Assimilação de dados das estações meteorológicas automática da FUNCEME. / Assimilation of data from automatic weather stations FUNCEME.

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

08/08/2008

RESUMO

An observed data assimilation (ODA) technique is evaluated regarding its effects on the performance of a mesoscale atmospheric model (Regional Atmospheric Modeling System, RAMS 6.0) in a weather forecast simulation for the five first days of January 2005, which represents a transitional period in the wind regime over northern Northeast Brazil (between the dry and rainy seasons). The ODA, based on a Newtonian Relaxation technique, is implemented for observations of wind speed and direction, humidity and temperature collected at the automatic meteorological stations from the Ceará State Foundation for Meteorology and Water Resources (Fundação Cearense de Meteorologia e Recursos Hídricos, FUNCEME). A description of the model is presented, emphasizing the aspects related to the ODA. The performance of the numerical model with and without this data assimilation technique is compared, using an objective method based on statistical analysis. Such an intercomparison method is also described in detail. Results are shown as temporal series of wind speed and direction, humidity and temperature. Tables with statistical scores serve as basis for the choice of the best ODA parameters for weather forecast simulations. The data assimilation was implemented in the numerical model and results from simulation with ODA influence radii (used in Kriging interpolation) around the surface stations of 10km, 20km, 50km and 100km show improvements from the simulation without ODA, especially for 50km and 100km. In an operational weather forecast mode, i.e., assimilating data only for the time before the typical beginning of the operational runs done at FUNCEME, the results demonstrate that the beneficial influence of ODA is limited to the first day of forecast.

ASSUNTO(S)

assimilação de dados modelagem interpolação fisica data assimilation modeling interpolation

ACESSO AO ARTIGO

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