Comparisons of temperature profiles from nearby GPS radio occultations over a high wave activity region

LUNA, DIEGO; ALEXANDER PEDRO; DE LA TORRE ALEJANDRO; LLAMEDO PABLO; SCHMIDT TORSTEN; WICKERT JENS

Montreal, Canada

Congreso; COSPAR 2008; 2008

COSPAR

The Global Positioning System (GPS) Radio Occultation (RO) techniquehas global coverage and is capable of generating high verticalresolution temperature profiles of the troposphere and lower stratospherewith sub-Kelvin accuracy and long-term stability, regardlessof weather conditions. Fluctuations in these profiles give informationabout gravity waves. COSMIC is a six-satellite RO constellation,launched in April 2006, that performs a larger amount of occultationsper day than any previous mission. In this work, we take advantageof the anomalous high density of COSMIC occultation events at theeastern side of the highest Andes Mountains during the initial missionmonths. This region is well-known for its high gravity waveactivity. From 669 profiles examined in this zone, 50 pairs of themoccurring within 2 hours and 200 km of one another, were found. Wecompared these nearby cases. One particular pair has shown a significantdifference in the wave energy content associated to each profile.Numerical simulations with a mesoscale model were performed, inorder to understand this discrepancy. This kind of studies may helpto better understand the GPS RO retrieval process and its advantagesand drawbacks in describing atmospheric temperature.