Articles | Volume 18, issue 23
https://doi.org/10.5194/gmd-18-9791-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/gmd-18-9791-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Comparison of precipitation parameterizations in Regional Climate Model (RegCM5): a case study of the Upper Blue Nile Basin (UBNB)
Eatemad Keshta
CORRESPONDING AUTHOR
Irrigation and Hydraulics Department, Faculty of Engineering, Ain Shams University, Cairo 11517, Egypt
Water Resources Research Institute (WRRI), National Water Research Center (NWRC), Ministry of Water, Resources and Irrigation (MWRI), Qalyubia 13621, Egypt
Doaa Amin
Water Resources Research Institute (WRRI), National Water Research Center (NWRC), Ministry of Water, Resources and Irrigation (MWRI), Qalyubia 13621, Egypt
Ashraf M. ElMoustafa
Irrigation and Hydraulics Department, Faculty of Engineering, Ain Shams University, Cairo 11517, Egypt
Mohamed A. Gad
Irrigation and Hydraulics Department, Faculty of Engineering, Ain Shams University, Cairo 11517, Egypt
Cited articles
Abdelwares, M., Haggag, M., Wagdy, A., and Lelieveld, J.: Customized framework of the WRF model for regional climate simulation over the Eastern Nile basin, Theor. Appl. Climatol., 134, 1135–1151, 2018.
Abtew, W., Melesse, A. M., and Dessalegne, T.: El Niño Southern Oscillation link to the Blue Nile River Basin hydrology, Hydrol. Process., 23, 3653–3660, 2009.
Amin, D. and Kotb, A.: Assessment of the Skill of Seasonal Meteorological Forecasts in the Eastern Nile, Nile Water Science & Engineering Journal, 8, 31–40, 2015.
Birhan, M. W., Raju, U. J. P., and Kenea, S. T.: Estimating the role of upper Blue Nile basin moisture budget and recycling ratio in spatiotemporal precipitation distributions, J. Atmos. Sol. Terr. Phys., 193, 105064, https://doi.org/10.1016/j.jastp.2019.105064, 2019.
Bretherton, C. S., McCaa, J. R., and Grenier, H.: A New Parameterization for Shallow Cumulus Convection and Its Application to Marine Subtropical Cloud-Topped Boundary Layers. Part I: Description and 1D Results, Mon. Weather Rev., 132, 864–882, 2004.
Brier, G. W.: Verification of Forecasts Expressed in terms of Probability, Mon. Weather Rev., 78, 1–3, 1950.
Camberlin, P.: Nile Basin Climates, in: The Nile: Origin, Environments, Limnology and Human Use, edited by: Dumont, H. J., Monographiae Biologicae, Springer, 307–333, ISBN 978-1-4020-9725-6, 2009.
Camberlin, P. and Philippon, N.: The East African March–May Rainy Season: Associated Atmospheric Dynamics and Predictability over the 1968–97 Period, J. Clim., 15, 1002–1019, 2002.
Conway, D.: The Climate and Hydrology of the Upper Blue Nile River, Geogr. J., 166, 49–62, 2000.
Conway, D. and Hulme, M.: Recent fluctuations in precipitation and runoff over the Nile sub-basins and their impact on main Nile discharge, Clim. Change, 25, 127–151, 1993.
Coppola, E., Giorgi, F., Mariotti, L., and Bi, X.: RegT-Band: a tropical band version of RegCM4, Clim. Res., 52, 115–133, 2012.
Diro, G. T., Grimes, D. I. F., and Black, E.: Large Scale Features Affecting Ethiopian Rainfall, in: African Climate and Climate Change: Physical, Social and Political Perspectives, edited by: Williams, C. J. R. and Kniveton, D. R., Springer Netherlands, Dordrecht, 13–50, https://doi.org/10.1007/978-90-481-3842-5_2, 2011.
Elsanabary, M. H. and Gan, T. Y.: Wavelet Analysis of Seasonal Rainfall Variability of the Upper Blue Nile Basin, Its Teleconnection to Global Sea Surface Temperature, and Its Forecasting by an Artificial Neural Network, Mon. Weather Rev., 142, 1771–1791, 2014.
