Detection of Methane Emission from a Local Source Using GOSAT Target Observations

Abstract

Emissions of atmospheric methane (CH4), which greatly contributes to radiative forcing, have larger uncertainties than those for carbon dioxide (CO2). The Thermal And Near-infrared Sensor for carbon Observation Fourier-Transform Spectrometer (TANSO-FTS) onboard the Greenhouse gases Observing SATellite (GOSAT) launched in 2009 has demonstrated global grid observations of the total column density of CO2 and CH4 from space, and thus reduced uncertainty in the global flux estimation. In this paper, we present a case study on local CH4 emission detection from a single-point source using an available series of GOSAT data. By modifying the grid observation pattern, the pointing mechanism of TANSO-FTS targets a natural gas leak point at Aliso Canyon in Southern California, where the clear-sky frequency is high. To enhance local emission estimates, we retrieved CO2 and CH4 partial column-averaged dry-air mole fractions of the lower troposphere (XCO2 (LT) and XCH4 (LT)) by simultaneous use of both sunlight reflected from Earth’s surface and thermal emissions from the atmosphere. The time-series data of Aliso Canyon showed a large enhancement that decreased with time after its initial blowout, compared with reference point data and filtered with wind direction simulated by the Weather Research and Forecasting (WRF) model.

Biogenic link to the recent increase in atmospheric methane over India

“…Since GOSAT has a high pixel resolution and precision (10 × 10 km 2 and 0.6%), the measurements are suitable for analysing temporal and spatial changes in atmospheric CH 4 (Turner et al, 2015). From the TANSO-FTS (Thermal and Near Infrared Sensor for carbon Observation-Fourier Transform Spectrometer) instrument onboard the GOSAT, CH 4 columns have been continuously available since May 2009 (Kuze et al, 2020). To identify the cloudy pixel, it has a dedicated Cloud and Aerosol imager (CAI).…”

Meteorological Drivers of Permian Basin Methane Anomalies Derived from TROPOMI

“…This study provides an example of the potential future value of utilizing satellitederived CH 4 for atmospheric photochemical transport studies (assuming emission locations and rates are known). CH 4 from satellite has been used in previous atmospheric inversion modeling and transport studies to estimate CH 4 emissions [74][75][76]. The advent of high-resolution satellite data now provides new opportunities for observing from space the impacts of atmospheric flow patterns on the regional distribution of pollutants.…”

XCO<sub>2</sub> retrieval for GOSAT and GOSAT-2 based on the FOCAL algorithm

“…Chevallier et al, 2014;Chevallier, 2015;Reuter et al, 2014bReuter et al, , 2017aSchneising et al, 2014;Basu et al, 2013;Houweling et al, 2015;Kaminski et al, 2017;Liu et al, 2017;Yin et al, 2018;Palmer et al, 2019) and on anthropogenic CO 2 emissions (e.g. Schneising et al, 2008Schneising et al, , 2013Reuter et al, 2014aReuter et al, , 2019aNassar et al, 2017;Miller et al, 2019;Labzovskii et al, 2019;Wu et al, 2020;Zheng et al, 2020).…”