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Philip J. Riggan

Research Ecologist
4955 Canyon Crest Drive
Riverside, CA 92507

current research

Dr. Riggan is investigating the spatial patterns and rates of spread and energy release of large fires and effects on large-fire behavior of fire-altered winds, fuel loading and condition, and aerially delivered fire retardant and suppressants. He and his team are developing and applying airborne remote-sensing systems for the quantitative measurement of wildland fires and developing applications for making fire intelligence readily available to and interpretable by incident management teams during ongoing large fires. He is also co-principal investigator on an interagency study that is developing applications of fire observations by new satellite-based sensors, including the Visible Infrared Imaging Radiometer Suite (VIIRS), and is principal investigator for a bilateral research program and interagency working group on fire and environmental change in tropical ecosystems.

research interest

fire remote sensing, fire behavior, global consequences of wildland fire in tropical ecosystems

past research

Dr. Riggan has conducted research on remote measurement of wildfire properties; the biogeochemistry, primary production, plant community development, and effects of fire in Mediterranean ecosystems of California; and the global consequences of wildland fire in tropical ecosystems. He has been Principal Investigator and leader of the Forest Service/IBAMA Working Group on Fire and Environmental Change in Tropical Ecosystems and led eight airborne remote sensing campaigns in Brazil from 1992 through 2000 that made the first synoptic, quanitiative measurements of large wildland fires. He also managed interagency teams studying watershed-scale fires and fire effects on biogeochemistry and the atmosphere in 1984/85 in California and under sponsorship of the Defense Nuclear Agency in California and Canada in 1986 and 1987. Since 2000 he has led development of the FireMapper thermal-imaging radiometer and its application to measurement and monitoring of large wildland fires and forest drought stress and mortality in mixed conifer forest.


Wildland fires continue to threaten life, property, natural resources, and ecosystems in the western United States. They are an important global source of greenhouse gas emissions to the atmosphere and can adversely affect air quality in both rural and urban settings for weeks at a time. Management of fires and their impacts requires strategic information, such as long-term changes in fire frequency and behavior or structural changes in ecosystems from burning, and tactical fire intelligence, such as current fire locations, intensity, and rates and direction of spread. Dr. Riggan's research has provided the remote sensing tools and systems to measure the physical properties of large wildland fires, and is providing the first synoptic and high-resolution measurements of fire behavior. His work with the Government of Brazil is estimating the rates and impacts of burning in tropical savanna and forests and seeking solutions to mitigate fire emissions of greenhouse gases and air pollutants with potentially regional or global consequences on climate change and human and ecosystem health.


  • University of Washington, College of Forest Resources Forest nutrition: measurement and simulation of growth and yield and nitrogen cycling in Douglas-fir forest Doctor Of Philosophy 1979
  • San Diego State University Chemistry (with emphasis on analytical chemistry) and systems ecology B.S. 1973

Professional Experience

  • Forest Service, Pacific Southwest Research Station
    Research Ecologist
    2010 - Current
  • Forest Service, Pacific Southwest Research Station
    Soil Scientist
    1978 - 2010

Awards & Recognition

  • Distinguished Publication Award, Pacific Southwest Research Station, 1996
    for the publication, "Riggan, P. J., F. H. Weirich, L. F. DeBano, et al. 1994. Effects of fire severity on nitrate mobilization in watersheds subject to chronic atmospheric deposition. Environmental Science and Technology 28(3): 369-375."
  • Distinguished Publication Award, Pacific Southwest Research Station, 1990
    for the publication, "Anderson, I. C., J. S. Levine, M. A. Poth, and P. J. Riggan. 1988. Enhanced biogenic emissions of nitric oxide and nitrous oxide following surface biomass burning. Journal of Geophysical Research 93(D4): 3893-3898."
  • NASA National Group Achievement Award, 1988
    for contributions towards assessment of the effects of biomass combustion on the global environment


R&D Affiliations

Priority Research Areas

  • Climate Change