Chapter 5 Flashcards
Imbalance
Atmospheres circulation caused by imbalance.
Air Pressure
Motion, since and number created by air molecules.
Force/Area
Pressure Maps
Lines on a map that show pressure. (Isobars)
Pressure Maps are similar to
Temperature values (Isotherms)
Wind
Horizontal movement of air.
(Wind) Produced
By differences in air pressure.
(Wind) Measured
By its speed and direction.
(Wind) Named
For the direction from which they originate.
Winds link the Earths
Atmosphere
Mixing gases
Dust
Pollutants
What are driving forces?
Gravitatonal Force
Pressure Gradient Force
Coriolis Force
Frictional Force
Gravitational Forcs
Counteracts outward centrifugal forces acting on Earths spinning surface and atmosphere.
(Gravitational Force) Exerts a
____on the atmosphere.
Virtually uniform pressure.
What compresses the atmosphere (increases density at surface?
Gravitational Force
If gravity didn’t exist,
There would be no pressure.
Pressure Gradient Force
Flow from high pressure to low pressure (just like heat)
Change in pressure/distance
Coriolis
Deflection force due to rotation of our Earth.
Frictional Force
Drag on wind. Opposite direction on wind. Being against the wind.
High Pressure
High
Descending dividing
Goes down
Low Pressure
Low
Ascending Conviging
Going up
Primary Pressure Areas
Equatorial low-pressure trough
Polar high-pressure cells
Subtropical high-pressure cells
Sub-polar low-pressure cells
Equatorial Low-Pressure Trough
Intertropical convergence zone (ITCZ)
ITCZ
High insolation area, increase evaporative potential.
Cyclone pattern, convergence, ascending air.
Rising moist air.
Trade Winds
Northeast and southeast trade winds.
Hadley circulation cells.
Calm winds, mildly variable due to weak pressure gradient and upward movement.
Polar High-Pressure Cells
Little energy from the sun.
Weak and variable; cold and dry
Anticyclone pattern, divergence, descending air.
Polar easterlies.
Subtropical Highs
Between 20-35N and S
Broad high-pressure zone - hot, dry air (Sahara)
Calm winds
Anticyclone, diverging
Air pushed down
Westerlies
Subpolar Lows
Cool and moist
Too low-pressure cyclones dominate over oceans around 60N
Land-Sea Breezes
Onshore during daytime (heating land)
Offshore during nighttime (warmer water.
Santa Ana Winds
Result from pressure gradient generated from high pressure system in Great Basin.
Dry and warm winds move through the valleys into S, CA.
Beginning at higher elevation, air descends where it then compresses (compression increases temperatures)
Amount of moist air is small to begin with and remains the same.
Winds pick up speed due to channeling through canyons.
Atmosphere and Ocean Connection
Atmospheric and oceanic systems are connected -> Driving force for ocean currents is frictional grad of winds.
Coriolis (deflection), density differences (temperature and salinity), bathymetry, and astronomical forces (tides) also shape how ocean currents.
Surface Oceanic Currents
Driven by the atmospheric circulation around subtropical high pressure cells (both hemispheres)
Circulation systems -> Gyres
Circular flows of water in the ocean basin.
Surface Oceanic Currents
At the equator, strong westward currents from due to trade winds.
Coriolis effect is weaker at
The equator and creates western intensification (water piles up)
(Downwelling and Upwelling) Where surface water accumulates, do swelling currents occur
Cool, nutrient rich water rises from below replacing the surface water (Pacific coasts of N & S America)
