Atmospheric Moisture and Stability Current Weather Humidity Adiabatic

Atmospheric Moisture and Stability Current Weather Humidity Adiabatic Processes Atmospheric Stability Return and Go Over Exam I For Next Class: Read Chapter 6: pp. 167 -181

Humidity What are some common measures of water vapor in the atmosphere and what do they mean?

Water Vapor in the Atmosphere Relative Humidity Compares the actual amount of water vapor in the air with the amount of water vapor that would be present if that same air were saturated Expressed as a percentage When air is saturated, relative humidity is 100% Varies inversely with temperature © AMS 6

Relative Humidity Figure 7. 8

Water Vapor in the Atmosphere Vapor Pressure produced by the gas molecules composing air depends on mass of the molecules kinetic molecular activity © AMS 8

Specific humidity: grams of water vapor per kilogram of air (g/kg) Absolute humidity: grams of water vapor per cubic meter of air (g/m 3) Source: Wikipedia

Precipitable Water Depth of water that would be produced if all the water vapor in a vertical column of air were condensed into liquid water © AMS 10

Dewpoint The dewpoint is the temperature at which dew forms and is a measure of atmospheric moisture. It is the temperature to which air must be cooled at constant pressure and water content to reach saturation. Source: Wikipedia

Wet Bulb Temperature The wet-bulb temperature is the temperature a parcel of air would have if it were cooled to saturation (100% relative humidity) by the evaporation of water into it, with the latent heat being supplied by the parcel. Critical temperature for snowmaking at ski resorts Source: Wikipedia