Abstract
Emissions of methane (CH4) in the Permian basin (U.S.A.)
have been derived for 2019 and 2020 from satellite observations of the
Tropospheric Monitoring Instrument (TROPOMI) using the divergence
method, in combination with a data driven method to estimate the
background concentrations. The resulting CH4 emission
data, which have been verified using model with known emissions, have a
spatial resolution of approximately 10 km. The spatial patterns of the
emissions are in a good agreement with the locations of oil and gas
production and drilling activities in the Permian basin, as well as with
emissions of nitrogen oxides (NOx). Analysis of
time-series of locations with large CH4 emissions
indicated that there are significant continuous emissions in this
region. The CH4 emissions can be characterized as a
continuous area source, rather than as dominated by a few large
unplanned releases. This is important considering possible
CH4 emission mitigation strategies. In addition to
providing spatially resolved emissions, the divergence method also
provides the total emissions of the Permian basin and its main
sub-basins. The total CH4 emission of the Permian is
estimated as 3.0 ± 0.7 Tg yr-1 for 2019, which agrees
with other independent estimates based on TROPOMI data. For the Delaware
sub-basin, it is estimated as 1.4 ± 0.3 Tg yr-1 for
2019, and for the Midland sub-basin 1.2 ± 0.3 Tg yr-1.
In 2020 the emissions are 8% lower compared to 2019, which could be a
result of strong decreases in drilling activities due to the COVID-19
crisis.