Amber J. Soja

Amber J. Soja

Senior Research Scientist

Tel: (757) 864-5603


Amber J. Soja


  • Ph.D., Environmental Sciences, University of Virginia, VA, 2004
  • B.Sc., Environmental Sciences, Department of Environmental Sciences, University of Virginia, 1997

Research Interests

  • Explore the dynamic relationships between fire regimes, weather and climate using ground-based, satellite and airborne data;
  • Elucidate fire-induced feedbacks to and from the biosphere, atmosphere, weather and climate systems to include: direct emissions, smoke plume injection height, radiative balance, and cloud, ice-snow and land-cover albedo change;
  • Partner with public and private organizations to work towards data use and applicability in an effort to improve air quality and our understanding of climate interactions to ultimately benefit humankind through enlightened mitigation via informed decision making by management, regulators and policy specialists; and
  • Investigate the human and climatic impacts of altered fire regimes and vegetation change as climate is altered, particularly at Northern Hemisphere upper latitudes, where climate is rapidly changing and is predicted to experience the greatest future change.

Recent Research

Climate- and Fire-induced Vegetation, Agricultural and Albedo Change in Northern Eurasia: Consequences to Gases, Aerosols and Radiative Fluxes: The objective of this research is to use an integrated approach to investigate the impact of changes in the terrestrial environment and biomass burning on the gas and aerosol particle composition of the troposphere, cloud cover, patterns of precipitation and the energy cycle. This will be done by: (1) simulating and verifying the current state of our understanding using two nested sets of ecological and chemical transport models (CTM), Surface Radiation Budget (SRB) data, and explicit biomass burning (BB) emissions that are linked to fire weather; and (2) by simulating and quantifying the affects of future changes in ecosystems, and BB, on the distribution of gases and aerosols in the troposphere, patterns of precipitation, and the ultimate influence of these changes on the energy cycle and climate system. BB and Land Cover Land Use Change (LCLUC) directly influence gas and aerosol particle distribution, which can alter patterns of precipitation, creating changes that can be persistent and regionally dispersed.  Recently, the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) field campaign found unexpectedly high levels of BB from extreme, early season fires in Siberia. It is likely this pattern will become more prevalent in the future due to increased and earlier fire seasons and climate- and fire-induced changes in ecosystems. In boreal regions, fire is the dominant disturbance that serves as a catalyst to move ecosystems more quickly towards a new equilibrium with climate.

This is a large-scale, interdisciplinary project is led by Dr. Amber Soja.  The global- and regional-scale CTM, Goddard Chemistry Aerosol Radiation and Transport (GOCART) and Weather Research and Forecasting (WRF-Chem), portion of this work is led by Dr. Mian Chin and Dr. Irina Sokolik, respectively, to investigate the impact of changes in BB and LCLUC on regional and global aerosol radiative forcing, surface radiative fluxes, sensible and latent heat fluxes, cloud cover, altered patterns of precipitation and modified transport pathways that may provide additional feedback mechanisms to the climate system (i.e. black carbon deposited on early season Arctic ice). Drs. Nadezda Tchebakova, Elena Parfenova, Jacqueline Shulman, and Herman H. Shugart are responsible for current and future vegetation modeling, which will be altered under current climate change scenarios, influencing the solar radiation budget, atmospheric chemistry, and patterns of precipitation.  Dr. Paul Stackhouse is leading the effort to understand related changes in the solar radiation budget due to cloud cover and vegetation change. Amber Soja, David Westberg and Paul Stackhouse are responsible for modeling historic and future fire regimes and emissions.

Using these models, Soja is investigating questions of scale, the potential influence of small-scale processes on regional and global phenomena. Soja’s team intends to focus on Northern Eurasia because this extremely continental region is predicted to and is currently experiencing some of the greatest temperature increases from climate change on Earth, and land cover and fire regimes are rapidly responding to that change.  This region has the size and carbon store necessary to influence regional and global feedbacks to climate change, and this is an understudied region.

