Inversion and Analysis of Atmospheric Boundary Layer Height Using FY-3C Radio Occultation Refractive Index Data

  Objectives  The first meteorological satellite for global navigation satellite system (GNSS) radio occultation (RO) observation of China, Fengyun-3C (FY-3C), whose products have been released since June 2014, was launched in 2013. But the references about the application of FY-3C RO data in the study of atmospheric boundary layer height (ABLH) are still not available.

  Methods  Firstly, we derived ABLH values by the wavelet covariance transform (WCT) method, based on FY-3C RO refractive index data. Secondly, the feasibility of the method was verified by representative and statistical comparison with the ABLH inversion results of COSMIC (constellation observing system for meteorology ionosphere and climate) RO refractive index data. Then, we presented the global distribution of FY-3C ABLHs, and made a detailed analysis.

  Results  The heights of steep transitions in the FY-3C RO refractivity index profiles of lower atmosphere, which correspond to the ABLHs, can be derived by using the WCT method with constraints on relative sharpness. The latitudinal differences and land-sea differences in the global distributions of ABLHs basically reflect the relationship between ABLH and climate and topography.

  Conclusions  Because of the low precision and vertical resolution of FY-3C RO products in the lower atmosphere, the success rate for the inversion process is not high on the whole, and the representations on the detailed characteristics of the distribution of ABLH need to be improved.