Comparative Assessment of COSMIC Radio Occultation Data and TIMED/SABER Satellite Data over China

Abstract

he accuracy of temperature data from the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) radio occultation and Thermosphere, Ionosphere, Mesosphere Energetics, and Dynamics/Sounding of the Atmosphere using Broadband Emission Radiometry (TIMED/SABER) observation over China is analyzed. High-resolution sounding data are used to assess the accuracy of these two kinds of satellite observation data at corresponding heights, and the two sets of data are compared in the height range 15?40 km. Very good agreement between radiosondes and COSMIC is observed in the stratosphere. In the troposphere COSMIC temperatures are about 2 K higher than the radiosonde observations. SABER detection at 15?32 km agrees well with a maximum warm bias of ~2 K around 25-km altitude. The comparison between SABER and COSMIC for altitudes 15?40 km also indicates higher temperatures of SABER in the lower stratosphere. The standard deviations are all greater than 2.5 K and are larger near 15 km and smallest at 20 km. The temperature deviation and in particular the standard deviation comparing SABER and COSMIC changes with altitude, season, and latitude. The results of this comparative assessment can offer a basis for research into the application of COSMIC and TIMED/SABER over China.