Abstract
The influence of interannual components (wavenumbers 2 - OCA2 and 3 - OCA3) of the Antarctic Circumpolar Wave on regional annual precipitation anomalies of Rio Grande do Sul was investigated using meteoceanographic data covered the period from 1981 to 2006. The results found here showed that while there is a clearest pattern of association between the behavior of OCA3 along the extratropical latitude belt and annual precipitation anomalies in the four homogeneous regions identified in the RS, the same was not observed for OCA2. It was found that SLP anomalies associated with OCA3 on the west sector of the South Atlantic Ocean, appear to have a major role in the modulation of annual precipitation anomalies in Rio Grande do Sul. On the other hand, the SST anomalies associated with OCA3 seem to have a secondary role. Moreover, was observed a strong influence of both components on annual precipitation anomalies by local annual anomalies of specific humidity. The patterns of association between the behavior of OCA2 and OCA3 components and the annual precipitation anomalies founded here provide important informations to both the understanding of the climate in the state and for the improvement of climate forecasts for the RS.
Keywords:
Antarctic Circumpolar Wave; Rio Grande do Sul; annual anomalies of precipitation
