Exceptional emissions of NH₃ and HCOOH in the 2010 Russian wildfires

Abstract

Abstract. In July 2010, several hundred forest and peat fires broke out across Central Russia during its hottest summer on record. Here, we analyze these wildfires using observations of the Infrared Atmospheric Sounding Interferometer (IASI). Carbon monoxide (CO), ammonia (NH3) and formic acid (HCOOH) total columns are presented for the year 2010. Maximum total columns have been observed reaching over 40 (for CO and HCOOH) and 200 (for NH3) times higher than typical background values. The temporal evolution of NH3 and HCOOH enhancement ratios relative to CO are presented. Strong evidence of secondary formation of HCOOH is found, with enhancement ratios exceeding 10 times reported emission ratios in fresh plumes. We estimate the total emitted masses for the period July–August 2010 over the center of Western Russia; they are 19–33 Tg (CO), 0.7–2.6 Tg (NH3) and 0.9–3.9 Tg (HCOOH). For NH3 andHCOOH, these quantities are comparable to what is emitted in the course of a whole year by all extratropical forest fires.