Elsanabary, M. H. and Gan, T. Y.: Evaluation of climate anomalies impacts on the Upper Blue Nile Basin in Ethiopia using a distributed and a lumped hydrologic model, J Hydrol (Amst), 530, 225–240, 2015.
Emanuel, K. A.: A Scheme for Representing Cumulus Convection in Large-Scale Models, Journal of Atmospheric Sciences, 48, 2313–2329, 1991.
Endris, H. S., Omondi, P., Jain, S., Lennard, C., Hewitson, B., Chang'a, L., Awange, J. L., Dosio, A., Ketiem, P., Nikulin, G., Panitz, H.-J., Büchner, M., Stordal, F., and Tazalika, L.: Assessment of the Performance of CORDEX Regional Climate Models in Simulating East African Rainfall, J. Clim., 26, 8453–8475, 2013.
Fekadu, K.: Ethiopian Seasonal Rainfall Variability and Prediction Using Canonical Correlation Analysis (CCA), Earth Sciences, 4, 112–119, 2015.
Fraedrich, K. and Leslie, L. M.: Evaluation of Techniques for the Operational, Single Station, Short-Term Forecasting of Rainfall at a Midlatitude Station (Melbourne), Mon. Weather Rev., 115, 1645–1654, 1987.
Giorgi, F.: Dependence of the surface climate interannual variability on spatial scale, Geophys. Res. Lett., 29, 14–16, 2002.
Giorgi, F.: Thirty Years of Regional Climate Modeling: Where Are We and Where Are We Going next?, Journal of Geophysical Research: Atmospheres, 124, 5696–5723, 2019.
Giorgi, F. and Marinucci, M. R.: A Investigation of the Sensitivity of Simulated Precipitation to Model Resolution and Its Implications for Climate Studies, Mon. Weather Rev., 124, 148–166, 1996.
Giorgi, F., Marinucci, M. R., and Bates, G. T.: Development of a second generation regional climate model (RegCM2). Part I: Boundary layer and radiative transfer processes, Mon. Weather Rev., 121, 2794–2813, 1993.
Giorgi, F., Coppola, E., Giuliani, G., Ciarlo, J., Pichelli, E., Nogherotto, R., Raffaele, F., Malguzzi, P., Davolio, S., Stocchi, P., and Drofa, O.: RegCM-NH V5 code, Zenodo [code], https://doi.org/10.5281/zenodo.7548172, January 2023a.
Giorgi, F., Coppola, E., Giuliani, G., Ciarlo`, J. M., Pichelli, E., Nogherotto, R., Raffaele, F., Malguzzi, P., Davolio, S., Stocchi, P., and Drofa, O.: The Fifth Generation Regional Climate Modeling System, RegCM5: Description and Illustrative Examples at Parameterized Convection and Convection-Permitting Resolutions, Journal of Geophysical Research: Atmospheres, 128, e2022JD038199, https://doi.org/10.1029/2022JD038199, 2023b.
Grell, G. A.: Prognostic Evaluation of Assumptions Used by Cumulus Parameterizations, Mon. Weather Rev., 121, 764–787, 1993.
Gudoshava, M. and Semazzi, F. H. M.: Customization and Validation of a Regional Climate Model Using Satellite Data Over East Africa, Atmosphere (Basel), 10, https://doi.org/10.3390/atmos10060317, 2019.
Haerter, J. O., Hagemann, S., Moseley, C., and Piani, C.: Climate model bias correction and the role of timescales, Hydrol. Earth Syst. Sci., 15, 1065–1079, https://doi.org/10.5194/hess-15-1065-2011, 2011.
Hersbach, H., Bell, B., Berrisford, P., Hirahara, S., Horányi, A., Muñoz-Sabater, J., Nicolas, J., Peubey, C., Radu, R., Schepers, D., Simmons, A., Soci, C., Abdalla, S., Abellan, X., Balsamo, G., Bechtold, P., Biavati, G., Bidlot, J., Bonavita, M., De Chiara, G., Dahlgren, P., Dee, D., Diamantakis, M., Dragani, R., Flemming, J., Forbes, R., Fuentes, M., Geer, A., Haimberger, L., Healy, S., Hogan, R. J., Hólm, E., Janisková, M., Keeley, S., Laloyaux, P., Lopez, P., Lupu, C., Radnoti, G., de Rosnay, P., Rozum, I., Vamborg, F., Villaume, S., and Thépaut, J.-N.: The ERA5 global reanalysis, Quarterly Journal of the Royal Meteorological Society, 146, 1999–2049, 2020.
