Energy Transfer Conduction, Convection, Radiation Global Warming

Thermal Conduction Materials in _________ ________ _____________ energy transferred by atoms and free electrons Metals are _________ thermal conductors Gases are _______ thermal conductors ____ of energy transfer depends on material Fig. 11.5, p. 366 L

Home Insulation In U.S. units are BTUs, feet,  F, hours Compound slabs use __ ______ Thin layer of _________ air at surfaces also insulates Rate of heat transfer given by

Convection Transfer of energy by ____________ of substance Natural convection – movement from _______ differences Forced convection – movement by ____ or _____ Fig , p. 371

Radiation ______________ waves from thermal vibration of molecules carry energy Characterized by – object’s ___________, e – Stefan-Boltzmann constant,  – Surface _______, A Can also _____ radiation

Global Warming and Greenhouse Effect Some gases transmit _______ light, _______ infrared light (like glass of greenhouse) CO 2, CH 4, N 2 O, SO 2 Leads to ______ surface temperature (properly called the atmospheric effect) Too little  ________ changes in temp. (Mars) Too much  ________ high temp. (Venus) Seeds, Foundations of Astronomy, p. 490

Wolff, E., et al. (2005), Modeling past atmospheric CO 2 : results of a challenge, EOS 86(38), pp. 341, 345 Predictions based on marine sediments (1); deuterium, dust, deep ocean carbonate dissolution, calculated insolation (2); insolation only + model of ice formation (3); and deuterium levels (4) Four predictions of Earth’s CO 2 History

Wolff, E., et al. (2005), Modeling past atmospheric CO 2 : results of a challenge, EOS 86(38), pp. 341, 345 CO 2 : Measured from ice core samples from Antarctica Minima are _______ periods; maxima are ___________ periods

Graedel, T.E. and P.J. Crutzen (1993), Atmospheric Change: An Earth System Perspective, p. 255, W.H. Freeman and Company, New York. CO 2 measured at Mauna Loa Observatory along with fossil fuel emissions Deforestation

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