Investigation of forest fire impact on atmospheric aerosol on satellite data

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As a result of forest fires enormous mass of combustion products, a mixture of different gases, carbon
compounds, aerosol particles, is emitted that have a significant impact on physical and chemical processes in
the atmosphere.
Investigation of variations of aerosol optical thickness (AOT) depending on the level of pyrogenic activity
was conducted on AVHRR (NOAA) and MODIS (Terra, Aqua) data. On the territory of Prilenskoye plateau
(Central Yakutia) a research area located in sector 600-640 N and 1200-1320 E was selected. From north
(partially), east and south the investigated area is surrounded by mountains of Verkhoyanskii and Stanovoy
ridges that impede horizontal removal of injected smoke particles away from the research area.
Data for the period May–September 2000–2009 were processed. Forest fires regular monitoring on the
territory of Yakutia, carried out since 1998 on the data of NOAA satellites, show that during 2001-2003 extremely
high level of pyrogenic activity was observed with the maximum in 2002. On the contrary, 2000 and 2004-2009
were marked as years with extremely low level of pyrogenic activity. Corresponding graphs of variations of mean
month values of "fire" pixels and AOT for the years with high (2001-2003) and low (2000, 2004-2009) pyrogenic
level were drawn.
In general, preliminary analysis of satellite data for the period May-September, 2000-2009 shows that forest
fires have a great impact on aerosol component of the atmosphere, thus forming seasonal increase in values of
AOT in July-August. On several days (2002) with the highest level of pyrogenic activity mean daily values of
AOT on the selected area (central Yakutia) significantly exceeded background (undisturbed) values, reaching
1,5-1,6. AOT values in some cells (1x1 degree) of a mean daily map reached 4,9.
This work was supported by Presidium RAS Program №16/3.