Awarded by CAS-TWAS President’s Fellowship Programme in 2014, Dike Victor Nnamdi came to China from Nigeria to pursue his doctoral study at CAS-TWAS Centre of Excellence for Climate and Environment Sciences, which is also known as International Center for Climate and Environment Sciences (ICCES) at Institute of Atmospheric Physics, Chinese Academy of Sciences.
Dike Victor Nnamdi studied under the supervision of Prof. Zhaohui LIN, the director of ICCES, and a member of the coordinating council of the Commission on Science and Technology for Sustainable Development in the South (COMSATS).
Victor's research mainly focused on climate extremes and the associated mechanism. This includes drought and flood episodes which are the most occurring climate disasters in West Africa. The region is largely dependent on agriculture, food insecurity intensified by disruptions in rainfall cycles creates tension. Notably, the diminishing water resources due to the West African Sahel drought is linked to migrations which escalated the civil conflict in the region. In an effort to understand climate extremes over the region, he focused on air-sea interactions associated with extreme rainfall over West Africa. During his four-year study, Victor published six articles in peer-reviewed journals with an average of at least one article each year. Particularly his study led to the development of Trans-Atlantic-Pacific Ocean Dipole (TAPOD), a measure of tropical ocean phenomenon to be closely connected to the West African summer rainfall anomalies. The study demonstrated that enhanced precipitation over West Africa is closely related to the positive phase of the TAPOD, which is characterized by warm sea surface temperature anomalies (SSTAs) in the tropical Atlantic and cool SSTAs in the tropical eastern Pacific Ocean. It is found that during the positive phase of the TAPOD, significant westerly anomalies over the tropical Atlantic Ocean drive anomalous water vapor convergence over West Africa, leading to enhanced precipitation in the region. His study confirms the recovery of rainfall over the West African Sahel after the prolonged drought that ravaged the region in the recent past.
Inspired by the success of the TAPOD index as a possible predictor of summer rainfall over West Africa, Victor design an idealized but realistic numerical experiment implemented on the state-of-the-art Institute of Atmospheric Physics Atmospheric General Circulation Model version 4.1 IAP-AGCM4.1. Remarkably, the model reproduced the observed characteristics of the TAPOD, including the positive and negative phases of the dipole index which further established the index as a veritable tool for the prediction of summer rainfall over West Africa. In a related research which is necessitated by the sequence of disaster climate events over West Africa and its far-reaching impact on the populates. Victor started to explore another idea to understand the characteristics of extreme rainfall events over the region. The study established the intensification of rainfall extremes, especially over the West African Sahel known for the widespread drought that ravaged the region in the 1970s-1980s. His study linked several flood disasters over West Africa to the increasing frequency and the intensification of rainfall extremes. Particularly, the 2017 Sierra Leone flood and mudslide that killed more than 1100 people and displaced many more from their homes. Consequently, through several conference presentations, he has advocated for broad mitigation and adaptation strategy for the management of risks associated with climate extremes in the region.
Given the enabling environment created by the international research collaboration mandate of the ICCES, and in pursuance of his penchant for community service. Victor participated actively in the activities of the Young earth system scientist community which vision is highlighted in Earth System Science Frontiers: An Early Career Perspective, an initiative under the sponsorship of the World Climate Research Programme (WCRP) networks. His shared commitment to the course of ameliorating the plights of early-career scientists in developing countries led to the publication of the Obstacles facing Africa’s young climate scientists, an article intended to initiate discussions towards addressing the brain drain in Africa amongst other challenges. As a representative of early-career scientists, Victor contributed immensely to the deliberations in high-level meetings organized by the World Meteorological Organization, on the need to nurture scientific talents a workforce needed in Advancing Research for Seamless Earth System Prediction while he ensured that perspectives of early-career scientists are captured in the WCRP strategic and implementation plans 2019-2029 during the 39th session of the Joint Scientific Committee of WCRP.
Following his diligence and strong research motivation, he was awarded CAS President's International Fellowship Initiative, a post-doctoral research fellowship for young talents to enable him to advance his research at ICCES. His postdoctoral research work is mostly focused on process-based analysis of climate extremes in CMIP6 simulations. Using a multi-model ensemble approach, his work has shown the impact of climate change on rainfall changes over West Africa. Particularly, the intensification of rainfall extreme as well as changes in rainfall seasonality over the region, especially under high shared socioeconomic pathways. Understandably, changes in rainfall seasonality will have a significant impact on critical economic sectors like agriculture, which is the mainstay of livelihood of the most populous region in the African continent. Hence, he believes that intended nationally determined contributions on the reduction of greenhouse emissions are met the projected impact of climate change will be significantly mitigated. Victor hopes that the results of his work will be of practical significance for decision-making and the management of climate-related hazards in West Africa.
Introduction of CAS-TWAS Centre of Excellence for Climate and Environment Sciences
International Center for Climate and Environment Sciences (ICCES) was founded in 1991. It was selected as the representative center of China to join the network of Centre of Excellence of COMSATS (Commission on Science and Technology for Sustainable Development in the South) in 1995. ICCES also holds the secretariat of CAS-TWAS-WMO Forum (CTWF) on Climate Science since 2000, and annually organizes international symposiums and training workshops. In 2013, ICCES was selected as one of the first five CAS-TWAS Centre of Excellence to build scientific strength and drive innovation in the developing world.
ICCES focuses its research on the key scientific problems related to global climate and environmental changes. The main research fields include the development of Dynamical Earth System Model and numerical simulation, meteorological and environmental forecast and related disaster assessment theory and technique, data assimilation theory and methodology, and earth system theory and natural cybernetics.
ICCES is devoted to establishing the cooperative and innovation research center of CAS and TWAS in the area of climate and environment sciences and provides services to the developing countries with scientific support and advisory, capacity building.
