COSMIC Data Analysis and Archival Center Status and Challenges C. Rocken

Key Achievements Over 3 Million profiles All six satellites continue to operate Switched to NOAA ground stations (and added McMurdo & Wallops) Daily count holds at ~1800 in spite of slowly degrading satellite performance Advanced understanding of refractivity biases First new GPS “L2C” test results - no soundings lost due to “bad L2” Agreement to obtain global fiducial data from EUMETSAT

3.2 Million Profiles pass QC 1.5 Million Neutral Atmosphere 1.7 Million Ionosphere 952 registered data users & major operational weather centers

Data Latency: ~90% < 3hours

Mission Overview: Total Count by satellite

Statistical comparison of COSMIC-retrieved N to ECMWF SNR (60-80km) > 800 V/V SNR (60-80km) < 600 V/V Positive N-bias (~0.7% between 2-6 km) - due to antenna gain limitation (only low SNR soundings affected) Negative N-bias (~0.5% in bottom 2 km) - due to antenna gain limitation and possibly atmospheric super refraction

RO Biases and Solar Activity BA Bias F10.7 solar flux 6-year 60-80 km bending angle bias from CHAMP F10.7 Flux vs. Bending Angle bias regression Changes in solar activity(diurnal and 11-year solar cycle) introduce changes in the RO bias. These changes are significant for the RO climate record > 20 km Discussion of magnitude, causes, correction methods in COSMIC Workshop on Wednesday afternoon (last talk)

A remaining bias puzzle …. Compared to ECMWF rising occultations have a larger N bias > 20 km than setting occs. We do not see this bias compared to NCEP/GFS This bias difference is not understood yet.

Tracking the new L2C GPS signal (height where L2 data stop) Only 25% of L2 is tracked < 10 km - compared to 90% of L2C. 30% of L2 tracking data cannot be processed compared to ~1% of L2C.

Tasks for next year Continue to improve COSMIC products Work with JPL on firmware: L2C open loop, “SNR splitting”, rising occultation count improvement, … Modify CDAAC processing to: Restructure processing for climate products Higher resolution vs. lower noise processing mode tradeoff & decision (talk on Wed. 1:45) Increase occultation count by relaxing L2 QC Improve space weather processing (new scientist will come on board) Support development of follow-on mission(s)

Summary Goals of data quality, latency, and reliability are met or exceeded for over 3.2 million profiles Daily occultation count is currently ~1800 profiles Increasing count proved difficult against backdrop of degrading hardware - but we have one more “card to play”: relaxing our L2 QC Current research into small RO biases yields interesting insight and helps with planning for future mission