Hersbach, H., Bell, B., Berrisford, P., Biavati, G., Horányi, A., Muñoz Sabater, J., Nicolas, J., Peubey, C., Radu, R., Rozum, I., Schepers, D., Simmons, A., Soci, C., Dee, D., and Thépaut, J.-N.: ERA5 hourly data on pressure levels from 1940 to present, Copernicus Climate Change Service (C3S) Climate Data Store (CDS) [data set], https://doi.org/10.24381/cds.bd0915c6, 2023a.
Hersbach, H., Bell, B., Berrisford, P., Biavati, G., Horányi, A., Muñoz Sabater, J., Nicolas, J., Peubey, C., Radu, R., Rozum, I., Schepers, D., Simmons, A., Soci, C., Dee, D., and Thépaut, J.-N.: ERA5 hourly data on single levels from 1940 to present, Copernicus Climate Change Service (C3S) Climate Data Store (CDS) [data set], https://doi.org/10.24381/cds.adbb2d47, 2023b.
Hoffmann, L., Günther, G., Li, D., Stein, O., Wu, X., Griessbach, S., Heng, Y., Konopka, P., Müller, R., Vogel, B., and Wright, J. S.: From ERA-Interim to ERA5: the considerable impact of ECMWF's next-generation reanalysis on Lagrangian transport simulations, Atmos. Chem. Phys., 19, 3097–3124, https://doi.org/10.5194/acp-19-3097-2019, 2019.
Holtslag, A. A. M., Bruijn, E. I. F. De, and Pan, H.-L.: A High Resolution Air Mass Transformation Model for Short-Range Weather Forecasting, Mon. Weather Rev., 118, 1561–1575, 1990.
Janjić, Z. I.: The Step-Mountain Eta Coordinate Model: Further Developments of the Convection, Viscous Sublayer, and Turbulence Closure Schemes, Mon. Weather Rev., 122, 927–945, 1994.
Kain, J. S.: The Kain–Fritsch Convective Parameterization: An Update, Journal of Applied Meteorology, 43, 170–181, 2004.
Kalmár, T., Pieczka, I., and Pongrácz, R.: A sensitivity analysis of the different setups of the RegCM4.5 model for the Carpathian region, International Journal of Climatology, 41, E1180–E1201, 2021.
Keshta, E.: A Multi-Component Model for Long-Term River Flow Forecasting, M.Sc. Thesis, Ain Shams University, Cairo, Egypt, https://doi.org/10.13140/RG.2.2.29798.86089, 2020.
Keshta, E.: Codes and data for the RegCM5 precipitation simulations over the Upper Blue Nile Basin (UBNB), Zenodo, https://doi.org/10.5281/zenodo.14864919, February 2025.
Keshta, E., Gad, M. A., and Amin, D.: A Long–Term Response-Based Rainfall-Runoff Hydrologic Model: Case Study of The Upper Blue Nile, Hydrology, 6, 22, https://doi.org/10.3390/hydrology6030069, 2019.
Koné, B., Diedhiou, A., Touré, N. E., Sylla, M. B., Giorgi, F., Anquetin, S., Bamba, A., Diawara, A., and Kobea, A. T.: Sensitivity study of the regional climate model RegCM4 to different convective schemes over West Africa, Earth Syst. Dynam., 9, 1261–1278, https://doi.org/10.5194/esd-9-1261-2018, 2018.
Li, B., Huang, Y., Du, L., and Wang, D.: Sensitivity experiments of RegCM4 using different cumulus and land surface schemes over the upper reaches of the Yangtze river, Front Earth Sci (Lausanne), 10, https://doi.org/10.3389/feart.2022.1092368, 2023.
