With dozens of forest fires burning in Russia’s Irkutsk region, authorities have declared a state of emergency.
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this image on May 18, 2014. The red outlines indicate hot spots where MODIS detected unusually warm surface temperatures associated with fires. The image is centered at 56.76 degrees North and 105.47 degrees East.
Some of the blazes likely began on farms but then spread into forests due to high winds and warm temperatures. MODIS began to detect small fires in Irkutsk on May 14. Many were along rivers near farmland. After burning at a moderate level for a few days, the size and intensity of the fires increased significantly on May 18.
The St. Petersburg Times reported that 77 fires had burned more than 39,000 hectares (150 square miles) in Irkutsk by May 19. Fire destroyed 22 homes in the village of Dalny and forced the evacuation of hundreds of people, according to the Russian Emergencies Ministry (EMERCOM).
In addition to producing thick plumes of smoke, the fires fueled numerous pyrocumulus clouds—tall, cauliflower-shaped clouds that billowed up above the smoke. Pyrocumulus are similar to cumulus clouds, but the heat that forces the air to rise—which leads to cooling and condensation of water vapor—comes from fire instead of sun-warmed ground. In satellite images, pyrocumulus clouds appear as opaque white patches hovering over darker smoke.
The Irkutsk fires triggered the first confirmed pyrocumulus clouds of the 2014 fire season in the northern hemisphere, according U.S. Naval Research Laboratory meteorologist Mike Fromm. Meteorologists monitor pyrocumulus because the clouds can pump smoke and pollutants high into the atmosphere, get dispersed by winds, and affect air quality over a broad area. On May 19, MODIS observed smoke from Irkutsk wildfires mixing with clouds and moving northeast. A preliminary analysis of data acquired by the Multi-Angle Imaging SpectroRadiometer (MISR) on NASA’s Terra satellite suggested the smoke had reached between 11 and 12 kilometers and was moving about 140 kilometers (87 miles) per hour.
References & Resources
- CIMSS PyroCb (2014, May 18) PyroCb in the Irkutsk region of Siberia. Accessed May 19, 2014.
- Emercom of Russia (2014, May 19) Fire in village of Dalny, Nizhneilimsky District, Irkutsk Region put out. Accessed May 19, 2014.
- Fromm et al (2010, September) The Untold Story of Pyrocumulonimbus. Bulletin of the American Meteorological Society, 91, 1193-1209.
- ITAR-TASS (2014, May 18) Emergency fire regime declared in Siberian region. Accessed May 19, 2014.
- U.S. Naval Research Laboratory (2010, August 27) NRL Scientist Seeing Clearly the Effects of Pyrocumulonimbus. Accessed May 19, 2014.
- Ozone Mapping & Profiler Suite blog (2014, May 19) Pryocb Event Over Russia. Accessed March 19, 2014.
- St. Petersburg Times (2014, May 19) State of Emergency Declared in Irkutsk Region Due to Fires. Accessed May 19, 2014.
- Tom Yulsman’s ImaGeo blog, via Discover (2014, May 5) Russian Wildfires Blaze on an Area Larger than Los Angeles. Accessed May 19, 2014.
NASA images courtesy of the LANCE/EOSDIS Rapid Response team. Caption by Adam Voiland, with information from Mike Fromm (Naval Research Laboratory) and David Nelson (Jet Propulsion Laboratory).














