EEB 3408W Lecture Notes - Lecture 18: Dendrochronology, Thermometer, Longwave
11 Apr 2017
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Document Summary
Long term = decades to centuries to millennia. What is the response of communities to past environmental fluctuations. Allos climatic record of 8000 -12000 years. Heavier water condense first and precipitates faster than lighter water isotopes. More energy needed to vaporize heavier isotopes. Equilibrium concentrations of the isotopes changes with temperature. Oceans will be relatively rich in heavier o when glaciers grow and hold precipitated lighter o. Heavier o content of ocean water is lower during warmer periods. Coral reefs indicate ocean level which varies with volume of glacial ice and temperature. 5-10000 years of glacial periods, 10-20000 year interglacial. Warming climate for last 20000 years and fluctuations between. Current climate is less cold and dry. Heat waves can cause drought and crop shortfall. Few degree change can have large effect on organisms. 11 year sunspot cycle affects solar radiation amount. Earth wobbles on axis that change distribution.
