Abstract
CHAMPCLIM is a joint project of WegCenter/UniGraz and GFZ Potsdam. The overall aim of the project is to exploit the CHAMP (CHAllenging Minisatellite Payload for geoscientific research) radio occultation (RO) data in the best possible manner for climate monitoring. This paper focuses on describing the pre-operational status and technical aspects of the CHAMPCLIM processing system at WegCenter/UniGraz. For creating RO based climatologies we ingest, on the one hand, the complete CHAMP RO dataset provided by GFZ at excess phase level (GFZ level 2, ∼180 profiles/day), which is processed to obtain atmospheric profiles of refractivity, geopotential height, and temperature (in future also humidity). On the other hand, we use operational atmospheric analysis fields from the European Centre for Medium-Range Weather Forecasts (ECMWF), at T42L60 resolution, as reference for quality control and evaluation. For delivering climatologies operationally, which will be prepared at monthly, seasonal, and annual time scales, our aim is to provide them with a delay of at most two weeks after the last measurement (e.g., JJA 2003 seasonal climatology available by September 14, 2003, latest). The climatologies are set up in overlapping equal-area and non-overlapping almost equal-area grids. In order to monitor the error characteristics of the climatologies, various types of error statistics (vs. ECMWF analyses) are performed. The main emphasis of this paper lies on processing the complete 2002–2004 data — starting from March 2002 when the CHAMP data stream became stable and quasi continuous — and on creation of climatologies including error estimates. The spatial set up of the climatologies, exemplary seasonal climatologies (as far as processed) as well as preliminary climatological error estimates are presented.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsPreview
Unable to display preview. Download preview PDF.
References
Foelsche U, Gobiet A, Loescher A, Kirchengast G, Steiner AK, Wickert J, Schmidt T (2005) The CHAMPCLIM Project: An Overview. In: Reigber C, Luehr H, Schwintzer P, Wickert J (eds) Earth Observation with CHAMP: Results from Three Years in Orbit. Springer, Berlin, pp 615–620
Foelsche U, Gobiet A, Steiner AK, Borsche M, Wickert J, Schmidt T, Kirchengast G (2006) Global Climatologies Based on Radio Occultation Data: The CHAMPCLIM Project. This issue
Gobiet A, Kirchengast G (2004) Advancements of Global Navigation Satellite System Radio Occultation Retrieval in the Upper Stratosphere for Optimal Climate Monitoring Utility. J Geophys Res 109(D24110), doi: 10.1029/2004JD005117
Gobiet A, Steiner AK, Retscher C, Foelsche U, Kirchengast G (2004) Radio Occultation Data and Algorithms Validation Based on CHAMP/GPS Data. IGAM/Uni Graz Tech Rep for ASA No 1/2004
Gobiet A, Foelsche U, Steiner AK, Borsche M, Kirchengast G, Wickert J (2005) Climatological validation of stratospheric temperatures in ECMWF operational analyses with CHAMP radio occultation data. Geophys Res Lett 32(L12806), doi:10.1029/2005GL022617
Hedin AE (1991) Extension of the MSIS thermosphere model into the middle and lower atmosphere. J Geophys Res 96:1159–1172
Hocke K, Igarashi K, Tsuda T (2003) High-resolution profiling of layered structures in the lower stratosphere by GPS occultation. Geophys Res Lett 30(8):1426, doi:10.1029/2002GL016566
Kirchengast G, Fritzer J, Ramsauer J (2002) End-to-end GNSS Occultation Performance Simulator Version 4 (EGOPS4) Software User Manual (Overview and Reference Manual). Tech Rep for ESA/ESTEC, Inst for Geophys, Astrophys, and Meteorol, Univ of Graz, Austria, No 3/2002
Löscher A, Kirchengast G (2006) Assimilation of GNSS Radio Occultation Profiles into GCM Fields for Global Climate Analysis. This issue
Schmidt T, Wickert J, Beyerle G, König R, Galas R, Reigber C (2005) The CHAMP Atmospheric Processing System for Radio Occultation Measurements. In: Reigber C, Luehr H, Schwintzer P, Wickert J (eds) Earth Observation with CHAMP: Results from Three Years in Orbit. Springer, Berlin, pp 597–602
Steiner AK, Gobiet A, Foelsche U, Kirchengast G (2004) Radio Occultation Data Processing Advancements for Optimizing Climate Utility. IGAM/Uni Graz Tech Rep for ASA No 3/2004
Syndergaard S (1999) Retrieval analysis and methodologies in atmospheric limb sounding using the GNSS radio occultation technique. DMI Sci Rep 99-6, Danish Meteorol Inst, Copenhagen, Denmark
Vorob’ev VV, Krasil’nikova TG (1994) Estimation of the accuracy of the atmospheric refractive index recovery from Doppler shift measurements at frequencies used in the NAVSTAR system. Phys Atmos Ocean 29:602–609
Wickert J, Galas R, Schmidt T, Beyerle G, Reigber C, Förste C, Ramatschi M (2004) Atmospheric sounding with CHAMP: GPS ground station data for occultation processing. Phys Chem Earth 29:267–275
Wickert J, Schmidt T, Beyerle G, Michalak G, König R, Heise S, Reigber C (2006) GPS radio occultation with CHAMP and GRACE: Recent results. This issue
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2006 Springer-Verlag Berlin Heidelberg
About this chapter
Cite this chapter
Borsche, M. et al. (2006). Pre-Operational Retrieval of Radio Occultation Based Climatologies. In: Foelsche, U., Kirchengast, G., Steiner, A. (eds) Atmosphere and Climate. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-34121-8_26
Download citation
DOI: https://doi.org/10.1007/3-540-34121-8_26
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-34116-1
Online ISBN: 978-3-540-34121-5
eBook Packages: Earth and Environmental ScienceEarth and Environmental Science (R0)