JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 99, NO. D9, PAGES 18,627-18,638, SEPTEMBER 20, 1994 Satellite analysis of the severe 1987 forest fires in northern China and southeastern Siberia Donald R. Cahoon Jr. Atmospheric Sciences Division, NASA Langley Research Center. Hampton, Virginia Brian J. Stocks Forest Fire Research. Forestry Canada, Ontario Region, Great Lakes Forestry Centre. Sault Saintc Marie Ontario, Canada Joel S. Levine, Wesley R. Cofer III, and Joseph M. Pierson Atmospheric Sciences Division, NASA Langley Research Center. Hampton, Virginia Abstract. Meteorological conditions, extremely conducive to fire development and spread in the spring of 1987, resulted in forest fires burning over extremely large areas in the boreal forest zone in northeastern China and the southeastern region of Siberia. The great China fire, one of the largest and most destructive forest fires in recent history, occurred during this period in the Heilongjiang Province of China. Satellite imagery is used to examine the development and arcal distribution of 1987 forest fires in this region. Overall trace gas emissions to the atmosphere from these fires arc determined using a satellite-derived estimate of area burned in combination with fuel consumption figures and carbon emission ratios for boreal forest fires. Introduction Recent concern over the impact of biomass burning on global atmospheric chemistry has resulted in increased re search, particularly in the tropics where biomass burning is most extensive [Cnilzen el al., 1979; Andreae, 1991]. Inter national projects arc addressing this major environmental issue, with initial emphasis on savanna burning in southern Africa and deforestation burning in Brazil. However, large areas of the world's boreal forest zone, which natural fire has shaped over millennia, are also burned annually. Industrial and recreational use of the boreal forest has increased dramatically over the past century, along with forest fire suppression capabilities. However, periodic extreme fire weather events ensure that fires will continue to be common, fulfilling an essential role in boreal forests [Stocks, 1991]. The fires that developed in northeastern China and south eastern Siberia in the spring of 1987 are a recent example of this process. This study began as an investigation of the great China fire, which occurred in May 1987 in the Heilongjiang Prov ince of northeastern China, burning in excess of 1.3 million hectares of prime forest and resulting in the loss of over 200 lives and 50,000 homes [Cahoon el al., 1991]. From exami nation of satellite imagery pertaining to the development of the great China fire, it became apparent that extensive forest fire activity was concurrently under way across the border in Siberia, particularly in the area east of Lake Baikal between the Amur and Lena Rivers. The widespread fire activity was evidence that the meteorological conditions responsible for the rapid growth of the great China fire were not local phenomena, but extended over a large geographical area. As Copyright 1994by the American Geophysical Union. Paper number 94JD0I024. 0148-0227/94/94JD-01024SO5.00 a result, this study is expanded to chronicle the development and extent of forest fires in southeastern Siberia during 1987. National Oceanic and Atmospheric Administration (NOAA) advanced very high resolution radiometer (AVHRR) and Defense Meteorological Satellite Program (DMSP) satellite imagery is used to document fire occur rence and growth and to estimate the arcal extent of burning. The general climatology of the region is examined, and trace gas emissions to the atmosphere are derived. Regional Climatology The climate in the extreme northeastern region of China and in southeastern Siberia is continental cold-temperate, with long, cold, dry winters and short, warm, humid sum mers. The region is dominated by the Asiatic high in the winter, which forms over the Lake Baikal region and blocks the progression of winter storms. The infrequency of winter storm passages produces relatively little precipitation, with most of the region receiving less than 5 mm. As spring approaches and warming begins, the Asiatic high breaks down and storm passages occur in rapid succession from west to east. These storms (and frontal systems) bring strong winds and little precipitation. At the same time that storm frequency increases, temperature rapidly increases and hu midity remains low. This combination of conditions leads to the drying of forest fuels, creating a prime situation for fire development. In the summer months the frequency of storm passages decreases, but the storm intensity increases. The greater amount of precipitation associated with the stronger storms reduces the fire hazard. With the cooling of autumn the behavior of the spring storms is repeated, but the storms lack the intensity and strong winds common in spring. Although smaller fires occasionally occur, they do not create a control problem. By November the Asiatic high has 18.627