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Dr. Nickolay Krotkov
Deputy Aura Project Scientist


Dr. Nickolay A. Krotkov has over 30 years experience in radiative transfer, remote sensing observations, retrieval algorithm development, data analysis and research in the field of atmospheric composition (gases and aerosols). His Ph. D work in oceanography included radiative transfer modeling of the polarization effects of the solar radiation in the atmosphere-ocean system, as applied to passive spectral and polarization remote sensing of the atmospheric aerosols and water quality. Since 1993 he works with NASA Goddard Space Flight Center scientists to improve retrievals and understanding of Earth’s gas species such as sulfur dioxide, nitrogen dioxide, ozone and aerosols using remote sensing observations from satellite platforms and ground. His experience in radiative transfer and retrievals has led to algorithms for operational satellite data production. He developed first satellite algorithm for mapping surface UV irradiance from TOMS ozone and reflectivity data, which was adopted by the Finnish Meteorological Institute (FMI) for the Ozone Monitoring Instrument (OMI) production data (2004-current). In 2004 he developed a passive remote sensing method that led to discovery of enhanced column UV aerosol absorption due to organic aerosol. In part through his work absorbing aerosols (e.g., “brown” organic carbon) are now recognized as key to a complete understanding of surface UV radiation and atmospheric photochemistry. He developed a first operational OMI algorithm for retrieving sulfur dioxide from volcanoes and anthropogenic pollution and serves as principle investigator for the OMI volcanic and pollution sulfur dioxide products. Dr. Krotkov’s empirical and theoretical analysis of the sulfur dioxide data has led to quantification of passive emissions from active volcanoes and of anthropogenic pollution sources affecting air quality in North America, Europe, Russia, Chian, and India. Satellite volcanic SO2 data are now used in near real-time for detection of aviation hazards. In 2008 he developed an improved multiangle UV algorithm to derive vertical profile of ozone from ground based Brewer spectrometer data. Since 2010 he serves as PI for the OMI operational NO2 data. He demonstrated the great value that satellite sulfur dioxide and nitrogen dioxide data have in remotely identifying and quantifying point sources of emissions to the atmosphere. He is currently member of NASA Aura. EV-I TEMPO and DSCOVER/EPIC science teams, and disasters response team.