Moisture
states of water: solid, liquid, vapor, melting, evaporation, sublimation, freezing, condensation, deposition
absolute humidity - mass of water in a given volume of air (gm/m3); vapor content of air
relative humidity - Temperature dependent (as T increases, relative humidity decreases; as T decreases, relative humidity increases)
amount of vapor x 100
max. capacity
dew point when RH = 100% air reaches saturation and condensation overwhelms evaporation, measures the amount of moisture in the air
clouds: adiabatic cooling, as air rises, it encounters lower pressure and expands and temperature decreases, relative humidity increases, if RH=100% condensation occurs and clouds form
Causes of uplift- convectional (warm air rises), orographic lifting , frontal lifting, convergence
classification of clouds: cirrus, stratus, cumulus, cumulo-nimbus, lenticular
Precipitation: rain, snow, sleet, hail
Explain relative humidity. How is it calculated? What is its relationship to dew point? Explain how relative humidity can be raised or lowered.
Be able to interpret the graph of water vapor content vs. temperature. (homework) Be able to determine the vapor capacity of air at a given temperature, to calculate the relative humidity given temperature and vapor content, to determine the dew point if given vapor content, and to use dew point to determine vapor content.
Describe how uplift and adiabatic cooling causes clouds to form. Describe the main types of clouds.
Describe the four main ways of causing the initial uplift of air masses. What type of clouds are associated with surface heating and convection? What type of clouds are associated with orographic lifting? Why do cumulonimbus clouds often have a flat top at the base of the stratosphere?