Instruction
Assignment #1
Air pressure (or atmospheric pressure) is the force exerted by a column of air above a point on the Earth's surface. Air pressure varies by elevation, with the highest air pressures exerted close to sea level and air pressure decreasing with increasing altitude. Read the following Air Pressure Lab Supplement to learn more about air pressure, how it's measured, and how air pressure is displayed on weather maps (The Station Model).
Air Pressure Lab Supplement
Google Earth
Open Google Earth and determine the elevations of each of the following cities. You can navigate to the cities by typing their name and state into the search menu. The city's elevation will be displayed in feet (above mean sea level) in the bottom right corner of the Google Earth window. Take note of each of the elevations, then order the cities by increasing average air pressure on the attached answer worksheet. Number 1 on the worksheet should be the city with the lowest average air pressure and number 4 should be the city with the highest average air pressure. Write the elevations of these cities in the space adjacent to each city name.
Denver, Colorado
Savannah, Georgia
Indianapolis, Indiana
Buffalo, New York
The Station Model
The Station Model is the system used by meteorologists to present data on weather maps. You read about the station model in the Air Pressure Lab Supplement. In this lab, you are going to interpret the data from four simplified station model examples. Examine the station models below and determine the air temperature and air pressure at each location. Add your answers to the attached answer worksheet.
Air Pressure Map
The map below is a simplified weather map of the United States showing surface pressure conditions in millibars. There is one high pressure center and one low pressure center on the map. Examine the map and determine which U.S. state the high pressure center is located over and which U.S. state the low pressure center is located over. Add these answers to the attached answer worksheet.
When you have completed all parts of the Air Pressure Lab and completely filled out the answer worksheet, save the worksheet and submit it for grading using the Assignments Tool in ACE.
Assignment #2
Wind is created by the movement of air from areas of high atmospheric pressure to areas of low atmospheric pressure across the planet. Wind speeds are determined by the change in air pressure, with the fastest winds being generated by a rapid change in pressure over a short horizontal distance. Read the following Wind Lab Supplement to learn more about wind, air circulation patterns, and how wind is displayed on weather maps.
Wind Lab Supplement
Isobar Maps
Isobar maps are maps of air pressure that connect areas with the same pressure with lines called isobars (iso- means "same" and "bars" refers to the measure of air pressure in millibars). The following image is of an isobar map of the United States. Use this map to answer the following questions. Add the answers to the attached answer worksheet and submit this worksheet for grading using the Assignments Tool in ACE.
What is the direction of wind movement (clockwise or counter-clockwise) coming out of the high pressure cell in the western United States?
What is the direction of wind movement (clockwise or counter-clockwise) coming out of the low pressure cell in the eastern United States?
What is the predominant direction of wind movement (south to north, north to south, west to east, east to west) across the entire United States?