caa a22 4500 467938016 CHVBK 20180406153003.0 cr unu---uuuuu 170328e20060601xx s 000 0 eng 10.1007/s00703-005-0162-7 doi (NATIONALLICENCE)springer-10.1007/s00703-005-0162-7 Observational study of the seasonality of the submonthly and intraseasonal signal over the tropics [Elektronische Daten] [M. I. Vitorino, P. L. da Silva Dias, N. J. Ferreira] Summary: Atmospheric variability in outgoing long-wave radiation (OLR) and tropospheric relative vorticity (VOR) over the South American region was studied from 1979 to 1996 using the complex Morlet wavelet function. The analyses focus on spatial variation in intraseasonal and submonthly scales. Scalograms were used to measure submonthly intraseasonal oscillations in convection, which were found to be predominant in the tropical regions. However, 7-day and 15-day oscillations were observed at tropical and extratropical latitudes in spring and winter, indicating that transient disturbances play a more prominent role. Regarding VOR, tropical energy intensities were highest in the spring and summer, whereas subtropical and extratropical energy intensities were highest in the autumn and winter. The dynamics of the 25-day and 45-day VOR oscillations indicates a possible correlation with Rossby waves over the eastern tropical Pacific Ocean, mainly during the summer. During winter, the 7-day and 15-day VOR oscillations are more frequent at higher latitudes and are enhanced along storm tracks. It was also observed that convection amplitudes in the regions of maximum intensity change appreciably from year to year and from season to season, showing that the behavior of the submonthly and intraseasonal oscillations is nonperiodic and correlates strongly with El Niño/Southern Oscillation years. These results confirm the efficiency of wavelet analysis for time-scale studies of atmospheric variability. Springer-Verlag, 2006 Vitorino M. I. Departamento de Ciências Atmosféricas, Instituto de Astronomia, Geofísica e Ciências Atmosféricas da Universidade de São Paulo, São Paulo, Brazil aut da Silva Dias P. L. Departamento de Ciências Atmosféricas, Instituto de Astronomia, Geofísica e Ciências Atmosféricas da Universidade de São Paulo, São Paulo, Brazil aut Ferreira N. J. Laboratório de Meteorologia e Oceanografia, Instituto Nacional de Pesquisas Espaciais, São Jose dos Campos, São Paulo, Brazil aut Meteorology and Atmospheric Physics Springer-Verlag 93/1-2(2006-06-01), 17-35 0177-7971 93:1-2<17 2006 93 703 https://doi.org/10.1007/s00703-005-0162-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00703-005-0162-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Vitorino M. I. Departamento de Ciências Atmosféricas, Instituto de Astronomia, Geofísica e Ciências Atmosféricas da Universidade de São Paulo, São Paulo, Brazil aut NATIONALLICENCE 700 1- da Silva Dias P. L. Departamento de Ciências Atmosféricas, Instituto de Astronomia, Geofísica e Ciências Atmosféricas da Universidade de São Paulo, São Paulo, Brazil aut NATIONALLICENCE 700 1- Ferreira N. J. Laboratório de Meteorologia e Oceanografia, Instituto Nacional de Pesquisas Espaciais, São Jose dos Campos, São Paulo, Brazil aut NATIONALLICENCE 773 0- Meteorology and Atmospheric Physics Springer-Verlag 93/1-2(2006-06-01), 17-35 0177-7971 93:1-2<17 2006 93 703 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer