Tracking a Tropical Cyclone Script, Run time: 15 - 20 minutes Amy Wood, Maryland Science Center 3/2010 1 Live program about to begin 1 Introduction to SOS: This special 2 projection system was given to the 3 Maryland Science Center by NOAA 4 (the National Oceanic and 5 Atmospheric Administration). The 6 screen is shaped like a sphere, which 7 is an ideal way to present views of the 8 Earth such as this one. NOAA studies 9 and observes the connection between 10 the ocean, atmosphere, and land so 11 that scientists and the public can learn 12 more about their interconnectivity, or 13 in other words, how one can affect the 14 other. 15 16 Today, we are going to talk about one 17 very special, powerful storm. The 18 ocean, atmosphere, and land all play 19 a part in this storm. It’s a storm that 20 develops over warm, tropic ocean 21 waters and operates very much like 22 an engine. Warm water act as the fuel 23 to power the engine. 24 ~ Use laser pointer to trace 25 These storms form in certain regions the lines of latitude that form the 26 within the Tropics. The tropics span tropics. 27 the globe near the equator. 28 ~rotate the sphere so that N. 29 The United States is very familiar with America comes into view. 30 these types of storms. They often Tracking a Tropical Cyclone Script, Run time: 15 - 20 minutes Amy Wood, Maryland Science Center 3/2010 2 ~ Use laser pointer to trace 1 make landfall on coastal regions and the path of hurricane to USA. 2 bring large amounts of rain, damaging 3 winds, and storm surge. Storm surge 4 is when ocean water rises onto the 5 shore due to high winds from a strong 6 storm. 7 8 Pose the question: Does anyone 9 know the name of this kind of powerful 10 storm? Blue Marble with clouds and pip 11 …. Pause for Audience responses …. of Hurricane Katrina 12 This storm is called a hurricane. 13 But this type of storm actually forms in 14 many areas around the world. So, 15 even though North Americans are 16 most familiar with the term hurricane, 17 meteorologists use the term tropical 18 cyclone. 19 Hurricane tracks without scale 20 You are looking at an image of ~rotate the sphere and point 21 tropical cyclone paths from 1950 to out all areas as they come into view 22 2005. Each dot on this image and are referenced. 23 represents a different time during a 24 storms life and connects to make a 25 line. Each line shows the path of a 26 tropical cyclone from its development 27 to when it is broken apart. 28 29 Although there are a large number of 30 tropical cyclones that develop in the Tracking a Tropical Cyclone Script, Run time: 15 - 20 minutes Amy Wood, Maryland Science Center 3/2010 3 1 Atlantic, tropical cyclones also 2 develop in the Pacific and Indian 3 Ocean basins. Tropical cyclones to 4 the west of Mexico are still referred to 5 as hurricanes. 6 7 Now, turn your attention to the 8 Western Pacific. Notice that more 9 storms develop in the Western Pacific 10 than in the Atlantic. 11 12 Pose the question: “Does anyone 13 know what people commonly call 14 tropical cyclones that develop in the 15 Western Pacific and travel towards 16 Asia?” 17 …. Audience response…… 18 (Anticipate tsunami as an answer) 19 Typhoons. 20 21 These tropical cyclones are often 22 called typhoons. 23 24 Tropical cyclones also develop off the 25 coasts of India. These are often 26 simply called cyclones. You may have 27 heard of the cyclone that hit Burma in 28 2008, or the cyclone that hit 29 Bangladesh in 2009, and had many 30 devastating effects for both areas. Tracking a Tropical Cyclone Script, Run time: 15 - 20 minutes Amy Wood, Maryland Science Center 3/2010 4 1 Tropical cyclones don’t all form in the 2 Northern Hemisphere. Southern 3 Hemisphere tropical cyclones 4 originate in the warm ocean waters of 5 the Southern Pacific and Southern 6 Indian Ocean basins. These too are 7 called cyclones, although Australians 8 often refer to these as “Willy Willy’s.” 9 Ty_cyc_hur.jpg 10 No matter whether you call a tropical 11 cyclone a hurricane, typhoon, or 12 simply a cyclone, they all work the 13 same and are equally as dangerous. 14 15 Over half of the world’s population 16 lives in coastal regions. And as more 17 and more people move to the coast 18 every day, it is becoming even more 19 vital to predict and forecast tropical 20 cyclone development and where they 21 might make landfall. 