Infrared Spectroscopy for Tropospheric Remote Sensing from Space

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

Johannes Orphal

Laboratoire Inter-Universitaire des Systèmes Atmosphériques, CNRS
Faculté des Sciences et Technologie, Université Paris-XII
61 avenue du Général de Gaulle, 94010 Crétéil Cedex
Tel.:  +33-(0)1 6915-7528
Fax:  +33-(0)1 6915-7530

This contribution concentrates on the use of infrared spectroscopy for remote sensing of tropospheric trace gases from space, in particular on the relevant aspects of laboratory and theoretical work required to provide accurate reference data. Indeed the accuracy of remote sensing in the infrared region is in many cases limited by the systematic errors of the database, a situation that urgently needs to be improved, especially for instruments that are already in orbit (MIPAS) or that will be launched in the near future (TES, IASI).

The proposed project will comprise three activities:

·   Intercomparison and inter-calibration of spectroscopic reference data in different spectral regions (in particular ultraviolet-visible and thermal-infrared) for tropospheric trace gases that are observed in both regions, such as O3, NO2, H2CO and SO2. This is essential for the consistency of data derived from different sensors, in particular for data assimilation, and for future projects with optical instruments operating in both spectral regions (e.g. GeoTROPE or similar).

·   Improvement of the spectroscopic database (in particular line parameters) in the mid- and near-infrared, for tropospheric species where information is already available in databases like HITRAN but systematic errors are observed in the analysis of atmospheric spectra (e.g. H2O, HNO3, …).

·   Measurements and analysis of laboratory spectra of other tropospheric trace gases that can potentially be observed in infrared spectra but where spectroscopic reference data (such as line positions, line intensities, lower states energies, broadening parameters, or absorption cross-sections) are still missing or incomplete, e.g. H2CO, PAN, C2H6, CH3CN, HCOOH, and (CH3)2CO.

Whenever possible the new data will be used for the retrieval of atmospheric data from infrared sensors, in order to demonstrate the impact of the new spectroscopic parameters, for species where the accuracy of previously available reference data will be improved, and to demonstrate the feasibility of detection of new species.

Time schedule

 

2004

2005

2006

2007

2008

2009

Activity 1

*

*

*

*

 

 

Activity 2

*

*

*

*

*

*

Activity 3

 

*

*

*

*

*

Approximate manpower and cost

 

2004

2005

2006

2007

2008

2009

Personnel / man-years

1

2

2

2

2

2

Yearly cost (kECU)

10

20

20

20

20

20

Likely funding agencies

CEE; Programme National “Chimie Atmosphérique” (PNCA); CNES

Co-workers

Dr. Agnès Perrin
Laboratoire Inter-Universitaire des Systèmes Atmosphériques, CNRS
Faculté des Sciences et Technologie, Université Paris-XII
61 avenue du Général de Gaulle, 94010 Crétéil Cedex
Tel.:  +33-(0)1 6915-7529
e-mail: agnes.
perrin@ppm.u-psud.fr

Dr. Laurent Coudert
Laboratoire Inter-Universitaire des Systèmes Atmosphériques, CNRS
Faculté des Sciences et Technologie, Université Paris-XII
61 avenue du Général de Gaulle, 94010 Crétéil Cedex
Tel.:  +33-(0)1 6915-5536
e-mail: laurent.
coudert@ppm.u-psud.fr

         

Dr. Jean-Marie Flaud

          Laboratoire Inter-Universitaire des Systèmes Atmosphériques, CNRS
Faculté des Sciences et Technologie, Université Paris-XII
61 avenue du Général de Gaulle, 94010 Crétéil Cedex
Tel.:  +33-(0)1 4517-1556
e-mail: flaud
@lisa.univ-paris12.fr

 

 

 


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