Article
Environmental Sciences
Frederic Bonou, Casimir Yelognisse Da-Allada, Ezinvi Baloitcha, Eric Alamou, Eliezer Iboukoun Biao, Josue Zandagba, Ezechiel Obada, Yves Pomalegni, Peter James Irvine, Simone Tilmes
Summary: Stratospheric Aerosol Geoengineering (SAG) has been proposed as a method to offset global warming, but it can have a significant impact on the hydrological cycle. This study analyzes the effects of SAG on precipitation in West Africa and the Sahel region using simulated data, and finds that it leads to a decrease in rainfall and changes in the monsoon circulation.
Article
Meteorology & Atmospheric Sciences
Thompson Annor, Benjamin Lamptey, Richard Washington
Summary: This study evaluates the performance of the Global Coupled configuration 2 (GC2) of the Unified Model (UM) in reproducing climate variables over West Africa. The results show that UM performs relatively well in simulating temperature and precipitation, with larger biases in precipitation. The overall performance of UM is better than the 4 CMIP6 GCMs, and the simulation is more accurate in the southern parts of the region. It is recommended to further investigate how the model reproduces precipitation and temperature-based processes and to use the model for future climate research in West Africa.
THEORETICAL AND APPLIED CLIMATOLOGY
(2022)
Article
Environmental Sciences
Ghouse Basha, Madineni Venkat Ratnam, Jonathan H. Jiang, Pangaluru Kishore, Saginela Ravindra Babu
Summary: The study found that the Indian Summer Monsoon (ISM) activity has a significant impact on the tropopause altitude, water vapor, carbon monoxide, attenuated scattering ratio, ozone, and lower tropopause temperatures in the Asian Summer Monsoon Anticyclone (ASMA) region, especially during the peak monsoon months of July and August. Additionally, significant increases in water vapor and carbon monoxide, as well as decreases in ozone, were observed during the active phase of the ISM, strong monsoon years, and strong La Nina years in the ASMA.
Article
Energy & Fuels
Stewart Isaacs, Olga Kalashnikova, Michael J. Garay, Aaron van Donkelaar, Melanie S. Hammer, Huikyo Lee, Danielle Wood
Summary: The proximity of West Africa to the Sahara Desert leads to significant power generation reductions in photovoltaic (PV) systems due to soiling caused by particulates settling on solar panel surfaces. Existing global PV soiling models have limitations in this region due to the accuracy of input PM concentration values, methods for computing power loss, and the use of decentralized solar systems. In this study, a new methodology based on the Coello framework is developed and applied, reducing error in soiling-related power loss estimates by approximately 50%. The study also finds that soiling losses can exceed 50% in highly affected locations during the Harmattan season.
Article
Meteorology & Atmospheric Sciences
Christopher J. Diekmann, Matthias Schneider, Peter Knippertz, Andries J. Vries, Stephan Pfahl, Franziska Aemisegger, Fabienne Dahinden, Benjamin Ertl, Farahnaz Khosrawi, Heini Wernli, Peter Braesicke
Summary: The Lagrangian framework presented in this study is used to identify mechanisms controlling the isotopic composition of mid-tropospheric water vapor during the West African Monsoon in the Sahel region in 2016. By analyzing air mass mixing, convective processes, and microphysical processes along different transport pathways, the study reveals that isotopic changes in water vapor are determined by contributions from different processes such as air mass mixing, condensation during convection, and microphysical processes depleting the vapor beyond the Rayleigh prediction.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2021)
Article
Multidisciplinary Sciences
Martin Kohler, Geoffrey Bessardon, Barbara Brooks, Norbert Kalthoff, Fabienne Lohou, Bianca Adler, Oluwagbemiga Olawale Jegede, Barbara Altstaedter, Leonard Kofitse Amekudzi, Jeffrey Nii Armah Aryee, Winifred Ayinpogbilla Atiah, Muritala Ayoola, Karmen Babic, Konrad Baerfuss, Yannick Bezombes, Guillaume Bret, Pierre-Etienne Brilouet, Fred Cayle-Aethelhard, Sylvester Danuor, Claire Delon, Solene Derrien, Cheikh Dione, Pierre Durand, Kwabena Fosu-Amankwah, Omar Gabella, James Groves, Jan Handwerker, Corinne Jambert, Norbert Kunka, Astrid Lampert, Jeremy Leclercq, Marie Lothon, Patrice Medina, Arnaud Miere, Falk Paetzold, Xabier Pedruzo-Bagazgoitia, Irene Reinares Martinez, Steven Sharpe, Victoria Smith, Andreas Wieser
Summary: This article provides an overview of extensive in-situ measurements conducted as part of the DACCIWA project to study the southern West African atmospheric boundary layer. The measurements aimed to improve our understanding of the formation and influence of low-level clouds in this region. Scientific findings based on the dataset analyses are briefly summarized.
