GNSS Radio Occultation Constellation Observing System Experiments

AbstractObserving system experiments within the operational ECMWF data assimilation framework have been performed for summer 2008 when the largest recorded number of Global Navigation Satellite System (GNSS) radio occultation observations from both operational and experimental satellites were available. Constellations with 0%, 5%, 33%, 67%, and 100% data volume were assimilated to quantify the sensitivity of analysis and forecast quality to radio occultation data volume. These observations mostly constrain upper-tropospheric and stratospheric temperatures and correct an apparent model bias that changes sign across the upper-troposphere–lower-stratosphere boundary. This correction effect does not saturate with increasing data volume, even if more data are assimilated than available in today’s analyses. Another important function of radio occultation data, namely, the anchoring of variational radiance bias corrections, is demonstrated in this study. This effect also does not saturate with increasing data vo...

[1]  D. P. DEE,et al.  Bias and data assimilation , 2005 .

[2]  Christian Rocken,et al.  The COSMIC/FORMOSAT-3 Mission: Early Results , 2008 .

[3]  W. G. Melbourne,et al.  Initial Results of Radio Occultation Observations of Earth's Atmosphere Using the Global Positioning System , 1996, Science.

[4]  Dick Dee,et al.  Adaptive bias correction for satellite data in a numerical weather prediction system , 2007 .

[5]  R. Treadon,et al.  Assimilation of Global Positioning System Radio Occultation Observations into NCEP’s Global Data Assimilation System , 2007 .

[6]  Paul Poli,et al.  Preliminary assessment of the scalability of GPS radio occultations impact in numerical weather prediction , 2008 .

[7]  Godelieve Deblonde,et al.  Impact of the Assimilation of CHAMP Refractivity Profiles on Environment Canada Global Forecasts , 2008 .

[8]  Jean-Noël Thépaut,et al.  Assimilation experiments with CHAMP GPS radio occultation measurements , 2006 .

[9]  Paul Poli,et al.  Assimilation of Global Positioning System radio occultation data in the ECMWF ERA–Interim reanalysis , 2010 .

[10]  Rolf König,et al.  Atmosphere sounding by GPS radio occultation: First results from CHAMP , 2001 .

[11]  Paul Poli,et al.  Quality Control, Error Analysis, and Impact Assessment of FORMOSAT-3/COS MIC in Numerical Weather Prediction , 2009 .

[12]  D. Dee,et al.  Variational bias correction of satellite radiance data in the ERA‐Interim reanalysis , 2009 .

[13]  M. Rennie,et al.  The impact of GPS radio occultation assimilation at the Met Office , 2010 .

[14]  X. Zou,et al.  Analysis and validation of GPS/MET data in the neutral atmosphere , 1997 .

[15]  Erik Andersson,et al.  Influence‐matrix diagnostic of a data assimilation system , 2004 .