What we know, don’t know and need to know about future East African Climate | 4 September cross-project meeting
Dr Ellen Dyer (University of Oxford), Dr Laura Burgin (Met Office) and Dr Linda Hirons (University of Reading)
On 4 September, REACH hosted a meeting on East-African climate, in collaboration with African SWIFT, the IMPALA and HyCristal FCFA projects. The aim of the meeting was to share latest findings on climate-related research in East-Africa, highlight overlapping research, as well as to discuss gaps, and encourage collaboration.
While these projects all focus on different climatic themes and timescales, and have different regional partners, there is a significant opportunity to share valuable insights and foundational work. We also wanted to highlight work being led by early career researchers (ECRs) who are tackling a host of challenges associated with climate and adaptation in East-Africa.
This kind of exchange is particularly valuable for projects like REACH, which has an overall thematic focus on water security and incorporates climate research to inform policies and practices around climate resilient WASH, water allocation, and provision of safe and affordable water with a focus on poor and marginalised communities. There was representation from a range of other projects including ForPAC, UpGro, FRACTAL, and FATHOM.
A
number of themes and synergies emerged over the course of the day:
The importance of the Turkana jet: This low-level jet, being examined by REACH and HyCristal, is a moisture conduit into Africa, which has a strong drying influence in Kenya (see short video below from Dr Callum Munday, postdoctoral researcher at REACH). Research shared in an orography and high-resolution model session showed the difference that high-resolution models, such as the CP4 Africa model developed as part of the IMPALA project, can make to modelling the rainfall and climate of areas influenced by complex topography like northwestern Kenya.
Forecasting the long rains season in East Africa is challenging: Future projections generally point to a shift in the timing of the rainy season and an increase in rainy season rainfall. But there is still a low level of confidence amongst models in terms of predicting the long rains season (March to May). The scale of forecasts for user relevance was also explored. Participants highlighted different types of forecasting system outputs available in the region, and discussed the issue of forecast scale which makes regionally coarse forecasts less reliable for some local regions, such as those with complex topography.
Long rains are poorly
captured by general circulation models (GCMs): Moisture flux into,
and out of East Africa were common themes in model evaluation, with models
exhibiting behaviour in the Indian ocean such as decreased moisture inflow, and
strong cloud-SST feedback influencing moisture in the southern Indian ocean.
Producing and communication must be done in collaboration with users to be useful: From forecasts to end of century projections, projects strategies are being used to improve the process of knowledge production, including methods such as forecast co-production, context specific climate narratives, and community level dissemination of adaptation methods. Practices from a number of projects including REACH, FRACTAL, UpGro, HyCristal, and FATHOM were shared in this discussion.
We also asked ECRs across programmes to expand on a pressing question in East-African climate and tell us how their research is addressing it.
Which climate models are used for forecasting future climate in East Africa?
Here, Dean Walker (PhD students at the University of Leeds) highlights that different forecasting systems can over-predict normal conditions, or extremes, in essence to be risk-averse. Understanding the bias in different forecasts such as dynamical forecasts and consensus forecasts, like the GAHCOF, can add context to seasonal forecasts and improve their skill in the future.
How are climate models being used for planning and adaptation?
Joyce Kimutai (PhD student, University of Cape Town) highlights the growing demand for information about extreme events in East Africa. Models can be used to understand the likelihood of events, present and future, and the effect of climate change on extremes. They play an important role in improving preparedness in terms of resources and budgetary allocations and building community resilience.
Models are used to inform adaptation and as part of early warning systems in East Africa, says Maureen Wanzala (PhD student, University of Reading). They add value by untangling the connections between East African climate and large-scale modes of variability like ENSO.
What are limitations of models forecasting rainfall in Africa?
Michael Baidu (PhD student, University of Leeds) talks about a key challenge to climate forecasting: mesoscale convective systems (MCSs). MCSs are high impact weather systems in West Africa, which also have a strong influence on rainfall across the rest of the continent. Using high-resolution models from the UK Met Office can increase understanding of different type of MCSs.
Why does forecast scale matter?
Here Dr Matthew Young (postdoctoral researcher, University of Reading) talks about the importance of scale. Although entire regions of Africa experience the same rainfall during a season, certain characteristics influence rainfall locally. Better understanding and quantifying the spatial variability of rainfall is crucial to improve regional weather forecasts. This ultimately makes them more relevant to and usable at the local level.
How can scientists, policy makers, and practitioners better work together to ensure climate information is useful and understandable?
Dr Elisabeth Thompson (postdoctoral researcher, University of Reading) talks about the benefits of and work as part of the African SWIFT project getting national meteorological services, universities and forecast users to work together to co-develop more useful and tailored climate forecast information.
Aside from his work on the relationship between convective systems in East and Central Africa, Godwin Ayesiga (PhD student, University of Reading) highlights the need for better communication between researchers and policy makers, and the value that can be added by committing to this.
