Project Funding: 2012 - 2016

NRA: 2011 NASA: HyspIRI Preparatory Airborne Activities and Associated Science and Applications   

Funded by NASA

Abstract:
On a 20-year timescale, CH4 has a larger greenhouse effect than CO2 and its decadal lifetime makes it more amenable to regulatory approaches. Yet sources remain poorly quantified. Top-down and bottom-up regional and global CH4 budgets often disagree significantly, eg, Hsu et al (2009) found an ~40% discrepancy for the LA Basin. Much of the discrepancy could relate to fossil CH4 from fugitive industrial (FFI) and geologic sources; a recent LA Basin survey (NOAA) suggests FFI. Some studies suggest recent CH4 stabilization was from global FFI CH4 emission decreases. Recent transcontinental ground CH4 data validated SCIAMACHY & GOSAT data with similar conclusions. Others suggest an ~50% US FFI underestimate. The planned AVIRIS/MASTER flights cover significant FFI industrial activity and geologic CH4 emission sites. The key study science question is: What are the relative California contributions of fossil geologic and FFI CH4? I.e., addressing the relationship between fossil CH4 emissions and geologic, marine, and atmospheric (eg, inversion layers, buoyant rise) controls. This primarily is an application study using AVIRIS (eg, HyspIRI VSWIR) and MASTER (eg, HyspIRI TIR) and to a lesser extent a research study. It directly addresses the RFP by: 1) Demonstrating science applications (CH4 emission) enabled by HyspIRI-like sensors and aids HyspIRI mission design (band selection and binning, algorithms); 2) Providing unprecedented information for resource management to resource managers though merging AVIRIS data with existing data. The study fits HyspIRI mission goals through addressing science definition team questions: cq5 (terrestrial surface composition), tq4 (urbanization and environment), and vq2 (seasonal cycles of terrestrial ecosystem and land disturbance and climate change). Our team comprises scientists and resource managers with specific expertise to assure project success. We will study factors affecting trace gas (CH4, CO2) SWIR retrievals in AVIRIS SWIR data for fossil sources to characterize the effect of albedo, nadir angle, aerosols, water vapor, path radiance, vertical profiles, surface spectral non-uniformity, pixel size, spectral resolution, and spectral spacing. SWIR-derived CH4 will be compared with MASTER TIR spectral CH4 anomalies. Retrieval approaches including neighboring pixel normalization, band ratio, residual minimization, and statistical measures, based on radiative transfer calculations for SWIR and TIR absorption features will be investigated. Improved SWIR trace gas retrievals using TIR-derived vertical profiles will be studied. Mobil ground-reference CH4 measurements including eddy covariance fluxes, and alkane gas chromatography of C2-C8 will provide relevant size scales and natural gas fingerprinting. We will identify the best remote sensing and in situ plume characterization approaches, relevant CH4 size scales, and merging of mobile in situ data with airborne and satellite remote sensing to improve flux estimation and source attribution. Regional scaling is by comparison with SCIAMACHY/GOSAT data, and maps of FFI activity and geologic structures. We leverage planned 2013/2014 CARVE (JPL) FTIR spectrometer, California transit flights and MAKO (Aerospace Corp.) high-spectral resolution TIR airborne flights, and DISCOVER (AQ) airborne data at NO COST to the study. MAKO TIR data will enable allow evaluation of MASTER TIR spectral response characteristics. The study focuses on the Coal Oil Point (COP) seep field (natural geologic), the Elk Hills and Kern oil fields (anthropogenic), La Brea seepage, and a range of urban cites. Prior SEBASS data from these sites and AVIRIS/MASTER COP data are available, and surface CH4 data were collected Feb. 2012 for this proposal. Several studies have demonstrated successful AVIRIS COP CH4 retrieval. La Brea CH4 emissions were found to dominate other LA Basin sources. Much of this study's basis was accomplished since the 2009 proposal.

Publications:

Arc, J. 2015. Concise Physics for Ancillary Degree Students. Physics Bulletin. 13(11), 307-308. DOI: 10.1088/0031-9112/13/11/017

Farrell, P., Culling, D., Leifer, I. 2013. Transcontinental methane measurements: Part 1. A mobile surface platform for source investigations. Atmospheric Environment. 74, 422-431. DOI: 10.1016/j.atmosenv.2013.02.014

Leifer, I., Culling, D., Schneising, O., Farrell, P., Buchwitz, M., Burrows, J. P. 2013. Transcontinental methane measurements: Part 2. Mobile surface investigation of fossil fuel industrial fugitive emissions. Atmospheric Environment. 74, 432-441. DOI: 10.1016/j.atmosenv.2013.03.018

Leifer, I., Tratt, D. M., Realmuto, V. J., Gerilowski, K., Burrows, J. P. 2012. Remote sensing atmospheric trace gases with infrared imaging spectroscopy. Eos, Transactions American Geophysical Union. 93(50), 525-525. DOI: 10.1029/2012eo500006

More details may be found in the following project profile(s):

• NASA Biological Diversity & Ecological Conservation (BDEC) Project Profile