Articles | Volume 5, issue 4
https://doi.org/10.5194/wcd-5-1457-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/wcd-5-1457-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
12 Nov 2024
Research article |
| 12 Nov 2024
| 12 Nov 2024
Dynamic and thermodynamic contribution to the October 2019 exceptional rainfall in western central Africa
Kevin Kenfack
CORRESPONDING AUTHOR
Laboratory for Environmental Modelling and Atmospheric Physics (LEMAP), Department of Physics, University of Yaoundé 1, Yaoundé, Cameroon
Francesco Marra
Department of Geosciences, University of Padua, Padua, Italy
Zéphirin Yepdo Djomou
Laboratory for Environmental Modelling and Atmospheric Physics (LEMAP), Department of Physics, University of Yaoundé 1, Yaoundé, Cameroon
National Institute of Cartography, Yaoundé, Cameroon
Lucie Angennes Djiotang Tchotchou
Laboratory for Environmental Modelling and Atmospheric Physics (LEMAP), Department of Physics, University of Yaoundé 1, Yaoundé, Cameroon
Alain Tchio Tamoffo
Climate Service Center Germany (GERICS), Helmholtz-Zentrum Hereon, Fischertwiete 1, 20095 Hamburg, Germany
Derbetini Appolinaire Vondou
Laboratory for Environmental Modelling and Atmospheric Physics (LEMAP), Department of Physics, University of Yaoundé 1, Yaoundé, Cameroon
Related authors
No articles found.
Hermann N. Nana, Roméo S. Tanessong, Masilin Gudoshava, and Derbetini A. Vondou
EGUsphere, https://doi.org/10.5194/egusphere-2025-2656, https://doi.org/10.5194/egusphere-2025-2656, 2025
This preprint is open for discussion and under review for Natural Hazards and Earth System Sciences (NHESS).
Short summary
Short summary
The results of this study reveal that the seasonal forecast model used here successfully reproduces the observed annual precipitation cycle and seasonal spatial pattern of rainfall over the region for both September and August initial conditions, with notably better skills for September, compared to August. In addition, the model effectively captures the teleconnections between rainfall and tropical sea surface temperature, including the Indian Ocean dipole and El Niño-Southern Oscillation.
Francesco Marra, Nadav Peleg, Elena Cristiano, Efthymios I. Nikolopoulos, Federica Remondi, and Paolo Tarolli
Nat. Hazards Earth Syst. Sci., 25, 2565–2570, https://doi.org/10.5194/nhess-25-2565-2025, https://doi.org/10.5194/nhess-25-2565-2025, 2025
Short summary
Short summary
Climate change is escalating the risks related to hydro-meteorological extremes. This preface introduces a special issue originating from a European Geosciences Union (EGU) session. It highlights the challenges posed by these extremes, ranging from hazard assessment to mitigation strategies, and covers both water excess events like floods, landslides, and coastal hazards and water deficit events such as droughts and fire weather. The collection aims to advance understanding, improve resilience, and inform policy-making.
Francesco Marra, Eleonora Dallan, Marco Borga, Roberto Greco, and Thom Bogaard
EGUsphere, https://doi.org/10.5194/egusphere-2025-3378, https://doi.org/10.5194/egusphere-2025-3378, 2025
Short summary
Short summary
We highlight an important conceptual difference between the duration used in intensity-duration thresholds and the duration used in the intensity-duration-frequency curves that has been overlooked by the landslide literature so far.
Nathalia Correa-Sánchez, Xiaoli Guo Larsén, Giorgia Fosser, Eleonora Dallan, Marco Borga, and Francesco Marra
Wind Energ. Sci. Discuss., https://doi.org/10.5194/wes-2025-111, https://doi.org/10.5194/wes-2025-111, 2025
Revised manuscript under review for WES
Short summary
Short summary
We examined the power spectra of wind speed in three convection-permitting models in central Europe and found these models have a better representation of wind variability characteristics than standard wind datasets like the New European Wind Atlas, due to different simulation approaches, providing more reliable extreme wind predictions.
