doctoralThesis
Vórtices ciclônicos em altos níveis sobre o nordeste do Brasil e mudanças climáticas: análise para o clima atual e cenários futuros
Fecha
2015-03-18Registro en:
PINHEIRO, José Ueliton. Vórtices ciclônicos em altos níveis sobre o nordeste do Brasil e mudanças climáticas: análise para o clima atual e cenários futuros. 2015. 99f. Tese (Doutorado em Ciências Climáticas) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2015.
Autor
Pinheiro, José Ueliton
Resumen
In this work, was analysed the climate change models's output from IPCC/AR5/CMIP5 that
best express the performance of Upper Tropospheric Cyclonic Vortices (UTCV) in Northeast
Brazil (NEB), its influence on rainfall and the possibility of projection of future climate
scenarios. To achieve the proposed objectives in the thesis were made four EXPERIMENTAL
STUDIES.The first, called Pilot, which were evaluated 13 models of climate change and
selected the model that best expressed the actions of UTCV in the NEB. The second that
evaluated the efficiency of the best model (MIROC4h), comparing it with reanalysis data for a
period of 31 years (1975-2005). The third where the future climate scenarios from MIROC4h
were analyzed for the period of 21 years (2015-2035). And the fourth where it was analyzed
the contribution of UTCV in precipitation over the NEB through the reanalysis data from
NCEP/NCAR/DOE. Two approaches comparative statistics were used in the Experimental
Studies 1 and 2 with the use of statistical indices: Pearson , Kendall and Spearman's
correlations, mean square error of the square root (RMSE), square of the normalized root mean
square error (NRMSE), Nash-Sutcliffe (NSE), Kling-Gupta (KGE), Willmott Index (d)
Proportion Correct Index (PCI), Critical Success Index (CSI), Probability of Detection (POD),
False Alarm Rate (TAF ) and trend rate (BIAS). And in Experiments 3 and 4 were calculated
deviations and averages. The results show that the representation of UTCV in climate change
models of CMIP5 is feasible, either for the past climate and for the projection of future
scenarios. Regarding the contribution of UTCV to precipitate the NEB these present
percentages ranging from 47.88% (LNE) to 49.89% (NNE) for the period from October to
March. Ceará (49.89%), Piauí (49.49%) and Maranhão (47.88%) are the states where UTCV
induce more rainfall and Alagoas (41.93%) and Sergipe (38.03%) are the states where UTCV
induce less precipitation. The projection of future scenario for UTCV revealed a 8.97% negative
difference in the occurrence of this phenomenon in the NEB and surrounding areas for the
period 2015 to 2035. What may impact -4.08% the precipitation of the NEB.