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

Total column water vapour measurements from GOME-2 MetOp-A and MetOp-B

Grossi, M. and Valks, P. and Loyola, D. and Aberle, B. and Slijkhuis, S. and Wagner, T. and Beirle, S. and Lang, R. (2015) Total column water vapour measurements from GOME-2 MetOp-A and MetOp-B. Atmospheric Measurement Techniques, 8, pp. 1111-1133. Copernicus Publications. doi: 10.5194/amt-8-1111-2015. ISSN 1867-1381.

[img] PDF

Official URL: http://www.atmos-meas-tech.net/8/1111/2015/amt-8-1111-2015.pdf


Knowledge of the total column water vapour (TCWV) global distribution is fundamental for climate analysis and weather monitoring. In this work, we present the retrieval algorithm used to derive the operational TCWV from the GOME-2 sensors aboard EUMETSAT's MetOp-A and MetOp-B satellites and perform an extensive inter-comparison in order to evaluate their consistency and temporal stability. For the analysis, the GOME-2 data sets are generated by DLR in the framework of the EUMETSAT O3M-SAF project using the GOME Data Processor (GDP) version 4.7. The retrieval algorithm is based on a classical Differential Optical Absorption Spectroscopy (DOAS) method and combines a H2O and O2 retrieval for the computation of the trace gas vertical column density. We introduce a further enhancement in the quality of the H2O total column by optimizing the cloud screening and developing an empirical correction in order to eliminate the instrument scan angle dependencies. The overall consistency between measurements from the newer GOME-2 instrument on board of the MetOp-B platform and the GOME-2/MetOp-A data is evaluated in the overlap period (December 2012–June 2014). Furthermore, we compare GOME-2 results with independent TCWV data from the ECMWF ERA-Interim reanalysis, with SSMIS satellite measurements during the full period January 2007–June 2014 and against the combined SSM/I + MERIS satellite data set developed in the framework of the ESA DUE GlobVapour project (January 2007–December 2008). Global mean biases as small as ±0.035 g cm−2 are found between GOME-2A and all other data sets. The combined SSM/I-MERIS sample and the ECMWF ERA-Interim data set are typically drier than the GOME-2 retrievals, while on average GOME-2 data overestimate the SSMIS measurements by only 0.006 g cm−2. However, the size of these biases is seasonally dependent. Monthly average differences can be as large as 0.1 g cm−2, based on the analysis against SSMIS measurements, which include only data over ocean. The seasonal behaviour is not as evident when comparing GOME-2 TCWV to the ECMWF ERA-Interim and the SSM/I+MERIS data sets, since the different biases over land and ocean surfaces partly compensate each other. Studying two exemplary months, we estimate regional differences and identify a very good agreement between GOME-2 total columns and all three data sets, especially for land areas, although some discrepancies (bias larger than ±0.5 g cm−2) over ocean and over land areas with high humidity or a relatively large surface albedo are observed.

Item URL in elib:https://elib.dlr.de/95553/
Document Type:Article
Title:Total column water vapour measurements from GOME-2 MetOp-A and MetOp-B
AuthorsInstitution or Email of AuthorsAuthor's ORCID iD
Date:5 March 2015
Journal or Publication Title:Atmospheric Measurement Techniques
Refereed publication:Yes
Open Access:Yes
Gold Open Access:Yes
In ISI Web of Science:Yes
DOI :10.5194/amt-8-1111-2015
Page Range:pp. 1111-1133
Publisher:Copernicus Publications
Keywords:water vapour GOME-2
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 - Projekt ENVISAT (old), R - Vorhaben Informationstechnische Systeme für die Fernerkundung (old), R - Vorhaben Datenprodukte für Klima- und Atmosphärenanwendungen (old), R - Atmospheric and climate research
Location: Oberpfaffenhofen
Institutes and Institutions:Remote Sensing Technology Institute > Atmospheric Processors
Deposited By: Grossi, Margherita
Deposited On:09 Dec 2015 11:21
Last Modified:02 May 2019 14:13

Repository Staff Only: item control page

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