Hermann N. Nana, Masilin Gudoshava, Roméo S. Tanessong, Alain T. Tamoffo, and Derbetini A. Vondou
Weather Clim. Dynam., 6, 741–756, https://doi.org/10.5194/wcd-6-741-2025, https://doi.org/10.5194/wcd-6-741-2025, 2025
Short summary
Short summary
The results of this study show that extreme rainfall in November 2023 over Equatorial Africa was controlled by several factors, including strong sea-surface-temperature anomalies in the Niño-3.4, North Tropical Atlantic, Equatorial Atlantic and Indian Ocean Dipole regions; changes in zonal winds; the Walker circulation; the moisture flux and its divergence; and the easterly jets. The information we derive can be used to support risk assessment in the region and to improve our resilience to ongoing climate change.
Talia Rosin, Francesco Marra, and Efrat Morin
Hydrol. Earth Syst. Sci., 28, 3549–3566, https://doi.org/10.5194/hess-28-3549-2024, https://doi.org/10.5194/hess-28-3549-2024, 2024
Short summary
Short summary
Knowledge of extreme precipitation probability at various spatial–temporal scales is crucial. We estimate extreme precipitation return levels at multiple scales (10 min–24 h, 0.25–500 km2) in the eastern Mediterranean using radar data. We show our estimates are comparable to those derived from averaged daily rain gauges. We then explore multi-scale extreme precipitation across coastal, mountainous, and desert regions.
Rajani Kumar Pradhan, Yannis Markonis, Francesco Marra, Efthymios I. Nikolopoulos, Simon Michael Papalexiou, and Vincenzo Levizzani
EGUsphere, https://doi.org/10.5194/egusphere-2024-1626, https://doi.org/10.5194/egusphere-2024-1626, 2024
Short summary
Short summary
This study compared global satellite and one reanalysis precipitation dataset to assess diurnal variability. We found that all datasets capture key diurnal precipitation patterns, with maximum precipitation in the afternoon over land and early morning over the ocean. However, there are differences in the exact timing and amount of precipitation. This suggests that it is better to use a combination of datasets for potential applications rather than relying on a single dataset.
Francesco Marra, Marika Koukoula, Antonio Canale, and Nadav Peleg
Hydrol. Earth Syst. Sci., 28, 375–389, https://doi.org/10.5194/hess-28-375-2024, https://doi.org/10.5194/hess-28-375-2024, 2024
Short summary
Short summary
We present a new physical-based method for estimating extreme sub-hourly precipitation return levels (i.e., intensity–duration–frequency, IDF, curves), which are critical for the estimation of future floods. The proposed model, named TENAX, incorporates temperature as a covariate in a physically consistent manner. It has only a few parameters and can be easily set for any climate station given sub-hourly precipitation and temperature data are available.
Stefan Steger, Mateo Moreno, Alice Crespi, Peter James Zellner, Stefano Luigi Gariano, Maria Teresa Brunetti, Massimo Melillo, Silvia Peruccacci, Francesco Marra, Robin Kohrs, Jason Goetz, Volkmar Mair, and Massimiliano Pittore
Nat. Hazards Earth Syst. Sci., 23, 1483–1506, https://doi.org/10.5194/nhess-23-1483-2023, https://doi.org/10.5194/nhess-23-1483-2023, 2023
Short summary
Short summary
We present a novel data-driven modelling approach to determine season-specific critical precipitation conditions for landslide occurrence. It is shown that the amount of precipitation required to trigger a landslide in South Tyrol varies from season to season. In summer, a higher amount of preparatory precipitation is required to trigger a landslide, probably due to denser vegetation and higher temperatures. We derive dynamic thresholds that directly relate to hit rates and false-alarm rates.
Nadav Peleg, Herminia Torelló-Sentelles, Grégoire Mariéthoz, Lionel Benoit, João P. Leitão, and Francesco Marra
Nat. Hazards Earth Syst. Sci., 23, 1233–1240, https://doi.org/10.5194/nhess-23-1233-2023, https://doi.org/10.5194/nhess-23-1233-2023, 2023
Short summary
Short summary
Floods in urban areas are one of the most common natural hazards. Due to climate change enhancing extreme rainfall and cities becoming larger and denser, the impacts of these events are expected to increase. A fast and reliable flood warning system should thus be implemented in flood-prone cities to warn the public of upcoming floods. The purpose of this brief communication is to discuss the potential implementation of low-cost acoustic rainfall sensors in short-term flood warning systems.
