. You will use ImageJ, the distance scale, and the two points you just labeled to determine the distance between your hurricane location marks.

 Click Line Selection Tool button . Click and hold on left end of distance scale, drag to 500 km mark on distance scale (the first mark to the right, not the right end) and release.

 Click Analyze > Set scale; set Known distance to 500; set Unit of length to kilometer; click OK.

 Click Analyze > Set measurement; uncheck everything in the Set Measurement dialogue;

Student Activity

click OK.

 Click Analyze > Clear results.

 Click Line Selection Tool button. Click and hold on the center of the first hurricane location mark on your tracking chart, drag to the center of the second mark, and release.

 Click Analyze > Measure. Read the results in the Results window. Remember, the number in the Length column is distance measured in kilometers.

 When finished measuring, click the Scrolling Tool button.

25. How far in kilometers did Katia’s eye move between these two images?

26. How many hours passed between these images?

27. Calculate Katia’s average speed in kilometers per hour.

 Close the Results window. Click No to saving the measurement.

The winds in a hurricane can reach nearly 200 miles per hour, while the hurricane as a whole moves over the ground at the speed you calculated. Katia was a typical hurricane of mid-size and strength. Maria was very strong reaching

Category 5. Hurricanes can have different paths and different speeds. The amount of damage to populated areas is sometimes greater with smaller but slower moving hurricanes that expose the area to high winds and rain for longer periods of time.

28. Describe something in your experience that travels at about the same speed as a hurricane.

29. In what ways are satellites valuable in weather forecasting?

 Close Track_Chart.tif. Close Katia_Stack_HUIR.gif. Exit ImageJ.

 With guidance from your teacher, select and complete two or more of the Your Turn activities listed below.

Your Turn

Plot the path and speed of Hurricane Maria on the same hurricane tracking chart using ImageJ. Compare the tracks of Katia and Maria and study the images to identify the forces that affect a hurricane’s path. Add sufficient marks to the tracking chart to accurately describe the path of each storm system as imaged in their respective stacks. Based on your team’s additional research, extend the path to predict the future direction of the storm, its likely intensity, and potential areas of damage.

Carefully observe the ocean in the Katia animated stack and look for evidence of ocean currents and their direction of rotation. (To identify major currents of the Atlantic Ocean, visit https://www.weather.gov/jetstream/circulation.) Repeat with Hurricane Maria. Compare and contrast the relevant currents and their influence on each hurricane.

Measure the diameter of Katia’s eye when it was a Category 3 hurricane and measure the average diameter of the entire Category 3 cyclone. (HINT: Using ImageJ, measure in number of pixels and multiply by 8 km/pixel.) Using the formula for the area of a circle, (1) calculate the area of the eye and (2) calculate the area of the storm. What percentage of the storm is the eye? Is the size of the eye (taken as a percentage of the storm’s area) the same for all hurricanes: Follow the same procedure for Hurricane Maria. Compare the two hurricanes in terms of the eye size as a percentage of the storm size.

Research the ImageJ documentation to decide on a procedure for using ImageJ’s thresholding and measurement tools to determine the area of the eye and the area of the entire cyclone directly. Briefly describe the procedure your team agreed upon and then follow it. How do the results compare with your own calculations (last bullet above)? What do the results suggest about the relationship between the size of the eye and the strength of the storm?

With your teacher’s help, research sea surface temperature before, during, and after Hurricane Katrina, Katia, or Maria passed over a section of ocean or land. Determine and describe the relationship, if any, between sea surface temperature and the formation and strength of a tropical storm.

List and explain at least five significant things you have learned about tropical cyclones from this activity. Working with your research team, prepare an oral report of your findings supported with graphic examples.

Name______Date ______Class ______

Tracking Hurricanes from Space Interpreting Weather Satellite Imagery Answer Sheet

1. From this information, briefly explain in your own words how a geosynchronous orbit works.

2. At what local time was the first satellite picture in this stack captured?

3. At what local time was the last satellite picture in this stack captured?

4. How do the land areas change in brightness over time?

5. How do the oceans change in brightness over time?

6. In general, do the clouds appear darker or lighter than Earth’s surface?

7. From your personal experience, are clouds usually cooler or warmer than Earth’s surface?

8. In these images, cold appears ______and warm areas appear ______.

9. With this rule in mind, how can you tell which images were captured when the sun was shining on North America?

10. Do the oceans change brightness as much as land areas do? Why do you think this happens?

11. Land heats up and cools down _____ and water heats up and cools down ______.

13. In general, do you see more clouds over the land or over the oceans? Why do you think this is true?

14. In general, in which direction do the cloud patterns move in each zone – east to west, or west to east?

15. Check out the swirling cloud patterns that look like suds going down the drain— what do you think they are?

16. In which direction do these features rotate—clockwise or counterclockwise?

17. Large, clear areas are associated with______pressure systems and cloudy

areas are associated with______pressure systems.

18. Which type of pressure system seemed to cover the southeastern states during the first 24 hours of the movie? How can you tell?

19. Using this pattern, Katia is the______Atlantic hurricane of the season.

20. What would be an appropriate name for the next hurricane of the season after Katia?

21. What kind of pressure system is this storm—high or low?

22. Describe what happens to Maria—both the eye and the clouds—when it passes over land. Why do you think this occurs?

23. What happens to the eye just before landfall—the point when it reaches the shore? Does the storm appear to get stronger or weaker?

24. Explain which current(s) is affecting Katia’s behavior and why.

Hurricane Katia Data Slice No. Date UTC Lat (N) Lon (W)

25. How far in kilometers did Katia’s eye move between these two images?

26. How many hours passed between these images?

27. Calculate Katia’s average speed in kilometers per hour.

28. Describe something in your experience that travels at about the same speed as a hurricane.

29. In what ways are satellites valuable in weather forecasting?