Linking NASA Satellite Data and Science to Enhance Fire Emissions within the EPA’s National Emissions Inventory: Developing Agricultural/Rangeland Fire Emissions Estimates, Connecting Models to Plume Injection Height Data, and Verifying Modeled Emissions Estimates: This work focuses on the application of NASA’s Earth Science observations to support essential Environmental Protection Agency, Western Region Air Partnership, and other operational decision support tools concerned primarily with national Air Quality that includes connections to Climate and Agriculture. The decision support tools, the National Emissions Inventory (NEI), and Community Multiscale Air Quality (CMAQ) model, are used for numerous critical environmental management and policy activities including regulation setting and regional strategy development for attainment of National Ambient Air Quality Standards. This work is aligned with NASA’s strategic objectives regarding the use of NASA spacecraft- and aircraft-observations, in concurrence with coincident field missions to advance scientific and technological understanding, and applying this knowledge for societal benefit. The goal is to use satellite, aircraft and in-situ observations to enhance inputs to CMAQ with the ultimate goal of improving human health and the environment. Specifically, we are working towards: (1) Enhancing satellite-based fire data to improve fire emissions within the NEI, with a particular focus on poorly represented agricultural and rangeland fires. Soja’s team is using satellite and in-situ data to enhance an existing algorithm, produce and validate the product, and benchmark fire emission improvements to the NEI, which is an input to CMAQ and other chemical transport models; (2) Synthesize agricultural and rangeland fire research into a format usable by the Wildland Fire Emissions Information System (WF-EIS); and (3) Analyze CALIPSO data to build an injection height database that links fire behavior and fire weather to plume rise, validate the product using satellite-, aircraft- and in-situ data, and verify and enhance injection height within CMAQ. Soja’s team will continually interact within regional- and global- air quality and climate modeling communities to solicit requirements for plume rise applications. This work is led by Amber Soja and her colleagues: Duncan Fairlie, Nancy French, Jessica McCarty, Thomas Pierce, George Pouliot, James Szykman, and David Westberg

Integrating Historic Patterns of Wildfire, Emissions, and Climate for Siberia as a Basis for Estimating the Impacts of Fire on Carbon Cycling, Quantifying Past Fire/Climate Interactions, and Projecting Future Fire/Climate Change Impacts: Projecting future fire regimes and impacts of fire on carbon storage under a changing climate requires baseline data on fire activity that can be coupled with weather and emission data to quantify past fire effects. This project derives fire patterns, emissions, and a carbon balance in Siberia using historic dendrochronological data (multiple centuries) and current fire data (30-year record) to provide a basis for projecting the future effects of changing climate on fire patterns, emissions, and the carbon cycle. This project is led by Dr. Susan G. Conard and the co-investigators Amber Soja, Nadezda Tchebakova, Bill DeGroot, Brian Stocks, Don Cahoon, Douglas McRae, Evgenii Ponomarov, Alexandr Alexeyev, and Wei Min Hao will collaborate to analyze fire/climate/landscape interactions and to generate future projections of fire/climate interactions and the implications for future ecosystems, carbon cycle, and feedbacks to global warming. 

The influence of changing forestry practices on the effects of wildfire and on interactions between fire and changing climate in central Siberia: The Russian boreal zone is a region of global significance in terms of climate change impacts and carbon storage, but it is also a tremendous, largely untapped, reservoir of wood products. Both legal and illegal logging are increasing rapidly in many forest areas of Siberia. These logged areas often have extremely high fuel loads due to logging debris and typically experience higher severity fires than unlogged forests. The project will integrate data and models derived from field sampling with analysis of Landsat and MODIS imagery to enable extrapolation of fire effects and processes to a landscape level. The results will provide a basis for improved projections of impacts of climate change and land use patterns on burned area, fire severity, and carbon cycle. This project is led by Dr. Susan G. Conard and Amber Soja’s role is primarily to work with Nadezda Tchebakova to improve the large-scale understanding between wildfire and forestry.


