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The number of solar power plants has increased in West Africa in recent years. Reliable reanalysis data and short-term forecasting of solar irradiance from numerical weather prediction models could provide an economic advantage for the planning and operation of solar power plants, especially in data-poor regions such as West Africa. This study presents a detailed assessment of different shortwave (SW) radiation schemes from the Weather Research and Forecasting option Solar (WRF-Solar) model with appropriate configurations for different atmospheric conditions in Ghana and the southern part of Burkina Faso. We applied a two one-way nested domain (D1=15 km and D2=3 km) to investigate four different SW schemes namely, CAM, Dudhia, RRTMG, Goddard and RRTMG without aerosol and with aerosol inputs (RRTMG_AERO). The simulation results were validated using hourly measurements from different automatic weather stations established in the study region in recent years. The results show that the RRTMG_AERO_D01 generally outperforms the other SW radiation schemes to simulate GHI under all-sky condition (RMSE=235 W/m2 (19%); MAE=172 W/m2 (14%)) and also under cloudy skies. Moreover, RRTMG_AERO_D01 shows the best performance on a seasonal scale. Both the RRTMG_AERO and Dudhia experiments indicate a good performance under clear skies. However, the sensitivity study of different SW radiation schemes in the WRF-Solar model suggests that RRTMG_AERO gives better results. Therefore, it is recommended to use it for solar irradiance forecasts over Ghana and the southern part of Burkina Faso.

Global horizontal irradiance (GHI) is the primary driver for photovoltaic (PV) technology. For PV system design and monitoring, hourly and sub-hourly GHI from reanalysis and satellite-based data are frequently used, especially in data-poor regions like Sub-Saharan Africa. However, the use of these datasets is uncertain and need to be assessed in detail. In this study, we evaluated the performance of state-of-the-art reanalysis and satellite-based datasets (ERA5, CAMS, MERRA-2 and SARAH-2) with in situ measurements of hourly GHI for the main climatic zones (Guinea, Savannah, and Sahel) in West Africa. The in situ measurements come from novel regional and national meteorological networks consisting of 51 automatic weather stations in Burkina Faso and Ghana. The performance assessment was done for the year 2020 for different weather conditions (cloudy, clear and all sky). The effects of clouds and aerosols were also investigated. Moreover, a new overall performance measure is introduced for joint evaluation of different standard measures, such as the root-mean-square error and the index of agreement. The results show that the data from SARAH-2 performs best under cloudy-sky conditions, while ERA5 performs worse under all atmospheric conditions. The low performance under cloudy skies for all datasets is the result of a large bias observed during the Harmattan period, when the region has a high concentration of aerosols. The average diurnal variation of GHI shows good agreement between the in situ measurements, the satellite and the reanalysis data under clear and all-sky conditions, but an overestimation under cloudy skies at some stations. The new overall performance value clearly indicates hourly GHI from SARAH-2 is the best alternative for assessing solar energy in West Africa.

Proposal of a poster for the EMS2022Intention:Within the research project EnerSHelF (Energy-Self-Sufficiency for Health Facilities in Ghana), i. a. energy-meteorological and load-related measurement data are collected, for which an overview of the availability is to be presented on a poster.Context:In Ghana, the total electricity consumed has almost doubled between 2008 and 2018 according to the Energy Commission of Ghana. This goes along with an unstable power grid, resulting in power outages whenever electricity consumption peaks. The blackouts called "dumsor" in Ghana, pose a severe burden to the healthcare sector. Innovative solutions are needed to reduce greenhouse gas emissions and improve energy and health access.The aim of the project is therefore to develop PV-based energy solutions for healthcare facilities and to improve the reliability and integrability of such systems in the local electricity grid.The work is based on a measurement campaign that has been running since 2020 at three hospitals spread across the country. The variables measured include:Global tilted irradiance (GTI)Soiling ratio and temperature of the PV panelsAll-sky camera recordingsLoad measurement aggregate (grid node)Load measurement sub-distribution (departments and devices)In addition, weather stations are operated at the sites to improve weather forecasts.These datasets can be used to follow different approaches to managing the harsh conditions caused by dry and rainy seasons, and to design and control PV hybrid systems appropriately.According to the World Bank (2017) only 3% of the population in West Africa and the Sahel can currently access PV power through off-grid systems. As an important catalyst for sustainable development, access to a reliable source of clean energy is vital for inclusive economic development, improved human health, wellbeing and security. As such, EnerSHelF can contribute to Sustainable Development Goals (SDG) of health (SDG 3), energy (SDG 7) and partnerships (SDG 17).

Water is an important resource needed in every aspect of life, e.g. human habitats, economic prosperity, food security, etc. There is a need to simulate and quantify the availability of water using hydrologic models with reliable data. For this reason, this study successfully calibrated and validated the water balance of the Sherigu catchment using the Soil and Water Assessment Tool (SWAT) model. The model performed satisfactorily with statistical values of Nash-Sutcliffe and correlation coefficient greater than 0.7. Evapotranspiration consumed 72% of the total annual precipitation. The total discharge was estimated to be 14%, which comprises surface runoff of about 9% and baseflow of 5%, whiles percolation into the unconfined and confined aquifers as soil and groundwater storages also accounted for 14%. The average soil storage across the catchment suggests that the shallow aquifer store more water with the potential of a high water table for extraction during the dry season.