22 23 Pose the question: “How do scientists 24 observe and collect information about 25 tropical cyclones?” 26 …… Slight Pause….. 27 By using technology. 28 29 Researchers use satellites in space 30 and radar from ground stations. They Tracking a Tropical Cyclone Script, Run time: 15 - 20 minutes Amy Wood, Maryland Science Center 3/2010 5 1 also use ocean buoys, which are 2 weather stations that float in the 3 ocean and collect information as 4 tropical cyclones pass over them. 5 Even airplanes are used to fly through 6 storms and collect information – North 7 Americans call them “Hurricane 8 Hunters.” 9 10 We have not always had modern 11 technology such as aircraft, and 12 satellites. How did people observe 13 tropical cyclones before these were 14 invented? 15 16 Let’s talk about one example of an 17 ancient culture which was very 18 familiar with tropical cyclones: the 19 Taíno. [Pronounced Tai-YEE-no] The 20 Taíno were one of the native peoples 21 of the Caribbean Islands who lived 22 centuries ago. Through their legends, 23 we know that the Taino could sense 24 when a tropical cyclone was headed 25 toward shore by observing its 26 common signs: humid air, big, rolling 27 ocean waves, and a red sky. 28 Hurucan_transition.mp4 29 The Taíno thought these storms were 30 the work of an angered spirit. They Tracking a Tropical Cyclone Script, Run time: 15 - 20 minutes Amy Wood, Maryland Science Center 3/2010 6 1 even sculpted a symbol of a spirit that 2 some call Huracán [pronounced oo- 3 ra-CAN]. It had a spiral shape just like 4 a tropical cyclone. This name gave us 5 the English word for hurricane. Thus it 6 appears that the Taíno observed have 7 observed the spiral nature of tropical 8 cyclones long before scientists did. 9 10 As civilization continued, new 11 technologies enabled people to 12 observe tropical cyclones in greater 13 detail. Sailors and explorers like 14 Christopher Columbus noticed these 15 large, intense storms and recorded 16 observations—even temperatures and 17 pressures—on journeys across the 18 vast oceans. Yet observations of 19 tropical cyclones recorded by ships 20 were not plentiful enough to decipher 21 the patterns of tropical cyclones and 22 how they work. 23 Instruments.jpg 24 Eventually, with the development of 25 airplanes, radar, and ocean buoys, 26 modern scientists were able to 27 observe and record more and more 28 data about tropical cyclones. 29 30 Slowly, scientists began to unravel Tracking a Tropical Cyclone Script, Run time: 15 - 20 minutes Amy Wood, Maryland Science Center 3/2010 7 1 information about where these storms 2 formed. They began to notice the 3 patterns. 4 5 A major advancement for studying 6 tropical cyclones came as scientists 7 began to use satellites in the 1970’s. 8 Scientists were then able to observe 9 tropical cyclones from space from 10 their development until the storms 11 broke apart. 12 13 Let’s look at what some of these 14 storms look like using satellite 15 imagery. 16 sepstorms.mp4 17 This image is from an infrared 18 satellite. This type of imagery does 19 not take a picture of the Earth. The 20 satellite reads the temperatures of the 21 clouds. In other words, it is reading 22 temperature not the amount of light. 23 The highest cloud tops will be bright 24 white and lower clouds will be gray. 25 Does anyone know why scientists 26 would use infrared satellite imagery 27 instead of visible imagery? Infrared 28 satellite imagery is really useful to 29 meteorologists because it gives them 30 an aerial view of tropical cyclones no Tracking a Tropical Cyclone Script, Run time: 15 - 20 minutes Amy Wood, Maryland Science Center 3/2010 8 1 matter if it is day or night. It also 2 allows them to see where tropical 3 cyclones form and follow their path 4 across the ocean. Sometimes the 5 storms will even hit land. 6 7 It is easy to observe tropical cyclones 8 forming over tropical ocean water in 9 the Atlantic and moving to the West. 10 The counterclockwise rotation of the 11 storm is also easy to see. 12 13 Look at the shape of the storm. It is 14 very symmetrical and organized. 15 Almost circular. 16 ~ Use laser pointer to point 17 Notice that when the tropical cyclones out and trace the movement of the 18 move into the mid-latitudes above the westerlies from West to East. 19 tropics they begin to move in a 20 Northeast direction. This is because 21 mid-latitude weather, like our weather 22 in the US, is driven by the westerlies. 