Atmosphere 2- How does it work? Flashcards
What will the solar rays be like in mid-latitude and polar areas?
Oblique- more diffuse, larger area covered
What will solar rays be like on the equator?
direct- more concentrated smaller area covered
How much more energy does the equator receive than the poles annually?
2.5 times
How much light is reflected from a white/ light surface?
80%
How much light is reflected from a dark surface?
10%
What is the albedo range % for some different surfaces?
Fresh snow or ice- 60-90
Old melting snow- 40-70
Clouds- 40-90
Desert sand- 30-50
Soil- 5-30
Tundra- 15-35
Grasslands- 18-25
Forest- 5-20
Water- 5-10
How much energy is absorbed and reflected by the ocean at high latitudes?
Absorbed- 67%
Reflected- 33%
How much energy is absorbed and reflected by the ocean at low latitudes?
Absorbed- 95%
Reflected- 5%
What is earths climate system primarily driven by?
heat energy arriving from the sun
What 3 fundamental factors control atmospheric energy balance?
The energy received as short-wave radiation.
Short wave energy reflected (by albedo).
How much outgoing long-wave radiation is trapped (by GHGs)
What does the heating imbalance between the tropics and the poles drive?
general circulation of earths atmosphere and ocean
What is energy transferred in the climate system by convection as?
sensible heat
What does a large flux of sensible heat energy from the lower layers of the atmosphere lead to?
higher altitude and latitudes large scale convection
What is coriolis deflection?
circulating air is deflected toward the right in the Northern Hemisphere and toward the left in the Southern Hemisphere
What are the 3 atmospheric cells?
Hadley
Ferrel
Polar
How is latent heat part of the climate system?
energy transfer
What is sensible heat flux?
direct heating, a function of surface and air temperature
What is latent heat flux?
function of surface wetness and relative humidity
What does positive values for sensible and latent heat mean?
energy is moving towards the atmosphere
What does a positive value for change in heat storage mean?
energy moving out of storage
What are the key features of general circulation in the tropics?
Ascending air/ low pressure
warm/intense seasonal rainfall
What are the key features of general circulation in the sub-tropics?
Descending air/ high pressure
Warm/ clear skies/ dry/ semi-arid
What will form when centre of high pressure cell is over continent?
Deserts
What are the key features of general circulation in the polar regions?
Cold descending air/ high pressure
Dry/arid (polar desert)
Where is the driest place on earth?
Antarctic dry valleys
What are the key features of general circulation in the mid-lat. westerlies?
Ferrel cell (forms where warm air Hadley meets cold air of polar)
Warm air rises over cold-low pressure-cyclonic circulation
Prevailing westerly
What is orographic rainfall?
mountains of uplands act as barriers to airflow, forcing the air to rise and the moist air moving upslope coo down by producing clouds and precipitation
What is a rain shadow?
area of significantly reduced rainfall behind a mountainous region, on the side facing away from prevailing winds
What are the three Milankovitch cycles?
Eccentricity
Obliquity
Procession
What is eccentricity?
earths orbit changing from roughly circular to roughly elliptical 100ka to 400ka cycle
What is procession?
Earths axis of rotation changes on a 19-23ka cycle
the wobble on rotation
What is earths current angle of rotation?
23.5*
What is obliquity?
Tilt on earths axis
41ka cycle
range between 22.1 to 24.5*
