Retrieval of Vertical Columns of Carbon Monoxide and Long-lived Greenhouse Gases (Methane, Carbon Dioxide, Nitrous Oxide)
from SCIAMACHY/ENVISAT Satellite Data

A contribution to ACCENT-TROPOSAT-2, Task Group 1

Michael Buchwitz

University of Bremen, FB1, Institute of Environmental Physics / Remote Sensing (iup/ife)
Otto Hahn Allee 1, 28334 Bremen, Germany
Tel.:  +49-(0)421-218 4475
Fax:  +49-(0)421-218 4555

Within the framework of the ACCENT/TROPOSAT programme it is envisaged to further improve the University of Bremen algorithm for the retrieval of total columns of important atmospheric gases from SCIAMACHY near-infrared nadir spectra (current version: WFM-DOAS v0.4), i.e., carbon monoxide (CO), methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O). Starting with WFM-DOAS version 0.4 an iterative approach is foreseen based on the iteration steps: (i) Processing of a large (statistically significant) set of SCIAMACHY spectra, (ii) analysis of the accuracy and precision of this data set using independent measurements and models, and (iii) algorithm improvements. Intermediate (column) data products will be made available for ACCENT and feedbacks (especially from Task Groups 2 and 3) will be used to further improve the algorithm (see Figure 1).

 Figure 1.  Enhanced concentrations of carbon monoxide (CO) due to biomass burning in eastern central Africa as retrieved by        WFM-DOAS (Version 0.4) from SCIAMACHY near-infrared nadir spectra recorded on October 27, 2003 (Atmos.          Chem. Phys., 4, 1954-1960, 2004).

 The (5-year) goal is to have a highly accurate (nearly bias free) and precise (single pixel column precision (1-sigma) close to theoretical limit: ~1% for CH4 and CO2, and ~10% for CO and N2O).

The objectives for the first 18 months are:

·   To process all the available SCIAMACHY Level 1 consolidated orbit files currently available for the year 2003 to generate the following data products: Vertical columns of CO, CH4, CO2, and N2O, and the “dry air column averaged mixing ratios” XCH4, XCO2, and XN2O (definition: Greenhousegas-column / O2-columns ´ 0.2095)

·   To make these data products available for ACCENT

·   To use feedbacks to determine the quality of the data products and if/how the algorithm needs to be improved

Time schedule

 

2004

2005

2006

2007

2008

Processing SCIAMACHY data

*

*

*

*

*

Analysis of results including validation

*

*

*

*

*

Algorithm improvements

*

*

*

*

*

Approximate manpower and cost

 

2004

2005

2006

2007

2008

Personnel / man-years

1.0

1.0

1.0

1.0

1.0

Yearly cost (kECU)

60

60

60

60

60

An “ACCENT year” starts on 1. March and lasts 12 month

Likely funding agencies

German BMBF via DLR-Bonn

Co-worker

Dr. Rüdiger de Beek
Address and phone number: same as M. Buchwitz
 

 


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