Latitude Flashcards
Why does insolation vary with latitude
Because of variations in day length and the angle of incidence of the sun’s rays
Length of daylight hours
Tropics = little seasonal difference in the length of day and night
Varied at poles
The length of night and day varies gradually with latitude
Why are the polar regions cold during the dark winter months
Because heat energy from the sun can old be received during the hours of daylight
Why is the sun less concentrated outside the tropics (angle of incidence)
The angle of the sun is lower and the suns rays travel a greater distance through the earth’s atmosphere, losing energy. On reaching the surface each ray heats up a larger area than in the tropics so the suns energy is less concentrated
What is the adiabatic lapse rate
The temperature change with height for a parcel of air that has no exchange of heat or moisture with the air surrounding it
What are the three different types of adiabatic lapse rates
Environmental lapse rate
Dry adiabatic lapse rate
Saturdays adiabatic lapse rate
What is the environmental lapse rate (ELR)
The change of temperature with height, within the atmosphere. The average value of the ELR is 6.5 degrees Celsius for every 1,000m (but this varies)
What is the dry adiabatic lapse rate
When the air is dry (not become saturated by cooling to its dewpoint), it’s temperature changes at the adiabatic lapse rate (DALR) or 1 degree Celsius per 100m
What is the saturated adiabatic lapse rate (SALR)
One air is saturated it’s temperature changes. This is lower than the DALR because when air reaches 100% humidity condensation releases latent heat. This process offsets the normal decrease of temperature with height and the rate at which temperature varies with altitude is taken to be 0.5 degrees Celsius per 100m.
