MAHYVA: Multi-disciplinary Analysis of Hydro-climatic Variability at the catchment scale
Over the last century, Southern Africa has suffered from dramatic interannual changes in rainfall characterized by severe droughts and wet spells. Such variability of rainfall affects the agricultural industry, water reserves and thus the Gross National Product. It has a particularly detrimental effect on rural subsistence farmers, the health of people in rural areas and the management of a sustainable natural environment.
The project, funded by WRC is a multidisplinary analysis of climate variability involving climatology, meteorology, hydrology, oceanography and the impact of climate variability on water resources and the ecosystem. An important goal will be to train the participants, their students and team members in data analysis of large dataset and foster long term visit in between the collaborating institutions and their foreign partners. Foreign collaborators are keen to work on the project and various existing cooperative project will provide the necessary funds for long term visit and training overseas. It will also help to finance Masters and PHD bursary. This project will fit in the international GEWEX, CLIVAR and GOOS projects. It will collaborate with SAGRADEX and ACCES and seek to get more funding to allow for long term visits of students and researchers.
The most severe droughts happen in Southern Africa during the mature phase of El Niño, when the central and eastern Pacific and the Indian Ocean are warmer. Conversely, wet spells and floods are more likely to happen during La Nina. Due to high sea surface temperature, important heat content of the first hundred meters and high associated rainfall rates, the equatorial and tropical oceans have a profound effect on Southern Africa climate interannual variability and this offers predictability at the seasonal scale as warm event in the Pacific (El Niño), the Indian Ocean (Indian Ocean Dipole), the Atlantic Ocean (Benguela and Atlantic Niños) usually last for a few months and have a profound effect on the atmosphere globally through teleconnections. The El Niño Southern Oscillation (ENSO) phenomenon is an important regulator of Southern Africa summer rainfall but the Indian and Atlantic Ocean have also a role to play. The Antarctic Annular Oscillation is equally important for South Africa winter but also summer rainfall. Not to be forgotten the Agulhas Current is an important regulator of ocean circulation and global climate. Due to high evaporation rate and associated surface turbulent humidity fluxes there, it has a local impact on weather and a global impact on the net heat budget of the ocean.