elib
DLR-Header
DLR-Logo -> http://www.dlr.de
DLR Portal Home | Imprint | Privacy Policy | Contact | Deutsch
Fontsize: [-] Text [+]

A sulfur dioxide Covariance-Based Retrieval Algorithm (COBRA): application to TROPOMI reveals new emission sources

Theys, Nicolas and Fioletov, Vitali and Li, Can and De Smedt, Isabelle and Lerot, Christophe and McLinden, Chris and Krotkov, Nickolay and Griffin, Debora and Clarisse, Lieven and Hedelt, Pascal and Loyola, Diego and Wagner, Thomas and Kumar, Vinod and Inness, A. and Ribas, Roberto and Hendrick, Francoise and Vlietinck, Jonas and Brenot, Hugues and Van Roozendael, M. (2021) A sulfur dioxide Covariance-Based Retrieval Algorithm (COBRA): application to TROPOMI reveals new emission sources. Atmospheric Chemistry and Physics (ACP) (21), pp. 16722-16744. Copernicus Publications. doi: 10.5194/acp-21-16727-2021. ISSN 1680-7316.

[img] PDF - Published version
21MB

Official URL: https://acp.copernicus.org/articles/21/16727/2021/acp-21-16727-2021.pdf

Abstract

Sensitive and accurate detection of sulfur dioxide (SO2) from space is important for monitoring and estimating global sulfur emissions. Inspired by detection methods applied in the thermal infrared, we present here a new scheme to retrieve SO2 columns from satellite observations of ultraviolet back-scattered radiances. The retrieval is based on a measurement error covariance matrix to fully represent the SO2-free radiance variability, so that the SO2 slant column density is the only retrieved parameter of the algorithm. We demonstrate this approach, named COBRA, on measurements from the TROPOspheric Monitoring Instrument (TROPOMI) aboard the Sentinel-5 Precursor (S-5P) satellite. We show that the method reduces significantly both the noise and biases present in the current TROPOMI operational DOAS SO2 retrievals. The performance of this technique is also benchmarked against that of the principal component algorithm (PCA) approach. We find that the quality of the data is similar and even slightly better with the proposed COBRA approach. The ability of the algorithm to retrieve SO2 accurately is further supported by comparison with ground-based observations. We illustrate the great sensitivity of the method with a high-resolution global SO2 map, considering 2.5 years of TROPOMI data. In addition to the known sources, we detect many new SO2 emission hotspots worldwide. For the largest sources, we use the COBRA data to estimate SO2 emission rates. Results are comparable to other recently published TROPOMI-based SO2 emissions estimates, but the associated uncertainties are significantly lower than with the operational data. Next, for a limited number of weak sources, we demonstrate the potential of our data for quantifying SO2 emissions with a detection limit of about 8 kt yr−1, a factor of 4 better than the emissions derived from the Ozone Monitoring Instrument (OMI). We anticipate that the systematic use of our TROPOMI COBRA SO2 column data set at a global scale will allow missing sources to be identified and quantified and help improve SO2 emission inventories.

Item URL in elib:https://elib.dlr.de/146049/
Document Type:Article
Title:A sulfur dioxide Covariance-Based Retrieval Algorithm (COBRA): application to TROPOMI reveals new emission sources
Authors:
AuthorsInstitution or Email of AuthorsAuthor's ORCID iD
Theys, NicolasRoyal Belgian Institute for Space Aeronomy (BIRA)UNSPECIFIED
Fioletov, VitaliEnvironment Climate Change Canada, Toronto, Ontario, Canadahttps://orcid.org/0000-0002-2731-5956
Li, CanNASA Goddard Space Flight Center, Greenbelt, MD 20771, USAUNSPECIFIED
De Smedt, IsabelleBelgian Institute for Space Aeronomy, Brussels, Belgiumhttps://orcid.org/0000-0002-3541-7725
Lerot, ChristopheBelgian Institute for Space Aeronomy (BIRA-IASB), Brussels, BelgiumUNSPECIFIED
McLinden, ChrisEnvironment Climate Change Canada, Toronto, Ontario, Canadahttps://orcid.org/0000-0001-5054-1380
Krotkov, NickolayUniv. of Maryland at Baltimore County, Baltimore, MD USAhttps://orcid.org/0000-0001-6170-6750
Griffin, DeboraEnvironment Climate Change Canada, Toronto, Ontario, Canadahttps://orcid.org/0000-0002-4849-9125
Clarisse, LievenUniv. Libre de Bruxelles, Brussels, Bhttps://orcid.org/0000-0002-8805-2141
Hedelt, PascalPascal.Hedelt (at) dlr.dehttps://orcid.org/0000-0002-1752-0040
Loyola, DiegoDiego.Loyola (at) dlr.dehttps://orcid.org/0000-0002-8547-9350
Wagner, ThomasMax Planck Institute for Chemistry, Mainz, GermanyUNSPECIFIED
Kumar, VinodMax Planck Institute for Chemistry, Mainz, GermanyUNSPECIFIED
Inness, A.European Centre for Medium-range Weather Forecasts, ECMWF, Shinfield Park, Reading RG2 9AX, UKUNSPECIFIED
Ribas, RobertoEuropean Centre for Medium-range Weather Forecasts, ECMWF, Shinfield Park, Reading RG2 9AX, UKUNSPECIFIED
Hendrick, FrancoiseBelgian Institute for Space Aeronomy, Brussels, BelgiumUNSPECIFIED
Vlietinck, JonasBelgian Institute for Space AeronomyUNSPECIFIED
Brenot, HuguesBelgian Institute for Space Aeronomy, Brussels, BelgiumUNSPECIFIED
Van Roozendael, M.BIRA-IASB – Royal Belgian Institute for Space Aeronomy, Brussels, BelgiumUNSPECIFIED
Date:17 November 2021
Journal or Publication Title:Atmospheric Chemistry and Physics (ACP)
Refereed publication:Yes
Open Access:Yes
Gold Open Access:Yes
In SCOPUS:Yes
In ISI Web of Science:Yes
DOI :10.5194/acp-21-16727-2021
Page Range:pp. 16722-16744
Publisher:Copernicus Publications
ISSN:1680-7316
Status:Published
Keywords:TROPOMI, SO2, Sulfur dioxide
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Space
HGF - Program Themes:Earth Observation
DLR - Research area:Raumfahrt
DLR - Program:R EO - Earth Observation
DLR - Research theme (Project):R - Spectroscopic methods of the atmosphere
Location: Oberpfaffenhofen
Institutes and Institutions:Remote Sensing Technology Institute > Atmospheric Processors
Deposited By: Hedelt, Pascal
Deposited On:25 Nov 2021 09:14
Last Modified:01 Dec 2021 10:20

Repository Staff Only: item control page

Browse
Search
Help & Contact
Information
electronic library is running on EPrints 3.3.12
Copyright © 2008-2017 German Aerospace Center (DLR). All rights reserved.