ATM S 111 Lecture 2: Global Warming Rain Responses

• School: UW
• Department: Atmospheric Sciences
• Course: ATM S 111
• Professor: Casey Cathlee Hilgenbrink

Document Summary

Increased evaporation => drier land: a warmer atmosphere is like a bigger sponge. Simply because warmer air holds more moisture: big demand for water from the atmosphere, there"s a lot of uncertainty about specific precipitation responses though, regional responses could change significantly due to shifts in rising motion. Small shift can make a big difference for rainfall: precipitation is much harder to predict than temperature. Locations where heavy rain is changing disproportionally (i. e. not just due to changes in average precipitation) Are floods increasing: extreme flood events should increase with increased heavy rain, trends in the frequency of flood events are difficult to quantify because, rare evets, especially when considered season-by-season. It"s difficult to establish statistical significance when dealing with rare events: hourly rainfall data are available only over limited regions of the globe, river configurations and land use are continually changing. Forests prevent flooding: less runoff, less erosion when trees are present.