ATMOSPHERIC MOISTURE

Note: Please refer to the GETTING STARTED lab module to learn tips on how to set up and maneuver through the Google Earth () component of this lab.

KEY TERMS

The following is a list of important words and concepts used in this lab module:

Adiabatic processes

Frontal uplift

Physical states of water

Cirrus clouds

Hydrologic cycle

Relative humidity

Condensation level

Maximum humidity

Specific humidity

Convectional uplift

Orographic uplift

Stratus clouds

Cumulus clouds

Precipitation

Wet (and dry) bulb temperature

LAB LEARNING OBJECTIVES

After successfully completing this module, you should be able to:

● Describe and explain the hydrologic cycle

● Identify different cloud types

● Explain the adiabatic process

● Compare and contrast different uplift mechanisms

● Compare and contrast different types of humidity

● Explain how precipitation occurs

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INTRODUCTION

In this lab module you will examine some fundamental concepts and principles related to atmospheric moisture. Topics include physical states of water, humidity, adiabatic processes, cloud classification and precipitation. While these topics may appear to be disparate, you will learn how they are inherently related.

The modules start with four opening topics, or vignettes, which are found in the accompanying Google Earth file. These vignettes introduce basic concepts related to atmospheric moisture. Some of the vignettes have animations, videos, or short articles that will provide another perspective or visual explanation for the topic at hand. After reading the vignette and associated links, answer the following questions. Please note that some components of this lab may take a while to download or open, especially if you have a slow internet connection.

Expand the ATMOSPHERIC MOISTURE folder and then expand the INTRODUCTION folder.

Read Topic 1: The Physical States of Water.

Question 1: Explain how this statement is false: Heat is temperature.

A. Temperature is energy, while heat is a measure of temperature

B. Heat is energy, while temperature is a measure of heat

C. Heat is energy, while temperature is the transfer of energy from one state to another

D. Temperature is energy, while heat is the transfer of energy from one state to another

Question 2: Is evaporation the absorption or release of latent heat?

A. Absorption

B. Release

C. Both

D. Neither

Read Topic 2: The Hydrologic Cycle

Question 3: According to the video, what is the common length of storage time for most atmospheric water (rainfall, snowfall) that fall onto land?

A. Only a few hours

B. Several days

C. Weeks or more

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D. It is unknown

Read Topic 3: Atmospheric Humidity

Question 4: How can you have a specific humidity that is low in the high latitudes of the northern hemisphere (as shown by the prominence of blue in first video) and yet have a high relative humidity (as shown by the prominence of red in the second video)?

A. Function of temperature – low temps have a low specific humidity but a low maximum humidity and thereby high relative humidity

B. Function of location – high altitudes (near the poles) have more humidity than low altitudes (near the Equator) and thereby high relative humidity

C. Function of climate – low temperatures have low specific humidity but a high maximum humidity and thereby a high relative humidity

D. Function of humidity – the specific humidity is high and therefore the relatively humidity must also be high

Read Topic 4: Human Interaction

Question 5: What is the primary coarse aerosol in the Atlantic Ocean, between Africa and South America? (Hint: Look to where the potential origin lies and what is found in that location)

A. Sea salts from the Indian Ocean

B. Smoke from fires in Africa

C. Nitrates from coastal populations

D. Dust (sand) from the Sahara Desert

GLOBAL PERSPECTIVE

In this module you will learn about factors influencing precipitation and that precipitation varies spatially and temporally. This section will introduce you to some of these patterns.

Expand GLOBAL PERSPECTIVE and then select June Precipitation.

This map shows total precipitation for the month of June 2011. Precipitation is the condensation of atmospheric water vapor into various forms of water, including rain, sleet, snow, and hail. The amount of precipitation for any given area is measured in millimeters (mm).

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Double-click and select Location A.

Question 6: What is the approximate latitude and longitude (degrees only) for this location?

A. 28 N 82 W

B. 28 S 82 E

C. 28 N 82 E

D. 29 S 82 W

Question 7: Estimate the precipitation for this location.

A. Approximately 1 mm

B. Approximately 100 mm

C. Approximately 200 mm

D. Approximately 2000 mm

Double-click and select Location B.

Question 8: What is the approximate latitude and longitude (degrees only) for this location?

A. 28 N 114 E

B. 28 N 114 W

C. 28 S 114 W

D. 28 S 114 E

Question 9: Estimate the precipitation for this location.

A. Approximately 1 mm

B. Approximately 100 mm

C. Approximately 200 mm

D. Approximately 2000 mm

Question 10: Does latitude play a prominent role in precipitation differences in these two examples in June?

A. Yes, latitude is a main reason for precipitation differences between Locations A and B

B. No, there are other geographic factors that account for the differences between Locations A and B

Select December Precipitation, and then double-click again on Location A.

Question 11: Estimate the precipitation for Location A.

A. Approximately 1 mm

B. Approximately 10 mm

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C. Approximately 200 mm

D. Approximately 2000 mm

Question 12: Does Location A have both a wet season and a dry season?

A. Very likely – there is more precipitation in winter than summer

B. Very likely – there is more precipitation in summer than winter

C. Not likely – there seems to be only a wet season (above 60mm) year-round

D. Not likely – there seems to be only a dry season (below 60 mm) year-round

Double-click and select Location C.

Question 13: What is the latitude (degrees only) for this location?

A. 4 N 114 E

B. 4 S 114 W

C. 4 N 114 W

D. 4 S 114 E

Toggle between June Precipitation and December Precipitation.

Question 14: Does Location C have both a wet season and a dry season?

A. Very likely – there is more precipitation in winter than summer

B. Very likely – there is more precipitation in summer than winter

C. Not likely – there seems to be only a wet season (above 60mm) year-round

D. Not likely – there seems to be only a dry season (below 60 mm) year-round