Development of a ground-based microwave radiometer for retrieval of water vapor profiles of the middle atmosphere and determination of atmospheric opacity

• Processo: 01/02336-9
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Data de Início da vigência: 01 de agosto de 2001
• Data de Término da vigência: 31 de julho de 2004
• Área de conhecimento: Ciências Exatas e da Terra - Astronomia - Instrumentação Astronômica
• Acordo de Cooperação: DAAD
• Pesquisador responsável: Zulema Abraham
• Beneficiário: Hermann Josef Berg
• Instituição Sede: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brasil
• Vinculado ao auxílio: 00/06769-4 - A galáxia e a formação de estrelas, AP.TEM
• Assunto(s): Radiometria Aeronomia
• Palavra(s)-Chave do Pesquisador: Aeronomy | Atmospheric Opacity | Microwave Radiometry | Radioastronomy

Resumo

The objective of the proposed project is to develop, test and operate a high precision water vapor radiometer (WVR). The WVR will be a ground-based, passive heterodyne receiver that detects the centimeter wave emission of atmospheric water molecules. Altitude profiles of the volume mixing ratio of water vapor in the middle atmosphere (20-80 km) will be inverted from the shape of the detected spectral line at 22 GHz. Total column amounts of water vapor, cloud liquid water and the atmospheric opacity can be determined from elevation scans and by broadband measurements of a supplementary channel at 32 GHz. Due to the influence of water vapor on the propagation of electromagnetic waves, detailed data are strongly demanded for radio astronomy. Furthermore water vapor is the key gas that dominates weather and climate. It plays an important role in the dynamics, the radiative balance and the chemistry of the atmosphere ("ozone hole", "global change"). The results gathered by the WVR will contribute substantially to the field of aeronomy and are very important for the understanding of short term, daily and seasonal atmospheric opacity variations, from centimeter to submillimeter wavelengths. (AU)