Eleonora Dallan, Francesco Marra, Giorgia Fosser, Marco Marani, Giuseppe Formetta, Christoph Schär, and Marco Borga
Hydrol. Earth Syst. Sci., 27, 1133–1149, https://doi.org/10.5194/hess-27-1133-2023, https://doi.org/10.5194/hess-27-1133-2023, 2023
Short summary
Short summary
Convection-permitting climate models could represent future changes in extreme short-duration precipitation, which is critical for risk management. We use a non-asymptotic statistical method to estimate extremes from 10 years of simulations in an orographically complex area. Despite overall good agreement with rain gauges, the observed decrease of hourly extremes with elevation is not fully represented by the model. Climate model adjustment methods should consider the role of orography.
Shalev Siman-Tov and Francesco Marra
Nat. Hazards Earth Syst. Sci., 23, 1079–1093, https://doi.org/10.5194/nhess-23-1079-2023, https://doi.org/10.5194/nhess-23-1079-2023, 2023
Short summary
Short summary
Debris flows represent a threat to infrastructure and the population. In arid areas, they are observed when heavy rainfall hits steep slopes with sediments. Here, we use digital surface models and radar rainfall data to detect and characterize the triggering and non-triggering rainfall conditions. We find that rainfall intensity alone is insufficient to explain the triggering. We suggest that antecedent rainfall could represent a critical factor for debris flow triggering in arid regions.
Assaf Hochman, Francesco Marra, Gabriele Messori, Joaquim G. Pinto, Shira Raveh-Rubin, Yizhak Yosef, and Georgios Zittis
Earth Syst. Dynam., 13, 749–777, https://doi.org/10.5194/esd-13-749-2022, https://doi.org/10.5194/esd-13-749-2022, 2022
Short summary
Short summary
Gaining a complete understanding of extreme weather, from its physical drivers to its impacts on society, is important in supporting future risk reduction and adaptation measures. Here, we provide a review of the available scientific literature, knowledge gaps and key open questions in the study of extreme weather events over the vulnerable eastern Mediterranean region.
Francesco Marra, Moshe Armon, and Efrat Morin
Hydrol. Earth Syst. Sci., 26, 1439–1458, https://doi.org/10.5194/hess-26-1439-2022, https://doi.org/10.5194/hess-26-1439-2022, 2022
Short summary
Short summary
We present a new method for quantifying the probability of occurrence of extreme rainfall using radar data, and we use it to examine coastal and orographic effects on extremes. We identify three regimes, directly related to precipitation physical processes, which respond differently to these forcings. The methods and results are of interest for researchers and practitioners using radar for the analysis of extremes, risk managers, water resources managers, and climate change impact studies.
Yoav Ben Dor, Francesco Marra, Moshe Armon, Yehouda Enzel, Achim Brauer, Markus Julius Schwab, and Efrat Morin
Clim. Past, 17, 2653–2677, https://doi.org/10.5194/cp-17-2653-2021, https://doi.org/10.5194/cp-17-2653-2021, 2021
Short summary
Short summary
Laminated sediments from the deepest part of the Dead Sea unravel the hydrological response of the eastern Mediterranean to past climate changes. This study demonstrates the importance of geological archives in complementing modern hydrological measurements that do not fully capture natural hydroclimatic variability, which is crucial to configure for understanding the impact of climate change on the hydrological cycle in subtropical regions.
Yair Rinat, Francesco Marra, Moshe Armon, Asher Metzger, Yoav Levi, Pavel Khain, Elyakom Vadislavsky, Marcelo Rosensaft, and Efrat Morin
Nat. Hazards Earth Syst. Sci., 21, 917–939, https://doi.org/10.5194/nhess-21-917-2021, https://doi.org/10.5194/nhess-21-917-2021, 2021
Short summary
Short summary
Flash floods are among the most devastating and lethal natural hazards worldwide. The study of such events is important as flash floods are poorly understood and documented processes, especially in deserts. A small portion of the studied basin (1 %–20 %) experienced extreme rainfall intensities resulting in local flash floods of high magnitudes. Flash floods started and reached their peak within tens of minutes. Forecasts poorly predicted the flash floods mostly due to location inaccuracy.
