The Impacts of Smoke Emitted from Boreal Forest Wildfires on the High Latitude Radiative Energy Budget—A Case Study of the 2002 Yakutsk Wildfires

• Published in: Atmosphere Vol. 9; no. 10; p. 410
• Main Authors: Lu, Zheng, Sokolik, Irina
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 19.10.2018
• Subjects: Aerosol effects; Aerosols; Atmospheric models; Biomass; biomass burning aerosols; Boreal forests; Budgets; Burning; Case studies; Climate; Cloud condensation nuclei; Cloud formation; Cloud water; Clouds; Computer simulation; Condensation nuclei; Cooling; Cooling effects; Datasets; Decks; Energy; Energy budget; Fires; Fluxes; Ice nuclei; Latitude; Mesoscale phenomena; Meteorological conditions; Meteorological satellites; modeling; Modelling; Nucleus; Plumes; Precipitation; Radiation; Radiation budget; Rain formation; Satellites; Simulation; Smoke; Smoke particles; Smoke plumes; Wildfires; United States > US; Siberia; Russia
• ISSN: 2073-4433; 2073-4433
• DOI: 10.3390/atmos9100410

We examine the 2002 Yakutsk wildfire event and simulate the impacts of smoke aerosols on local radiative energy budget, using the WRF-Chem-SMOKE model. When comparing satellite retrievals (the Surface Radiation Budget (SRB) dataset) with model simulations, we found that the agreement is generally good, except for the regions where the model predicts too few clouds or SRB misclassifies strong smoke plumes as clouds. We also found that the smoke-induced changes in upward shortwave fluxes at top of atmosphere (TOA) vary under different burning and meteorological conditions. In the first period of the fire season (9–12 August), smoke particles cause a warming effect around 3 W/m2, mainly through functioning as ice nuclei, which deplete the cloud water amount in the frontal system. At the beginning of the second period of the fire season (19–20 August), large amounts of pre-existing smoke particles cause a strong cooling effect of −8 W/m2. This is offset by the warming effect caused by relatively small amounts of cloud condensation nuclei increases, which promotes the rain formation and depletes the cloud water amount. After the cloud decks are well mixed with smoke plumes (21–22 August), the first indirect and direct effects of smoke together lead to a cooling of −10 W/m2. These results highlight the importance of meso-scale modeling efforts in estimating the smoke-induced changes in the radiative energy budget over high latitudes.