AIR PRESSURE AND WIND

You should recognize and understand these terms:

Atmospheric pressure

High pressure system

Pressure gradient force

Barometric pressure

Isobar

Pressure units (mmHg, inHg, mbar, hPa, kPa)

Beaufort wind scale

Katabatic winds

Solar radiation

Coriolis effect

Land-sea breeze

Wind

Frictional force

Low pressure system

Wind farms (wind arrays)

Gravity

Monsoon

Wind turbines

LAB MODULE LEARNING OBJECTIVES

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

œ Recognize atmospheric circulation at local, regional and global scales

œ Define and identify isobars on a map

œ Distinguish wind movement and weather conditions between high and low pressure systems

œ Identify the roles of gravity, pressure gradient, Coriolis and frictional forces on wind movement and wind patterns

œ Convert miles per hour to knots using the Beaufort wind scale

œ Recognize katabatic wind patterns

œ Explain daily (day and night)l land-sea breeze wind patterns

œ Provide examples of human uses of wind

In this lab module you learn about some fundamental principles of atmospheric pressure, wind processes and patterns, and global air circulation

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INTRODUCTION

In this lab module you learn about some fundamental principles of atmospheric pressure, wind processes and patterns, and global air circulation. Topics covered include the factors that influence air pressure, high and low pressure systems, the direction of airflow, Coriolis force, frictional forces, atmospheric circulation, local wind systems, and wind energy. In doing so, you will recognize and appreciate the roles of the Sun, the Earthfs atmosphere and surface of the Earth as they influence the movement of air at local to global scales.

The module starts with four opening topics, or vignettes, which are found in the accompanying Google Earth file. These vignettes introduce basic concepts and tools on which geographers rely. 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 links may take a while to upload based on your internet speed.

Expand the INTRODUCTION folder and then double-click and select Topic 1: Atmospheric Circulation.

Read Topic 1: Atmospheric Circulation.

Question 1: What are the three geographic scales of air movement and atmospheric circulation?

A. Global, National, Regional

B. National, Regional, Local

C. Global, National, Local

D. Global, Regional, Local

Read Topic 2: Weighing in on Atmospheric Pressure.

Question 2: Does an increase in elevation usually mean an increase or decrease in pressure?

A. A decrease

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B. An increase

C. Elevation does not affect atmospheric pressure

D. It depends on the humidity levels

Question 3: Would Mt. Everest have a higher or lower atmospheric pressure than a location at sea level?

A. A higher atmospheric pressure

B. A lower atmospheric pressure

C. Elevation does not affect atmospheric pressure

D. It depends on the humidity levels

Read Topic 3: The Highs and Lows of Weather.

Question 4: Is the air sinking (descending) or rising (ascending) in the picture?

A. The air is sinking

B. The air is rising

C. The air is stationary

D. Unable to discern from information provided

Read Topic 4: Human Interaction.

Question 5: How does data from wind turbines help weather forecasts?

A. They collect data at elevations where weather data are not routinely collected, which could improve forecasts

B. Wind speed data are used in the decision to turn on or off the turbines

C. Electricity generated from the turbines is used to power forecasting models

D. They donft. Turbines depend on weather forecasts

Collapse and uncheck the INTRODUCTION folder.

GLOBAL PERSPECTIVE

Wind power is a form of solar power. Solar radiation (sunlight) heats up the surface of the Earth, but does so unevenly. This is because surfaces on Earth absorb, retain, and release heat at different rates. The uneven heating of the Earthfs surface results in the formation of unequal pressures in the atmosphere; namely, high pressures and low pressures. As air pressure moves from high pressure areas

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to low pressure areas, wind forms. We can harness the power of wind near the Earthfs surface with wind turbines, and convert the kinetic energy of wind into electricity (measured by kilowatts, kW, or megawatts, MW) for our homes and businesses. Note that all the wind speeds have been rounded to the nearest mile per hour. Remember to include your unit of miles per hour.