Article
Meteorology & Atmospheric Sciences
Joshua Talib, Christopher M. Taylor, Cornelia Klein, Bethan L. Harris, Seonaid R. Anderson, Valiyaveetil S. Semeena
Summary: Intraseasonal soil moisture variability can feed back onto the West Africa monsoon circulation through its influence on surface turbulent fluxes and planetary boundary-layer characteristics. Surprisingly, even though the surface response across the Sahel to strong convection is short-lived, a coherent regional-scale surface response to intraseasonal variability is observed, which then influences the West African monsoon circulation.
QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY
(2022)
Article
Geochemistry & Geophysics
Alexander J. Thompson, Clay R. Tabor, Christopher J. Poulsen, Christopher B. Skinner
Summary: This study uses a water isotope-enabled Earth system model to compare the hydroclimate signal inferred from leaf wax n-alkanes with simulated northern African hydroclimatic changes, revealing a potential overestimation in past hydrologic reconstructions using leaf wax n-alkanes.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Ellen Berntell, Qiong Zhang, Qiang Li, Alan M. Haywood, Julia C. Tindall, Stephen J. Hunter, Zhongshi Zhang, Xiangyu Li, Chuncheng Guo, Kerim H. Nisancioglu, Christian Stepanek, Gerrit Lohmann, Linda E. Sohl, Mark A. Chandler, Ning Tan, Camille Contoux, Gilles Ramstein, Michiel L. J. Baatsen, Anna S. von der Heydt, Deepak Chandan, William Richard Peltier, Ayako Abe-Ouchi, Wing-Le Chan, Youichi Kamae, Charles J. R. Williams, Daniel J. Lunt, Ran Feng, Bette L. Otto-Bliesner, Esther C. Brady
Summary: The mid-Pliocene warm period was a time characterized by warm climate state with higher surface temperatures in West Africa and a strengthened West African Monsoon, resulting in increased summer rainfall over West Africa and the Sahara region but decreased rainfall over the equatorial Atlantic. Models also indicate a warming Sahara and deepening Saharan Heat Low, leading to a strengthening of the WAM and increased monsoonal flow into the continent.
CLIMATE OF THE PAST
(2021)
Article
Meteorology & Atmospheric Sciences
Anqi Wang, Xiaoning Xie, Xiaodong Liu, Zhi-Yong Yin
Summary: The direct radiative effect (DRE) of dust aerosols on the West African and East Asian monsoons was analyzed using the CAM4 model. The results showed that the DREs on the West African and East Asian monsoons were more significant when the ocean-atmosphere coupling was considered, leading to the strengthening of the West African monsoon and weakening of the East Asian monsoon.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2022)
Article
Meteorology & Atmospheric Sciences
Omon A. Obarein, Cameron C. Lee
Summary: This study evaluates the changes in rainfall components and their regional distribution in West Africa. The findings indicate that rainfall frequency is changing more significantly than rainfall totals, with most changes occurring in the tropical wet and dry regions.
THEORETICAL AND APPLIED CLIMATOLOGY
(2022)
Article
Meteorology & Atmospheric Sciences
Alain T. Tamoffo, Alessandro Dosio, Leonard K. Amekudzi, Torsten Weber
Summary: This study analyzed the representation of the West African Monsoon (WAM) system in two high-resolution regional climate models (RCMs) and identified biases caused by temperature and pressure differences between the landmass and the ocean. These biases led to errors in the strength of the monsoon flow, moisture advection, and convective circulation, affecting the rainfall patterns in the region.
