UNIT 8 Flashcards
For One cell model (Hadley Cell) we must assume two things:
- a non-rotating earth
- a uniform body of water
- A single thermally driven convection cell would occur in each hemisphere
What is happening aloft?
- polar low
- equatorial high
- winds flow from equator to poles
What is happening at surface?
- Equatorial low
- Polar High
- Winds flow from poles to equator
For multi-cell model we must assume two things:
- rotating earth
- a uniform body of water
equatorial low
- inter tropical convergence zone (ITCZ); rising motion; exists because equator is warm
Subtropical High
found at 30 degrees N and S; sinking motion; deserts found here; horse latitudes; north to the right, south to the left deflection
Subpolar low
60 N and S ex: London
Polar high
created due to the temperature at the poles; sinking motion, “cold deserts”
NE/SE Tradewinds
the most consistent winds that converge at the equator
Westerlies
wind is deflected to right in north and left in south
Easterlies
High to low- left and north high to low-right
Coriolis
windspeed and latitude; less deflection at equator
Overview…
- 7 surface systems
- 6 wind belts
Hadley Cell
cells 30-0 degrees latitude ; thermally direct
Ferrel Cell
cells 30-60 degrees latitude; thermally indirect
Polar cell
cells 60- poles latitude; thermally direct
Thermally Direct
warm air rises; cold air sinks (what we expect to have)
Thermally indirect
cold air rises; warm air sinks (the opposite of what we expect)
Jet Streams
rivers of rapidly moving air flowing within the same general direction:
Polar jet
Subtropical jet
Equatorial jet
Zonal flow pattern of jet streams
straight flow
meridional flow pattern of jet streams
wavy flow
Ocean Current
- large scale movements of water
- oceanic counterpart to the atmospheric system of wind belts
- Affects the 71 percent of planet covered by oceans
- also affects continental landmasses
Temperature profile of an ocean
Absorption of solar radiation heats the ocean and land surfaces; temperature DROPS with DEPTH (opposite of the troposphere)
Mixed Layer
- extends to 75 m (245 ft) in depth
- About 3% of the total ocean volume
- NO temperature change with depth because of waves which mix water together
Thermocline
- extends beneath the mixed layer to a depth about 1000m (3300 ft)
- Relatively sharp changes in temperature depth because it is far enough from mixing of water
Deep Water
- depths greater than 3300ft
- Temperatures are nearly uniform with depth (between 1-3C of 33.8-37.5) because if ice is created it will melt as it rises
- we don’t get to 32 degrees, salt water freezing point and pressure changes freezing point
ocean currents affect the atmosphere through the transport of heat because…
they STORE A LOT OF HEAT
The world ocean plays a vital role in constantly adjusting the Earth’s surface heat imbalance…
- equatorial surplus
- polar deficit
- The sea contains numerous horizontal, vertical, and diagonal currents at various depths
- horizontal and at the surface are where most heat transfer takes place
Warm current
travel from equator to the poles; Warm water pumps heat and moisture to the atmosphere which creates clouds and precipitation (unstable lower atmosphere)
Cold current
travel from poles to equator; Cold currents don’t add heat and have no moisture to the atmosphere (Stable conditions)
Surface Currents
Even though we call one a warm or cold current, they are not that different. Additionally, the currents are not very fast; they impact the globe regardless of their slight differences
Gulf stream
floats through gulf and comes out between Florida and Cuba into the east coast
