Multi-variate validation of a high-resolution application of the Community Land Model (CLM5) in Ghana

Exploring water and energy balance is crucial for understanding ecosystem functions and enhancing climate resilience, particularly in Ghana, where rainfall variability significantly impacts rainfed agriculture. The Community Land Model Version 5 (CLM5) offers a promising approach to understanding these interactions better, especially when applied at a high spatial resolution. This study assesses CLM5’s ability to simulate soil moisture, runoff, photosynthesis, and energy fluxes across Ghana using eddy covariance data from the WASCAL observatory, including two new stations (Janga and Mole Park) in addition to existing stations (Kayoro and Gorigo). The results show that CLM5 effectively captures the distinct hydrological patterns of the wetter southern regions compared to the drier north, aligning well with observed seasonal runoff peaks linked to the bimodal rainfall distribution. CLM5 reflects spatial variations in turbulent fluxes and seasonal fluctuations in gross primary production (GPP). However, challenges remain, particularly during dry periods, where evapotranspiration parameterization and input data inaccuracies contribute to overestimated sensible heat flux and underestimated latent heat flux. These results illustrate the potential of CLM5 for water resource management and agricultural planning in Ghana while emphasizing the need for targeted improvements in model parameterization and input data quality to enhance predictions of water balance and GPP. By addressing these challenges, CLM5 could provide valuable insights to support climate resilience and sustainable development in the region.