GEG 1301 Lecture Notes - Lecture 8: Cloud Condensation Nuclei, Fluid Parcel, Global Dimming

• School: University of Ottawa
• Department: Geography
• Course: GEG 1301
• Professor: Denis Lacelle

Document Summary

The vast majority of water transfer occurs over the oceans. The lowest amount of water transfer is from runoff and groundwater flow. Evapotranspiration encompasses all the transfer of moisture from land to atmosphere. Evaporation occurs when water is available, sufficient energy is present, and the air has the capacity to transport vapour (unsaturated) Actual evaporation is almost never equal to the potential evaporation (can"t be more) There has been a general downward trend in annual evaporation. Caused by global dimming, the reduction on solar radiation received at the earth"s surface (caused by increased industrial emission of aerosols) For condensation to occur the air must be at/near saturation and the presence of a condensation nuclei. Size of nuclei range from 10-3 to 10 m. Simplest way to increase the saturation of an air mass is by cooling it. Cooling can occur as the air mass rises or at the grounds surface.