Cited articles
Andrews, P. C., Cook, K. H., and Vizy, E. K.: Mesoscale convective systems in the Congo Basin: Seasonality, regionality, and diurnal cycles, Clim. Dynam., 62, 609–630, https://doi.org/10.1007/s00382-023-06903-7, 2023.
Aretouyap, Z., Kemgang, F. E. G., Domra, J. K., Bisso, D., and Njandjock, P. N.: Understanding the occurrences of fault and landslide in the region of West-Cameroon using remote sensing and GIS techniques, Nat. Hazards, 109, 1589–1602, https://doi.org/10.1007/s11069-021-04890-8, 2021.
Bell, J. P., Tompkins, A. M., Bouka-Biona, C., and Sanda, I. S.: A process-based investigation into the impact of the Congo basin deforestation on surface climate, J. Geophys. Res-Atmos., 120, 5721–5739, https://doi.org/10.1002/2014jd022586, 2015.
Black, E.: The relationship between Indian Ocean sea–surface temperature and East African rainfall, Philos. T. R. Soc. A, 363, 43–47, https://doi.org/10.1098/rsta.2004.1474, 2005.
Chen, J. and Bordoni, S.: Orographic effects of the Tibetan plateau on the east Asian summer monsoon: An energetic perspective, J. Climate, 27, 3052–3072, https://doi.org/10.1175/jcli-d-13-00479.1, 2014.
Cook, K. H. and Vizy, E. K.: Hydrodynamics of regional and seasonal variations in Congo Basin precipitation, Clim. Dynam., 59, 1775–1797, https://doi.org/10.1007/s00382-021-06066-3, 2021.
Cook, K. H., Liu, Y., and Vizy, E. K.: Congo Basin drying associated with poleward shifts of the African thermal lows, Clim. Dynam., 54, 863–883, https://doi.org/10.1007/s00382-019-05033-3, 2019.
Copernicus Climate Change Service (C3S): ERA5, Copernicus Climate Change Service [data set], https://cds.climate.copernicus.eu/datasets/reanalysis-era5-pressure-levels-monthly-means?tab=download, last access: 20 August 2024.
Dyer, E. L. E., Jones, D. B. A., Nusbaumer, J., Li, H., Collins, O., Vettoretti, G., and Noone, D.: Congo Basin precipitation: Assessing seasonality, regional interactions, and sources of moisture, J. Geophys. Res-Atmos., 122, 6882–6898, https://doi.org/10.1002/2016jd026240, 2017.
FloodList News: Kenya – over 100 dead, 18,000 displaced after recent floods and landslides – floodlist: http://floodlist.com/africa/kenya-floods-november-2019, last access: 2 April 2024.
Fontaine, B., Roucou, P., and Trzaska, S.: Atmospheric water cycle and moisture fluxes in the West African monsoon: Mean annual cycles and relationship using NCEP/NCAR reanalysis, Geophys. Res. Lett., 30, 3, https://doi.org/10.1029/2002gl015834, 2003.
Fotso-Nguemo, T. C., Chamani, R., Yepdo, Z. D., Sonkoué, D., Matsaguim, C. N., Vondou, D. A., and Tanessong, R. S.: Projected trends of extreme rainfall events from CMIP5 models over Central Africa, Atmos. Sci. Lett., 19, e803, https://doi.org/10.1002/asl.803, 2018.
Fotso-Nguemo, T. C., Diallo, I., Diakhaté, M., Vondou, D. A., Mbaye, M. L., Haensler, A., Gaye, A. T., and Tchawoua, C.: Projected changes in the seasonal cycle of extreme rainfall events from CORDEX simulations over Central Africa, Climatic Change, 155, 339–357, https://doi.org/10.1007/s10584-019-02492-9, 2019.
