INITIAL RESULTS OF RADIO OCCULTATION OBSERVATIONS OF EARTHS ATMOSPHERE USING THE GLOBAL POSITIONING SYSTEM

Recent radio occultation measurements using Global Positioning System satellite transmitters and an orbiting receiver have provided a global ly distributed set of high-resolution atmospheric profiles, suggesting that the technique may make a significant contribution to global chan ge and weather prediction programs. Biases in occultation temperatures relative to radiosonde and model data are about 1 kelvin or less in t he tropics and are generally less than 0.5 kelvin at higher latitudes. Data quality is sufficient to quantify significant model errors in re mote regions. Temperature profiles also reveal either an equatorial Ro ssby-gravity or an inertio-gravity wave. Such waves provide a fundamen tal source of momentum for the stratospheric circulation.