  • Tchebakova N.M., Parfenova E.I., Soja A.J., Chuprova V.V., and Lysanova G.I., submitted book chapter, Evaluating the Agroclimatic Potential and Carbon Budget of Agrosystems of Central Siberia, Novel Methods for Monitoring and Management of Land and Water Recourses of Siberia, L Mueller, E. Smolentseva, A, Syso, G. Licheid, editors Springer, In Review.
  • Tchebakova N.M., Parfenova E.I., and Soja A. J., submitted book chapter, Siberian Vegetation Change Compelled by the Changing Climate, Novel Methods for Monitoring and Management of Land and Water Recourses of Siberia, L Mueller, E. Smolentseva, A, Syso, G. Licheid, editors Springer, In Review.
  • Rogers B.M., A .J. Soja, M. L. Goulden, J. T. Randerson, Fire severity in boreal forests: can individual species regulate continental-scale carbon and energy exchange? Nature Geoscience, In Review.
  • McCarty, J.L., Pouliot, G.A., MIller, M.E., Soja, A.J., and T. Rao. Producing emission estimates from cropland burning in the contiguous United States for the 2011 National Emissions Inventory: Lessons learned from a remote sensing-based approach. Proceedings of the International Smoke Symposium, pub. Intern. Ass. of Wildland Fire. In Review.
  • J. K. Shuman, N. M. Tchebakova, E. I. Parfenova, A. J. Soja, H. H. Shugart, D. Ershov and K. Holcomb, in press, Forest Forecasting with Vegetation Models across Russia, Canadian Journal of Forest Research, in press.
  • Blyakharchuk T A, N M Tchebakova, E I Parfenova, and A J Soja, (2014)Reconstruction of the late Holocene climate in the Minusink Hollow, south-central Siberia, and its potential influence on settled farming versus nomadic cattle herding, Environ. Res. Lett. 9 065004,doi:10.1088/1748-9326/9/6/065004
  • V Ambrosia, A.J. Soja and L. Friedl, (2014) 2013 NASA Applied Sciences Wildland Fire Annual Report.
  • A. J. Soja (2014) Wildland Fire Management Science and Technology ‘One NASA’ Agency Response describing NASA’s current roles and responsibilities to establish a resource baseline that defines our current capacity to address the current national-level challenges, report.
  • French N.H.F., McKenzie D., Ottmar R.D., McCarty, J.L., Norheim R.A., Hamermesh N., and Soja A.J.(2013) A US national fuels database and map for calculating carbon emissions from wildland and prescribed fire, Proceedings of 4th Fire Behavior and Fuels Conference, and St. Petersburg, Russia. Pub: International Association of Wildland Fire, Missoula, MT, USA
  • Kukavskaya E. A., A. J. Soja, A. P. Petkov, E. I. Ponomarev, G. A. Ivanova, and S. G. Conard,(2013), Fire Emission Estimates in Siberia: Evaluation of Uncertainties in Area Burned, Land Cover, and Fuel Consumption, Canadian Journal of Forest Research, doi: 10.1139/cjfr-2012-036.
  • Soja A. J. and Groisman, P. Ya., (2012), Northern Eurasia Earth Science Partnership Initiative: evolution of scientific investigations to applicable science, Environ. Res. Lett. 7, 4 (2012) 045201 (5pp) doi:10.1088/1748-9326/7/4/045201.
  • de Groot William J., M. D. Flannigan, A. J. Soja, A. S. Cantin, L. Gowan and A Newbery, (2012) A comparison of Canadian and Russian boreal forest fire regimes, Forest Ecology and Management, doi: 10.1016/j.foreco.2012.07.033.