Funk, C., Peterson, P., Landsfeld, M., Pedreros, D., Verdin, J., Shukla, S., Husak, G., Rowland, J., Harrison, L., Hoell, A., and Michaelsen, J.: The climate hazards infrared precipitation with stations – a new environmental record for monitoring extremes, Scientific Data, 2, 150066, https://doi.org/10.1038/sdata.2015.66, 2015.
Garcin, Y., Deschamps, P., Ménot, G., de Saulieu, G., Schefuß, E., Sebag, D., Dupont, L. M., Oslisly, R., Brademann, B., Mbusnum, K. G., Onana, J.-M., Ako, A. A., Epp, L. S., Tjallingii, R., Strecker, M. R., Brauer, A., and Sachse, D.: Early anthropogenic impact on Western Central African rainforests 2,600 y ago, P. Natl. A. Sci. India. A, 115, 3261–3266, https://doi.org/10.1073/pnas.1715336115, 2018.
Gelaro, R., McCarty, W., Suárez, M. J., Todling, R., Molod, A., Takacs, L., Randles, C. A., Darmenov, A., Bosilovich, M. G., Reichle, R., Wargan, K., Coy, L., Cullather, R., Draper, C., Akella, S., Buchard, V., Conaty, A., da Silva, A. M., Gu, W., Kim, G.-K., Koster, R., Lucchesi, R., Merkova, D., Nielsen, J. E., Partyka, G., Pawson, S., Putman, W., Rienecker, M., Schubert, S. D., Sienkiewicz, M., and Zhao, B.: The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2), J. Climate, 30, 5419–5454, https://doi.org/10.1175/jcli-d-16-0758.1, 2017.
Gou, Y., Balling, J., De Sy, V., Herold, M., De Keersmaecker, W., Slagter, B., Mullissa, A., Shang, X., and Reiche, J.: Intra-annual relationship between precipitation and forest disturbance in the African rainforest, Environ. Res. Lett., 17, 044044, https://doi.org/10.1088/1748-9326/ac5ca0, 2022.
Harris, I., Osborn, T. J., Jones, P., and Lister, D.: Version 4 of the CRU TS monthly high-resolution gridded multivariate climate dataset, Scientific Data, 7, 109, https://doi.org/10.1038/s41597-020-0453-3, 2020.
He, Y., Tian, W., Huang, J., Wang, G., Ren, Y., Yan, H., Yu, H., Guan, X., and Hu, H.: The mechanism of increasing summer water vapor over the Tibetan plateau, J. Geophys. Res-Atmos., 126, https://doi.org/10.1029/2020jd034166, 2021.
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.: The ERA5 global reanalysis, Q. J. Roy. Meteor. Soc., 146, 1999–2049, https://doi.org/10.1002/qj.3803, 2020.
Hua, W., Zhou, L., Nicholson, S. E., Chen, H., and Qin, M.: Assessing reanalysis data for understanding rainfall climatology and variability over Central Equatorial Africa, Clim. Dynam., 53, 651–669, https://doi.org/10.1007/s00382-018-04604-0, 2019.
Huffman, G. J., Adler, R. F., Bolvin, D. T., and Gu, G.: Improving the global precipitation record: GPCP Version 2.1, Geophys. Res. Lett., 36, https://doi.org/10.1029/2009gl040000, 2009.
Jackson, B., Nicholson, S. E., and Klotter, D.: Mesoscale convective systems over Western Equatorial Africa and their relationship to large-scale circulation, Mon. Weather. Rev., 137, 1272–1294, https://doi.org/10.1175/2008mwr2525.1, 2009.
Jiang, J., Zhou, T., Chen, X., and Zhang, L.: Future changes in precipitation over Central Asia based on CMIP6 projections, Environ. Res. Lett., 15, 054009, https://doi.org/10.1088/1748-9326/ab7d03, 2020.
Johannsen, F., Ermida, S., Martins, J. P. A., Trigo, I. F., Nogueira, M., and Dutra, E.: Cold bias of ERA5 summertime daily maximum land surface temperature over Iberian Peninsula, Remote. Sens-Basel, 11, 2570, https://doi.org/10.3390/rs11212570, 2019.
