Joëlle Sihon Joint Research Unit “Geosciences Environment Toulouse” (UMR GET) CNRS, IRD, UT3, CNAP, CNES Midi‐Pyrénées Observatory Toulouse, France
Vinícius Alencar Siqueira Institute of Hydraulic Research Federal University of Rio Grande do Sul Porto Alegre, Brazil
Mark W. Smith School of Geography University of Leeds Leeds, UK
Denis Sonkoué Laboratory for Environmental Modeling and Atmospheric Physics Department of Physics University of Yaoundé I Yaoundé, Cameroon
Rogert Sorí Environmental Physics Laboratory Marine Research Center University of Vigo Ourense, Spain; and Institute Dom Luiz University of Lisbon Lisbon, Portugal
Robert G. M. Spencer Department of Earth, Ocean and Atmospheric Sciences Florida State University Tallahassee, Florida, USA
Venkataramana Sridhar Department of Biological Systems Engineering Virginia Polytechnic Institute and State University Blacksburg, Virginia, USA
Milica Stojanovic Environmental Physics Laboratory Marine Research Center University of Vigo Ourense, Spain
Roméo Stève Tanessong Faculty of Agronomy and Agricultural Sciences University of Dschang Dschang, Cameroon; and Laboratory for Environmental Modeling and Atmospheric Physics University of Yaoundé I Yaounde, Cameroon
Blaise‐Leandre Tondo International Commission for the Congo‐Oubangui‐Sangha Basin Kinshasa, Democratic Republic of the Congo
Laurent Touchart CEDETE Laboratory (Center for Development Studies and the Environment) University of Orléans Orléans, France
Mark A. Trigg School of Civil Engineering University of Leeds Leeds, UK
Raphael M. Tshimanga Congo Basin Water Resources Research Center (CRREBaC) Department of Natural Resources Management University of Kinshasa Kinshasa, Democratic Republic of the Congo
Derbetini Appolinaire Vondou Laboratory for Environmental Modelling and Atmospheric Physics Department of Physics University of Yaoundé I Yaoundé, Cameroon
Thorsten Wagener Institute of Environmental Science and Geography University of Potsdam Potsdam, Germany
Nicholas D. Ward Marine and Coastal Research Laboratory Pacific Northwest National Laboratory Sequim, Washington, USA; and School of Oceanography University of Washington Seattle, Washington, USA
Jean‐Pascal Waterendji Department of Geography University of Bangui Bangui, Central African Republic
Ross Woods Department of Civil Engineering University of Bristol Bristol, UK
Athanase Yambele National Directorate of Meteorology Ministry of Transport and Civil Aviation Bangui, Central African Republic
Zéphirin Yepdo‐Djomou Laboratory for Environmental Modeling and Atmospheric Physics Department of Physics University of Yaoundé l Yaoundé, Cameroon; and Climate Change Research Laboratory National Institute of Cartography Yaoundé, Cameroon
Ting Yuan Department of Geography University of California, Los Angeles Los Angeles, California, USA
PREFACE
The Congo River Basin is the world’s second largest in terms of river discharge and drainage area. The largest is the better known Amazon River Basin. Because the Congo is much less studied compared to the Amazon, there are unanswered questions regarding the Congo’s precipitation, hydrology, hydraulics, and carbon ecology. For example, based on a few remotely sensed altimeter measurements, it appears that the wetland water levels of the Cuvette Centrale are higher in elevation than the immediately adjacent Congo mainstem. The wetland does not appear to have large channels. Both of these observations are rather unlike what we find in the more familiar Amazon and its floodplain. Therefore, the question regarding how water exchanges between the world’s second‐largest river and one of the world’s largest wetlands is an open one. In turn, this question regarding hydrodynamics factors into how carbon is exchanged and the role of precipitation in the wetland water balance. Questions like this are also evident for understanding how precipitation is driven by atmospheric jets, how much carbon is evading from the waters, and so on. These are first‐order questions that require a collection of measurements and models to thoroughly understand and know the answers.
This monograph is an important step toward answering these questions. It is an outcome from an AGU Chapman Conference held in Washington, D.C., in September 2018 (see photo; Beighley et al., 2019). The conference was, in turn, an outcome of a paper published in Reviews of Geophysics (Alsdorf et al., 2016) that brought wider attention to the status of Congo research. There are a modest number of historic and recent studies of the Congo, but many are published in French or in journals that are difficult to obtain, thus the findings are not as widely known as those of the comparable Amazon Basin.
This monograph builds upon decades of study by dedicated Congo‐based researchers, who are among the contributors to this monograph. Researchers were invited to contribute within the broad categories of hydrology, climate, and biogeochemistry of sub‐Saharan Africa with a special emphasis on the Congo Basin. The content is divided into five parts, with two focused on the variations in and influences on rainfall, and others focused on hydrology, sediments, and carbon. The final part discusses water resources.
We are pleased with the international diversity of authorship across the book’s 28 chapters. Of the 106 authors, 40 live in sub‐Saharan Africa, 40 are from Europe, and 26 are from other countries such as the United States and Brazil. More than 50 referees were involved in peer‐reviewing the chapters, and similar to the authorship, hail from a variety of countries and continents, many are bilingual, and all are renown experts. The entire monograph is published in both English and French; indeed, several chapters were submitted and reviewed in French. This is a bilingual first for any AGU publication.
It is our goal that all Earth scientists enjoy reading the chapters, that they contact some of the authors, and create new collaborations that answer the first‐order questions and hence make new scientific discoveries. Anyone studying the Amazon will immediately see opportunities for new research in the Congo. It’s also quite possible that the interdisciplinary researcher will see opportunities, such as working with chapter authors who collect field measurements that can be combined with new observations such as GPS and gravity to better understand lithospheric geodynamics and the Earth’s geoid. This monograph is the starting point for new and exciting partnerships.
We are deeply indebted to the researchers who have been studying the Congo and sub‐Saharan Africa for decades. This small group of dedicated scientists established the foundations upon which the chapter authors have built their findings. Several science funding agencies from around the world have provided financial support. About two hundred people were involved in this monograph including the authors, referees, staff at AGU and at Wiley, and program officers at our funding organizations. We sincerely thank Emma Guzowski and Emma Cole for their dedicated work translating the chapters. Merci beaucoup à nos amis!
Guy D. Moukandi N’kaya Marien Ngouabi University, Republic of the Congo
Raphael M. Tshimanga University of Kinshasa, Democratic Republic of the Congo
Douglas Alsdorf The Ohio State University, USA
REFERENCES
1 Alsdorf, D., Beighley, E., Laraque, A., Lee, H., Tshimanga, R.,