  • Petrenko, M, R Kahn; M Chin, A. J. Soja, T. Kucsera, Harshvardhan, (2012) The use of satellite-measured aerosol optical depth to constrain biomass burning emissions source strength in the global model GOCART, J Geophysical Research-Atmospheres, 117, D18212 doi:10.1029/2012JD017870.
  • Soja A., D. Fairlie, D. Westberg, G. Pouliot and J. Szykman, (2012) Biomass Burning Plume Injection Height Estimates using CALIOP, MODIS and the NASA Langley Trajectory Model, Environmental Protectin Agency (EPA) International Emission Inventory Conference (EIC) Emission Inventories – Meeting the Challenges Posed by Emerging Global, National, Regional and Local Air Quality Issues, Tampa Florida.
  • Pouliot G., J. McCarty, and A. Soja, (2012) Development of a Crop Residue Burning Emission Inventory for Air Quality Modeling, EPA EIC Emission Inventories – Meeting the Challenges Posed by Emerging Global, National, Regional and Local Air Quality Issues.
  • McCarty J., G. Pouliot and J. Szykman, S. Raffuse, M. Ruminski, and A. Soja (2012) Using Satellite Data to Quantify Cropland Burning and Related Emissions in the contiguous United States: Lessons Learned, EPA EIC Emission Inventories – Meeting the Challenges Posed by Emerging Global, National, Regional and Local Air Quality Issues.
  • Natarajan M., R. B. Pierce, T K. Schaack, A. J. Lenzen, J. A. Al-Saadi, A. J. Soja, T. P. Charlock, F. G. Rose, D. M. Winker, and J. R. Worden, (2011) Radiative forcing due to enhancements in tropospheric ozone and carbonaceous aerosols caused by Asian fires during spring 2008 J of Geophysical Research, Vol. 117, D06307, doi:10.1029/2011JD016584.
  • Tchebakova N. M., E. I. Parfenova, G. I. Lysanova and A. J. Soja, Agroclimatic potential across central, Siberia in an altered twenty-first century, (2011), Environ. Res. Lett. 6 045207 (11pp) doi:10.1088/1748-9326/6/4/045207.
  • Wiedinmyer C., S. K. Akagi, R. J. Yokelson, L. K. Emmons, J. A. Al-Saadi, J. J. Orlando, and A. J. Soja, (2011), The Fire INventory from NCAR (FINN): a high resolution global model to estimate the emissions from open burning, Geosci. Model Dev., 4, 625–641, doi:10.5194/gmd-4-625-2011.
  • Soja, A.J.,T.D. Fairlie, D.J. Westberg, G. Pouliot, C.M. Ichoku, L. Giglio, and J.J. Szykman, Biomass Burning Plume Injection Height Estimates Using CALIOP, MODIS and the NASA Langley Back Trajectory Model, in International Symposium of Remote Sensing of the Environment, Sydney, Australia, 2011a.
  • Soja, A.J., D.J. Westberg, P. Stackhouse Jr., D.J. McRae, J.-Z. Jin, and A.I. Sukhinin, Analysis of the Ability of Large-Scale Reanalysis Data to Define Siberian Fire Danger in Preparation for Future Fire Weather, in International Symposium of Remote Sensing of the Environment, Sydney, Australia, 2011b.
  • Tchebakova NM, Parfenova EI and Soja AJ.2011. Climate change and climate-induced hot spots in forest shifts in central Siberia at the turn of the 21st century, Regional Environmental Change, 11, 4, 817-827,doi: 10.1007/s 10113-011-0210-4
  • Ivanova, G.A., V.A Ivanov, E.A. Kukavskaya and A.J Soja, (2010), Forest Fire Frequency in Scots Pine Stands of Tuva, Russia, Environmental Research Letters, doi:10.1088/1748-9326/5/1/015002
  • Tchebakova N.M, E.I. Parfenova and A.J Soja, (2009) The effects of climate, permafrost and fire on vegetation change in Siberia in a changing climate, Environmental Research Letters, doi:10.1088/1748-9326/4/4/045013.

