The Atmosphere
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X. Human Impact on Atmospheric Energy: Human can alter the energy balance and thus the temperature of the atmosphere over different space and time-scales by deliberate or unconscious action with beneficial or harmful results. The energy balance is altered by: - changing the nature and composition of the atmosphere; and - altering the character of the earth's surface. The urban heat island effect can be explained in part by atmospheric change through heat release and pollution emission from city areas. The heat storage capacity and dry surface character of city structures also contribute to the urban heat island effect. Increased anthropogenic (man-made) accumulations of carbon dioxide have been implicated as a potential cause of global warming. Such warming may enhance aridity in the mid-latitudes and cause rising sea levels due to glacier melt. Particulate emission, whether by natural or anthropogenic means, may contribute to a global cooling effect. Human modification of the earth's surface albedo, in particular by desertification, may also be responsible for planetary cooling. Table below shows the typical climatic changes caused by urbanization. Typical climatic changes caused by urbanization Type of change Comparison with rural env. Temperature Annual mean 0.5-1.0oC higher Winter mean 1.0-3.0oC higher Relative humidity Annual mean 6 % lower Winter 2 % lower Summer 8 % lower Dust particles 10 times more Cloudiness Cloud cover 5 - 10% more Fog, winter 100 % more frequent Fog, summer 30 % more frequent Radiation Total on horizontal surface 15-20 % less Ultraviolet, winter 30 % less Ultraviolet, summer 5 % less Wind speed Annual mean 20 -30 % lower Extreme gusts 10 -20 % lower Calms 5 - 20 % more Precipitation Amounts 5 - 10 % more Days with over 0.5 cm 10 % more Directory: subject subject -> A bibliography of Literary Theory, Criticism and Philology subject -> K 11: History of belief in the uk (2) subject -> 4. lab meeting times, places: S. 9: 30-11 (Lab 65) subject -> Progression in writing and the Northern Ireland Levels for Writing a research review undertaken for ccea by David Wray and Jane Medwell University of Warwick March, 2006 Contents subject -> Significant patterns subject -> Course Title Code / No subject -> Diploma in Law Download 3.83 Mb. Share with your friends:
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