Avaliação de perfis atmosféricos de rádio ocultação GPS do satélite CHAMP sobre a América do Sul
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Data
2010-06-01
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Sociedade Brasileira de Meteorologia
Resumo
Com o advento dos satélites artificiais Global Positioning System (GPS) em conjunto com os satélites Low Earth Orbiting (LEO), surge a Rádio Ocultação GPS (RO GPS), técnica que permite obter remotamente perfis atmosféricos com boas perspectivas para aplicações em modelagem numérica de tempo. O satélite LEO denominado Challenging Minisatellite Payload of Geophysical Research and Application (CHAMP), embora tenha sido lançado com o objetivo principal voltado para estudos geofísicos, tem permitido também acessar o potencial da RO GPS. Nesse trabalho objetiva-se avaliar a qualidade dos perfis atmosféricos obtidos com o satélite CHAMP sobre a América do Sul, comparando-os com os perfis provenientes de radiossondagens e da reanálise regional de 5 anos do CPTEC/INPE. Os resultados da comparação entre os perfis obtidos por RO GPS e por radiossondas, apontam uma diferença média na temperatura abaixo de 1K e um desvio padrão de até 3K, distribuídos na camada entre 9 e 18 km. Os resultados da comparação entre os perfis de temperatura advindos de RO GPS e da reanálise do CPTEC entre 9 e 13 km, mostram que o viés é praticamente nulo e o desvio padrão próximo a 1K.
With the advent of Global Positioning System (GPS), together with Low Earth Orbit (LEO) satellites, the Radio Occultation GPS (RO GPS) technique appears as a possibility of obtaining atmospheric profiles remotely, with positive perspectives of applications in atmospheric numerical modeling. The LEO satellite mission denominated Challenging Minisatellite Payload of Geophysical Research and Application (CHAMP), although with the main objective being in the area of geophysical studies, it has also allowed studies about the potential of RO-GPS. This study is related to the evaluation of the atmospheric profiles quality obtained by the LEO CHAMP satellites over South America, comparing them to radiosondes profiles and of regional reanalysis of five years from CPTEC/INPE. The results of the comparisons between RO GPS and RSO profiles pointed out a mean temperature difference below 1 K and a standard deviation of up to 3 K, distributed in altitudes from 9 to 18 km. The comparisons of temperature profiles from RO GPS and CPTEC's reanalysis between 9 and 13 km showed that the bias is almost null and the standard deviation is around 1 K.
With the advent of Global Positioning System (GPS), together with Low Earth Orbit (LEO) satellites, the Radio Occultation GPS (RO GPS) technique appears as a possibility of obtaining atmospheric profiles remotely, with positive perspectives of applications in atmospheric numerical modeling. The LEO satellite mission denominated Challenging Minisatellite Payload of Geophysical Research and Application (CHAMP), although with the main objective being in the area of geophysical studies, it has also allowed studies about the potential of RO-GPS. This study is related to the evaluation of the atmospheric profiles quality obtained by the LEO CHAMP satellites over South America, comparing them to radiosondes profiles and of regional reanalysis of five years from CPTEC/INPE. The results of the comparisons between RO GPS and RSO profiles pointed out a mean temperature difference below 1 K and a standard deviation of up to 3 K, distributed in altitudes from 9 to 18 km. The comparisons of temperature profiles from RO GPS and CPTEC's reanalysis between 9 and 13 km showed that the bias is almost null and the standard deviation is around 1 K.
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Palavras-chave
RO GPS, GPS meteorologia, Reanálise CPTEC, RACCI, RO GPS, GPS meteorology, CPTEC Reanalysis, RACCI
Como citar
Revista Brasileira de Meteorologia. Sociedade Brasileira de Meteorologia, v. 25, n. 2, p. 147-155, 2010.