Energética do trem de Onda Associado às Geadas em Latitudes Tropicais

PICCININI SILVEIRA VIRGINIA; MÜLLER GABRIELA V; GAN, MANOEL ALONSO; AMBRIZZI, TÉRCIO

Belén, Brasil

Congreso; XVI Congresso Brasileiro de Meteorologia; 2010

SMBET

This study presents a new vision on the extreme cold events that affect the tropical region of South America considering the energetic of wave train propagation associated to these systems. The geopotential height composite analysis indicate that the extreme cold events observed in tropical latitudes are associated with a single Rossby wave pattern propagating in the Pacific Ocean which rapidly drives the low level anticyclone from the southwest of the continent to low latitudes. This propagation involves a southern circulation due to the meridional wind penetration and consequently polar advection causing temperatures to drop below 0ºC. The evolution of the kinetic energy maxima for frost events shows that the Downstream Development term was very important to the formation and to modulate the intensification and dissipation phase of the kinetic energy maxima. However, the baroclinic instability conversion was more important to increase the energy maxima.