Tropopause Height Variabilities Derived from COSMIC GNSS Radio Occultation Observations over Nigeria

Abstract

This paper investigates the use of GNSS radio Occultation (RO) technique for tropopause height estimation over Nigeria. The changes or variations in the tropopause height is/are key indicators to anthropogenic climate change in the different region of the world. In this study, RO data from the Formosat‐3/COSMIC (Formosa Satellite Mission 3/Constellation Observing System for Meteorology, Ionosphere, and Climate) mission for the period of 2012-2016 were used to probe the tropopause height over Nigeria. Firstly, the atmospheric profiles from the COSMIC mission were checked with ground in-situ observations (radiosonde) at two different epochs and good agreement was established between the two observing systems. The COSMIC mission is able to map the variations in solar illumination as represented in the tropopause height variation over the Nigerian region. The tropopause height varies between 15 and 18km across the different seasons and a typical range of difference between -0.235 to 3.125km was recorded between the COSMIC RO and radiosonde observations. In view of the great potential that the COMIC RO has demonstrated, the study recommends for further exploration of the troposphere utilizing datasets from recent and expected follow-on missions for the different RO missions.