Download Online Research Laboratory

Online Research Laboratory – Pressure & Winds
Go to the address below & answer the questions on this page.
http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/fw/home.rxml
Go to Pressure, click on it to start.
1. Define atmospheric pressure.
2. What are the different types of units for pressure? Who uses which ones?
Continue on to variation with height.
3. What is the relationship between pressure and altitude?
Continue to isobars.
4. What is an isobar?
5. Why are not ALL of the pressure points connected to a specific line (isobar)? How do you
determine which ones are connected and which ones are not?
6. What are cyclones?
7. What are anticyclones?
8. What are pressure gradients?
Continue on to pressure surfaces.
9. What is constant pressure? Give an example.
10. What is the approximate constant pressure at 10,000 feet?
What’s the correlating temperature?
11. What are the typical variables included in an isobaric map?
Continue on to variation with temperature.
12. What happens to the height of a given pressure surface when the temperature decreases? WHY?
Continue on to high pressure center.
13. What is a high pressure center? What is the symbol for a high pressure center on a weather
map?
14. In what direction do winds move in a high pressure center? Illustrate.
15. Why is fair weather associated with high pressure centers?
Continue on to low pressure centers.
16. What is a low pressure center? What is the symbol for a low pressure center on a weather map?
17. In what direction do winds move in a low pressure center? Illustrate.
18. Why is cloudy weather associated with low pressure centers?
Continue on to Forces, Winds.
19. What is a pressure gradient force? What is it responsible for?
Continue to Coriolis force.
20. What is a Coriolis force? What is it due to?
21. In what direction is the effect felt in the Northern Hemisphere? Southern Hemisphere?
(Illustrate)
22. The amount of deflection is due to what factors?
23. What’s a real-life example of the Coriolis effect?
Continue on to geostrophic wind.
24. What are geostrophic winds? What are they the result of?
25. Why do true geostrophic winds rarely occur in nature?
Continue to gradient winds.
26. What is the most important information you learned from this page?
Continue on to friction.
Read the two web pages associated with friction, and then answer the questions associated with it at
the bottom of the page titled boundary layer winds. The questions have been pasted below.
Does the total wind deflect towards higher or lower pressure in the boundary layer? (isobars in
dark gray).
What happens to the Coriolis force vector as the total wind changes?
Compare the strength of the pressure gradient force vector and the Coriolis force vector. What
happens to them as the altitude changes?
How does the roughness of the terrain affect the surface wind?
What are the differences between the northern and southern hemisphere in the example?
Air Masses and Moving Fronts
Go to the following website and read through and answer the following questions:
http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/af/home.rxml
Click on “fronts” and proceed:
1. Define a front.
2. What is true about the density of clashing air masses?
3. Make a sketch of the cold front shown in the diagram:
4. How would you define a stationary front?
5. How is a stationary front represented on a map?
6. How do the wind directions compare on either side of a stationary front?
7. How would you define a cold front?
8. What general direction do cold fronts move?
9. How does the air moisture and temperature compare ahead of the front and behind the cold
front?
10. Sketch a diagram of the cold front shown:
11. What is a good indicator for locating a cold front?
12. List several characteristics below about cold fronts with regard to: winds, pressure, clouds,
precipitation, and dew point.
13. What kind of wind direction is ahead of a cold front usually?
14. What kind of wind direction is behind a cold front usually?
15. What are the lines or flags called that indicate wind direction for a location on the map?
16. How are dew points used to indicate the passage of a cold front?
17. What kind of dew point would moist air have compared to drier air?
18. Sketch the simple model of a cyclone as shown on the cyclone page:
19. Sketch the diagram showing air masses and their position with regard to the LOW center and
showing temperature and moisture content:
20. What does an advancing cold front do to warmer air that is ahead of it?
21. What does this lifting of warm air cause to happen?
22. What kind of a slope does an approaching cold front have as it moves against a warm air mass?
23. How would you define a warm front?
24. What directions doe warm fronts generally move in the US?
25. How is the air temperature in front of a warm front compare to behind the warm front?
26. Sketch the warm front diagram that is shown:
27. List several characteristics of warm fronts using the following terms: winds, temperature,
pressure, clouds, precipitation, and dew point.
28. What kind of wind shift is noticed by the passage of a warm front?
29. What does warm air do as it approaches a cold air mass in place?
30. What kind of lifting of air takes place with the approach of a warm front?
31. What kind of precipitation intensity does this usually create?
32. What happens to the clouds during the approach of a warm front?
33. How does an occluded front occur?
34. Symbolically, how do you represent an occluded front on a map?
35. Sketch a diagram of an occluded front as shown: