Clouds and Precipitation Pressure and Wind Stability of Atmosphere Air rises due to a number of factors Expands as it rises cools as it does so Can calculate the new temperature Use the adiabatic lapse rate Dry for unsaturated Wet for saturated Compare the temperature of the air that has risen to the temperature of the air at that height Use the environmental lapse rate Higher density air that has risen is stable cooler Lower density air that has risen is unstable warmer Stable conditions Stability Environmental lapse rate 5 C 1000 m Dry adiabatic lapse rate 10 C 1000 m Rising g air is cooler than area it rises into Stable Absolute instability Stability Environmental lapse rate 12 C 1000 m Dry adiabatic lapse rate 10 C 1000 m Rising g air becomes warmer than area it rises into Unstable More unstable upon reaching dew point Conditional stability Surface inversion Note the environmental temperature is cool at the surface increases for some distance then decreases at greater height Inversion aloft These inversions are stable because the warmer air is buoyant over colder surface LA Basin Inversion Inversion Layer Layer Los Los Angeles Cloud Development Air cools upon rising Cools to dew point dew point temperature Condensation begins Lifting condensation level Cloud Shapes Cirrus curl of hair thin wisps Stratus Stratus blanket blanket extensive layers Cumulus pile puffy masses Additional modifier of name Nimbus rain Cumulonimbus puffy rain clouds Nimbostratus layered rain clouds Cloud Groups High clouds 6000 m or more above surface Middle clouds 2000 clouds 2000 m to 6000 m above Low clouds less than 2000 m above surface Clouds of vertical development Present through more than one level Product of atmospheric instability cirrus Cirrocumulus Cirrostratus Altocumulus Altostratus Nimbostratus Cumulus Cumulonimbus Cloud classification classification left left Cloud classification classification right right Fog Golden Gate Bridge Fog Golden Fog Tule Fog Fog Tule Condensation in clouds Bergeron notes Bergeron Process of ice crystal growth Collision coalescence Glaze ice Giant hailstone Hail damage Rime ice Pogonip http grannysatticquilts com pogonip html Precipitation measurement http www ptguide com weather index html Precipitation Map of Washington Weather radar display Windfarm in California Hurricane at Corpus Christi Mercury Barometer Aneroid Barometer Aneroid Barograph Isobars No Coriolis Effect Coriolis Effect Geostrophic Winds 500 millibar altitude chart Ridge and trough of 500 mb Upper level wind Surface Wind Cyclonic and anticyclonic winds Cyclonic circulation northern hemisphere Cyclonic winds southern hemisphere Vertical Airflow around cyclonic anticyclonic winds
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