Recent Variability in Surface Water Inundation within Arctic Permafrost Zones: Potential Implications for Regional Methane Emissions

Jennifer Dawn Watts, University of Montana, jennifer.watts@ntsg.umt.edu (Presenter)
John S Kimball, University of Montana, johnk@ntsg.umt.edu
Lucas A Jones, University of Montana, lucas@ntsg.umt.edu
Mahta Moghaddam, University of Southern California, mahta@usc.edu

Surface water inundation strongly influences the magnitude of methane (CH4) emissions in northern high latitude systems. We examine recent (2003-2011) variability in surface water extent across North American and Eurasian permafrost zones using satellite passive microwave remote sensing retrievals of fractional open water (Fw) derived from Advanced Microwave Scanning Radiometer for EOS (AMSR-E) 18.7 and 23.8 GHz brightness temperatures. The daily Fw retrievals sense sub-grid scale (25-km resolution) inundated areas and are insensitive to solar illumination and signal attenuation from clouds, smoke, and other atmosphere effects which constrain optical remote sensing. We estimate changes in methane emissions from permafrost-affected regions corresponding to Fw variability using a modification of the Joint UK Land Environment Simulator (JULES) wetland CH4 emission model. In addition to daily AMSR-E Fw retrievals, model inputs include soil temperature obtained from GMAO MERRA reanalysis and surface metabolic carbon pools derived using a Level 4 carbon (L4_C) algorithm developed for the NASA Soil Moisture Active Passive (SMAP) mission. Our results indicate widespread Fw wetting across the continuous permafrost zone, but with considerable seasonal and interannual variability. Negative Fw anomalies reflect regional drying in 2004 and 2009 within the Canadian permafrost zones, reducing CH4 fluxes, whereas Alaska shows an increase in CH4 emissions over the same period due to warmer summer temperatures. Variability in surface inundation and the contrasting influence of temperature anomalies underscore the importance of monitoring these two factors for regional CH4 emissions.

Presentation: 2013_Poster_Watts_83_64.pdf (3834k)

Presentation Type:  Poster

Session:  Poster Session 2-A   (Wed 11:00 AM)

Associated Project(s): 

• Related Activity or Previously Funded TE Activity

Poster Location ID: 83