cc: "francis.zwiers@ec.gc.ca" date: Mon Apr 18 08:01:43 2005 from: Phil Jones subject: RE: Global warming to: Francis Zwiers , "Fudge, Dennis WLAP:EX" Dennis, Hopefully Francis' colleague will be able to answer. I am also not qualified to answer. Cheers Phil At 21:16 15/04/2005, Francis Zwiers wrote: Hi Dennis, I do not have the expertise to respond to this question, but I will pass it onto a colleague (an expert on aerosols) who may be able to respond. Cheers, Francis At 14:07 14/04/2005, Fudge, Dennis WLAP:EX wrote: Sorry to bother you, considering your positions, but I thought if anyone had an answer for this, you two would be the best bet. The following web pages are articles on the transport of black soot to the arctic which melts the snow and causes global warming, in which I assume you are already aware of this event. [1]http://www.nasa.gov/vision/earth/environment/arctic_soot.html [2]http://www.cleanairnet.org/caiasia/1412/article-59690.html Now the question of the day..... Does this black soot increase or decrease the rate of fresh snow melting? Based on what you were learn in school this answer is quite obvious. But, the albedo of the ultraviolet light on fresh snow is high, and low for infrared/microwaves. Based on Oke, 1987, a reverse exist for soil and vegetation. Which is responsible for melting snow, short waves or long waves? Also, the top portion of soot on top of the snow only heats up (I believe soot has a low conductivity) and that heat may rise into the air rather than being transfer to the snow. I am not certain how efficient that would be when dealing with very fine particles. During the spring, I have seen black particles on snow but the clean snow surrounding it seem to be melting faster. Polar bears, arctic foxes and many other resident arctic and Antarctic animals have white coats. They actually absorb more heat from the sun and surrounding environment than darker-colored objects. Which could be due to microwaves generating more heat than ultraviolet wavelengths. Oke also stated that the maximum absorption of radiation is just below the surface during the day which would be the site of maximum heating and highest temperature. Coating the surface with fine soot may interfere with this heating. Most people don't question this because it seems too obvious to question (Black surface in the summer is hotter than a white surface). Perhaps at high solar radiation intensity the short waves are the dominant factor and at low solar radiation the infrared is the dominant factor. I am not saying that this theory is correct but it may be worth looking at further, if it have not already been examined. Dennis Fudge Air Pollution Meteorologist Ministry of Water, Land and Air Protection 250-565-4210 If you woke up breathing, congratulations! You have another chance! ___________________________________________________________ Francis Zwiers, Chief Canadian Ctr for Climate Modelling and Analysis Meteorological Service of Canada c/o University of Victoria PO Box 1700, STN CSC Victoria, BC V8W 2Y2 Phone: (250)363-8229 Fax: (250)363-8247 Web: [3]http://www.cccma.bc.ec.gc.ca Prof. Phil Jones Climatic Research Unit Telephone +44 (0) 1603 592090 School of Environmental Sciences Fax +44 (0) 1603 507784 University of East Anglia Norwich Email p.jones@uea.ac.uk NR4 7TJ UK ----------------------------------------------------------------------------