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

Albedo

Energy deficit

Longwave radiation

Conduction

Energy surplus

Net radiation (net flux)

Convection

Global energy budget

Radiation

Constant gases

Heat

Radiation budget

Electromagnetic radiation

Heat transfer

Shortwave radiation

Electromagnetic spectrum

Incoming and outgoing radiation

Solar constant

Electromagnetic waves

Insolation

Solar radiation

Energy

Irradiance

Variable gases

LAB MODULE LEARNING OBJECTIVES

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

œ Recognize aspects of the electromagnetic spectrum

œ Distinguish between shortwave and longwave radiation and its sources

œ Describe the composition of the atmosphere

œ Explain how heat is transferred and measured

œ Define and identify patterns of global solar insolation and albedo

œ Describe the flow of solar radiation

œ Describe the spatial patterns of net radiation

œ Provide examples of human interactions and uses with sunlight (solar radiation)

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INTRODUCTION

In this lab module you will examine some of the fundamental concepts and principles related to global energy. Topics include the electromagnetic spectrum, the composition of the atmosphere, solar radiation, the movement of radiation in the atmosphere, albedo and the global energy budget. While these topics may seem disparate, you will learn how they are inherently related.

The module starts with four opening topics, or vignettes, which are found in the accompanying Google Earth file. These vignettes introduce basic concepts related to global energy. Some of the vignettes have animations, videos, or short articles that provide another perspective or visual explanation for the topic at hand. After reading each 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 GLOBAL ENERGY and then expand the INTRODUCTION folder.

Read Topic 1: Electromagnetic Radiation.

Question 1: Which electromagnetic waves have the most energy?

A. Radio waves

B. Microwaves

C. X-rays

D. Gamma rays

Question 2: How is Earthfs radiation budget described in the video?

A. The difference between sunlight that comes into the Earth, minus the amount of sunlight that is reflected by, and energy emitted from, the Earth

B. The difference between sunlight that is reflected by Earth, minus the energy emitted, plus the sunlight coming into the Earth

C. The difference between energy emitted by the Earth, minus the sunlight coming into the Earth, minus the sunlight reflected by the Earth

D. The difference between energy emitted by the Earth, minus the sunlight coming into the Earth, plus the sunlight reflected by the Earth

Read Topic 2: Atmospheric Composition.

Question 3: What are the three ingredients needed for an ozone hole?

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A. Warm temperatures, sunlight, and high levels of smog

B. Cold temperatures, darkness, and high levels of smog

C. High level of chlorine and bromine, warm temperatures, and sunlight

D. High level of chlorine and bromine, cold temperatures, and sunlight

Read Topic 3: Transfer of Heat Energy.

Question 4: Which of the following is not true regarding the transfer of heat energy?

A. Air conducts heat effectively

B. Dark-colored objects absorb more radiant energy than light-colored objects

C. Convection is the transfer of heat energy in the atmosphere

D. Sunlight is a form of radiation

Question 5: Of these means of transferring heat, which tend directly produce weather systems?

A. Radiation

B. Conduction

C. Convection

D. None of these

Read Topic 4: Human Interaction.

Question 6: From the article, all of the following are recognized disadvantages of generating electricity from solar power except?

A. The amount of pollution generated

B. Cost

C. Daylight hours for operation

D. Locations with low available sunlight

Question 7: From the map in the article, what area of the United States shows the highest annual average daily solar radiation per month (measured in kWh/m2/day)?

A. Northeastern United States

B. Southeastern United States

C. Southwestern United States

D. Northwestern United States

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For the rest of this module, you will identify and explain the geographic distribution, patterns, and processes associated with electromagnetic radiation. In doing so, you will recognize and appreciate the role of the Sun, atmosphere and the Earthfs surface as they influence the worldfs global energy budget.

Collapse and uncheck the INTRODUCTION folder.

GLOBAL PERSPECTIVE

Insolation (incoming solar radiation) is the amount of direct or diffused electromagnetic radiation the Earth receives from the Sun. Insolation can be quantified by its irradiance, which is the power . or rate of electromagnetic radiation – that strikes the surface of a given area. As power is measured in Watts (W), and area is measured in meters squared (m2), irradiance is commonly measured in Watts per meter squared (W/m2).

The Sun produces a fairly constant rate of solar radiation at the outer surface of the Earthfs atmosphere; this solar constant averages to approximately 1370 W/m2. However, the average amount of solar radiation received at any one location on the Earth is not ~1370 W/m2 . it is far less, due in part to the conditions of the atmosphere, the land cover, the given latitude, the time of day, and the time of year.

Expand the GLOBAL PERSPECTIVE folder and select Insolation in June. To close the citation, click the X in the top right corner of the window.

This map shows the average global solar insolation . or where and how much sunlight fell on the Earthfs surface – for the month of June in 2012. The legend in the top left corner shows how much sunlight fell on Earthfs surface, which ranges from a low of 0 W/m2 (purple/dark red) to a high of 550 W/m2 (white). Use this map layer to answer the following questions.