Kamae, Y., Mei, W., and Xie, S.-P.: Climatological relationship between warm season atmospheric rivers and heavy rainfall over East Asia, J. Meteorol. Soc. Jpn., Ser. II, 95, 411–431, https://doi.org/10.2151/jmsj.2017-027, 2017.
Kenfack, K., Tamoffo, A. T., Djiotang Tchotchou, L. A., and Vondou, D. A.: Assessment of uncertainties in reanalysis datasets in reproducing thermodynamic mechanisms in the moisture budget's provision in the Congo Basin, Theor. Appl. Climatol., 154, 613–626, https://doi.org/10.1007/s00704-023-04576-0, 2023.
Kenfack, K., Tamoffo, A. T., Tchotchou, L. A. D., Marra, F., Kaissassou, S., Nana, H. N., and Vondou, D. A.: Processes behind the decrease in Congo Basin precipitation during the rainy seasons inferred from ERA-5 reanalysis, Int. J. Climatol., 44, i–iv, https://doi.org/10.1002/joc.8410, 2024.
Kuete, G., Pokam Mba, W., and Washington, R.: African Easterly Jet South: Control, maintenance mechanisms and link with Southern subtropical waves, Clim. Dynam., 54, 1539–1552, https://doi.org/10.1007/s00382-019-05072-w, 2019.
Li, P., Zhou, T., and Chen, X.: Water vapor transport for spring persistent rains over southeastern China based on five reanalysis datasets, Clim. Dynam., 51, 4243–4257, https://doi.org/10.1007/s00382-017-3680-3, 2017.
Liu, S., Wen, N., and Li, L.: Dynamic and thermodynamic contributions to Northern China dryness in El Niño developing summer, Int. J. Climatol., 41, 2878–2890, https://doi.org/10.1002/joc.6995, 2021.
Longandjo, G.-N. T. and Rouault, M.: Revisiting the seasonal cycle of rainfall over Central Africa, J. Climate, 37, 1015–1032, https://doi.org/10.1175/jcli-d-23-0281.1, 2024.
Lutz, K., Rathmann, J., and Jacobeit, J.: Classification of warm and cold water events in the eastern tropical Atlantic Ocean, Atmos. Sci. Lett., 14, 102–106, https://doi.org/10.1002/asl2.424, 2013.
Mariotti, L., Diallo, I., Coppola, E., and Giorgi, F.: Seasonal and intraseasonal changes of African monsoon climates in 21st century CORDEX projections, Climatic Change, 125, 53–65, https://doi.org/10.1007/s10584-014-1097-0, 2014.
Marra, F., Levizzani, V., and Cattani, E.: Changes in extreme daily precipitation over Africa: Insights from a non-asymptotic statistical approach, J. Hydrol. X, 16, 100130, https://doi.org/10.1016/j.hydroa.2022.100130, 2022.
Moon, S. and Ha, K.-J.: Future changes in monsoon duration and precipitation using CMIP6, NPJ Clim. Atmos. S., 3, 45, https://doi.org/10.1038/s41612-020-00151-w, 2020.
Moudi Pascal, I., Kammalac Jores, T., Talib, J., Appolinaire, V. D., Hirons, L., Christian, N., Tene Romeo-Ledoux, D., Fogang Michael, T., Marceline, M., Tanessong Roméo, S., Dione, C., Thompson, E., Salih, A. A. M., and Ngaryamgaye, S.: Strengthening weather forecast and dissemination capabilities in Central Africa: Case assessment of intense flooding in January 2020, Climate Services, 32, 100411, https://doi.org/10.1016/j.cliser.2023.100411, 2023.
Nana, H. N., Tanessong, R. S., Tchotchou, L. A. D., Tamoffo, A. T., Moihamette, F., and Vondou, D. A.: Influence of strong South Atlantic Ocean Dipole on the Central African rainfall's system, Clim. Dynam., 62, 1–16, https://doi.org/10.1007/s00382-023-06892-7, 2023.
NCAR Command Language: UCAR/NCAR/CISL/TDD [software], Boulder, Colorado, https://doi.org/10.5065/D6WD3XH5, 2017.
Neelin, J. D.: Moist dynamics of tropical convection zones in monsoons, teleconnections, and global warming, in: The Global Circulation of the Atmosphere, Princeton University Press, 267–301, 2021.
