Caracterização das circulações rotacional e divergente e as energias associadas sobre o setor tropical da América do Sul para dois meses de 1978.

Abstract

We present some aspects of Atmospheric Circulation on the Tropical sector of South America through the fields of rotational and divergent wind. Based on KRISHNAMURTI and RAMANATHAN (1982) we use daily data in grid points generated by the NATIONAL METEOROLOGYCAL CENTER (NMC) of the components zonal and southern wind for the months of March and June 1978. Periods of increasing and decreasing the horizontal gradient of the Velocity Potential between the North sector of South America, the South Atlantic Ocean and the Northeast Region of Brazil suggest the existence of a direct circulation cell over these regions. It is also verified, based on the spatial distribution of the Interaction Term, that over northern South America there is a predominance of energy transfer from the divergent component to the rotational component, while over the southern sector of South America the energy transfer and the rotational to divergent. About the northern sector of the Region Northeastern Brazil, the rotational mode receives energy in the divergent mode while over the southern sector of this region, and the rotational mode which gives energy to the divergent mode. The results show that the kinetic energy associated with the rotational component does not undergo significant variations in the upper troposphere over the northern and southern sectors of South America. In the four areas studied, the kinetic energy associated with the divergent and more representative component.