Using GPS Radio Occultation Data Operationally at NOAA: Plans and Issues James G. Yoe NOAA/NESDIS Office of Research and Applications (ORA) Climate Research and Applications Division (CRAD) M.K. Rama Varma Raja Information Management Systems Group (IMSG)

Overview Activities Past & Present Anticipated GPS/RO Applications Operational Issues Foreseen Plans for Addressing Issues Summary

NOAA Participants NESDIS/ORA and Office of Systems Development –J. Yoe, Rama Varma Raja, J. Silva, and D. McGinnis, NESDIS/CIMSS –Eva Borbas and Paul Menzel Integrated Program Office for NPOESS –Stephen Mango National Centers for Environmental Prediction - NCEP –Stephen Lord, John Derber, D. Keyser, and Mel Gelman Joint Center for Satellite Data Assimilation - JCSDA –NCEP plus NASA’s J. Joiner and P. Poli

Early NOAA GPS/RO Initial NIH (“Not Invented Here”) reaction, but Interest in complementary sounding grew –All weather, Vertical Resolution, Accuracy Possibilities for climate application –Lack of conventional upper level soundings Potential for Numerical Weather Prediction Vertical coverage, number, computational cost (Matsumura, et al, 1999)

Recent/Current Emphasis Workshop, Washington DC May 2000 Support development of operational missions –NPOESS/GPSOS and METOP/GRAS –Requirements, reviews/TIMS, OAT and IFCT Support for external missions –COSMIC (CDAAC development support) Product development –Borbas et al, 2003 – Combined T and e soundings Prototype mission assessment on-going –GPS/MET, OERSTED, SAC-C, CHAMP (next slides)

Depth of RO Soundings Achieved by CHAMP Compare to GPS/MET with median cut-off height ~ 500 mb. Improved HW, firmware, and software have extended vertical coverage for RO. Note that Kuo et al (2003) still find enhanced refractivity bias (against model predictions) below 5 km.

Operational Applications Climate Monitoring, Analysis, & Prediction –NWS/NCEP/CPC and NESDIS/STAR SCMD Explore upper stratospheric temperature trends Investigate refractivity as a climate data record Satellite Data Calibration and Validation –NESDIS/ORA/CRAD Intercomparisons of GPS/RO and radiometric soundings Numerical Weather Prediction –NWS/NCEP/EMC and JCSDA –Assimilation and Impact assessment

Operational Issues CRITICAL issues are TEMPORAL Affected Application is NWP –Receiving and formatting (BUFR) of data in time for model cycle inclusion –Cost in computational time – First operational missions are imminent GRAS COSMIC

Actions Planned (I) GPS/RO team formed at JCSDA –NASA/DAO, NCEP, NESDIS POCS – Joiner, Derber, Yoe –Collaboration with UCAR and the NSF –Three Young Scientists to be hired RO Modeling (Dr. Lidia Cucurull 04/01/03) RO/advanced sounder specialist at JCSDA Advanced sounder/RO specialist at UCAR All to interact closely –End-to-end GPS/RO data assimilation, error characterization, impact assessment

Actions (II) GPS/RO Workshop Planned –Washington, DC Area –October 28 – 30, 2003 (to be confirmed) –Point of Contact: General Announcement by this month WebPage will be set-up to keep info current –Purpose is to advance, accelerate, and optimize operational usage of GPS/RO for NWP

WS Goals Science –Emphasize robustness/stability, documentation –Avoid “academic” diversions Engineering –Emphasize efficiency and stability of IT, communications, data handling Welcome GRAS, European participation –At workshop and beyond

Summary Considerable scientific, technical, and programmatic progress has been made world- wide with GPS/RO Varied products/applications anticipated –Bending angles, N (NWP) –T, N (Climate) – Moisture products (Inter-satellite cal/val) Critical issue now is preparation for effective use –Especially for NWP –Efficient collaboration & exchange