Statistical Prediction of Summer Rainfall and Vegetation in the Ethiopian Highlands

Abstract EN

Year-to-year fluctuations of Ethiopia climate are investigated to develop statistical predictions at one-season lead time.

Satellite vegetation data from NASA and rainfall from ARC2 are the basis for analysis.

The “target” seasons are May–July and August–October, while “predictors” are December–February and March–May, respectively.

Global fields of surface temperature, sea level air pressure, and upper and lower level zonal winds are employed in point-to-field correlations.

After step-wise multivariate regression, the leading predictors are: surface temperature across Europe (cold-favourable), 850 mb zonal winds over the tropical Atlantic (easterly-favourable), and surface temperature in the tropical Indian Ocean (cold-favourable).

Predictive algorithms for early and late rainfall exhibit a consistent r2 fit of ~0.50, while those for vegetation reach ~0.65 in late summer, indicating that fluctuations in food resources could be forewarned.