Radiosonde observations at 0000Z 10 OCT 2001 from Caribou, Maine (CAR), and Miami, Florida (MFL) are plotted on Stüve diagrams shown in Images 1 and 2, respectively. At the time of the soundings, Caribou was to the north of the center of high pressure that was associated with the expansive cold air mass that crossed the eastern half of the nation at the beginning of the week. Miami was to the south.
Trace over the temperature profiles (curves to the right on the Stüve diagrams) with heavy dark pencil lines. Comparing the two temperature curves, from the surface up to about 250 mb, the atmosphere was warmer above [(Caribou) (Miami)]. (Note: This can be seen by laying one Stüve over the other and holding up to the light.)
Looking at the Image 1 Caribou (CAR) Stüve diagram, the altitude at which 500 mb was found over the station was 5700 meters (values are plotted on the pressure lines at the left edge of the chart). On the Image 2 Miami (MFL) sounding, 500 mb occurred at an altitude of ________ m.
Compare the altitudes of the pressure levels on the two soundings. Circle the following pressures which were higher over Miami (MFL) than over Caribou (CAR):
900 mb | 700 mb | 500 mb | 300 mb | 200 mb |
These values indicate the constant-pressure surfaces slope [(downward) (upward)] from the warm air over Miami to the cold air over Caribou.
In general, one would expect that the altitudes of a constant-pressure surface would be [(higher) (lower)] as one moves poleward in response to [(rising) (falling)] air temperature.
Assume you were to fly from Miami to Caribou using your pressure altimeter which was set in Miami to 10,000 feet (approximately 700 mb). As you approached Caribou, your aircraft would actually be at a [(higher) (lower)] altitude than that indicated by your altimeter.
The tropopause above Miami was located at 143 mb (see TROP value above chart), while it was located at ________ mb above Caribou. The altitude at which the tropopause was located at Caribou was [(higher) (lower)] than at Miami. Generally, the colder the atmosphere, the lower the tropopause.
As the autumn season progresses, dramatic cooling episodes often follow the passage of intense storm systems. Such occurrences may also produce temperature contrasts.
The DataStreme Homepage shows upper air information for selected stations around the US graphically in Stüve diagrams and in detailed text listings. Print out the text data for a reporting station near you and have your students plot these data on a blank Stüve diagram, which you can print from the Homepage Extras section. You can compare your plots to the Homepage version. See if you can find differences for fair and stormy weather situations.
After completing this week's applications, fax the following pages to your LIT mentor by Monday, 15 October 2001:
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URL: datastreme/learn/b_act.html
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