Radio-Occultation based Monthly Gridded Dry Temperature, Bending Angles, and Refractivities

Introduction Radio occultation uses observed radio wave bending angles from global navigation satellite systems (including GPS and GLONASS) to derive atmospheric properties. The resulting derived profiles provide a high-accuracy, high vertical resolution, limited footprint, product featuring atmospheric variables such as dry temperature and refractivity. For more detailed information please refer to https://www.cosmic.ucar.edu/what-we-do/gnss-radio-occultation This gridded, monthly mean dataset is constructed through merging 13 radio occultation (RO) profile datasets provided by the COSMIC Data Analysis and Archive Center (CDAAC) and subsequently gridding into a monthly 5°x10° product. All valid (non-bad flagged) profiles from each mission were incorporated with the exception of COSMIC-2 data, which was bound to profiles within the 30 S - 30 N latitude window due to discrepancies found at higher latitudes. All tropopause calculations were carried out independently from CDAAC calculations and were derived directly from the profile data. Specifications Included datasets: Name Date Range Profile Count CHAMP 2002/03/01-2008/10/05 404,558 COSMIC 2006/04/22-2020/04/25 5,788,267 COSMIC-2 2019/10/01-2025/05/31 8,106,885 GRACE 2007/02/28-2017/11/30 428,668 KOMPSAT-5 2015/01/22-2025/05/31 614,590 MetOp-A 2007/10/01-2021/11/27 2,875,424 MetOp-B 2013/02/01-2025/05/31 2,198,720 MetOp-C 2019/07/14-2025/05/30 804,099 PAZ 2018/05/10-2025/05/31 267,172 SAC-C 2006/03/09-2011/08/03 348,812 Spire 2020/12/16-2025/05/31 3,874,933 TamDEM-X 2016/01/01-2025/05/31 292,896 TerraSAR-X 2008/02/10-2025/05/31 868,648 Gridded Resolution: 5° Latitude, 10° Longitude, 200 m Vertical for Dry Temperature 5° Latitude Zonal Mean, 200 m Vertical for Bending Angle and Refractivity 5° Latitude, 10° Longitude for tropopause parameters Variables included: Dry Temperature, (Temp), 10 – 40 km Bending Angle, (Bend_ang), 0 – 60 km Refractivity, (Ref), 0 – 60 km Tropopause Parameters Cold Point Temperature (cpt) (for latitudes 30 N - 30 S) Lapse Rate Tropopause (lapse_rate) Potential Temperature Gradient Tropopause (ptgt) Data Timeframe: March 2002 – May 2025