Ngandam Mfondoum, A. H., Wokwenmendam Nguet, P., Mefire Mfondoum, J. V., Tchindjang, M., Hakdaoui, S., Cooper, R., Gbetkom, P. G., Penaye, J., Bekoa, A., and Moudioh, C.: Adapting sudden landslide identification product (SLIP) and detecting real-time increased precipitation (DRIP) algorithms to map rainfall-triggered landslides in Western Cameroon highlands (Central-Africa), Geoenvironmental Disasters, 8, 17, https://doi.org/10.1186/s40677-021-00189-9, 2021.
Nicholson, S. E., Fink, A. H., Funk, C., Klotter, D. A., and Satheesh, A. R.: Meteorological causes of the catastrophic rains of October/November 2019 in equatorial Africa, Global. Planet. Change, 208, 103687, https://doi.org/10.1016/j.gloplacha.2021.103687, 2022.
Oueslati, B., Yiou, P., and Jézéquel, A.: Revisiting the dynamic and thermodynamic processes driving the record-breaking January 2014 precipitation in the southern UK, Sci. Rep.-UK, 9, 2859, https://doi.org/10.1038/s41598-019-39306-y, 2019.
Pokam, W. M., Djiotang, L. A. T., and Mkankam, F. K.: Atmospheric water vapor transport and recycling in Equatorial Central Africa through NCEP/NCAR reanalysis data, Clim. Dynam., 38, 1715–1729, https://doi.org/10.1007/s00382-011-1242-7, 2011.
Pokam, W. M., Bain, C. L., Chadwick, R. S., Graham, R., Sonwa, D. J., and Kamga, F. M.: Identification of processes driving low-level westerlies in West Equatorial Africa, J. Climate, 27, 4245–4262, https://doi.org/10.1175/jcli-d-13-00490.1, 2014.
Reed, R. J., Norquist, D. C., and Recker, E. E.: The Structure and Properties of African Wave Disturbances as Observed During Phase III of GATE, Mon. Weather Rev., 105, 317–333, https://doi.org/10.1175/1520-0493(1977)105<0317:tsapoa>2.0.co;2, 1977.
Seager, R., Naik, N., and Vecchi, G. A.: Thermodynamic and dynamic mechanisms for large-scale changes in the hydrological cycle in response to global warming, J. Climate, 23, 4651–4668, https://doi.org/10.1175/2010jcli3655.1, 2010.
Sheng, B., Wang, H., Li, H., Wu, K., and Li, Q.: Thermodynamic and dynamic effects of anomalous dragon boat water over South China in 2022, Weather and Climate Extremes, 40, 100560, https://doi.org/10.1016/j.wace.2023.100560, 2023.
Sonkoué, D., Monkam, D., Fotso-Nguemo, T. C., Yepdo, Z. D., and Vondou, D. A.: Evaluation and projected changes in daily rainfall characteristics over Central Africa based on a multi-model ensemble mean of CMIP5 simulations, Theor. Appl. Climatol., 137, 2167–2186, https://doi.org/10.1007/s00704-018-2729-5, 2018.
Taguela, T. N., Pokam, W. M., and Washington, R.: Rainfall in uncoupled and coupled versions of the Met Office Unified Model over Central Africa: Investigation of processes during the September–November rainy season, Int. J. Climatol., 42, 6311–6331, https://doi.org/10.1002/joc.7591, 2022.
Tamoffo, A. T., Vondou, D. A., Pokam, W. M., Haensler, A., Yepdo, Z. D., Fotso-Nguemo, T. C., Tchotchou, L. A. D., and Nouayou, R.: Daily characteristics of Central African rainfall in the REMO model, Theor. Appl. Climatol., 137, 2351–2368, https://doi.org/10.1007/s00704-018-2745-5, 2019.
Tamoffo, A. T., Dosio, A., Weber, T., and Vondou, D. A.: Dynamic and Thermodynamic Contributions to Late 21st Century Projected Rainfall Change in the Congo Basin: Impact of a Regional Climate Model's Formulation, Atmosphere-Basel, 14, 1808, https://doi.org/10.3390/atmos14121808, 2023a.