23 The westerlies are strong, fast winds 24 at upper levels of the atmosphere that 25 from west to east around the globe. 26 The tropical cyclones change 27 directions because of the influence of 28 westerly winds. 29 30 When the storms move over land or d2 8 Tracking a Tropical Cyclone Script, Run time: 15 - 20 minutes Amy Wood, Maryland Science Center 3/2010 9 1 too far north into colder ocean waters, 2 they begin to die and lose their 3 organization and symmetry. 4 5 Satellites also provide vital information 6 about the temperature of the ocean 7 and its connection to tropical cyclone 8 development. 9 Hurricane Season 2005: Water 10 Our next image will help show the Vapor with SST 11 connection between warm ocean 12 surface temperatures and hurricane ~ Change the rotation as needed 13 development. This image is from the or have people walk to the 14 2005 hurricane season which is the appropriate location to view the 15 most active season on record to date. Atlantic and United States 16 17 The orange and red coloring ~Use laser pointer to 18 represents warmer ocean surface highlight colors 19 temperatures. The blue coloring seen 20 at the North and South Poles 21 indicates cold ocean surface 22 temperatures and the yellow and 23 green represent mid-range 24 temperatures. 25 26 Tropical cyclones can develop in the 27 tropics over warm water of at least 28 80°F is present when the right 29 atmospheric conditions are present. 30 Scientists use satellites as a tool to Tracking a Tropical Cyclone Script, Run time: 15 - 20 minutes Amy Wood, Maryland Science Center 3/2010 10 1 locate areas that have these favorable 2 conditions. 3 ~Try to highlight a few 4 Above the ocean surface, you can see examples with laser pointer 5 storms developing over warm water in 6 the tropical regions. Some will 7 organize and strengthen. 8 9 Some tropical cyclones begin and end 10 their life in the ocean while others will 11 make landfall. Also, some storms can 12 remain fairly weak while others will 13 become very strong storms like 14 Hurricane Katrina in 2005 or Ike in 15 2008. 16 17 Tropical cyclone intensity, or strength, 18 is referred to by wind speed. But 19 intensity scales vary depending on 20 where the storm forms. 21 22 The satellite age brought a wealth of 23 knowledge and considerable 24 advancement to the field of tropical 25 cyclone study. We now have a good 26 idea of how they work. Let’s take a 27 closer look. 28 Schematic.mp4 - animation of 29 This is an animation of a typical storm cross section 30 tropical cyclone. Tracking a Tropical Cyclone Script, Run time: 15 - 20 minutes Amy Wood, Maryland Science Center 3/2010 11 1 ~Pause on the aerial view 2 A center of low pressure develops of the storm 3 from a system of rotating 4 thunderstorms that form over warm 5 ocean waters. This means that the 6 atmospheric pressure at the center of 7 the rotating cluster of thunderstorms is 8 lower relative to that of the 9 atmospheric pressure surrounding it. 10 Air will flow from high pressure ~ Demonstrate rotation with 11 regions toward the center of low laser pointer 12 pressure and begin to rotate 13 counterclockwise around the center. 14 ~Resume animation and 15 Wind, or air, converges at the center use laser pointer to point out 16 of low pressure, meaning it collides features 17 with air rushing in from the other side ~Pause the animation when 18 of the storm, which causes it to rise. needed 19 This will create storm development. 20 This region is referred to as the eye 21 wall. It is the most intense part of the 22 tropical cyclone. 23 24 As the air rotates inward, it flows over 25 the warm ocean surface and gains 26 heat and moisture. This heat and 27 moisture is the fuel needed for the 28 tropical cyclone to develop and 29 strengthen. Warm, moist air is less 30 dense, than the dry air above. So the Tracking a Tropical Cyclone Script, Run time: 15 - 20 minutes Amy Wood, Maryland Science Center 3/2010 12 1 warm, moist air rises. This contributes 2 to the development of the eye wall but 3 also causes strong thunderstorm 4 development in bands, called rain 5 bands, extending around the center of 6 the tropical cyclone. 7 8 As the warm moist air rises to higher, 9 the water in the air condenses into 10 droplets of rain. Rain can be thought 11 of as the exhaust from the tropical 12 cyclone engine. 