  • Groisman, P. and A.J. Soja,Northern Eurasia Earth Science Partnership Initiative Focus on Climatic and Environmental Change in Northern Eurasia, Environmental Research Letters, 4 (045001), doi: 10.1088/1748-9326/4/4/045001, 2009a.

  • Groisman, P. and A.J. Soja, Ongoing climatic change in Northern Eurasia: justification for expedient research, Environmental Research Letters, 4 (045002), doi: 10.1088/1748-9326/4/4/045002, 2009b.

  • Soja, A.J., J. Al-Saadi, L. Giglio, D. Randall, C. Kittaka, G. Pouliot, J. Kordzi, S. Raffuse, T.G. Pace, T.E. Pierce, T. Moore, B. Roy, R.B. Pierce, and J.J. Szykman, (2009), Assessing satellite-based fire data for use in the National Emissions Inventory, Journal of Applied Remote Sensing, 3 (031504), 29.

  • Al-Saadi, J., A.J. Soja, R.B. Pierce, J. Szykman, C. Wiedinmyer, L. Emmons, S. Kondragunta, X. Zhang, C. Kittaka, T. Schaack, and K. Bowman, (2008), Evaluation of Near-Real-Time Biomass Burning Emissions Estimates Constrained by Satellite Active Fire Detections, Journal of Applied Remote Sensing, 2, 021504.

  • Pierce, R. B., J. Al-Saadi, C. Kittaka, T. K. Schaack, A Lenzen, K. Bowman, J. Szykman, A. J. Soja, T Ryerson, A. Thompson, P. Bhartia, G. Morris,       (2009), Impacts of background ozone production on Houston and Dallas, Texas, air quality during the Second Texas Air Quality Study field mission, Journal of Geophysical Research, Vol 117, D7, doi: 10.1029/2008JD011337.

  • Soja, A.J., Al-Saadi, D. Randall, L. Giglio, C. Kittaka, S. Raffuse, J. Kordzi, G. Pouliot, X. Zhang, S. Kondragunta,, D.J. Williams, T. Pace, T.E. Pierce, T. Moore, C. Schmidt, B. Pierce and J. Szykman, (2008), Comparing fire emissions estimates for CONUS in support of the NEI: Let’s take a step a backwards to move forwards, EPA EIC.

  • Choi, Y., S.A.Vay, K.P. Vadrevu, A.J. Soja, Woo, Nolf, Sachse, Diskin, Blake, Blake, Singh, Avery, Fried, Pfister and Fuelberg, (2008), Characteristics of the atmospheric CO2signal as observed over the conterminous US during INTEX-NA, J. of Geophysical Research, 113 (D07301), doi:10.1029/2007JD008899.

  • Roy, B. A.; Pouliot, G. A.; Mobley, J. D.; Pace, T. G.; Pierce, T. E.; Soja, A. J.; Szykman, J. J.; Al-Saadi, J. (2008) Development of fire emissions inventory using satellite data, 29th NATO/CCMS International Technical Meeting on Air Pollution Modeling and Its Application:Air Pollution and its Application XIX Nato Science for Peace and Security Series C- Environmental Security, Aveiro, Portugal,Sept 24-28, 2007: NATO; CCMS; Univ Aveiro,, Pp:217-225,doi:10.1007/978-1-4020-8453-9_24.
  • Soja, A.J., N Tchebakova, N.H.F. French, M Flannigan, H.H. Shugart, B.J. Stocks, AI Sukhinin, E Parfenova, F.S. Chapin III, and P.W. Stackhouse Jr. (2007), Climate-induced boreal forest change: Predictions versus current observations, Global and Planetary Change, 56 (3-4).
  • Pierce, R.B., T.K. Schaack, J. Al-Saadi, T.D. Fairlie, Kittaka, Lingenfelser, Natarajan, Olson, A.J. Soja, Zapotocny, Lenzen, Stobie, Johnson, Avery, Sachse, et al., 2007. Chemical data assimilation based estimates of Continental US Ozone and Nitrogen budgets during the Intercontinental Chemical Transport Experiment – North America, Journal Geophysical Research, 112 (D12S21), doi:10.1029/2006JD007722.
  • Groisman P. Ya., and A. J. Soja, (2007) Northern Hemisphere high latitude climate and environmental change, Environ. Res. Lett., 2, 4 (045008), D06307doi:10.1029/2011JD016584

  • Soja, A.J., J. Al-Saadi, D. Randall, L. Giglio, C. Kittaka, S. Raffuse, J. Kordzi, G. Pouliot, R.B. Pierce, D. Roy, D.J. Williams, T. Pace, T. Pierce, T. Moore and J.J. Szykman, (2007),  A methodology for estimating area burned using satellite-based data in Near-Real-Time in Oregon and Arizona., EPA internal manuscript.

