Convection over the Congo Basin

The Congo Basin is one of the most convectively active regions of the world and is a key part of the large- scale air circulation that drives the climate system. The region receives around 1500–2000 mm of rainfall per year with over 60% of the rainfall occurring in the wet seasons of March to May and September to November. Approximately 75% of the rainfall is delivered by mesoscale convective systems which are contiguous areas of cold cloud that exceed 25,000 km² in size.

The regional climate system is associated with the world’s greatest frequency of thunderstorms and lightning (Cecil et al., 2015; Clulow et al., 2018). A maximum of thunderstorm activity occurs over the eastern Congo Basin, which has one of the highest rainfall totals in the tropics, with an average of 10 mm day⁻¹. Knowledge of the processes that affect Congo Basin rainfall and its future change is essential for adaptation planning as the basin region has a population of more than 75 million people, the majority of whom rely on subsistence agriculture for food and income. The Congo Basin is also the location of the world’s second largest tropical forest.

General Introduction Field Campaign

The CRAFT project involves a field campaign which consists of two elements – an Extended Operation Period (EOP) and an Intensive Operation Period (IOP). The goal of the EOP is to deploy 30 automatic weather stations (AWSs) across the basin, including 6 in Gabon, Cameroon and Republic of Congo respectively and 12 in the DRC. The AWSs will be set to record temperature, pressure, humidity, solar radiation, wind speed and direction at minute intervals. The AWSs will be deployed as early in the project as possible and will run for at least the length of the project.

The IOP will see the deployment of two Lidar systems and three radiosonde stations. Lidar will run through the 30-day IOP and will be deployed so as to observe low level winds in the case of the LLWs in Gabon and in the core of the basin at Yangambi. Lidar will record winds to around 2000m at a vertical resolution of 10m and a time resolution of 15 minutes for the 30-day IOP. Supplementing the Lidar will be three radiosonde stations with weather balloons released every three hours recording temperature, pressure, humidity and winds from the surface to the top of the atmosphere.

Oxford PhD description

Theme: Convection over the Congo Basin: Satellite and CMIP/AMIP model analysis

This project will investigate the organisation of convection over the Congo Basin as represented in satellite data, high resolution numerical model simulations and reanalysis. Particular attention will be given to characterising mesoscale convective systems and their role in maintaining the rainfall climatology and extreme events (floods and droughts). The CRAFT observational campaign led by Yaoundé and Kinshasa will provide underpinning data for satellite and reanalysis evaluation. The consequences of exclusion of these systems from global climate models for climate simulation and projections will be evaluated.

You will be encouraged to develop and strengthen collaborations with other CBSI students and researchers work in in related fields. You will be supported to publish your work in leading academic journals and communicate your results as widely as possible, including to policy makers.

This project is part of the Congo Basin Science Initiative’s Climate and Meteorology Observatory which will extend monitoring of the climate across the Congo Basin, as part of the CBSI Science and Capacity Building Plan.

The project is a collaboration between the University of Oxford, the University of Yaounde, Yaounde, and the Higher Institute of Applied Techniques in Kinshasa, DRC.