Análise de distúrbios ondulatórios de leste sobre o Oceano Atlântico Equatorial Sul / Analysis of wave disturbances from east over equatorial South Atlantic Oceanic

AUTOR(ES)
DATA DE PUBLICAÇÃO

1990

RESUMO

Using the National Meteorological Center (NMC) daily data and Outgoing Longwave Radiation data (OLR), this study focus on the main features of wave disturbances over the Equatorial Atlantic Ocean, vicinity of South America, during the First GARP Global Experiment (FGGE). Hovmoller diagrams and spectrum analysis of the meridional component of wind at 850 hPa are used to estimate the time scale and the propagation features of wave disturbances. Analysis of Hovmoller diagrams reveal, throughout the year, the existence of waves propagating westward with a period of 5-6 days, phase speed of 10-12 m/s, and wavelength of about 4800-6200 km. During the southern autumn, the waves are relatively short while during the southern winter the waves are relatively long. Also during these seasons the amplitude of the waves are relatively larger than during the other seasons. These disturbances are only weakly observed in OLR data, while disturbances of 10-30 days and 30-60 days period were more evident. Power spectra of meridional wind component show peaks between 3-5 days over the Atlantic Ocean at 5°S. These peaks are more prominent during autumn and winter and at about 20°W and 25°W. Cross spectra indicate waves travelling westwards at speed of 9.5 m/s and wavelength of 3300 km during southern autumn, and at phase speed of 15 m/s and wavelength of about 5200 km during southern winter.

ASSUNTO(S)

disturbios equatoriais climatologia atlantic ocean meteorologia equatorial disturbance oceano atlantico equatorial sul meteorology climatology

ACESSO AO ARTIGO

Documentos Relacionados