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INTERANNUAL RAINFALL VARIABILITY IN NORTH‐EAST BRAZIL: OBSERVATION AND MODEL SIMULATION
Author(s) -
HARZALLAH A.,
ROCHA DE ARAGÃO J. O.,
SADOURNY R.
Publication year - 1996
Publication title -
international journal of climatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.58
H-Index - 166
eISSN - 1097-0088
pISSN - 0899-8418
DOI - 10.1002/(sici)1097-0088(199608)16:8<861::aid-joc59>3.0.co;2-d
Subject(s) - climatology , precipitation , sea surface temperature , tropical atlantic , environmental science , geology , geography , meteorology
The relationship between interannual variability of rainfall in north‐east Brazil and tropical sea‐surface temperature is studied using observations and model simulations. The simulated precipitation is the average of seven independent realizations performed using the Laboratoire de Météorologie Dynamique atmospheric general model forced by the 1970–1988 observed sea‐surface temperature. The model reproduces very well the rainfall anomalies (correlation of 0ċ91 between observed and modelled anomalies). The study confirms that precipitation in north‐east Brazil is highly correlated to the sea‐surface temperature in the tropical Atlantic and Pacific oceans. Using the singular value decomposition method, we find that Nordeste rainfall is modulated by two independent oscillations, both governed by the Atlantic dipole, but one involving only the Pacific, the other one having a period of about 10 years. Correlations between precipitation in north‐east Brazil during February–May and the sea‐surface temperature 6 months earlier indicate that both modes are essential to estimate the quality of the rainy season.