Remote forcing of East African rainfall and relationships with fluctuations in levels of Lake Victoria

2003 ◽  
Vol 23 (1) ◽  
pp. 67-89 ◽  
Author(s):  
Vinay V. Mistry ◽  
Declan Conway
Keyword(s):  
Lake Victoria ◽  
East African ◽  
Remote Forcing ◽  
African Rainfall

Hypoxia Tolerance in Twelve Species of East African Cichlids: Potential for Low Oxygen Refugia in Lake Victoria

1995 ◽  
Vol 9 (5) ◽  
pp. 1274-1288 ◽  
Author(s):  
LAUREN J. CHAPMAN ◽  
LESLIE S. KAUFMAN ◽  
COLIN A. CHAPMAN ◽  
F. ELLIS MCKENZIE
Keyword(s):  
Lake Victoria ◽  
Hypoxia Tolerance ◽  
Low Oxygen ◽  
East African ◽  
East African Cichlids ◽  
African Cichlids

scholarly journals Characterizing the genomic variation and population dynamics of Plasmodium falciparum malaria parasites in and around Lake Victoria, Kenya

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ashley Osborne ◽  
Emilia Manko ◽  
Mika Takeda ◽  
Akira Kaneko ◽  
Wataru Kagaya ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Population Dynamics ◽  
Malaria Elimination ◽  
Lake Victoria ◽  
Genomic Variation ◽  
Genomic Diversity ◽  
Sub Saharan Africa ◽  
Lake Victoria Basin ◽  
East African ◽  
Lake Region

AbstractCharacterising the genomic variation and population dynamics of Plasmodium falciparum parasites in high transmission regions of Sub-Saharan Africa is crucial to the long-term efficacy of regional malaria elimination campaigns and eradication. Whole-genome sequencing (WGS) technologies can contribute towards understanding the epidemiology and structural variation landscape of P. falciparum populations, including those within the Lake Victoria basin, a region of intense transmission. Here we provide a baseline assessment of the genomic diversity of P. falciparum isolates in the Lake region of Kenya, which has sparse genetic data. Lake region isolates are placed within the context of African-wide populations using Illumina WGS data and population genomic analyses. Our analysis revealed that P. falciparum isolates from Lake Victoria form a cluster within the East African parasite population. These isolates also appear to have distinct ancestral origins, containing genome-wide signatures from both Central and East African lineages. Known drug resistance biomarkers were observed at similar frequencies to those of East African parasite populations, including the S160N/T mutation in the pfap2mu gene, which has been associated with delayed clearance by artemisinin-based combination therapy. Overall, our work provides a first assessment of P. falciparum genetic diversity within the Lake Victoria basin, a region targeting malaria elimination.

Cartographical Quandaries: the Limits of Knowledge Production in Burton's and Speke's Search for the Source of the Nile

2008 ◽  
Vol 35 ◽  
pp. 455-479 ◽  
Author(s):  
Adrian S. Wisnicki
Keyword(s):  
Knowledge Production ◽  
Lake Tanganyika ◽  
Lake Victoria ◽  
Julius Caesar ◽  
East African ◽  
Blue Nile ◽  
Historical Series ◽  
The World ◽  
Limits Of Knowledge ◽  
White Nile

When he sighted the southern end of Lake Victoria on 3 August 1858, John Hanning Speke (1859b:397) realized that he had discovered the “source” of the White Nile, the most important tributary of the Nile proper, and so had “almost, if not entirely, solved a problem which it has been the first geographical desideratum of many thousand years to ascertain, and the ambition of the first monarchs of the world to unravel.” That Speke was an unknown explorer and that he had made his discovery on a solo “flying trip” during the East African Expedition of 1856-59, which, under the command of the renowned explorer Richard Francis Burton, had already also discovered Lake Tanganyika, made Speke's accomplishment all the more remarkable.As contemporaries soon asserted, Speke's discovery culminated a historical series of excursions, real and imagined, into the interior of Africa and placed Speke at the pinnacle of a line of explorers and geographers that ran from Herodotus, Julius Caesar, and Ptolemy to, in more recent times, James Bruce (the Scotsman who “discovered” the source of the Blue Nile, the second most important tributary of the Nile, in 1770), the German missionaries Ludwig Krapf and Johannes Rebmann (who “discovered,” respectively, the snow-capped mountains of Kilimanjaro in 1848 and Kenya in 1849), and noted “armchair geographers” like W.D. Cooley, Charles Beke, and James M'Queen.

