In:
Atmospheric Measurement Techniques, Copernicus GmbH, Vol. 14, No. 4 ( 2021-04-12), p. 2771-2785
Kurzfassung:
Abstract. We demonstrate the capability of the Sentinel-2
MultiSpectral Instrument (MSI) to detect and quantify anomalously
large methane point sources with fine pixel resolution (20 m) and rapid
revisit rates (2–5 d). We present three methane column retrieval methods
that use shortwave infrared (SWIR) measurements from MSI spectral bands 11
(∼ 1560–1660 nm) and 12 (∼ 2090–2290 nm) to
detect atmospheric methane plumes. The most successful is the
multi-band–multi-pass (MBMP) method, which uses a combination of the two
bands and a non-plume reference observation to retrieve methane columns. The
MBMP method can quantify point sources down to about 3 t h−1 with a
precision of ∼ 30 %–90 % (1σ) over favorable
(quasi-homogeneous) surfaces. We applied our methods to perform
high-frequency monitoring of strong methane point source plumes from a
well-pad device in the Hassi Messaoud oil field of Algeria (October 2019 to
August 2020, observed every 2.5 d) and from a compressor station in the
Korpezhe oil and gas field of Turkmenistan (August 2015 to November 2020,
observed every 5 d). The Algerian source was detected in 93 % of
cloud-free scenes, with source rates ranging from 2.6 to 51.9 t h−1 (averaging 9.3 t h−1) until it was shut down by a flare lit in August
2020. The Turkmen source was detected in 40 % of cloud-free scenes, with
variable intermittency and a 9-month shutdown period in March–December 2019
before it resumed; source rates ranged from 3.5 to 92.9 t h−1
(averaging 20.5 t h−1). Our source-rate retrievals for the Korpezhe
point source are in close agreement with GHGSat-D satellite observations for
February 2018 to January 2019, but provide much higher observation density.
Our methods can be readily applied to other satellite instruments with
coarse SWIR spectral bands, such as Landsat-7 and Landsat-8. High-frequency
satellite-based detection of anomalous methane point sources as demonstrated
here could enable prompt corrective action to help reduce global methane
emissions.
Materialart:
Online-Ressource
ISSN:
1867-8548
DOI:
10.5194/amt-14-2771-2021
Sprache:
Englisch
Verlag:
Copernicus GmbH
Publikationsdatum:
2021
ZDB Id:
2505596-3
