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This guide provides a practical overview of the first pan-African, kilometre-scale convection-permitting regional climate simulations (CP4-Africa), run as part of the Future Climate for Africa (FCFA) programme’s Improving Model Processes for African Climate (IMPALA) project. CP4-Africa provides the first convection-permitting resolution, multi-year climate simulations for present-day and idealised future climates on an African-wide domain. The simulations have provided an unprecedented level of climate detail across Africa and initial studies have shown improvements in the simulation of many, but not all, aspects of African climate. The goal of this guide is to promote adoption of the CP4-Africa approach within the climate community and is targeted at researchers with interest in progressing this relatively new modelling approach to improve understanding and representation of the drivers of African climate. It is also targeted at potential users of the high-resolution simulations for impact studies and decision support. While this is not an exhaustive review of the CP4-Africa simulations, from a practical perspective it highlights what one has to be aware of when designing similar simulations or using CP4-Africa simulation outputs. The guide is envisaged to be a living document that will be updated as new experiences become available from further analysis of CP4-Africa simulations data; and running CP4-Africa simulations under different experimental set ups. The guide is structured as a series of questions on CP4-Africa simulations and the application of the results, including how to access the simulations’ data. It begins with background information on what convection-permitting models are. A description of the CP4-Africa simulations performed by the IMPALA project is then presented. This is followed by an illustration of what is new in the CP4-Africa regional climate simulations, its limitations and how the simulations’ data can be accessed. Finally, case studies on user experiences in accessing and using CP4-Africa simulation are presented.

Nairobi, Kenya exhibits a wide variety of micro-climates and heterogeneous surfaces. Paved roads and high-rise buildings interspersed with low vegetation typify the central business district, while large neighborhoods of informal settlements or “slums” are characterized by dense, tin housing, little vegetation, and limited access to public utilities and services. To investigate how heat varies within Nairobi, we deployed a high density observation network in 2015/2016 to examine summertime temperature and humidity. We show how temperature, humidity and heat index differ in several informal settlements, including in Kibera, the largest slum neighborhood in Africa, and find that temperature and a thermal comfort index known colloquially as the heat index regularly exceed measurements at the Dagoretti observation station by several degrees Celsius. These temperatures are within the range of temperatures previously associated with mortality increases of several percent in youth and elderly populations in informal settlements. We relate these changes to surface properties such as satellite-derived albedo, vegetation indices, and elevation. Published version