Surface observations provide ground evidence of climate change to support the scientific guidance paving the way to better adaptation and mitigation actions. The West African Science Service Centre on Climate Change and Adapted Land Use (WASCAL) has designed a multi-stakeholder initiative to rescue the deteriorated near-surface weather, climate and hydrological equipment of West African countries. The main goal for this multi-stakeholder framework was to monitor the climate and collect long term and high-quality records of essential climate variables in support of research, education, capacity building, and climate services provision. Proactive and inclusive partnership initiatives were developed to jointly (re)design and (re)implement near surface observatiories with the national meteorological and hydrological services or agencies (NMHS/As) in West Africa. The co-production scheme used by this framework succeeded in evaluating the existing observations networks, to modernizing sensors and field equipment, and densifying the sites in order to improve the quality of data collection, transmission, archiving, processing and sharing policies. After more than four years of community-of-practice, the existing regional basic hydroclimatic was increased/upgraded by 45% with automatic weather observing systems while fifty automatic water level, ten water quality sensors, three mesoscale research catchments, and several pilot sites to benefit countries’ services provision, research infrastructure, education, and capacity building. Country-specific data sharing policies were harmonized and signed to support data services delivery. This practice paper exposes the concepts, outcomes, challenges, lessons learned and the ways forward in setting-up the framework and keeping it on working to leverage the co-production of data & information services for better-informed decision-making in the field of sustainable development in West Africa.

In the future the Sudanian savanna – one of West Africa's high-potential “bread baskets” – will likely face shorter rainy seasons with more extreme rains and droughts. That could have serious impacts on the vegetation and its carbon dioxide (CO2) exchange with potentially increasing CO2 emissions accelerating climate warming. Understanding how the CO2 fluxes in this area respond to environmental variables, in particular rain events, is essential, but available data are scarce. In this study, we monitored net ecosystem exchange (NEE) of CO2, rainfall and other environmental parameters during four years at three savannas. Savannas were characterized by different vegetation due to different land use: i) woody and nearly pristine, ii) mixture of cropland and grassland and iii) intensive grazing. The impact of rain events on CO2 exchange for these contrasting ecosystems were analyzed for single rain events (short-term) and on a yearly time scale (long-term) using three eddy covariance towers. We found that the woody pristine savanna site was a prominent sink of CO2 (−864 to −1299 g CO2 m−2 y−1) while the degraded sites were net CO2 sources (118 to 605 g CO2 m−2 y−1) with a complicated relation with annual rainfall amounts. The NEE responses to single rain events revealed that daytime rain systematically decreased the sink strengths at all sites, which might be associated with decreased light availability. At the degraded sites, additional factors increasing CO2 losses were rain duration and dry spell length. The observed patterns of immediate CO2 flux responses to rainfall at differently used savannas indicate strong internal feedbacks between vegetation and land use changes and raise the question whether the CO2 sink strengths might be overestimated with possible implications for global CO2 budgets. Sustainable adaptation strategies need to be developed for West Africa.

In the future the Sudanian savanna - one of West Africa's high-potential "bread baskets" - will likely face shorter rainy seasons with more extreme rains and droughts. That could have serious impacts on the vegetation and its carbon dioxide (CO

In sub-Saharan Africa, studies on land-use/cover change have focused more on transformation from forest or woodland to other types of land-use/cover. Few studies have addressed the dynamics in agricultural landscapes which could accompany impacts on the environment. This paper identified potential drivers of agricultural land-use/cover via household surveys and interviews of stakeholders, as well as information gathered from literature. Identified drivers were used to develop descriptive scenarios (what-if questions) that were presented to farmers during participatory scenario exploration exercises. The scenarios were used to view the farmers' agricultural land-use/cover options under changing climatic and socio-economic conditions. The parameters used include climate change resulting from rainfall, and socioeconomic variables like availability of finance, access to fertiliser and change in the price of seeds. The agricultural land-use change options identified includes maize, soy-bean, potatoes, etc. Rainfall availability, tradition and land suitability influences farmers' agricultural land-use change options. We observed that climate change (rainfall)-related scenarios may influence the replacement of crop(s) from agricultural land (agricultural-land-conversion) while socioeconomic scenarios may influence the incorporation of crop(s) to an existing agricultural land (agricultural-land-modification). Farmers may change their agricultural land-use/cover under certain conditions/stressors and this might have accompanied environmental impact. In this part of the world, in-depth and well documented impacts of agricultural land-use/cover on the environment are scant. Therefore, to effectively relate policy in this direction, it will be necessary to investigate more on the likely environmental trade-offs associated with diverse agricultural land-use/covers. In addition, minimising the associated trade-offs should be our priority.