Validation of five years (2003-2007) of SCIAMACHY CO total column measurements using ground-based spectrometer observations
Journal article, 2010
This paper presents a validation study of SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) carbon monoxide (CO) total column measurements from the Iterative Maximum Likelihood Method (IMLM) algorithm using ground-based spectrometer observations from twenty surface stations for the five year time period of 2003-2007. Overall we find a good agreement between SCIAMACHY and ground-based observations for both mean values as well as seasonal variations. For high-latitude Northern Hemisphere stations absolute differences between SCIAMACHY and ground-based measurements are close to or fall within the SCIAMACHY CO 2 sigma precision of 0.2 x 10(18) molecules/cm(2) (similar to 10%) indicating that SCIAMACHY can observe CO accurately at high Northern Hemisphere latitudes. For Northern Hemisphere mid-latitude stations the validation is complicated due to the vicinity of emission sources for almost all stations, leading to higher ground-based measurements compared to SCIAMACHY CO within its typical sampling area of 8 degrees x 8 degrees. Comparisons with Northern Hemisphere mountain stations are hampered by elevation effects. After accounting for these effects, the validation provides satisfactory results. At Southern Hemisphere mid-to high latitudes SCIAMACHY is systematically lower than the ground-based measurements for 2003 and 2004, but for 2005 and later years the differences between SCIAMACHY and ground-based measurements fall within the SCIAMACHY precision. The 2003-2004 bias is consistent with previously reported results although its origin remains under investigation. No other systematic spatial or temporal biases could be identified based on the validation presented in this paper. Validation results are robust with regard to the choices of the instrument-noise error filter, sampling area, and time averaging required for the validation of SCIAMACHY CO total column measurements. Finally, our results show that the spatial coverage of the ground-based measurements available for the validation of the 2003-2007 SCIAMACHY CO columns is sub-optimal for validation purposes, and that the recent and ongoing expansion of the ground-based network by carefully selecting new locations may be very beneficial for SCIAMACHY CO and other satellite trace gas measurements validation efforts.
retrievals
wfm-doas
error
space
atmospheric carbon-monoxide
ftir measurements
northern japan
variability
methane
analysis
ch4
Author
A. T. J. de Laat
Royal Netherlands Meteorological Institute
Netherlands Institute for Space Research (SRON)
A. M. S. Gloudemans
Netherlands Institute for Space Research (SRON)
H. Schrijver
Netherlands Institute for Space Research (SRON)
I. Aben
Netherlands Institute for Space Research (SRON)
Y. Nagahama
Yokohama National University
K. Suzuki
Yokohama National University
E. Mahieu
University of Liège
N. B. Jones
University of Wollongong
C. Paton-Walsh
University of Wollongong
N. M. Deutscher
University of Wollongong
D. W. T. Griffith
University of Wollongong
M. De Maziere
Belgian Institute for Space Aeronomy (BIRA-IASB)
R. L. Mittermeier
Environment Canada
H. Fast
Environment Canada
J. Notholt
Universität Bremen
M. Palm
Universität Bremen
T. Hawat
University of Denver
T. Blumenstock
Karlsruhe Institute of Technology (KIT)
F. Hase
Karlsruhe Institute of Technology (KIT)
M. Schneider
Karlsruhe Institute of Technology (KIT)
C. Rinsland
National Aeronautics and Space Administration (NASA)
A. V. Dzhola
Saint Petersburg State University - Spsu
E. I. Grechko
Saint Petersburg State University - Spsu
A. M. Poberovskii
Russian Academy of Sciences
M. V. Makarova
Russian Academy of Sciences
Johan Mellqvist
Chalmers, Department of Radio and Space Science, Optical Remote Sensing
Anders Strandberg
Chalmers, Department of Radio and Space Science, Optical Remote Sensing
R. Sussmann
Karlsruhe Institute of Technology (KIT)
T. Borsdorff
Karlsruhe Institute of Technology (KIT)
M. Rettinger
Karlsruhe Institute of Technology (KIT)
Atmospheric Measurement Techniques
1867-1381 (ISSN) 1867-8548 (eISSN)
Vol. 3 5 1457-1471Subject Categories (SSIF 2011)
Earth and Related Environmental Sciences
DOI
10.5194/amt-3-1457-2010