edu.ucar.opensky::articles:17339 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T16:11:23.883255 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7hq4173 Impact of 837 GPS/MET bending angle profiles on assimilation and forecasts for the period June 20 - 30, 1995 2001-12-16T00:00:00Z publication https://n2t.org/ark:/85065/d7hq4173 https://doi.org/10.1029/2001JD000345 Liu, H. author Zou, X. author Shao, H. author Anthes, Richard A. author Chang, J. author Tseng, J. author Wang, B. author UCAR/NCAR - Library publisher With a ray-tracing procedure and variational data assimilation techniques, it is now possible to make direct use of radio occultation bending angles, rather than their derived temperature and moisture retrievals, in atmospheric data analysis and assimilation. This paper describes results obtained from including more than 800 GPS/MET bending angle profiles, available over an 11-day period, 20 - 30 June 1995, into the National Centers for Environmental Prediction spectral statistical interpolation analyses. The methodology for assimilating the bending angles (including an impact parameter offset correction) is briefly summarized. Verified with 56 collocated radiosonde profiles, the assimilation of only GPS/MET bending angles improves the temperature and specific humidity analysis above 850 mbar. Even though the number of GPS/MET soundings is still far less than conventional data and operational satellite soundings, our results from two continuous 11-day data assimilation cycles demonstrate a closer fit of both GPS/MET and conventional observations to the analyses between 850 and 200 hPa when the bending angles are incorporated. Including the bending angles also results in a small but consistent improvement in the short-range (6 hours) and medium-range (1 - 5 days) forecast skills, especially in the Southern Hemisphere. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication An edited version of this paper was published by the American Geophysical Union. Copyright 2001 AGU. None eng geoscientificInformation