title: Indonesian fire activity and smoke pollution in 2015 show persistent nonlinear sensitivity to El Niño-induced drought.
abstract: The 2015 fire season and related smoke pollution in Indonesia was more severe than the major 2006 episode, making it the most severe season observed by the NASA Earth Observing System satellites that go back to the early 2000s, namely active fire detections from the Terra and Aqua Moderate Resolution Imaging Spectroradiometers (MODIS), MODIS aerosol optical depth, Terra Measurement of Pollution in the Troposphere (MOPITT) carbon monoxide (CO), Aqua Atmospheric Infrared Sounder (AIRS) CO, Aura Ozone Monitoring Instrument (OMI) aerosol index, and Aura Microwave Limb Sounder (MLS) CO. The MLS CO in the upper troposphere showed a plume of pollution stretching from East Africa to the western Pacific Ocean that persisted for 2 mo. Longer-term records of airport visibility in Sumatra and Kalimantan show that 2015 ranked after 1997 and alongside 1991 and 1994 as among the worst episodes on record. Analysis of yearly dry season rainfall from the Tropical Rainfall Measurement Mission (TRMM) and rain gauges shows that, due to the continued use of fire to clear and prepare land on degraded peat, the Indonesian fire environment continues to have nonlinear sensitivity to dry conditions during prolonged periods with less than 4 mm/d of precipitation, and this sensitivity appears to have increased over Kalimantan. Without significant reforms in land use and the adoption of early warning triggers tied to precipitation forecasts, these intense fire episodes will reoccur during future droughts, usually associated with El Niño events.
authors.affiliation: NASA Goddard Institute for Space Studies, New York, NY 10025; Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10025; robert.field@columbia.edu.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Field
authors.affiliation: Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands;
authors.forename: Guido R
authors.initials: GR
authors.lastname: van der Werf
authors.affiliation: Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands;
authors.forename: Thierry
authors.initials: T
authors.lastname: Fanin
authors.affiliation: Earth Science Section, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109;
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Fetzer
authors.affiliation: Earth Science Section, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109;
authors.forename: Ryan
authors.initials: R
authors.lastname: Fuller
authors.affiliation: NASA Goddard Space Flight Center, Greenbelt, MD 20771; Goddard Earth Sciences Technology and Research, Universities Space Research Association, Columbia, MD 21046;
authors.forename: Hiren
authors.initials: H
authors.lastname: Jethva
authors.affiliation: NASA Goddard Space Flight Center, Greenbelt, MD 20771;
authors.forename: Robert
authors.initials: R
authors.lastname: Levy
authors.affiliation: Earth Science Section, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109;
authors.forename: Nathaniel J
authors.initials: NJ
authors.lastname: Livesey
authors.affiliation: Earth Science Section, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109;
authors.forename: Ming
authors.initials: M
authors.lastname: Luo
authors.affiliation: NASA Goddard Space Flight Center, Greenbelt, MD 20771;
authors.forename: Omar
authors.initials: O
authors.lastname: Torres
authors.affiliation: National Center for Atmospheric Research, Boulder, CO 80301.
authors.forename: Helen M
authors.initials: HM
authors.lastname: Worden
mesh_terms: D000397:Air Pollution; D002248:Carbon Monoxide / Q000032:analysis; D055864:Droughts; D059000:El Nino-Southern Oscillation; D005390:Fires; D007214:Indonesia; D012906:Smoke; D013997:Time Factors
chemical_list: D012906:Smoke; D002248:Carbon Monoxide
keywords: El Niño; Indonesia; biomass burning; haze; pollution