Transcript Chapter 18
Chapter 18 • Characteristics of water… • Frozen water = ice • Liquid water = water • Water as a gas = water vapor • Melting • Evaporation • Condensation • Sublimation • Deposition • Freezing • Ice to water • Water to water vapor • Water vapor to water • Ice to water vapor • Water vapor to ice • Water to ice • Humidity • Specific humidity • Relative humidity • Water vapor in the air • The grams of water in the air (not really used) • The % of water vapor in the air • If the humidity is 50%……… • Warm air holds MORE moisture than cold air • Then the air is “holding” 50% of what it can possibly hold • What happens at 100% humidity? • Condensation (NOT RAIN!!!) • Psychrometer • Measures the humidity in the air • Dew • Dew Point • Water vapor that has condensated on the ground • The temperature at which the air can no longer “hold” the water vapor and it condenses on the ground • Condensation nuclei • Dust or small particles floating in the air that water vapor will condense on …helps to form fog • Frost • When the dew point is below freezing, water vapor DEPOSITS on the ground as frost………..it is not frozen dew • Sublimation……… • When there is frost on the ground and the temperature rises above freezing, the frost SUBLMATES straight to water vapor • Fog • Radiation fog • Advection Fog • A low cloud • Clear night, warm ground loses heat to the cool air……especially over a body of water • Moist, warm air blows over a cool surface (like a fog over snow) 18.2 – Types of Clouds • Clouds • A collection of cooled water at any level of the troposphere • • • • Stratus Cumulus Nimbus cirrus • • • • Sheets/layers Puffy Rain Wispy/horse tails (very high and mostly ice) • cumulonimbus • Thunderstorm cloud • Anvil shaped • Formation of clouds occurs at the condensation level…. • Air is cool enough for the water vapor to condense and begin to form clouds 18.3 Precipitation • Rain • Hail • Freezing Rain • Sleet • Snow • Water • Only from t-storm clouds (Ice) • Rain that freezes when it contacts the earth’s surface • Ice • Crystallized water Windward vs. Leeward • Windward • Leeward • Rising airs cools, condensates in a clouds then precipitates…………. • Dry - desert