Journal ArticleDOI
Climate and weather factors modulating river flows in southern Angola
Mark R. Jury,Mark R. Jury +1 more
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The large-scale circulation and thermodynamic fields that modulate the flow of the Kavango River in southern Angola during austral summer are studied in this paper, where composite patterns constructed from National Center for Environmental Prediction (NCEP) data, enhanced river flow is associated with an anomalous wave train of upper level winds that emanate from the North Atlantic.Abstract:
The large-scale circulation and thermodynamic fields that modulate the flow of the Kavango River in southern Angola during austral summer are studied. According to composite patterns constructed from National Center for Environmental Prediction (NCEP) data, enhanced river flow is associated with an anomalous wave train of upper level winds that emanate from the North Atlantic. Sea-surface temperatures (SST) show a warm-north/cool-south Atlantic dipole condition as the Kavango River rises. Correlations are analysed with respect to the Kavango River flow and a 0 lag value of − 0.41 is found for the upper zonal wind over the North Atlantic. Rainfall over the African Sahel region is positively linked with Kavango River flow at 6 month lead time (r = + 0.34). The work is extended to the event scale and it is found that winds draw tropical moisture over southern Angola in response to an anomalous low-high pair and bifurcated subtropical jet stream. A continental scale sea breeze circulation amplifies the convection during afternoons. Knowledge of run-off into Namibia is critical to the management and planning of water resources in the northern Kalahari savanna. Copyright © 2009 Royal Meteorological Societyread more
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Provenance versus weathering control on the composition of tropical river mud (southern Africa)
Eduardo Garzanti,Marta Padoan,Massimo Setti,Alberto López-Galindo,Igor M. Villa,Igor M. Villa +5 more
TL;DR: In this paper, the authors present an integrated mineralogical-geochemical database on fine-grained sediments transported by all major rivers of southern Africa, including the Zambezi, Okavango, Limpopo, Olifants, Orange and Kunene.
Journal ArticleDOI
Provenance of Passive-Margin Sand (Southern Africa)
Eduardo Garzanti,Pieter Vermeesch,Marta Padoan,Alberto Resentini,Giovanni Vezzoli,Sergio Andò +5 more
TL;DR: In this paper, petrographic, mineralogical, geochronological, and geochemical signatures of river sands across southern Africa were investigated, and several factors that control sand generation, including weathering and recycling, were identified.
Journal ArticleDOI
Uncertainty in water resources availability in the Okavango River basin as a result of climate change
TL;DR: In this paper, the authors assessed the hydrological response to scenarios of climate change in the Okavango River catchment in Southern Africa and showed that a substantial change in mean flow associated with a global warming of 2 °C.
Journal ArticleDOI
Spatial and temporal precipitation variability in the Okavango–Kwando–Zambezi catchment, southern Africa
TL;DR: This paper investigated the variability in inter-annual regional precipitation dynamics pre/post the late 1970s climate shift within the Okavango-Kwando-Zambezi (OKZ) catchment in southern Africa through a descriptive spatio-temporal analysis of rainfall patterns from 1950 to 2005.
Journal ArticleDOI
Ethno-meteorology and scientific weather forecasting: Small farmers and scientists' perspectives on climate variability in the Okavango Delta, Botswana
TL;DR: In this article, the utility of a seasonal hydrological forecasting system for the study area in the context of supporting farmer's information needs were assessed, specifically addressing the questions on how local farmers read and predict the weather; and how they can collaborate with weather scientists in devising adaptation strategies for climate variability (CV) in the Okavango Delta of Botswana.
References
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Journal ArticleDOI
The NCEP/NCAR 40-Year Reanalysis Project
Eugenia Kalnay,Masao Kanamitsu,Robert Kistler,William D. Collins,D.G. Deaven,L. S. Gandin,M. Iredell,Suranjana Saha,Glenn H. White,John S. Woollen,Yuejian Zhu,Muthuvel Chelliah,Wesley Ebisuzaki,Wayne Higgins,John E. Janowiak,Kingtse C. Mo,Chester F. Ropelewski,Julian X. L. Wang,Ants Leetmaa,Richard W. Reynolds,Roy L. Jenne,Dennis Joseph +21 more
TL;DR: The NCEP/NCAR 40-yr reanalysis uses a frozen state-of-the-art global data assimilation system and a database as complete as possible, except that the horizontal resolution is T62 (about 210 km) as discussed by the authors.
Journal ArticleDOI
Extension to the North Atlantic oscillation using early instrumental pressure observations from Gibraltar and south-west Iceland
TL;DR: Early instrumental pressure measurements from Gibraltar and the Reykjavik area of Iceland have been used to extend to 1821 the homogeneous pressure series at the two locations In winter the two sites are located close to the centres of action that comprise the North Atlantic Oscillation (NAO) as mentioned in this paper.
Journal ArticleDOI
Improved Extended Reconstruction of SST (1854–1997)
TL;DR: In this paper, an improved SST reconstruction for the 1854-1997 period is developed, which uses sea ice concentrations to improve the high-latitude SST analysis and a modified historical bias correction for the 1939-41 period.
Journal ArticleDOI
North atlantic climate variability: Phenomena, impacts and mechanisms
John Marshall,Yochanan Kushnir,David S. Battisti,Ping Chang,Arnaud Czaja,Robert R. Dickson,James W. Hurrell,Michael S. McCartney,Ramalingam Saravanan,Martin Visbeck +9 more
TL;DR: Variability of the North Atlantic Oscillation and the Tropical Atlantic dominate the climate of North Atlantic sector, the underlying ocean and surrounding continents on interannual to decadal time scales as mentioned in this paper.
Journal ArticleDOI
Seasonality and atmospheric dynamics of the teleconnection between African rainfall and tropical sea‐surface temperature: Atlantic vs. ENSO
TL;DR: A 47-year record (1951-1997) of gridded data covering Africa south of the Sahara was used to document the spatial and seasonal patterns of the correlation between precipitation and sea-surface temperatures (SST) in key tropical areas, as depicted by the NIN O3, South Atlantic and North Atlantic indices.
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