Definitions: Modules 11-15

Question 1

winds

Answer 1

• air that is moving horizontally relative to Earth’s surface
• caused by the unequal heating of Earth’s atmosphere, creating a pressure gradient
• they blow in an attempt to equalize the imbalances in air pressure in the atmosphere

Question 2

constant height maps

Answer 2

• smoothed and drawn relative to a constant elevation

- can be used to show variations in pressure at any altitude

Question 3

constant pressure maps

Answer 3

• show variations in altitudes for a constant pressure
• high altitudes for a given pressure correspond to higher than normal pressures at a given latitude
• low altitudes for a given pressure correspond to lower than normal pressures at a given latitude

Question 4

cyclone

Answer 4

• a centre of low pressure with a counterclockwise rotation in the Northern hemisphere and a clockwise rotation in the Southern Hemisphere
• creates surface convergence

Question 5

anticyclone

Answer 5

• centre of high pressure with a clockwise rotation in the Northern hemisphere and a counterclockwise rotation in the Southern Hemisphere
• creates surface divergence

Question 6

subgeostrophic flow

Answer 6

• when Coriolis force < PGF

- wind flows slowly

Question 7

cyclostrophic

Answer 7

Coriolis force is negligible near the equator

Question 8

supergeostrophic flow

Answer 8

• when Coriolis force > PGF

- wind flows quickly

Question 9

Coriolis effect

Answer 9

• force caused by earth’s rotation
• only important for broad-scale winds
• northern hemisphere: Coriolis effect pulls to the right
• Southern Hemisphere: Coriolis effect pulls to the left
• with this effect, any free-moving object heading in any direction will appear to deviate from its path

Question 10

one-cell model

Answer 10

assumes earth is covered by uniform water surface, sun’s directly overhead the equator, and earth doesn’t rotate

Question 11

three-cell model

Answer 11

incorporates Earth’s rotation, assumes no land surface

Question 12

polar front

Answer 12

polar jet occurs here, warm air from the Ferrell cell meets cold air from the Polar cell

Question 13

ekman spiral

Answer 13

generated by surface currents that don’t move in the same direction as the wind and whose speed and direction isn’t uniform with depth

Question 14

gyres

Answer 14

large-scale circular currents bounded by continents and turn under the Subtropical highs

Question 15

thermohaline circulation

Answer 15

• slow circuit of deep currents, starting from 1km below the surface to the ocean bottom
• begins as surface currents reach the waters near Greenland
• it becomes colder, saltier, and more dense
• then water sinks to ocean depths in the high latitude waters of the North and South Atlantic
• forms deep water currents, coupled with slow surface circulation

Question 16

deep water circulation

Answer 16

• North Atlantic deep water goes south of Africa and joins water from South Atlantic
• then it meets the Antarctic Intermediate Water and the Antarctic Bottom Water
• eventually it makes its way back to the Atlantic

Question 17

El Nino

Answer 17

• coincides with a time of unusually warm water off the coat of Peru
• occurs approximately every 3-8 years

Question 18

El Nino conditions

Answer 18

• decrease in differences in ocean temperatures, decrease in pressure gradients
• warm water pod approaches South American coast
• absence of cold upwelling increases warming
• warmer air extends out East, causing air to rise, decreasing pressure

Question 19

air mass

Answer 19

• extremely large body of air whose temperatures and humidity are uniform horizontally and vertically
• classified by latitude and surface type

Question 20

source regions

Answer 20

• areas of the globe where air masses form

- usually have a flat and uniform composition and light surface winds

Question 21

temperature regime

Answer 21

annual cycle of temperature at a place due to its latitude and location

Question 22

climograph

Answer 22

shows the climate of a given location or region using two or more variables

Question 23

moist climate

Answer 23

• soil remains moist all year round

- hosts perennial streams and supports forests or tall grasses

Question 24

dry climate

Answer 24

• evaporation exceeds precipitation by a lot

- can be further split into steppe climate and arid climate

Question 25

precipitation regime

Answer 25

pattern of precipitation determined by air masses

Question 26

limiting factors

Answer 26

factors that limits the growth of an organism

Question 27

freshwater

Answer 27

renewable resource that ecosystems and all living things depend on

Question 28

wetlands

Answer 28

area where the land is saturated to a depth of a few centimetres for at least a few days per year