Comparison of pressure, temperature and specific humidity from COSMIC-2 with radiosonde and ERA5

ABSTRACTPressure, temperature and specific humidity profiles from COSMIC-2 are compared with those from ERA5 and radiosonde data from October 2019 to September 2020. The results demonstrate that COSMIC-2 pressure and specific humidity profiles show relatively poor accuracy and stability in the lower troposphere. The 1D-Var solution effectively improves the accuracy of temperature parameters in the troposphere. Three parameters show high accuracy over one climatological year, but show slight seasonal fluctuations, especially for the specific humidity profiles in summer. Furthermore, COSMIC-2 specific humidity data show low consistency with radiosonde and ERA5 in the equatorial region.KEYWORDS: COSMIC-2ERA5radiosonde1D-Var AcknowledgementsThe authors would like to thank the UCAR (University Corporation for Atmospheric Research) for providing COSMIC-2 profiles data and University of Wyoming for providing radiosonde data. The ECMWF (European Centre for Medium-Range Meteorological Weather Forecasts) is appreciated for providing ERA5 reanalysis products. The numerical calculatione in this study have been done on the supercomputing system in the Supercomputing Center, Shandong University, Weihai.Disclosure statementNo potential conflict of interest was reported by the authors.Data availability statementThe COSMIC-2 profiles data can be downloaded from https://data.cosmic.ucar.edu/gnss-ro/cosmic2/nrt/level2/. The radiosonde data can be downloaded from http://weather.uwyo.edu/upperair/sounding.html. The ERA5 reanalysis products can be downloaded from https://www.ecmwf.int/en/forecasts/datasets/reanalysis-datasets/era5/.Additional informationFundingThis research is founded by the Startup Foundation for Doctors of Liaoning Province. [2021-BS-275], the Scientific Study Project for lnstitutes of Higher Learning, Ministry of Education, Liaoning Province [LJKMZ20220673], the Project supported by the State Key Laboratory of Geodesy and Earths' Dynamics, Innovation Academy for Precision Measurement Science and Technology [SKLGED2023-3-2]; Project supported by the State Key Laboratory of Geodesy and Earths'Dynamics, Innovation Academy for Precision Measurement Science and Technology.