GPS Radio Occultation: Results from CHAMP, GRACE and FORMOSAT-3/COSMIC

Abstract

AB STRACTThe Tai wan/US FORMOSAT-3/COS MIC (FORMOsa SAT el lite mis sion -3/Con stel la tion Ob serv ing Sys tem for Me te o rol ogy, Ion o sphere and Cli mate) sat el lite con stel la tion was suc cess fully launched on 14 April 2006. It is ex pected to le ver age the use of the GPS (Global Po si tion ing Sys tem) ra dio occultation data for at mo spheric and ion o spheric re search to im prove global weather fore casts and aid cli mate change re lated stud ies. FORMOSAT-3/COS MIC, to gether with the Eu ro pean MetOp, Ger man CHAMP and US/Ger man GRACE-A sat el lites, form a 9 sat el lite con stel la tion for pre cise at mo spheric sound ing on a global scale. This sat el lite con stel la tion is expected to provide about 3500 occultation measurements daily.Re cent re sults and the sta tus of the CHAMP and GRACE-A or bit and occultation data anal y sis are re viewed and com ple mented with a re view of ini tial re sults from FORMOSAT-3/COS MIC at GFZ. The sig nif i cantly in creased po ten tial of the CHAMP, GRACE-A and FORMOSAT-3/COS MIC con stel la tion for at mo spheric stud ies, com pared to sin gle sat el lite mis sions, is dem on strated for se lected ap pli ca tions such as global mon i tor ing of wa ter va por dis tri bu tions, tropo pause parameters and ionospheric irregularities.

Exploring Earth's atmosphere with radio occultation: contributions to weather, climate and space weather

“…Radio occultation observations are well suited for establishing a stable, long-term record required for climate monitoring (Goody et al, 1998;Steiner et al, 2001Steiner et al, , 2009Leroy et al, 2006a,b;Mannucci et al, 2006;Foelsche et al, 2008aWickert et al, 2009). In spite of the enormous importance of detecting climate trends, before RO there were no global atmospheric observing systems that could meet the stringent climate monitoring requirements of 0.5 K accuracy and better than 0.10 K decade −1 stability (Ohring et al, 2005;Luntama et al, 2008).…”

Semidiurnal tidal signature in sporadic E occurrence rates derived from GPS radio occultation measurements at higher midlatitudes

“…Recent RO missions like the German CHAMP (Wickert et al, 2009), the U.S./German GRACE and the joint Taiwan-US FORMOSAT-3/COSMIC (Anthes et al, 2008) constellation are providing a total of ∼3000 globally distributed measurements per day. GPS radio occultation measurements from LEO (Low Earth Orbiter) satellites have already successfully been used to derive vertical profiles of ionospheric electron density (e.g., Hajj and Romans, 1998;Jakowski et al, 2002).…”

“…Therefore it is not possible to observe sporadic E layers at higher altitudes where its formation might be influenced by the meridional wind or the descending intermediate layers. A more detailed description and initial results of the application of this technique are given by Arras et al (2008) and Wickert et al (2009).…”

Ionospheric electron density observed by FORMOSAT-3/COSMIC over the European region and validated by ionosonde data

“…Straus et al 2003), CHAMP (e.g. Jakowski et al 2002;Jakowski 2005;Wickert et al 2009), GRACE (e.g. Beyerle et al 2005).…”