Study of Atmospheric Processes over the Maritime Continent with Radio Occultation Technique

Abstract:

The atmospheric limb sounding technique making use of radio signals transmitted by the Global Positioning System (GPS) satellites has emerged as a powerful and relatively inexpensive all weather global observing system. As demonstrated by the proof-of-concept GPS Meteorology (GPS/MET) experiment in 1995 and more recently by the CHAMP and SAC-C missions, the GPS radio occultation (RO) sounding data are shown to be of high accuracy and high vertical resolution. The GPS RO data provided by the joint U.S.-Taiwan COSMIC/FORMOSAT-3 mission, a constellation of six microsatellites launched in 2006, have been shown to be extremely valuable for global numerical weather prediction, and the study of weather and climate processes. In particular, the temperature and moisture profiles derived from the GPS RO soundings have been found to be useful in revealing the salient vertical structure of the MJO. Stimulated by the success of the COSMIC mission, U.S. and Taiwan are developing a follow-on mission, known as COSMIC-2, which consists of a constellation of 12 satellites. The first tropical constellation of six satellites will be launched in May 2016 and the second polar constellation of another six satellites will be launched in 2019. COSMIC-2 will make use of an advanced receiver, and will track the Russian GLONASS system in addition to GPS. With the production of ~10,000 high quality radio occultation soundings per day, COSMIC-2 will be extremely valuable for the study of atmospheric processes over the maritime continent. In this presentation, we will discuss the applications of COSMIC-2 RO data to the study of MJO, and the support for the field campaign of the Year of Maritime Continent.