Sarah J. Doherty

Senior Research Scientist

Affiliate Associate Professor, Department of Atmospheric Sciences

BA in Physics (1988) from Colby College in Waterville, Maine

MS (1998) and PhD (2001) in Atmospheric Sciences from the University of Washington

Office: JISAO 141

Phone: 206-543 6674

Fax: 206-685-3397

Research Interests

Through her graduate and post-graduate studies Sarah has been very actively involved in research on atmospheric aerosols and how they affect climate. Aerosols are small particles suspended in the atmosphere that interact with sunlight, thereby reducing the amount of sunlight that reaches the surface of the earth and, when the particles are dark (i.e. gray, brown or black), heating the atmosphere. Sarah's research has focused on assessing the optical properties of aerosols from both natural and anthropogenic sources.

For seven years (2003-2010) Sarah was the Executive Officer of the International Global Atmospheric Chemistry Project where she combined her research efforts with organizing multi-national science initiatives, workshops and conferences. She left this position to return to full-time research at JISAO. Her recent research has focused on a certain type of aerosols, those containing "black carbon" (more commonly known as soot). Climate model studies indicate that black carbon in soot from biomass burning, biofuel burning, transportation and industrial activities warms climate by absorbing sunlight, thereby heating the atmosphere and, when deposited on snow and ice, it can accelerate snow and ice melt. Aerosols containing black carbon also affect clouds, by changing the thermodynamic structure of the atmosphere and by acting as cloud condensation nuclei.

Sarah and her colleagues in the University of Washington Dept. of Atmospheric Sciences conducted a pan-Arctic campaign to quantify the amount of soot and dust/soil in snow from samples across the Arctic. Model studies indicate that soot in snow is contributing to Arctic warming, and this data set is being used to improve estimates of this warming.  She has also collaborated with colleagues in China to made similar measurements across northern China and co-lead an expedition (winters 2013 & 2014) measuring soot in snow in the North American Great Plains region.

More recently her research has shifted back towards the atmosphere: She is a Flight Scientist on the NASA ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) project. ORACLES is using the NASA P3 and ER2 research aircraft to measure smoke from agricultural fires in central Africa. This smoke flows out over the southeast Atlantic ocean. It is known that the smoke affects climate, but the effect is poorly quantified. My making measurements over three years (2016-2018) and working with climate modeling teams to improve simulations of the smoke this project should improve our understanding of how this smoke is affecting regional and global climate.

Sarah has a particular interest in translating focused research into assessments that address overarching scientific questions of relevance to society. She is second Coordinating Lead Author on a multi-national 2013 paper, “Bounding the role of black carbon in climate: A scientific assessment”. She is one of the Lead Authors on the 2017 "National Climate Assessment Volume I: Climate Science Special Report", and she is currently Assessment Coordinator for the next Scientific Assessment of Ozone Depletion.

Current Activities

  • Flight Scientist on the NASA ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) project
  • Establishing collaborations between the observational and modeling communities to use use the ORACLES measurements to test and improve climate models
  • Using ORACLES measurements for analysis related to better quantifying direct radiative forcing by smoke from central African fires
  • Lead Author on the 2017 National Climate Assessment Volume I: Climate Science Special Report & Author on the 2018 National Climate Assessment Volume II: Climate Change Impacts, Risks and Adaptation in the United States
  • Assessment Coordinator, Scientific Assessment of Ozone Depletion: 2018

Selected Publications

Fahey, D.W., S. Doherty, K.A. Hibbard, A. Romanou, and P.C. Taylor, 2017: Physical drivers of climate change. In: Climate Science Special Report: Fourth National Climate Assessment, Volume I [Wuebbles, D.J., D.W. Fahey, K.A. Hibbard, D.J. Dokken, B.C. Stewart, and T.K. Maycock (eds.)]. U.S. Global Change Research Program, Washington, DC, USA, pp. 73-113, doi:10.7930/J0513WCR.

Tedesco, M., S. J. Doherty, X. Fettweis, P. Alexander and J. Stroeve, The darkening of the Greenland ice sheet: trends, drivers, and projections (1981–2100), The Cryosphere, 10, 477–496, doi:10.5194/tc-10-477-2016, 2016.

Doherty. S. J., C. Dang, D. A. Hegg, R. Zhang and S. G. Warren, Black carbon and other light-absorbing particles in snow of central North America, J. Geophys. Res. Atmos., 119, doi:10.1002/2014JD022350, 2014.

Yang, Q., C. M. Bitz, S. J. Doherty, Offsetting effects of aerosols on Arctic and global climate in the late 20th century, Atmos. Chem. Phys., 14, 3969-3975, doi:10.5194/acp-14-3969-2014, 2014.

Bond, T. C., S. J. Doherty, D. W. Fahey, P. M. Forster, et al., Bounding the Role of Black Carbon in Climate: A scientific assessment, J. Geophys. Res., 118 (11),5380-5552, doi:10.1002/jgrd.50171, 2013.

Wang, X., S. J. Doherty and J. Huang, Black carbon and other light-absorbing impurities in snow across Northern China, J. Geophys. Res., 118 (3), 1471-1492, doi:10.1029/2012JD018291, 2013.

Doherty, S. J., S. G. Warren, T. C. Grenfell, A. D. Clarke, R. Brandt, Light-absorbing impurities in Arctic snow, Atmos. Chem. Phys., 10, 11647-11680, doi:10.5294/acp-10-11647-2010, 2010.

Doherty, S. J., S. Bojinski, A. Henderson-Sellers, K. Noone, D. Goodrich, N. L. Bindoff, J. A. Church, K. A. Hibbard, T. R. Karl, L. Kajfez-Bogataj, A. H. Lynch, D. E. Parker, I. C. Prentice, V. Ramaswamy, R. W. Saunders, A. J. Simmons, M. Stafford Smith, K. Steffen, T. F. Stocker, P. W. Thorne, K. E. Trenberth, M. M. Verstraete, F. W. Zwiers, Lessons learned from IPCC AR4: Future scientific developments needed to understand, predict and respond to climate change, Bull. Amer. Met. Soc., 90(4), 497–513, 2009.

Doherty, S.J., P. Quinn, A. Jefferson, C. Carrico, T. L. Anderson, D. Hegg, A comparison and summary of aerosol optical properties as observed in-situ from aircraft, ship and land during ACE-Asia, J. Geophys. Res., 110, D04201, doi:10.1029/2004JD004964, 2005.