scholarly journals Climate Models Lack Jet–Rainfall Coupling over West Africa

2017 ◽  
Vol 30 (12) ◽  
pp. 4625-4632 ◽  
Author(s):  
D. Whittleston ◽  
S. E. Nicholson ◽  
A. Schlosser ◽  
D. Entekhabi
Keyword(s):  
West Africa ◽  
Large Scale ◽  
Climate Models ◽  
West African ◽  
Strongly Coupled ◽  
Zonal Jets ◽  
Remote Forcing ◽  
African Rainfall ◽  
Jet Variability ◽  
West African Sahel

Changes in large-scale dynamics over West Africa—the strength and position of zonal jets—are a key interim step by which local and remote forcing is communicated into changes in rainfall. This study identifies a key mode of jet variability and demonstrates how it is strongly coupled with rainfall. The approach provides a quantitative framework to assess jet–rainfall coupling and a useful tool to investigate the concerning spread in CMIP5 rainfall projections over the West African Sahel. It is shown that many CMIP5 simulations fail to capture this coupling, indicating a fundamental limitation in their ability to predict future rainfall conditions. The results demonstrate that West African rainfall in the coming CMIP6 ensemble should be interpreted with caution; key atmospheric processes that deliver rainfall must be validated before conducting detailed analysis on rainfall.

Seasonal prediction of East African rainfall

2014 ◽  
Vol 35 (10) ◽  
pp. 2698-2723 ◽  
Author(s):  
Chia-Jeng Chen ◽  
Aris P. Georgakakos
Keyword(s):  
Seasonal Prediction ◽  
East African ◽  
African Rainfall

scholarly journals Reconciling Theories for Human and Natural Attribution of Recent East Africa Drying

2017 ◽  
Vol 30 (6) ◽  
pp. 1939-1957 ◽  
Author(s):  
Andrew Hoell ◽  
Martin Hoerling ◽  
Jon Eischeid ◽  
Xiao-Wei Quan ◽  
Brant Liebmann
Keyword(s):  
Global Warming ◽  
East Africa ◽  
Decadal Variability ◽  
Coupled Model ◽  
Western Pacific ◽  
East African ◽  
Coupled Models ◽  
Central Pacific ◽  
Model Simulations ◽  
African Rainfall

Abstract Two theories for observed East Africa drying trends during March–May 1979–2013 are reconciled. Both hypothesize that variations in tropical sea surface temperatures (SSTs) caused East Africa drying. The first invokes a mainly human cause resulting from sensitivity to secular warming of Indo–western Pacific SSTs. The second invokes a mainly natural cause resulting from sensitivity to a strong articulation of ENSO-like Pacific decadal variability involving warming of the western Pacific and cooling of the central Pacific. Historical atmospheric model simulations indicate that observed SST variations contributed significantly to the East Africa drying trend during March–May 1979–2013. By contrast, historical coupled model simulations suggest that external radiative forcing alone, including the ocean’s response to that forcing, did not contribute significantly to East Africa drying. Recognizing that the observed SST variations involved a commingling of natural and anthropogenic effects, this study diagnosed how East African rainfall sensitivity was conditionally dependent on the interplay of those factors. East African rainfall trends in historical coupled models were intercompared between two composites of ENSO-like decadal variability, one operating in the early twentieth century before appreciable global warming and the other in the early twenty-first century of strong global warming. The authors find the coaction of global warming with ENSO-like decadal variability can significantly enhance 35-yr East Africa drying trends relative to when the natural mode of ocean variability acts alone. A human-induced change via its interplay with an extreme articulation of natural variability may thus have been key to Africa drying; however, these results are speculative owing to differences among two independent suites of coupled model ensembles.

The relationship between Indian Ocean sea–surface temperature and East African rainfall

2005 ◽  
Vol 363 (1826) ◽  
pp. 43-47 ◽  
Author(s):  
Emily Black
Keyword(s):  
Indian Ocean ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Southern Oscillation ◽  
Sea Surface ◽  
East African ◽  
African Rainfall ◽  
The Pacific ◽  
The Indian Ocean ◽  
The Relationship

Knowledge of the processes that control East African rainfall is essential for the development of seasonal forecasting systems, which may mitigate the effects of flood and drought. This study uses observational data to unravel the relationship between the Indian Ocean Dipole (IOD), the El Niño Southern Oscillation (ENSO) and rainy autumns in East Africa. Analysis of sea–surface temperature data shows that strong East African rainfall is associated with warming in the Pacific and Western Indian Oceans and cooling in the Eastern Indian Ocean. The resemblance of this pattern to that which develops during IOD events implies a link between the IOD and strong East African rainfall. Further investigation suggests that the observed teleconnection between East African rainfall and ENSO is a manifestation of a link between ENSO and the IOD.

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