PUBLICATIONS

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A classification of synoptic weather patterns linked to extreme rainfall over the Limpopo River Basin in southern Africa

Ramontsheng S. Rapolaki, Ross C. Blamey, Juliet C. Hermes, Chris J. C. Reason

In the last few decades, the Limpopo River Basin (LRB) has experienced a number of extreme rainfall events which were responsible for considerable socio-economic and environmental impacts. Most of the population here is poor and dependent on rain-fed agriculture. In…

The Cape Town “Day Zero” drought and Hadley cell expansion

Natalie J. Burls, Ross C. Blamey, Benjamin A. Cash, Erik T. Swenson, Abdullah al Fahad, Mary-Jane M. Bopape, David M. Straus & Chris J. C. Reason

In early 2018, Cape Town (population ~3.7 million) was at risk of being one of the first major metropolitan areas in the world to run out of water. This was due to a severe multi-year drought that led to the…

Variability in the Mozambique Channel Trough and impacts on southeast African rainfall

Rondrotiana Barimalala, Ross C. Blamey, Fabien Desbiolles, and Chris J. C. Reason

The Mozambique Channel Trough (MCT) is a cyclonic region prominent in austral summer in the central and southern Mozambique Channel. It first becomes evident in December with a peak in strength in February when the Mozambique Channel is warmest and…

Tropical Lows in Southern Africa: Tracks, Rainfall Contributions, and the Role of ENSO

Emma Howard, Richard Washington, Kevin I. Hodges

Tropical lows are storms that are a bit like very weak tropical cyclones. They occur in summer in tropical regions. This paper tracks individual tropical lows across southern Africa in weather records from the last 39 years. We then look at…

Larger Future Intensification of Rainfall in the West African Sahel in a Convection‐Permitting Model

S. Berthou, E. J. Kendon, D. P. Rowell, M. J. Roberts, S. Tucker, R. A. Stratton

Monsoon rainfall in West Africa mostly comes from mesoscale convective systems, which are not well represented by standard convection‐parameterized regional climate models (RCMs). We use a 4.5 km resolution convection‐permitting RCM (CP4A) which has a good representation of these processes in…

Sahelian Precipitation Change Induced by SST Increase: The Contrasting Roles of Regional and Larger‐Scale Drivers

Ross D. Dixon, Philippe Peyrillé Françoise Guichard

Representing the West African Monsoon is a major challenge in climate modeling because of complex mechanisms of interaction across scales. We study the monsoon precipitation response to a 4K increase in sea surface temperatures using an idealized meridional‐vertical (2D) model,…

The effect of westerlies on East African rainfall and the associated role of tropical cyclones and the Madden‐Julian Oscillation

Declan L. Finney, John H. Marsham Dean P. Walker Cathryn E. Birch Beth J. Woodhams Lawrence S. Jackson Sam Hardy

Variability of rainfall in East Africa has major impacts on lives and livelihoods. From floods to droughts, this variability is important on short daily timescales to longer decadal timescales, as is apparent from the devastating effects of droughts in East…

The impact of RCM formulation and resolution on simulated precipitation in Africa

Minchao Wu, Grigory Nikulin, Erik Kjellström, Danijel Belušić, Colin Jones, and David Lindstedt

We investigate the impact of model formulation and horizontal resolution on the ability of Regional Climate Models (RCMs) to simulate precipitation in Africa. Two RCMs – SMHI-RCA4 and HCLIM38-ALADIN are utilized for downscaling the ERA-Interim reanalysis over Africa at four…

Regional differences in the response of rainfall to convectively coupled Kelvin waves over tropical Africa

Lawrence S. Jackson, Richard J. Keane, Declan L. Finney, John H. Marsham, Douglas J. Parker, Catherine A. Senior, and Rachel A. Stratton

The representation of convection remains one of the most important sources of bias in global models, and evaluation methods are needed that show that models provide the correct mean state and variability, both for the correct reasons. Here we develop…

Deep Convection over Africa: annual cycle, ENSO, and trends in the hotspots

Neil Hart, Richard Washington, Ross Maidment

Africa is one of the three key regions of deep convection in the global tropics. There is a wealth of information on the intensity, variability and change of convection and associated rainfall in regions across the continent but almost all…