Arctic methane: a view from satellites.

Leonid Yurganov, University of Maryland Baltimore County, yurganov@hotmail.com (Presenter)
Ira Leifer, Bubbleology Research International, ira.leifer@bubbleology.com
Shawn Xiong, NOAA Center for Satellite Applications and Research, xiaozhen.xiong@noaa.gov
Gennady Chepurin, University of Maryland, chepurin@atmos.umd.edu

The Arctic is warming two times faster than the rest of the World. This warming may influence natural sources of methane, most of them being temperature-dependent. Methane, in turn, is a greenhouse gas and its growth builds up temperature further. Investigation of this positive feed-back requires an adequate monitoring system. Near IR satellite instruments (e.g., SCIAMACHY) use the Sun as a light source and are not effective in the Arctic, especially during polar night. In addition, a low reflectivity of snow, ice, and water surfaces diminishes the signal to noise ratio. Thermal IR (TIR) nadir-viewing spectrometers (AIRS, IASI, TANSO, etc) measure the radiance from the Earth surface and the atmosphere year-round, day and night. The sensitivity of methane retrievals to the lowermost layers of the troposphere is surprisingly high, even in comparing to the lower latitudes. In this report we analyze AIRS (version 6) and IASI (NOAA retrieval, CLASS archive) data and compare with other remote-sensing and surface flask NOAA data. A parameter “Thermal Contrast” (ThC) is defined as difference between temperatures on the surface and at the altitude of 4 km. For ThC >10 k satellite data appear to be independent on the ThC, they are assumed to reproduce the lower tropospheric concentration. Seasonal cycles of surface concentrations and those obtained by satellites for ThC>10 K are in agreement. Trends after 2006 are in agreement as well. This is treated as a proof of validity for the satellite data. An assumed acceleration of methane emission due to the Arctic warming has not been found yet.

Presentation Type:  Poster

Session:  Theme 3: Future research direction and priorities: perspectives relevant to the next decadal survey   (Mon 4:30 PM)

Associated Project(s): 

• Related Activity: Related Activity or Previously Funded CC&E Activity not listed ...details

Poster Location ID: 227