Article
Geosciences, Multidisciplinary
Fabius Cedric Kouogang Tchuenkam, Anselme Crepin Mama, Salvanus Yevalla Gah-Muti, Moacyr Araujo
Summary: The sea breeze characteristics of two coastal areas in Cameroon were studied. The occurrence, onset and cessation, and strength of sea breezes were examined using four years of data from Tiko and five years of data from Ebodje. The results showed that the sea breeze occurrence is strongly influenced by the West African monsoon winds and displays pronounced seasonal variation. The sea breeze strength is greater at Tiko during the monsoon season. The circulation of the sea breeze exhibits both clockwise and anticlockwise rotation. Local factors such as topography and vegetation also play a significant role in the sea breeze circulation.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Meteorology & Atmospheric Sciences
Alain T. Tamoffo, Akintomide A. Akinsanola, Torsten Weber
Summary: Understanding real uncertainties in projections is essential for decision and policy makers. This study investigates the response of the West African Monsoon system to different emission scenarios using regional climate models. The analysis reveals diverse rainfall change patterns under global warming, and identifies surface pressure changes and jet streams as key factors influencing rainfall distribution. The study suggests that the Delta Pr patterns from one model (REMO2015) are more plausible than another (RegCM4-v7), and highlights the importance of mitigating warming as recommended by the Paris agreement.
Article
Agronomy
Jacob Emanuel Joseph, Folorunso M. Akinseye, Omonlola Nadine Worou, Aliou Faye, Oumar Konte, Anthony M. Whitbread, Reimund P. Roetter
Summary: Accurate prediction of the onset of rain is crucial for adapting to climate variability and increasing the resilience of rain-fed systems. In this study, we compared different definitions of the West African Monsoon onset and found that Liebmann's definition was most suitable for hydrological and agronomic applications. The results highlight the importance of sowing dates and their accurate prediction for improving crop productivity, and recommend improved climate information services and agronomic interventions to enhance crop productivity.
AGRICULTURAL AND FOREST METEOROLOGY
(2023)
Editorial Material
Meteorology & Atmospheric Sciences
Alexander J. Roberts, Jennifer K. Fletcher, James Groves, John H. Marsham, Douglas J. Parker, Alan M. Blyth, Elijah A. Adefisan, Vincent O. Ajayi, Ronald Barrette, Estelle de Coning, Cheikh Dione, Abdoulahat Diop, Andre K. Foamouhoue, Morne Gijben, Peter G. Hill, Kamoru A. Lawal, Joseph Mutemi, Michael Padi, Temidayo I. Popoola, Pilar Ripodas, Thorwald H. M. Stein, Beth J. Woodhams
Article
Meteorology & Atmospheric Sciences
Douglas J. Parker, Alan M. Blyth, Steven J. Woolnough, Andrew J. Dougill, Caroline L. Bain, Estelle de Coning, Mariane Diop-Kane, Andre Kamga Foamouhoue, Benjamin Lamptey, Ousmane Ndiaye, Paolo Ruti, Elijah A. Adefisan, Leonard K. Amekudzi, Philip Antwi-Agyei, Cathryn E. Birch, Carlo Cafaro, Hamish Carr, Benard Chanzu, Samantha J. Clarke, Helen Coskeran, Sylvester K. Danuor, Felipe M. de Andrade, Kone Diakaria, Cheikh Dione, Cheikh Abdoulahat Diop, Jennifer K. Fletcher, Amadou T. Gaye, James L. Groves, Masilin Gudoshava, Andrew J. Hartley, Linda C. Hirons, Ishiyaku Ibrahim, Tamora D. James, Kamoru A. Lawal, John H. Marsham, J. N. Mutemi, Emmanuel Chilekwu Okogbue, Eniola Olaniyan, J. B. Omotosho, Joseph Portuphy, Alexander J. Roberts, Juliane Schwendike, Zewdu T. Segele, Thorwald H. M. Stein, Andrea L. Taylor, Christopher M. Taylor, Tanya A. Warnaars, Stuart Webster, Beth J. Woodhams, Lorraine Youds
Summary: Africa has the potential to benefit greatly from advancements in weather predictions, and the SWIFT project is playing a significant role in advancing scientific solutions and enhancing forecasting capabilities in the region. By focusing on research, training, and collaboration between academia and operational agencies, SWIFT is helping to build capacity in African meteorology and improve the quality and relevance of weather forecasts.
BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
(2022)
Article
Meteorology & Atmospheric Sciences
Beth J. Woodhams, Paul A. Barrett, John H. Marsham, Cathryn E. Birch, Caroline L. Bain, Jennifer K. Fletcher, Andrew J. Hartley, Stuart Webster, Solomon Mangeni
Summary: The study observed the circulation of lake-land breeze over Lake Victoria in unprecedented detail, with significant findings on lake and land breezes, as well as the convergence at the leading edge of the land breeze. The MetUM simulations were able to reasonably reproduce the lake breeze front and its propagation, but further investigation is needed to address biases in timing, resolution, and boundary-layer depth. Overall, the pilot campaign provided valuable insights into the lake-land breeze circulation and motivates the need for a more comprehensive field campaign in the future.
QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY
(2022)
Article
Environmental Sciences
Christopher M. Taylor, Cornelia Klein, Cheikh Dione, Douglas J. Parker, John Marsham, Cheikh Abdoulahat Diop, Jennifer Fletcher, Abdoul Aziz Saidou Chaibou, Dignon Bertin Nafissa, Valiyaveetil Shamsudheen Semeena, Steven J. Cole, Seonaid R. Anderson
Summary: In tropical convective climates, combining near-real time satellite observations of the land surface and convective clouds can aid in early warning of severe weather. Land surface temperature (LST) data can be used as a proxy for soil moisture deficit to characterize the state of the surface energy balance. LST data show high predictive skill early in the rainy season and can extend the skill in predicting intense convection beyond the afternoon. The developed technique using LST data and convective features allows for nowcasting of existing and likely new convective systems.
ENVIRONMENTAL RESEARCH LETTERS
(2022)
Article
Multidisciplinary Sciences
Christopher M. Taylor, Cornelia Klein, Douglas J. Parker, France Gerard, Valiyaveetil Shamsudheen Semeena, Emma J. Barton, Bethan L. Harris
Summary: Deforestation not only leads to warming in tropical regions, but also increases the frequency of storms and rainfall. This study focuses on Southern West Africa (SWA) and demonstrates that deforestation patterns strongly modulate convective activity. Additionally, near the coast, where sea breeze convection dominates, the frequency of storms has doubled in deforested areas. The findings have important implications for other tropical deforestation hotspots worldwide.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Meteorology & Atmospheric Sciences
Leif Denby, Steven J. Boing, Douglas J. Parker, Andrew N. Ross, Steven M. Tobias
Summary: This study analyzes the shallow cumulus clouds using two techniques to characterize cloud-feeding coherent boundary-layer structures. The first technique extracts the correlation length-scale and orientation of the structures, while the second technique decomposes the vertical transport of individual coherent structures. The results show that the bulk-correlation technique captures the elongation and orientation of coherence by ambient wind, but cannot characterize individual structures. The object-based approach reveals that the dominating structures have plume-like characteristics and rise vertically in the absence of ambient wind.
QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY
(2022)
Article
Meteorology & Atmospheric Sciences
R. R. Burton, A. M. Blyth, Z. Cui, J. Groves, B. L. Lamptey, J. K. Fletcher, J. H. Marsham, D. J. Parker, A. Roberts
Summary: The paper investigates the potential of using the freely available nowcasting package pySTEPS to provide short-term nowcasts of satellite-derived convective rain rate in West Africa. The analysis shows that a simple optical flow approach can achieve useful skill in 2-hour lead time forecasts at a 10-km scale and 4-hour lead time forecasts at larger scales (200 km). The study also reveals a diurnal variation in nowcast skill, with the worst-performing forecasts being those initialized at 1500 UTC. Comparison with existing nowcasts is presented, suggesting significant benefits if these nowcasts are implemented operationally.
