A43A-0240
COMPARISON OF GROUND TECHNIQUES USED TO ESTIMATE CLOUD COVER
Thursday, 17 December 2015
Poster Hall (Moscone South)
Mariza Pereira de Souza Echer, INPE National Institute for Space Research, Geophysics, Sao Jose dos Campos, Brazil, Fernando Ramos Martins, Universidade Federal de São Paulo, Department of Marine Science, Santos, Brazil, Marcos Luiz de Andrade Pinto, Centro Tecnico Aeroespacial, São José dos Campos, Brazil and Williamary Portugal, INPE National Institute for Space Research, Geophysics - CEAII, Sao Jose dos Campos, Brazil
Abstract:
Clouds are the most important factor modulating the solar radiation incident on the earth’s surface. Information on cloud cover state also play significant role for several applications, as weather forecast and climate knowledge. Several studies have been conducted to establish a methodology and experimental setup in order to acquire reliable cloud cover data from remote sense observations performed on the surface. This work comparing ground data acquired by different systems for the same atmospheric scenario regarding cloud cover. We used two ground sites located at Florianópolis, Brazil, where cloud cover and solar irradiance data were acquired. Solar radiation data and sky images were acquired at SONDA station (-27◦28’, -48◦29’, 15m asl) and cloud cover data collected at the international airport meteorological station (-27◦40’, -48◦29’). This study compares these two datasets for sky scenarios presenting only stratocumulus cloud cover. The results show the complexity of the interaction process between solar irradiance and cloud cover and how it affects ground observations. It can be seen that even when sky is completely cloudy (8/8 or 100%) by a single type of cloud, the ratio between global and diffuse irradiance varied from 0.75 till 0.98.