Mellander, P.-E., Gebrehiwot, S. G., Gärdenäs, A. I., Bewket, W., and Bishop, K.: Summer rains and dry seasons in the upper Blue Nile Basin: the predictability of half a century of past and future spatiotemporal patterns, PLoS One, 8, e68461, https://doi.org/10.1371/journal.pone.0068461, 2013.
Mohamed, Y. A., van den Hurk, B. J. J. M., Savenije, H. H. G., and Bastiaanssen, W. G. M.: Hydroclimatology of the Nile: results from a regional climate model, Hydrol. Earth Syst. Sci., 9, 263–278, https://doi.org/10.5194/hess-9-263-2005, 2005.
Moriasi, D. N., Arnold, J. G., Liew, M. W. Van, Bingner, R. L., Harmel, R. D., and Veith, T. L.: Model Evaluation Guidlines for Systematic Quantification of Accuracy in Watershed Simulations, Trans ASABE, 50, 885–900, 2007.
NFC: Nile Forecasting System (NFS), Version 6.0. Manual, Nile Forecast Center (NFC), internal report, Ministry of Water Rsources and Irrigation (MWRI), Giza, Egypt, 2009.
Nicholson, S. E.: Climate and climatic variability of rainfall over eastern Africa, Reviews of Geophysics, 55, 590–635, 2017.
Nikulin, G., Jones, C., Giorgi, F., Asrar, G., Büchner, M., Cerezo-Mota, R., Christensen, O. B., Déqué, M., Fernandez, J., Hänsler, A., van Meijgaard, E., Samuelsson, P., Sylla, M. B., and Sushama, L.: Precipitation Climatology in an Ensemble of CORDEX-Africa Regional Climate Simulations, J. Clim., 25, 6057–6078, 2012.
Nogherotto, R., Tompkins, A. M., Giuliani, G., Coppola, E., and Giorgi, F.: Numerical framework and performance of the new multiple-phase cloud microphysics scheme in RegCM4.5: precipitation, cloud microphysics, and cloud radiative effects, Geosci. Model Dev., 9, 2533–2547, https://doi.org/10.5194/gmd-9-2533-2016, 2016.
Oleson, K., Lawrence, D., Bonan, G., Drewniak, B., Huang, M., Koven, C., Levis, S., Li, F., Riley, W., Subin, Z., Swenson, S., Thornton, P., Bozbiyik, A., Rosie, F., Heald, C., Kluzek, E., Lamarque, J.-F., Lawrence, P., Leung, L., and Yang, Z.-L.: Technical description of version 4.5 of the Community Land Model (CLM), https://doi.org/10.5065/D6RR1W7M, 2013.
Osman, M., Zittis, G., Haggag, M., Abdeldayem, A. W., and Lelieveld, J.: Optimizing Regional Climate Model Output for Hydro-Climate Applications in the Eastern Nile Basin, Earth Systems and Environment, 5, 185–200, https://doi.org/10.1007/S41748-021-00222-9, 2021.
Pal, J. S., Small, E. E., and Eltahir, E. A. B.: Simulation of regional-scale water and energy budgets: Representation of subgrid cloud and precipitation processes within RegCM, Journal of Geophysical Research: Atmospheres, 105, 29579–29594, 2000.
Qi, H., Lin, C., Peng, T., Zhi, X., Cui, C., Chen, W., Yin, Z., Shen, T., and Xiang, Y.: Diurnal Characteristics of Heavy Precipitation Events under Different Synoptic Circulation Patterns in the Middle and Lower Reaches of the Yangtze River in Summer, Atmosphere (Basel), 14, https://doi.org/10.3390/atmos14081320, 2023.
Rientjes, T., Haile, A. T., and Fenta, A. A.: Diurnal rainfall variability over the Upper Blue Nile Basin: A remote sensing based approach, International Journal of Applied Earth Observation and Geoinformation, 21, 311–325, 2013.
Segele, Z. T. and Lamb, P. J.: Characterization and variability of Kiremt rainy season over Ethiopia, Meteorology and Atmospheric Physics, 89, 153–180, 2005.
Segele, Z. T., Leslie, L. M., and Lamb, P. J.: Evaluation and adaptation of a regional climate model for the Horn of Africa: rainfall climatology and interannual variability, International Journal of Climatology, 29, 47–65, 2009.