WEATHER AND FORECASTING
(2022)
Article
Geochemistry & Geophysics
Michael Baidu, Juliane Schwendike, John H. Marsham, Caroline Bain
Summary: Vertical wind shear has a significant impact on the organization and intensity of mesoscale convective systems in West and Central Africa. Strong vertical shear is associated with long-lasting, moderate speed, moderate size, and cold storms with high rain rates. The observed cloud top heights of storms over the oceans are closer to their level of neutral buoyancies compared to their land counterparts at the same latitudes. Modeling the impacts of vertical shear is important for predicting high-impact weather and modeling the distribution of storm heights across Africa.
ATMOSPHERIC SCIENCE LETTERS
(2022)
Article
Meteorology & Atmospheric Sciences
Lawrence S. Jackson, John H. Marsham, Douglas J. Parker, Declan L. Finney, Rory G. J. Fitzpatrick, David P. Rowell, Rachel A. Stratton, Simon Tucker
Summary: This study investigates the impact of explicit convection on climate change in the central West African Sahel using a pan-African convection-permitting simulation. The results show that explicit convection has multiple-scale effects on West African monsoon processes compared to parameterized convection. Under climate change, explicit convection leads to a shift in the West African monsoon and a weakening of the Hadley circulation. The findings highlight the limitations of parameterized convection and demonstrate the value of explicit convection simulations for climate modeling and policy-making.
JOURNAL OF CLIMATE
(2022)
Article
Meteorology & Atmospheric Sciences
James Miller, Chris Taylor, Francoise Guichard, Phillippe Peyrill, Theo Vischel, Tazen Fowe, Geremey Panthou, Emma Visman, Maimouna Bologo, Karim Traore, Gnenakantanhan Coulibaly, Nicolas Chapelon, Florent Beucher, David P. Rowell, Douglas J. Parker
Summary: This article examines the significant impacts of an extreme weather event in Burkina Faso on its capital city, Ouagadougou, and discusses the role of global warming and climatic change. The study highlights the lack of evidence attributing extreme weather events to climate change in the West Africa region, limiting knowledge for urban planning. Recommendations are made to improve flood-resilience to future storms.
WEATHER AND CLIMATE EXTREMES
(2022)
Article
Geochemistry & Geophysics
Neil Ward, Andreas H. Fink, Richard J. Keane, Douglas J. Parker
Summary: This study finds that strong upper-level midlatitude troughs across the Atlantic-Africa-southwestern Asia sector have a significant impact on weather conditions in northern Africa, especially in central parts. These strong troughs lead to several days of weather fluctuations in northern Africa, including warming trends and abnormal precipitation patterns. The intertropical discontinuity and low-level heat low are also shifted north during these events.
ATMOSPHERIC SCIENCE LETTERS
(2023)
Article
Meteorology & Atmospheric Sciences
J. K. Fletcher, C. A. Diop, E. Adefisan, M. A. Ahiataku, S. O. Ansah, C. E. Birch, H. L. Burns, S. J. Clarke, J. Gacheru, T. D. James, C. K. Ngetich Tuikong, D. Koros, V. S. Indasi, B. L. Lamptey, K. A. Lawal, D. J. Parker, A. J. Roberts, T. H. M. Stein, E. Visman, J. Warner, B. J. Woodhams, L. H. Youds, V. O. Ajayi, E. N. Bosire, C. Cafaro, C. A. T. Camara, B. Chanzu, C. Dione, W. Gitau, D. Groves, J. Groves, P. G. Hill, I. Ishiyaku, C. M. Klein, J. H. Marsham, B. K. Mutai, P. N. Ndiaye, M. Osei, T. I. Popoola, J. Talib, C. M. Taylor, D. Walker
Summary: Testbeds have played a crucial role in advancing weather forecasting worldwide. The African Science for Weather Information and Forecasting Techniques (SWIFT) program recently conducted the first high-impact weather testbed in tropical Africa, involving researchers and forecasters from multiple African countries, the United Kingdom, and international organizations. The testbed focused on trialing new forecasting and nowcasting products, engaging users and researchers, and generating feedback for future research and development. The outcomes of the testbed, including improved forecasts and recommended operating procedures, have strengthened partnerships and garnered support from funding agencies and organizational directors.
BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
(2023)
