Model estimations of Siberian strong fires effect of atmosphericcomposition and regional climate during 2002-2003 warm periods

摘要

The strong large scale fires due to hot weather over the Siberia during the 2002-2003 warm seasons were recorded.They caused a substantial intensification of atmosphericpollution by various combustion products,including CO,NOX = NO + NO2,numerous aerosol types.Increase of North Asia CO emission is estimated by～30 - 70%in warm seasons of 2002 and 2003 due to above mentioned fires.The GOME measurements of NO2 vertical tropospheric column over China (30-40 2 40oN,110-123 oN,123oE) show its significant growth after 2000-2001 reaching 15-40% in various months.The above data are adapted for our study.The comparison of model variants with andwithout this additional source is carried out.The largest response of atmospheric compositionto Siberian fires is near the pollution sources location in August 2003 when thesurface concentrations increase for CO and Nox by 66 and 40% respectively.Their growth caused the OH content decrease by 12-14% and the ozone concentration increaseby 10-16%.The eastward transport of CO causes the CO content growth by 25-30%over the Pacific and about 20% near the western coast of North America.The obtained model distribution of species content is used further for radiative forcingcalculation due to the Siberian forest fires consequences.According to our analysis therelevant radiative forcing does exceed a few hundredths W/mm2 near the pollution sourcesand much less within remote regions.