Atmospheric Systems and Climate Review Flashcards

Intertropical Convergence Zone (ITCZ)

• A crucial planetary phenomenon occurring near the Equator.

• The Intertropical Convergence Zone is an equatorial phenomenon related to wind.

• It shifts with the sun, moving south during the Northern Hemisphere's winter and north during its summer.

• Characterized by the convergence of wind bands, specifically trade winds.

• The North East Trade Winds and South East Trade Winds meet at the ITCZ.

• These trade winds are consistent and were historically used by European explorers.

• The ITCZ is located in the torrid zone, receiving direct solar radiation between 23.5 degrees south and 23.5 degrees north latitude.

• On the equinox, at noon on the Equator, there is no shadow cast due to the sun's direct overhead position.

Equatorial Climate and Rainforests

• The equatorial region is the hottest and rainiest on Earth.

• Direct solar energy leads to significant evaporation.

• Winds collide and rise, leading to cloud formation and heavy rainfall.

• This process fosters the growth of rainforests such as the Amazon, Congo, and Southeast Asian equatorial forests.

Pressure Systems

• The Intertropical Convergence Zone (ITCZ) is a low-pressure zone because air rises and leaves.

• Another low-pressure zone exists near Alaska and in regions like Norway, Scotland, and Ireland.

• Low Pressure: Air rises, diminishing the effect of gravitational pressure, causing the barometer to lower.

• High Pressure: Air descends, increasing gravitational pressure, causing the barometer to display higher values.

• In a low-pressure zone, objects weigh slightly less due to air leaving the earth.

Hadley Cell

• Circulation of winds is part of the Hadley cell, responsible for energy distribution.

• In the Northern Hemisphere, air rises, sheds moisture, and descends in a clockwise direction.

• In the Southern Hemisphere, the air descends in a counterclockwise direction.

Coriolis Effect

• The Coriolis effect influences the direction of moving objects, including airplanes and missiles.

• North of the Equator, movement curves to the right; south of the Equator, it curves to the left.

Subtropical High-Pressure Systems

• The Hadley cell terminates around 30 degrees north and south latitude creating a high-pressure belt.

• Landmasses in the Northern Hemisphere break up this belt, concentrating high-pressure systems over oceans.

• Central and Southern California are under the influence of a subtropical high-pressure system.

• Descending air leads to compression heating and inhibits convection; causing clear, sunny, and hot conditions.

• High pressure evaporates water and increases groundwater usage.

• All deserts are located under areas of high-pressure, in which air descends, preventing cloud formation and rainfall.

• Air diverges from high pressure zones spreading from high to low pressure zones.

• Analogy: A leaf blower dispersing leaves on the ground simulates high pressure displacing water vapor.

• Air flows from high to low pressure, eventually rising back up into the atmosphere.

• Living under high pressure makes objects slightly heavier by adding to downward gravitational pressure.

• Subtropical high pressure induces aridity, leading to desert formation, and causes clear skies and heat.

Regional Climate Variations

• Mexico acts as a transition zone between desert dryness and tropical climates.

• During winter, high-pressure systems shift, allowing moisture to reach Central and Southern California.

• Atmospheric rivers feed moisture around high-pressure cells, causing rainfall in regions like Oregon, Washington, and Northern California.

• Europe experiences a similar pattern, with dry Spain and wet conditions in Ireland, England, and France.

• Subtropical high pressure can destroy hurricanes by depriving them of energy.

• High-pressure cells dominate during summer, causing dry conditions in regions like Oregon, Washington, Spain, and Morocco.

• The Saharan Desert is under high pressure, while its upper regions are green.

• There is a higher presence of high pressure in the Southern Hemisphere due to less landmass.

• Air flows from high to low pressure, influencing wind patterns.

Pressure Gradient

• Pressure is measured using barometric readings.

• 30.2 is typically considered high pressure.

• High pressure is characterized by descending air, while low pressure involves air leaving the earth.

Intertropical Convergence Zone (ITCZ)

• Near the Equator.

• Moves with the sun (north in summer, south in winter).

• Where North East and South East Trade Winds meet.

• Located in the torrid zone (between 23.5 degrees south and 23.5 degrees north).

Equatorial Climate and Rainforests

• Hottest and rainiest region.

• Direct sun causes evaporation.

• Winds collide, rise, form clouds, and cause rain.

• Creates rainforests like the Amazon and Congo.

Pressure Systems

• ITCZ is a low-pressure zone (air rises).

• Low pressure: Air rises, lower barometer.

• High pressure: Air descends, higher barometer.

Hadley Cell

• Wind circulation distributes energy.

• Northern Hemisphere: Air rises, descends clockwise.

• Southern Hemisphere: Air descends counterclockwise.

Coriolis Effect

• Affects moving objects (planes, missiles).

• North of Equator: Curves right.

• South of Equator: Curves left.

Subtropical High-Pressure Systems

• Hadley cell ends around 30 degrees north and south.

• Creates high-pressure belt, mainly over oceans.

• Causes clear, sunny, hot conditions.

• Leads to deserts (air descends, no clouds or rain).

• Air moves from high to low pressure.

• High pressure causes aridity and heat.

Regional Climate Variations

• Mexico is between desert and tropical climates.

• Winter: High pressure shifts, brings rain to California.

• Atmospheric rivers bring rain to Oregon, Washington.

• Summer: High pressure causes dryness in Oregon, Washington, Spain, Morocco.

• High pressure can weaken hurricanes.

• Deserts are under high pressure.

• More high pressure in Southern Hemisphere (less land).

• Air flows from high to low pressure.

Pressure Gradient

Intertropical Convergence Zone (ITCZ)

• Near the Equator.

• Moves with the sun (north in summer, south in winter).

• Where North East and South East Trade Winds meet.

• Located in the torrid zone (between 23.5 degrees south and 23.5 degrees north).

Equatorial Climate and Rainforests

• Hottest and rainiest region.

• Direct sun causes evaporation.

• Winds collide, rise, form clouds, and cause rain.

• Creates rainforests like the Amazon and Congo.

Pressure Systems

• ITCZ is a low-pressure zone (air rises).

• Low pressure: Air rises, lower barometer.

• High pressure: Air descends, higher barometer.

Hadley Cell

• Wind circulation distributes energy.

• Northern Hemisphere: Air rises, descends clockwise.

• Southern Hemisphere: Air descends counterclockwise.

Coriolis Effect

• Affects moving objects (planes, missiles).

• North of Equator: Curves right.

• South of Equator: Curves left.

Subtropical High-Pressure Systems

• Hadley cell ends around 30 degrees north and south.

• Creates high-pressure belt, mainly over oceans.

• Causes clear, sunny, hot conditions.

• Leads to deserts (air descends, no clouds or rain).

• Air moves from high to low pressure.

• High pressure causes aridity and heat.

Regional Climate Variations

• Mexico is between desert and tropical climates.

• Winter: High pressure shifts, brings rain to California.

• Atmospheric rivers bring rain to Oregon, Washington.

• Summer: High pressure causes dryness in Oregon, Washington, Spain, Morocco.

• High pressure can weaken hurricanes.

• Deserts are under high pressure.

• More high pressure in Southern Hemisphere (less land).

• Air flows from high to low pressure.

Pressure Gradient