Publication Date:
2016-01-27
Description:
We introduce a retrieval algorithm to estimate lower tropospheric methane (CH4) concentrations from surface to 1 km with uncertainty estimates using Hyperspectral Thermal Emission Spectrometer (HyTES) airborne radiance measurements. After resampling, retrievals have a spatial resolution of 6x6 m2. Total error from single retrieval is approximately 20 %, with the uncertainties determined primarily by noise and spectral interferences from temperature, surface emissivity, and atmospheric water vapor. We demonstrate retrievals for a HyTES flight line over storage tanks near Kern River Oil Field (KROF), Kern County, California and find an extended plume structure in the set of observations with elevated methane concentrations (3.0±0.6 ppm to 6.0±1.2 ppm), well above mean concentrations (1.8±0.4 ppm) observed for this scene. With a 20 % estimated precision, plume enhancements with more than 1 ppm are distinguishable from the background noise. HyTES retrievals are consistent with simultaneous airborne and ground-based in situ CH4 mole fraction measurements within the reported accuracy of approximately 0.2 ppm (or ~8 %), due to retrieval interferences related to temperature or H2O or both.
Electronic ISSN:
1867-8610
Topics:
Geosciences
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