EESA09H3 Lecture : lec 9
13 Dec 2011
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Document Summary
First noted in the 1950"s by aircraft pilots. Sinks are likely the arctic ocean and surrounding waters. Constituents: sulphate levels 10 to 20 times larger, which is greater than normal (vanadium detected, mixed with uncombusted carbon to form aerosol which blocks light and appears grayish or brownish in colour. 90% sulphate, remainder is soot (carbon), dust: coal burning the major culprit. Trace metals (vanadium, manganese) indicate sources: trace constituents such as metals and persistent pops can adhere to the aerosols and pool in the arctic. 1972 glen shaw: suggested long range transport as likely mechanism for source of arctic. Global circulation carries in pollutants from industrialized parts of the globe. Why do they pool in the arctic: stable atmosphere; temperature inversion. Little precipitation (no washout: circumpolar circulation, major source is eurasia. Seasonal cycle on vertical distribution of arctic haze: burrow, alaska. Impacts: reduced visibility, especially in spring, contamination of snow, ice and arctic waters, bioaccumulation.
