Luis CHONGUE and Kazuaki NISII

(Faculty of Bioresources, Mie University)

KEYWORDS

Climate, variability, precipitation, Mozambique

Severe events associated with year-to-year precipitation variability, such as droughts and floods, are recurrent in Mozambique, affecting the country's economy drastically, due to its strong dependence on agriculture and natural resources. Additionally, like most African countries, Mozambique has the most limited ability to adapt to climate change.

Earlier studies have associated anomalies in sea surface temperatures (SSTs) in tropical and subtropical oceans with interannual precipitation variability in Mozambique. La Niña and positive Subtropical Indian Ocean Dipole (SIOD) were found to lead to wetter conditions over the southern and central regions of Mozambique.

Our study confirms El Niño Southern Oscillation (ENSO) as the main mode that induces precipitation variability in Mozambique. ENSO significantly leads rainy-season precipitation there even by two seasons. Additionally, it is suggested that the intensity of Rossby wave propagation from the tropical Pacific to Southern Africa modulates the relationship between the precipitation in Mozambique and ENSO. Specifically, weaker Rossby wave propagation over the Southern Atlantic during La Niña, when wetter conditions are statistically expected, may lead to normal precipitation over southern Mozambique. The Indian Ocean Dipole (IOD), SIOD and Benguela Niño have also been shown to play a crucial role in controlling precipitation variability in Mozambique, although their influence is limited in Mozambique's southern and central regions.

Overall, the modes of climate variability have stronger control over the precipitation variability in south and central Mozambique, while they have weaker control in northern Mozambique, particularly in its northeast region.