Influência das anomalias de TSM dos oceanos Pacífico Equatorial e Atlântico Tropical na dinâmica e termodinâmica em um ambiente de mesoescala experimental no Estado da Paraíba.

Abstract

Here focuses observational evidence and numerical modeling of the influence of SST anomalies in the equatorial Pacific Ocean (El Niño and La Niña) and the Atlantic (dipole interhemispheric SST) that permeate the modes of global climate variability (MGCV) on the life cycle a category of MCS, the mesoscale convective complex tropical (MCCT) commonly formed on the Northeast of Brazil - NEB. The analysis includes reanalysis data set ERA - interim type with full resolution output 6 on 6 hours of the European Center for Medium Range Wheather Forecasting (ECMWF), as a boundary condition and side to set a numerical mesoscale senary. Also includes data from daily and monthly precipitation of rain gauge stations for the period 1957-1998 from the monitoring network of the Agência Executiva de Gestão das Águas do Estado da Paraíba – AESA - PB. The BRAMS model was adjusted for this purpose, which we used two nested grids with spatial resolution of 5 km. The environment simulated mesoscale numerical efficiently reproduced the developmental stages of the life cycle of the CCMT, where he investigated the main atmospheric surface features, the vertical structure of the dynamics and thermodynamics of the system. Emphasized the role of the combined work between moisture convergence at low levels as a source of energy and the formation of a favorable moisture corridor between the surface and 850 hPa, the core mass convergence in the intermediate layers of the troposphere associated with the center upward movements of the convective instability and vertical wind shear in the genesis and maintenance of the system. After submitting mesoscale numerical scenario in MGCV environment, it was found: abolition of associated upward movements to the falling supply of moisture at low levels resulting in the breakdown of the corridor of moisture between the surface and 850 hPa, among other atmospheric characteristics, in simulations with SST anomalies relative to El Niño and positive SST dipole. Standard contrast was observed in the simulations with SST anomalies related to La Niña and negative SST dipole. Similar signs were found in the analyzes of observed data. The observed rainfall interannual oscillation associated with MCSs reveals that in years of El Niño and negative SST dipole precipitating mesoscale systems are more numerous. If you subtracted the weak El Niño events observed an outcome below the number of possible MCSs found in normal years. Events in DTAT and La Niña the MCSs have a tendency to be more intense when compared with normal years. Most of the El Niño and La Niña ratings systems are regularly confined and intense west of the Plateau of Borborema. In relation to the SST dipole precipitating systems are more numerous and intense west and on the Plateau of Borborema respectively.