caa a22 4500 605473927 CHVBK 20210128100345.0 cr unu---uuuuu 210128e20150301xx s 000 0 eng 10.1007/s00382-014-2201-x doi (NATIONALLICENCE)springer-10.1007/s00382-014-2201-x Regional climate model performance in the Lake Victoria basin [Elektronische Daten] [Karina Williams, Jill Chamberlain, Carlo Buontempo, Caroline Bain] Lake Victoria, the second largest freshwater lake in the world, plays a crucial role in the hydrology of equatorial eastern Africa. Understanding how climate change may alter rainfall and evaporation patterns is thus of vital importance for the economic development and the livelihood of the region. Regional rainfall distribution appears, up to a large extent, to be controlled by local drivers which may be not well resolved in general circulation model simulations. We investigate the performance over the Lake Victoria basin of an ensemble of UK Met Office Hadley Centre regional climate model (HadRM3P) simulations at 50km, driven by five members of the Hadley Centre global perturbed-physics ensemble (QUMP). This is part of the validation of an ensemble of simulations that has been used to assess the impacts of climate change over the continent over the period 1950-2099. We find that the regional climate model is able to simulate a lake/land breeze over Lake Victoria, which is a significant improvement over the driving global climate model and a vital step towards reproducing precipitation characteristics in the region. The local precipitation correlates well with large-scale processes in the Pacific Ocean and Indian Ocean, which is in agreement with observations. We find that the spatial pattern of precipitation in the region and the diurnal cycle of convection is well represented although the amount of rainfall over the lake appears to be overestimated in most seasons. Reducing the observational uncertainty in precipitation over the lake through future field campaigns would enable this model bias to be better quantified. We conclude that increasing the spatial resolution of the model significantly improves its ability to simulate the current climate of the Lake Victoria basin. We suggest that, despite the higher computational costs, the inclusion of a model which allows two-way interactions between the lake and its surroundings should be seriously considered for any new climate projections for the region. Crown Copyright, 2014 Lake Victoria nationallicence Regional scale modelling nationallicence Climate nationallicence Perturbed-physics ensemble nationallicence Nile basin nationallicence Williams Karina Met Office Hadley Centre, FitzRoy Road, EX1 3PB, Exeter, Devon, UK aut Chamberlain Jill Department of Meteorology, University of Reading, Earley Gate, PO Box 243, RG6 6BB, Reading, UK aut Buontempo Carlo Met Office Hadley Centre, FitzRoy Road, EX1 3PB, Exeter, Devon, UK aut Bain Caroline Met Office Hadley Centre, FitzRoy Road, EX1 3PB, Exeter, Devon, UK aut Climate Dynamics Springer Berlin Heidelberg 44/5-6(2015-03-01), 1699-1713 0930-7575 44:5-6<1699 2015 44 382 https://doi.org/10.1007/s00382-014-2201-x text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00382-014-2201-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Williams Karina Met Office Hadley Centre, FitzRoy Road, EX1 3PB, Exeter, Devon, UK aut NATIONALLICENCE 700 1- Chamberlain Jill Department of Meteorology, University of Reading, Earley Gate, PO Box 243, RG6 6BB, Reading, UK aut NATIONALLICENCE 700 1- Buontempo Carlo Met Office Hadley Centre, FitzRoy Road, EX1 3PB, Exeter, Devon, UK aut NATIONALLICENCE 700 1- Bain Caroline Met Office Hadley Centre, FitzRoy Road, EX1 3PB, Exeter, Devon, UK aut NATIONALLICENCE 773 0- Climate Dynamics Springer Berlin Heidelberg 44/5-6(2015-03-01), 1699-1713 0930-7575 44:5-6<1699 2015 44 382