Shahin, M.: Ch2. Physiography of the Nile Basin, in: Hydrology of the Nile, Elsevier Netherlands, Amsterdam, 15–57, ISBN 9780080887562, 1985.
Siam, M. S. and Eltahir, E. A. B.: Climate change enhances interannual variability of the Nile river flow, Nat. Clim. Chang., 7, 350–354, 2017.
Silué, F., Diawara, A., Koné, B., Diedhiou, A., Kouassi, A. A., Kouassi, B. K., Yoroba, F., Bamba, A., Kouadio, K., Tiémoko, D. T., Yapo, A. L. M., Koné, D. I., and Famien, A. M. L.: Assessment of the Sensitivity of the Mean Climate Simulation over West Africa to Planetary Boundary Layer Parameterization Using RegCM5 Regional Climate Model, Atmosphere (Basel), 15, https://doi.org/10.3390/atmos15030332, 2024.
Sippel, S., Otto, F. E. L., Forkel, M., Allen, M. R., Guillod, B. P., Heimann, M., Reichstein, M., Seneviratne, S. I., Thonicke, K., and Mahecha, M. D.: A novel bias correction methodology for climate impact simulations, Earth Syst. Dynam., 7, 71–88, https://doi.org/10.5194/esd-7-71-2016, 2016.
Tariku, T. B. and Gan, T. Y.: Regional climate change impact on extreme precipitation and temperature of the Nile river basin, Clim. Dyn., 51, 3487–3506, 2018a.
Tariku, T. B. and Gan, T. Y.: Sensitivity of the weather research and forecasting model to parameterization schemes for regional climate of Nile River Basin, Clim. Dyn., 50, 4231–4247, 2018b.
Teutschbein, C. and Seibert, J.: Bias correction of regional climate model simulations for hydrological climate-change impact studies: Review and evaluation of different methods, J. Hydrol. (Amst), 456–457, 12–29, https://doi.org/10.1016/J.JHYDROL.2012.05.052, 2012.
Tiedtke, M.: A Comprehensive Mass Flux Scheme for Cumulus Parameterization in Large-Scale Models, Mon. Weather Rev., 117, 1779–1800, 1989.
Yin, J., Yuan, J., Peng, J., Cao, X., Duan, W., Nan, Y., Mao, M., and Feng, T.: Role of the subtropical westerly jet wave train in the eastward-moving heavy rainfall event over southern China in winter: A case study, Front. Earth Sci. (Lausanne), 11, https://doi.org/10.3389/feart.2023.1107674, 2023.
Zaroug, M. A. H., Eltahir, E. A. B., and Giorgi, F.: Droughts and floods over the upper catchment of the Blue Nile and their connections to the timing of El Niño and La Niña events, Hydrol. Earth Syst. Sci., 18, 1239–1249, https://doi.org/10.5194/hess-18-1239-2014, 2014.
Zeleke, T., Giorgi, F., Mengistu Tsidu, G., and Diro, G. T.: Spatial and temporal variability of summer rainfall over Ethiopia from observations and a regional climate model experiment, Theor. Appl. Climatol., 111, 665–681, 2013.
Zeleke, T., Yeshita, B. D., and Agidew, F. M.: Evaluation of a Regional Climate Model for the Upper Blue Nile Region, in: Topics in Climate Modeling, edited by: Hromadka, T. and Rao, P., IntechOpen, Rijeka, https://doi.org/10.5772/64954, 2016.
Zeng, X., Zhao, M., and Dickinson, R. E.: Intercomparison of Bulk Aerodynamic Algorithms for the Computation of Sea Surface Fluxes Using TOGA COARE and TAO Data, J. Clim., 11, 2628–2644, 1998.
Short summary
Regional Climate Model version 5 (RegCM5) reasonably reproduced the dominant spatiotemporal pattern of annual precipitation over the basin using the Emanuel convective scheme with the Nogherotto–Tompkins (NoTo) large-scale scheme. Using the MOLOCH non-hydrostatic dynamical core is recommended in future research for improving precipitation simulation and assessing the impacts of land-use change, due to dam-induced reservoirs on local climate.
Regional Climate Model version 5 (RegCM5) reasonably reproduced the dominant spatiotemporal...