13 14 The air continues to rise and, in 15 essence, the air hits a ceiling. The air, 16 which has lost most of its heat and 17 moisture to the production of rain, 18 then becomes denser than the air `~Use laser pointer to highlight 19 below it. Some air will sink quickly, path of the air 20 leading to the spaces between rain 21 bands where no cloud development is 22 seen. Air also sinks in the center of 23 the cyclone, which is referred to as 24 the eye of the storm. That is why it is 25 calm in the eye of the storm. 26 27 Not all of the air will immediately sink ~Use laser pointer to 28 though. The remaining air will flow out highlight path of the air 29 from the top of the cyclone and 30 radiate the remaining heat into space Tracking a Tropical Cyclone Script, Run time: 15 - 20 minutes Amy Wood, Maryland Science Center 3/2010 13 1 and then sink at the outside edge of 2 the cyclone. 3 4 The tropical cyclone will continue to 5 pull air in from its surroundings to 6 replace the air that has already risen 7 and produced rain. This replacement 8 air will gain heat and moisture, rise, 9 and continue fueling the storm. 10 11 So, the tropical cyclone is reforming 12 itself over and over again as it moves 13 across the ocean. 14 15 If the tropical cyclone loses its source 16 of warm water by moving too far north 17 over cooler ocean waters or by 18 moving over land the cyclone will no 19 longer be able to sustain itself. It no 20 longer has the fuel needed to run the 21 engine. 22 ***** Can be left out to save time 23 Also, the tropical cyclone might travel or if it is not appropriate for your 24 to an area where strong winds hit the audience 25 top layer of the storm. These strong 26 winds can shear off the top of the 27 cyclone basically slicing off the top 28 layer of the storm. The strong winds at 29 the top of the storm make it 30 impossible for the cyclone to continue Tracking a Tropical Cyclone Script, Run time: 15 - 20 minutes Amy Wood, Maryland Science Center 3/2010 14 1 the rising and sinking motion of air 2 that the cyclone needs to stay 3 organized and maintain itself. 4 5 Once scientists had enough 6 observations to understand the laws 7 of nature that drive tropical cyclones, 8 it became possible to model tropical 9 cyclones using supercomputers. 10 Computer models help meteorologists 11 make most of the weather predictions 12 you see on TV or the Internet. 13 computermodel.mp4 14 Models are complex computer 15 programs that meteorologists use to 16 try to simulate or imitate weather 17 events. Meteorologists can use 18 computer models to make predictions 19 about future tropical cyclone 20 development and if and where they 21 might make landfall. 22 23 First, meteorologists divide the globe 24 into a grid system breaking the 25 surface of the globe into small AMNH land, ocean, and 26 sections, essentially making small atmosphere images 27 boxes. Then, scientists break the grid ~Use your hand to 28 system into several vertical layers to demonstrate stacking of the 29 include the land, ocean, and vertical layers. 30 atmosphere. Basically stacking one Tracking a Tropical Cyclone Script, Run time: 15 - 20 minutes Amy Wood, Maryland Science Center 3/2010 15 1 layer on top of the other from the deep 2 ocean to the top of the atmosphere 3 where weather occurs. 4 5 By using both a horizontal grid system 6 and vertical layers, they are able to 7 model tropical cyclones more 8 accurately. 9 Grid.mp4 - AMNH computer grid 10 The computer model then runs the with equations animation 11 grid and vertical layer system through 12 a series of mathematical equations 13 using a super computer. The final 14 output will be a depiction of a tropical 15 cyclone – where it will move to and 16 even how strong or intense it might 17 become. 18 Modelcomparison.mp4 - AMNH 19 Current computer models are already computer model data compared 20 accurate and are able to simulate to satellite data animation 21 weather events; as seen by this 22 comparison on the sphere. 23 24 Even as technology and scientific 25 knowledge increases, no computer 26 model will ever be 100% accurate but 27 they are helping scientists predict the 28 path tropical cyclones will take and 29 their intensity more quickly and with 30 better precision. More timely and accurate forecasts will help save lives.
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