Retrieval of Source Gases in the Tropopause Region and Upper Troposphere from MIPAS/ENVISAT Measurements

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

Gabrielle Stiller

Institut für Meteorologie und Klimaforschung,
Universitaet Karlsruhe/Forschungszentrum Karlsruhe GmbH, Postfach 3640, D-76021 Karlsruhe, Germany
Telefon: (+49) 7247/82-5203
Fax: (+49) 7247/82-6141
 

Since March 2002 MIPAS onboard ENVISAT performs global measurements of atmospheric composition covering the mesosphere down to the upper troposphere. While ESA operational NRT Lv2 products cover the altitude range from the lower stratosphere to the mesosphere, the scientific retrieval processor operated at IMK provides trace gas and temperature profiles which extend the altitude range down to about 6 km, including the tropopause region and the upper troposphere for cloud free cases.

Currently the IMK processor provides profiles of water vapour (Milz et al.), HNO3, O3, further greenhouse gases, organic compounds, and cirrus clouds in this altitude region. These species are of interest with respect to their influence on the radiative budget, their use as tracers for transport processes across the tropopause, and for studying upper tropospheric ozone chemistry and horizontal transport.

The MIPAS measurements from September 2002 until December 2003 provide a unique data set. In the framework of several projects and for monitoring purposes a large amount of these data have already been processed at IMK. In future we aim for a full exploitation of the existing data sets with the aim of a global distribution of the above mentioned species for the upper troposphere with improved data quality.

Moreover we are able to process measurements which were operated with special measurement modes designed for an optimized observation of the tropopause region and the upper troposphere, namely the so called modes S2 and S6. These data shall be analysed by making use of the improved vertical and horizontal resolution provided for the upper troposphere and tropopause region.

A 2-D retrieval approach (Steck et al.) shall be further developed and applied to obtain improved information on the horizontal distribution of the trace species while considering horizontal gradients in the retrieval.

The existing retrieval approaches will be subject to robustness tests with respect to the influence of a priori knowledge, regularization parameters, and micro-window selection. Potential needs for improved quality of the spectroscopic data used for the retrievals shall be identified.

Time schedule

 

2004

2005

2006

2007

2008

2009

Activity

*

*

*

*

*

*

 Approximate manpower and cost

 

2004

2005

2006

2007

2008

2009

Personnel/man-years

1

1

1

1

1

1

Yearly cost (kECU)

60

60

60

60

60

60

Likely funding agencies

EU, national funding agencies (BMBF, DFG)

Co-worker

Gabriele Stiller

 

 


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