Tamoffo, A. T., Weber, T., Akinsanola, A. A., and Vondou, D. A.: Projected changes in extreme rainfall and temperature events and possible implications for Cameroon's socio-economic sectors, Meterol. Appl., 30, https://doi.org/10.1002/met.2119, 2023b.
Tamoffo, A. T., Weber, T., Cabos, W., Sein, D. V., Dosio, A., Rechid, D., Remedio, A. R., and Jacob, D.: Mechanisms of Added Value of a Coupled Global Ocean-Regional Atmosphere Climate Model Over Central Equatorial Africa, J. Geophys Res-Atmos., 129, https://doi.org/10.1029/2023jd039385, 2024.
Vallès-Casanova, I., Lee, S., Foltz, G. R., and Pelegrí, J. L.: On the Spatiotemporal Diversity of Atlantic Niño and Associated Rainfall Variability Over West Africa and South America, Geophys. Res. Lett., 47, https://doi.org/10.1029/2020gl087108, 2020.
Wainwright, C. M., Finney, D. L., Kilavi, M., Black, E., and Marsham, J. H.: Extreme rainfall in East Africa, October 2019–January 2020 and context under future climate change, Weather, 76, 26–31, https://doi.org/10.1002/wea.3824, 2020.
Wang, L. and Li, T.: Effect of vertical moist static energy advection on MJO eastward propagation: Sensitivity to analysis domain, Clim. Dynam., 54, 2029–2039, https://doi.org/10.1007/s00382-019-05101-8, 2020a.
Wang, T. and Li, T.: Diagnosing the column-integrated moist static energy budget associated with the northward-propagating boreal summer intraseasonal oscillation, Clim. Dynam., 54, 4711–4732, https://doi.org/10.1007/s00382-020-05249-8, 2020b.
Wantim, M. N., Ughe, W. G., Kwah, D. C., Bah, T. C., Quinette, N., and Ayonghe, S. N.: Forensic investigation of the Gouache landslide disaster, Western Region, Cameroon, Journal of the Cameroon Academy of Sciences, 19, 223–240, https://doi.org/10.4314/jcas.v19i3.3, 2023.
Washington, R., James, R., Pearce, H., Pokam, W. M., and Moufouma-Okia, W.: Congo Basin rainfall climatology: Can we believe the climate models?, Philos. T. R. Soc. B., 368, 20120296, https://doi.org/10.1098/rstb.2012.0296, 2013.
Wen, N., Liu, S., and Li, L. Z. X.: Diagnosing the dynamic and thermodynamic effects for the exceptional 2020 summer rainy season in the Yangtze River Valley, J. Meteorol. Res-Prc., 36, 26–36, https://doi.org/10.1007/s13351-022-1126-2, 2022.
Yanai, M. and Tomita, T.: Seasonal and interannual variability of atmospheric heat sources and moisture sinks as determined from NCEP–NCAR reanalysis, J. Climate, 11, 463–482, https://doi.org/10.1175/1520-0442(1998)011<0463:saivoa>2.0.co;2, 1998.
Zhao, D., Zhang, L., and Zhou, T.: Detectable anthropogenic forcing on the long-term changes of summer precipitation over the Tibetan Plateau, Clim. Dynam., 59, 1939–1952, https://doi.org/10.1007/s00382-022-06189-1, 2022.
Zhou, L., Tian, Y., Myneni, R. B., Ciais, P., Saatchi, S., Liu, Y. Y., Piao, S., Chen, H., Vermote, E. F., Song, C., and Hwang, T.: Widespread decline of Congo rainforest greenness in the past decade, Nature, 509, 86–90, https://doi.org/10.1038/nature13265, 2014.
Short summary
The results of this study show that moisture advection induced by horizontal wind anomalies and vertical moisture advection induced by vertical velocity anomalies were crucial mechanisms behind the anomalous October 2019 exceptional rainfall increase over western central Africa. The information we derive can be used to support risk assessment and management in the region and to improve our resilience to ongoing climate change.
The results of this study show that moisture advection induced by horizontal wind anomalies and...