  • Kittaka, C., B. Pierce, T. Schaack, J. Al-Saadi, A. Soja, G. Tripoli, A.d. Silva, D. Winker, C. Hostetler, J. Szykman, T. Baynard, R. Spackman, and B. Lambeth, (2007), Synthesis of multiple observations using a regional aerosol assimilation/forecast model (RAQMS) and assessment of biomass burning emission estimates, EPA EIC, 17 pp., Raleigh, North Carolina.

  • Al-Saadi, J., A. Soja, B. Pierce, C. Kittaka, L. Emmons, S. Kondragunta, X. Zhang, C. Wiedinmyer, T. Schaack, and J. Szykman, (2007), Global Near-Real-Time Estimates of Biomass Burning Emissions using Satellite Active Fire Detections, EPA EIC, 25 pp., Raleigh, NC.

  • Soja, A.J., H.H. Shugart, A.I. Sukhinin, S.G. Conard, and P.W. Stackhouse Jr., (2006), Satellite-derived mean fire return intervals as indicators of change in Siberia (1995-2002), Mitigation and Adaptation Strategies for Global Change, 11, 75-96.

  • Soja A.J., J. Al-Saadi, D. Randall, T. Moore, C. Kittaka, J. Kordzi, D.J. Williams, T. Pierce, T. Pace, R.B. Pierce and J.J. Szykman, April 2006, How well does satellite data quantify fire and enhance biomass burning emissions estimates?, EPA EIC Internal Doc.

  • Soja A.J., J. Al-Saadi, J.J. Szykman, W.R. Barnard, T. Pace, D.J. Williams, J. Kordzi, and R.B. Pierce, March 2005, Using Satellite-based Products to Enhance Existing Area Burned Data, EPA EIC Internal Doc.
  • Soja A.J., W.R. Cofer, H.H. Shugart, A.I. Sukhinin, P.W. Stackhouse Jr., D. McRae and S.G. Conard, 2004, Estimating fire emissions and disparities in boreal Siberia (1998 through 2002), Journal of Geophysical Research. 2004jd004570.
  • Soja A.J., A.I. Sukhinin, D.R. Cahoon, H.H. Shugart & P.W. Stackhouse Jr., 2004, AVHRR-derived fire frequency, distribution and area burned in Siberia. International J Remote Sensing, v25, 10, 1939-1960.
  • Sukhinin A.I., N.H.F. French, E.S. Kasischke, J.H .Hewson, A.J. Soja, I.A. Csiszar, E. Hyer, T. Loboda, S.G. Conard, V.I. Romasko, Pavlichenko, Miskiv & Slinkina, 2004, Satellite-based mapping of fires in Russia: New products for fire management & carbon cycle studies, Remote Sensing Environment, 93/4, 546-564.
  • Soja A. J., 2004, Impacts of Wildfire in Siberia: A Satellite-based Analysis of Fire Regimes, Dissertation, Department of Environmental Sciences, University of Virginia, pp 201.
  • Garstang M. and A.J. Soja, 2003. Dust-to-Dust: Wind Blown Material. In Coastal-Marine Conservation: Science and Policy, ed G.C. Ray & J. McCormick-Ray, Blackwell, Malden, MA. 80.
  • Shugart, H.H., D.F. Clark, and A.J. Hill, Ecological models of the dynamics of boreal landscapes, in Fire, Climate Change, and Carbon Cycling in the Boreal Forest, E.S. Kasischke and B.J. Stocks, Editors. 2000, Springer-Verlag: New York. p. 389-405.