Antônio Carlos Santana dos Santos

Evaluation of the AR4 CMIP3 and the AR5 CMIP5 Model and Projections for Precipitation in Northeast Brazil

With the simulations of the models used in the latest reports from the Intergovernmental Panel on Climate Change (IPCC), comparative studies are necessary between observations and the so-called historical run (C20) and future projections of the AR4 (A2) and AR5 (RCP8.5) experiments, in order to assess whether the AR5 models had a better performance in the representation of physical processes. This article compares the sensitivity of IPCC models (AR4 and AR5) in representing the anuall average and seasonal rainfall variation (summer and autumn) in three regions of the Northeast of Brazil between 1979 and 2000, using the CMAP - CPC (Merged Analysis of Precipitation) data as reference. The projections made by these models for the period 2040-2070 were also analyzed.

Estudo dos Padrões de Ventos Offshore no Litoral do Ceará Utilizando Dados Estimados pelo Produto de Satélites BSW

To know the spatial distribution of the wind patterns of a coastal region for monitoring the onshore and offshore wind potential goes through to the existence of a network of meteorological stations on the coast. On the coast of Ceará, a systematic analysis of the results obtained through prospective studies can be beneficial with the use of the results at 10 m estimated by satellites, BSW, with spatial and temporal resolution of 0.25° and six hours, respectively. In this work, BSW winds are validated in the vicinity of the coast of Ceará through oceanic buoys and anemometric towers. Verified its accuracy, these data are used to study spatial variability of sea winds in Ceará, in seasonal and interannual scale, and their correlation with the coastal winds.

Eventos Extremos Diários de Chuva no Nordeste do Brasil e Características Atmosféricas

Abstract This study investigated the means characteristics atmospherics associated with extreme precipitation events with untilthree-day delay before the occurrence of such extremes. The extreme events were chose when in most grid points on theNortheast of Brazil (2° S-12° S and 45° W-37° W), daily rainfall was equal or more than 50 mm. Daily data precipitationwere of a set of rainfall stations distributed over NEB, from the observational networks of the National Institute of Mete-orology, National Water Agency and Meteorology and Water Resources Regional’s Centers, covering the period1974-2003. These data were interpolated spatially using the technique of Inverse Square of the distance to a regular gridwith a resolution of 1° in latitude and longitude (about 111 km). For analyzes of atmospheric features were used in atmo-spheric variables reanalysis data as southern zonal wind, air temperature, relative humidity and other reanalysis ofNCEP-NOAA from the surface until 200 mb. The most significant results showed that three days before of the precipita-tion events considered extreme, there is a cold air incursion into the central area of the NEB, intensifying a day before ofthe events days, with lower anomalies below -4 °C, which do not appear to events considered of low rainfall over the re-gion.

Desenvolvimento de uma parametrização do efeito de rajadas associadas a sistemas convectivos nos fluxos de calor na superfície utilizando Modelagem de Ensemble de Nuvens

Precipitating convective systems produce gusts from downdrafts as they reach the surface. Those gusts are able to intensify the surface fluxes of sensible and latent heat, with possible consequences to the further evolution of deep convection itself. Despite advances in resolution and in the representation of physical processes, General Circulation Models and even regional models are still very far from representing clouds adequately (i.e., explicitly) and therefore surface flux enhancement by gusts is not simulated by them. In fact, such effect is not usually even parameterized. In this work, a CEM (Cloud Ensemble Model), driven by a prescribed large-scale forcing corresponding to tropical convective conditions, was used to find a parameterization that evaluates surface heat flux enhancement, as a function of precipitation rate, resolved wind and of the resolution of the larger-scale model. The enhancement factor is well correlated with both the resolved wind (-0.67 ρ > 0.4), which were used as input variables for calculating it. The parameterization equation was obtained by fitting the data from the CEM simulations.

ANÁLISE DO POTENCIAL EÓLICO OFFSHORE DO CEARÁ EM PERÍODOS DE EL NIÑO E LA NIÑA

A Energia Eolica Offshore ja e uma tecnologia amplamente desenvolvida na Uniao Europeia com aproximadamente 5GW instalados ate o final de 2012. No Brasil, sao poucos os estudos neste segmento e a analise do potencial e essencial para indicar os possiveis locais de implantacao de parques no mar. A analise feita, utilizando periodos de El Nino e La Nina, mostrou que mesmo em periodos com presenca de eventos extremos, a costa cearense apresenta valores de velocidade media do vento favoraveis a instalacao de parques eolicos offshore.

USO DO RAMS PARA ESTIMATIVA DO POTENCIAL OFFSHORE DO CEARÁ

1. Introdução A energia eólica offshore consiste em construir parques eólicos ao longo da costa marítima. Esta tecnologia aponta para um futuro promissor, porém é necessário analisar alguns aspectos como impactos ambientais, custos, e principalmente a utilização de métodos eficazes de previsão de vento. Hoje, graças ao crescimento vertiginoso do potencial dos computadores é possível realizar simulações de altíssima resolução e obter bons resultados (OLIVEIRA, 2007; DE MARIA, 2007). Este trabalho pretende mostrar áreas da costa cearense com grande potencial offshore.