Name of proposer: 
Stefan Buehler

Institution:
Institute of Environmental Physics
University of Bremen / FB 1                
p.o. box: 330440; 28334 Bremen; Germany

Contact:
phone: +49-421-218-4417; fax: +49-421-218-4555
email: sbuehler@uni-bremen.de
www:   http://www.sat.uni-bremen.de/

Title of contribution:
"Upper tropospheric humidity from satellite sensors"

Main elements:
(a) Generic radiative transfer program for longwave remote sensing
(b) 10 year UTH climatology from SSM-T2/AMSU
(c) Validation of satellite humidity sensors
(d) Water vapor retrieval algorithms for SSM-T2/AMSU
(e) Instrument studies for advanced satellite sensors


Relationship to MoU Objectives:

1. To help address and coordinate the development of new measurement
techniques that are particularly suited for the UTLS region.

Contributions (a) and (e) will directly address this objective. Radiative
transfer algorithms are important for all remote sensing
instruments. Instrument studies for new sensors are necessary in order
to assess their expected performance.

2. To evaluate measurement campaigns and use the results and
experience gathered to help plan and promote new campaigns.

Contributions (b) and (c) will provide background statistics for this
objective. Contribution (d) can be used for humidity campaign data
validation. 

3. To develop algorithms to assimilate an increasing variety of UTLS
datasets into global circulation models (GCMs) and chemistry transport
models (CTMs) which encompass the troposphere and stratosphere.

Contribution (a) can help to validate fast RT models needed for this
objective. 

4. Using the developed algorithms, to provide a quality-controlled
assimilated UTLS ozone and water vapor dataset for the use of the
scientific community.

Contribution (d) can help to validate the assimilated dataset.

5. To assess the state of the UTLS and to understand the relevant
processes, using both assimilated data and other data records.

Contribution (b) can be one of the "other data records" mentioned.

6. To use the collected information under the points above to give a
comprehensive analysis of the anthropogenic impact on the UTLS region.

The contributions will contribute only indirectly to this objective
(by contributing to the other 5 objectives above).


Relationship to scientific program:

The contributions are mainly related to part C-1 "Observations" of the
scientific program.


Deliverables:

Main elements (a), (b), and (d) directly represent deliverables. Main
elements (c) and (e) represent scientific activities, for which the
deliverables will be scientific publications.


Indicative timetable:

Year 1   (a) Generic radiative transfer program for longwave remote sensing
Year 1-2 (b) 10 year UTH climatology from SSM-T2/AMSU
Year 1-4 (c) Validation of satellite humidity sensors
Year 1   (d) Water vapor retrieval algorithms for SSM-T2/AMSU
Year 1-4 (e) Instrument studies for advanced satellite sensors

Contribution (c) has to be carried out continuously, as new data
becomes available. Contribution (e) will also be carried out
continuously, it is tied into instrument study programs at ESA/ESTEC. 


Manpower:

The contributions will be made in the context of the German national
research Project UTH-MOS in the AFO-2000-C framework (grant
07ATC04). The contributions are to a large part identical to the
objectives of that project (see
http://www.sat.uni-bremen.de/projects/uth-mos/ for details). The
project itself will greatly benefit from the data available through
Action 723. The available manpower is 1 group leader, 1 postdoc, 1
computer scientist, and 2 PhD students, for the time period up to 2005
(first 3 years of the Action). 

Assurance of availability of resources:

Since the UTH-MOS grant is already in force, it is extremely unlikely
that the resources outlined above are not available. 

Foreseen collaboration:

?

Previous experience:

Radiative transfer modeling work:

#   T. R. Sreerekha, S. Buehler, C. Emde: A Simple New Radiative
Transfer Model for Simulating the Effect of Cirrus Clouds in the
Microwave Spectral Region. Journal of Quantitative Spectroscopy and
Radiative Transfer, accepted for publication.

#   T. Kuhn, A. Bauer, M. Godon, S. Buehler, K. Kuenzi: Water vapor
continuum; absorption measurements at 350 GHz and model
calculations. Journal of Quantitative Spectroscopy and Radiative
Transfer Volume 74, Issue 5, pp 545-562, 2002.

#   S. Buehler and P. Eriksson (Editors): Atmospheric Millimeter and
Sub-Millimeter Wave Radiative Transfer Modeling, ISBN 3-8265-7486-9,
Shaker Verlag GmbH, 2000.  

Water vapor retrieval:

#   Stefan Buehler: Microwave Limb Sounding of the Stratosphere and
Upper Troposphere, ISBN 3-8265-4745-4, Shaker Verlag GmbH, 1999.  

New sensors:

Experience from numerous ESTEC studies for SOPRANO, MASTER (now
ACECHEM), and WATS (now ACE+)