The Assimilation of Radio Occultation Measurements

Assimilation of GPS Radio Occultation Data for Numerical Weather Prediction

With the availability of approximately 4,000 radio occultation soundings per day within three hours of observation, COSMIC has the potential to contribute significantly to global and regional weather analysis and prediction. However, the basic radio occultation measurements (phase delays) are very different from traditional meteorological measurements (i.e., temperature, water vapor), and to ef...

Validation of martian meteorological data assimilation for MGS/TES using radio occultation measurements

We describe an assimilation of thermal profiles below about 40 km altitude and total dust opacities into a general circulation model (GCM) of the Martian atmosphere. The data were provided by the Thermal Emission Spectrometer (TES) on board the Mars Global Surveyor (MGS) spacecraft. The results of the assimilation are verified against an independent source of contemporaneous data represented by...

Assimilation with a two-dimensional bending angle operator at ECMWF

ECMWF plans to start assimilating GPS radio occultation measurements with a two dimensional (2D) bending angle operator in 2014. We will describe the new operator, and explain how it has been implemented on the parallel computing system. Issues relating to the computational cost of the operator will be discussed, and a new hybrid approach using a 2D operator in the 4D-Var outer-loop and a 1D op...

Observation Operators for the Assimilation of Occultation Data into Atmospheric Models: A Review

During the past decade, researchers have been working to develop methods for the assimilation of Global Positioning System (GPS) radio occultation data into numerical weather prediction (NWP) models. Until recently, two strategies have received the most attention: 1) assimilation of the retrieved bending angle profiles, and 2) assimilation of the retrieved refractivity profiles. The assimilatio...

Evaluation of a non-local observation operator in assimilation of CHAMP radio occultation refractivity with WRF