02 Temperature and Heating Flashcards
Heating the Atmosphere Scales
Celsius 100°C
Kelvin 373
Fahrenheit 212F
Measuring Surface Air Temperature
Thermometers are housed in a Stevenson’s Screen.
1.2m (4ft) above surface.
What is the types of energy transferred from surface to atmosphere?
Long wave terrestrial radiation
Conduction (contact)
Convection (vertical flow)
Turbulence (mixing of air)
Advection (horizontal flow)
Latent Heat (with condensation, freezing)
What is radiosonde?
It directly measures upper air temperature, pressure and humidity.
Tracked by radar for wind.
What is Insolation?
The amount of energy that makes contact with the surface of the Earth.
E.g. Sun radiates short-wave radiation which cuts through our atmosphere.
What is Terrestrial Radiation?
Sun’s energy warms the earth’s surface which then emits long wave thermal/infrared radiation which our atmosphere can absorb.
Angle of inclination?
The energy received at 30° is spreading over greater surface area.
At high latitude surface receives lower level of insolation.
The heat equator and the ITCZ
Heat Equator shows areas of maximum temperature on earth.
Low pressure dominates due heating to give Equatorial Trough.
Convergence and thunderstorms occur along the ITCZ.
Low level insolation - ice and snow
Sun’s energy mostly reflected by ice and snow.
Used in melting or evaporation processes.
Water
Reflects some energy and absorbs rather than radiate into atmosphere.
Used in evaporation process.
Slow to heat, and slow to cool (high specific heat capacity).
High level insolation - solid surfaces
Sun’s energy easily absorbed and re-radiated by solid surfaces.
Quick to heat and cool (low specific heat capacity).
What is vegetation?
Sun’s energy absorbed and used in growing process.
Some energy re-radiated into atmosphere.
Diurnal variation of temperature?
Hottest time of day - 2hrs before local noon.
Coldest - 30 min after sunrise.
Temperature range reduced by cloud cover or wind (not as hot, not as cold as a clear day)
Winter - warmer seas, colder land
Summer - warmer land, colder seas
Factors affecting insolation:
Seasons
Latitude
Surface type
Reflectivity of surface (albedo)
Reflectivity of cloud
