Atmospheric Circulation Overview

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Questions and Answers

What primarily causes the pressure differences that create atmospheric circulation?

The presence of mountains and valleys

Seasonal changes in temperature

Large-scale heating differences between the equator and poles (correct)

Variations in humidity levels across different regions

What is the role of the Intertropical Convergence Zone (ITCZ)?

It separates the trade winds from the polar easterlies.

It serves as a belt of high humidity and low pressure near the equator. (correct)

It creates high pressure in the polar regions.

It influences seasonal winds in the mid-latitudes.

At what latitudes can Polar Easterlies be found?

60-90 degrees (correct)

45-60 degrees

30-60 degrees

0-30 degrees

How do Tropical Easterlies generally flow?

From east to west Signup and view all the answers

What is the primary characteristic of air in the Intertropical Convergence Zone?

It is warm, humid, and buoyant. Signup and view all the answers

What effect does the heating of the equatorial regions have on the wind patterns?

It causes the air to rise, creating prevailing winds. Signup and view all the answers

What are subtropical high-pressure belts associated with?

They occur in regions of descending air. Signup and view all the answers

Which of the following statements about wind systems is true?

Wind systems are influenced by the Earth's rotation and temperature gradients. Signup and view all the answers

What happens to the temperature in the troposphere as altitude increases?

Temperature decreases Signup and view all the answers

Which atmospheric layer contains the highest concentration of ozone?

Stratosphere Signup and view all the answers

What phenomenon occurs in the stratosphere under certain conditions?

Polar stratospheric clouds Signup and view all the answers

How does temperature behave in the thermosphere with altitude?

Temperature increases Signup and view all the answers

What is a significant feature of the troposphere compared to other atmospheric layers?

It is mixed by convection Signup and view all the answers

Which gas is the most abundant component of the Earth's atmosphere?

Nitrogen (N2) Signup and view all the answers

What is the primary reason why O2 and N2 are not considered greenhouse gases?

They do not absorb infrared radiation. Signup and view all the answers

Which process is NOT part of the nitrogen cycle?

Carbon fixation Signup and view all the answers

What form of nitrogen do plants primarily absorb from the soil?

Nitrate (NO3−) and ammonium (NH4+) Signup and view all the answers

At what concentration percentage is Argon (Ar) found in the atmosphere?

0.9% Signup and view all the answers

What effect does nitrogen's unreactive nature have on the biological cycles?

It facilitates the conversion processes when split into atoms. Signup and view all the answers

What is the predominant form of nitrogen available for absorption in aerobic soils?

Nitrate (NO3−) Signup and view all the answers

Which greenhouse gas has the lowest concentration in the atmosphere?

Carbon Dioxide (CO2) Signup and view all the answers

What process does ammonification refer to?

Conversion of organic nitrogen to ammonium Signup and view all the answers

Which of the following gases is not considered a significant greenhouse gas?

Argon Signup and view all the answers

What is the impact of greenhouse gases on Earth's atmosphere?

They trap heat and increase atmospheric temperature. Signup and view all the answers

According to the barometric law, how does atmospheric pressure change with altitude?

It decreases approximately 11.3 Pa per meter in the first 1000 meters. Signup and view all the answers

Which layer of the atmosphere is closest to the Earth's surface?

Troposphere Signup and view all the answers

What primarily causes ears to pop during an airplane ascent?

Change in atmospheric pressure Signup and view all the answers

Which greenhouse gas has the highest concentration at the tropical region?

Water Vapor Signup and view all the answers

What does the greenhouse effect primarily result from?

Increased levels of carbon dioxide and other gases Signup and view all the answers

Study Notes

Surface Winds on an Ideal Earth

An ideal Earth has no land-water pattern or seasonal changes, leading to uniform atmospheric behavior.
Maximum insolation occurs at the equator, causing warm temperatures, rising air, and low pressure.
Minimum insolation at the poles results in cooler temperatures, descending air, and high pressure.
Pressure gradients emerge between the equator and poles due to differences in heating, driving atmospheric circulation patterns.

Intertropical Convergence Zone (ITCZ) and Monsoon Circulation

The ITCZ is located near the equator and characterized by low pressure as trade winds from both hemispheres converge.
The intense heat from the sun raises air humidity in the ITCZ, making the air buoyant and contributing to tropical weather patterns.
Known for the "Doldrums," the ITCZ is a region of calm winds in the Atlantic and Pacific Oceans.

Wind and Pressure Features at Higher Latitudes

Hadley Cell:
- A tropical atmospheric circulation cell that transports warm air from the equator poleward in the upper atmosphere, then descends at 30 degrees latitude.
Polar Easterlies:
- Found at latitudes 60-90 degrees in both hemispheres, these winds are cold and dry, originating from the poles where air is dense and cool.
Tropical Easterlies:
- These east-to-west winds occur between 0-30 degrees latitude, flowing towards the equator; as warm air rises, it cools and returns to the equator.

Atmospheric Composition and Structure

Major atmospheric components: Nitrogen (78%), Oxygen (21%), Argon (0.9%), Carbon Dioxide (0.039%), Water Vapor (varies from 0.00001% at South Pole to 4% in Tropics).
Nitrogen is unreactive; plays key roles in biological cycles when converted into reactive forms.
Oxygen is essential for life and highly reactive; not a greenhouse gas.
Argon is chemically inert and does not contribute to climate change.

Nitrogen Cycle

The nitrogen cycle involves various processes: fixation, ammonification, nitrification, and denitrification.
Plants absorb nitrogen from soil primarily as nitrates (NO3−) and ammonium (NH4+).
Nitrification occurs in aerobic soils, predominantly providing nitrate for plant uptake.
Ammonification (or mineralization) converts organic nitrogen from decomposing plants/animals into ammonium.

Greenhouse Gases

Strong greenhouse gases: Carbon Dioxide (390 ppm), Water Vapor (40,000 ppm in Tropics), Methane (1.7 ppm), Nitrous Oxide (0.3 ppm), Ozone at surface (0.01 ppm), Freon-11 (0.00026 ppm), Freon-12 (0.00048 ppm).
Greenhouse effect: Increased concentrations of CO2 and other gases trap sunlight heat, raising Earth's atmospheric temperature.
Without greenhouse gases, Earth’s heat would escape as infrared radiation.

Atmospheric Pressure and Temperature

Atmospheric pressure decreases with altitude, described by the barometric law.
Pressure drops approximately 11.3 Pa per meter in the first 1000 meters above sea level.
Barometer: Instrument for measuring atmospheric pressure.

Vertical Temperature Profile

Troposphere: Temperature decreases with altitude; where weather phenomena occur.
Stratosphere: Temperature increases with altitude; contains majority of Earth's ozone, low humidity.
Mesosphere: Temperature decreases with altitude beyond the stratosphere.
Thermosphere: Temperature increases at higher altitudes due to short-wavelength UV radiation absorption.

Layers of the Atmosphere

Troposphere: Mixed by convection, involved in weather patterns.
Stratosphere: Low pressure, dry air, polar stratospheric clouds possible during cold conditions.
Ozone is concentrated in the stratosphere, filtering harmful UV radiation.

Special Phenomena

Aurora Borealis (Northern Lights) and Aurora Australis (Southern Lights) are atmospheric phenomena caused by charged particles from the sun interacting with the Earth's magnetic field.

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Description

Explore the key concepts of atmospheric circulation including the surface winds on an ideal Earth, the subtropical high-pressure belts, and the intertropical convergence zone. This quiz also delves into wind and pressure features at higher latitudes and their impact on climate. Test your knowledge of these fundamental atmospheric principles.