Tropical Storms PDF

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Summary

Students will use the tracks of hurricanes in 2005 to compare wind speed to the air pressure within the hurricane and sea surface temperature. Students will determine the impact of air pressure and sea surface temperature on hurricane strength...

Description

Tropical Storms Activity Use hurricane track information to understand factors that encourage the formation of hurricanes. Learning Outcomes • Students will use the tracks of hurricanes in 2005 to compare wind speed to the air pressure within the hurricane and sea surface temperature. • Students will determine the impact of air pressure and sea surface temperature on hurricane strength. Map URL: http://esriurl.com/earthgeoinquiry14 Engage Where and how do tropical storms form? Tropical storms form over warm ocean waters near the equator. They form when the warm air rises causing clouds to form and creates an area of lower air pressure below. Air from higher pressures push in the low areas causing a highpressure rotating effect. Click Modify Map, and then click the Contents button. Check the box next to Hurricanes Wind Strength to turn the layer on. Click any point on the trails of these hurricane. What information is stored for each point along the way? 1. How fast the wind was. 2. The category of the hurricane 3. Pressure 4. Sea temperature All hurricanes start as tropical depressions (TD). Use the Filter Tooltip instructions to filter Hurricane Wind Strength – Category - Is - TD. Where do most Atlantic storms reach TD status? Just north of the equator in between North and South America Explore How does air pressure relate to wind speed in hurricanes? The lower the air pressure the higher the wind speed. The 2005 Atlantic storms caused $160 billion in damage and 3,913 deaths. Winds cause property damage by blowing off roofs or collapsing buildings, but they also push the surface of the water into a storm swell. Homes and small buildings do not stand a chance against storm-driven ocean swells. Winds are generated by greater differences in air pressure and the geographic size of the low pressure.

Hover on the Hurricane Wind Strength layer name, click the right drop-down arrow, and then click Show Table. In the Hurricane Wind Strength table, click the WIND_KTS (wind speed in knots) column header. Click Sort Ascending to arrange the wind speed values in increasing order. As you scroll down the table, how does the pressure column change relative to wind speed? The pressure decreases as the wind speed rises. Explain What determines the path a storm takes? Global winds Are there areas where lower pressures do not have as strong of winds? Yes Why do wind speeds slow down over land? The land surfaces cause friction and the heat of evaporated water condensing into clouds is cut off over land. Close the Hurricane Wind Strength table. Elaborate Where do tropical storms get such strength? Storms get their strength from the warm sea waters and low air pressure produced from wind patterns near the surface the spiral air inward. Click the Hurricane Strengthening Zone bookmark. Turn on the Sea Temperature 05 layer. Click the Sea Temperature 05 title, and then click the AvSeaTemp05 subtitle to expand this layer’s legend. At what temperature do storms consistently pick up energy? (You can also click the dots to verify temperatures.) Around 30 C Evaluate What other areas of the world have good conditions for tropical storms? India and Spain

Use the Filter Data toolbox instructions to identify one of the names of the storms. Click each dot, and on a whiteboard, create a table of wind speeds and pressure. Create a graph of wind speed vs. pressure. Hurricane Rita 25 knots 1,009 mB 25 knots 1,009 mB 30 knots 1,007 mB 30 knots 1,007 mB 30 knots 989 mB 25 knots 995 mB 25 knots 1,000 mB 20 knots 1,003 mB

Hurricane Rita 1,015 1,010 1,005

Pressure

1,000 995 990 985 980 975 18

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Wind Speed

What type of relationship do these two variables have? The two are indirectly proportional. Click the Home button to zoom out to the entire world. List two other areas in the world that would be possible targets for tropical storms. Australia and India...