Meteorology: Cyclones, Anticyclones, Jet Streams, and Global Wind Patterns

- What is the rotation direction of a cyclone in the Northern Hemisphere?

Counterclockwise

- What is the rotation direction of a cyclone in the Southern Hemisphere?

Clockwise

- What is the vertical motion of air in a cyclone?

Rising air

- What is the rotation direction of an anticyclone in the Northern Hemisphere?

Clockwise

- What is the rotation direction of an anticyclone in the Southern Hemisphere?

Counterclockwise

- What is the vertical motion of air in an anticyclone?

Sinking air

- What type of pressure is associated with a cyclone?

Low pressure

- What type of pressure is associated with an anticyclone?

High pressure

- What causes opposite wind rotation in each hemisphere?

The Coriolis Effect

- What are jet streams?

Narrow bands of high-altitude winds blowing west to east

- Where do jet streams form?

Near the tropopause

- What causes jet streams to form?

Strong temperature gradients between air masses

- How many major jet streams exist globally?

Four — two polar jets and two subtropical jets

- What pressure belt is found at the equator?

Equatorial Low (ITCZ)

- What pressure belt is located at 30° latitude?

Subtropical High (Horse Latitudes)

- What pressure belt is found at 60° latitude?

Subpolar Low

- What pressure belt is located at the poles?

Polar High

- What kind of weather is typical at the ITCZ?

Rising air, thunderstorms, and heavy rainfall

- Why are the Horse Latitudes dry and calm?

Air sinks and diverges, suppressing cloud formation

- What is a sea breeze?

Cool air from the sea moving inland during the day

- What is a land breeze?

Cool air from land moving toward the sea at night

- What is a valley (anabatic) breeze?

Warm air rising upslope during the day

- What is a mountain (katabatic) breeze?

Cool air flowing downslope at night

- What are Foehn or Chinook winds?

Warm, dry downslope winds that rapidly warm regions

- Where does air rise in the Hadley Cell?

At the equator

- Where does air sink in the Hadley Cell?

Around 30° latitude

- What drives the Hadley Cell?

Intense solar heating at the equator

- Where does air rise in the Ferrel Cell?

Around 60° latitude

- Where does air sink in the Ferrel Cell?

Around 30° latitude

- What drives the Ferrel Cell?

Interaction with Hadley and Polar cells

- Where does air rise in the Polar Cell?

Around 60° latitude

- Where does air sink in the Polar Cell?

At the poles

- What kind of air dominates the Polar Cell?

Cold, dense, sinking air

- What winds blow from the subtropical high to the equatorial low?

Trade winds

- What direction do Northeast Trade Winds blow?

From northeast to southwest

- What direction do Southeast Trade Winds blow?

From southeast to northwest

- What winds dominate the midlatitudes including the U.S.?

Westerlies

- What direction do westerlies blow?

From west to east

- What causes the alternating wind belts on Earth?

The three-cell circulation system and the Coriolis Effect

- Which circulation pattern is characteristic of a cyclone in the Southern Hemisphere

air flowing inward clockwise

- Which circulation pattern is characteristic of a cyclone in the Northern Hemisphere

air flowing inward counterclockwise

- Which circulation pattern is characteristic of an anticyclone in the Southern Hemisphere

air flowing outward counterclockwise

- Which circulation pattern is characteristic of an anticyclone in the Northern Hemisphere

air flowing outward clockwise

- Which statement is true about surface air parcels

lower temperature higher density air sinks creating higher pressure at the surface

- Viewed from below the North Pole polar easterlies

flow clockwise around the pole

- Viewed from below the South Pole polar easterlies

flow counterclockwise around the pole

- Why does geostrophic wind move along isobars

no friction and high Coriolis effect

- More wind deflection occurs with height because

friction decreases with height and Coriolis effect increases with wind speed

- The Hadley Cell is characterized by

low pressure with rising air over the equator and high pressure with sinking air at 30 degrees

- The Ferrel Cell is characterized by

low pressure with rising air over the subpolar low and high pressure with sinking air at 30 degrees

- The Polar Cell is characterized by

low pressure with rising air over the subpolar low and high pressure with sinking air at the poles

- Why does the ITCZ shift more dramatically over land than over oceans in summer

the heating of the land is more intense

- In the Northern Hemisphere the westerlies are created by the Coriolis effect acting on air

from the subtropical high flowing north to the subpolar low

- In the Southern Hemisphere the westerlies are created by the Coriolis effect acting on air

from the subtropical high flowing south to the subpolar low