A Two-Century Precipitation Dataset for the Continent of Africa

A wealth of historical information on climate and weather exists for the African continent. Documentary information, hydrologic indicators, and rain gauge records have been compiled and combined into a semiquantitative precipitation dataset that extends from 1801 to 1900. That dataset describes “wetness” for 90 regions of Africa, using a seven-category index. A regional gauge dataset for 1901–2000 has been converted to the seven-class system, extending coverage to two centuries. These datasets are available through the Paleoclimate Data Center.

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Twentieth-Century Climate Change over Africa: Seasonal Hydroclimate Trends and Sahara Desert Expansion

Journal of Climate ◽

10.1175/jcli-d-17-0187.1 ◽

2018 ◽

Vol 31 (9) ◽

pp. 3349-3370 ◽

Cited By ~ 37

Author(s):

Natalie Thomas ◽

Sumant Nigam

Keyword(s):

Twentieth Century ◽

Source Region ◽

Surface Air Temperature ◽

Rain Gauge ◽

Mitigation Strategies ◽

Annual Rainfall ◽

Sahara Desert ◽

Seasonal Temperature ◽

African Continent ◽

Climate Simulations

Twentieth-century trends in seasonal temperature and precipitation over the African continent are analyzed from observational datasets and historical climate simulations. Given the agricultural economy of the continent, a seasonal perspective is adopted as it is more pertinent than an annual-average one, which can mask offsetting but agriculturally sensitive seasonal hydroclimate variations. Examination of linear trends in seasonal surface air temperature (SAT) shows that heat stress has increased in several regions, including Sudan and northern Africa where the largest SAT trends occur in the warm season. Broadly speaking, the northern continent has warmed more than the southern one in all seasons. Precipitation trends are varied but notable declining trends are found in the countries along the Gulf of Guinea, especially in the source region of the Niger River in West Africa, and in the Congo River basin. Rainfall over the African Great Lakes—one of the largest freshwater repositories—has, however, increased. It is shown that the Sahara Desert has expanded significantly over the twentieth century, by 11%–18% depending on the season, and by 10% when defined using annual rainfall. The expansion rate is sensitively dependent on the analysis period in view of the multidecadal periods of desert expansion (including from the drying of the Sahel in the 1950s–80s) and contraction in the 1902–2013 record, and the stability of the rain gauge network. The desert expanded southward in summer, reflecting retreat of the northern edge of the Sahel rainfall belt, and to the north in winter, indicating potential impact of the widening of the tropics. Specific mechanisms for the expansion are investigated. Finally, this observational analysis is used to evaluate the state-of-the-art climate simulations from a comparison of the twentieth-century hydroclimate trends. The evaluation shows that modeling regional hydroclimate change over the African continent remains challenging, warranting caution in the development of adaptation and mitigation strategies.

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Spatial reconstruction of semi-quantitative precipitation fields over Africa during the nineteenth century from documentary evidence and gauge data

Quaternary Research ◽

10.1016/j.yqres.2012.03.012 ◽

2012 ◽

Vol 78 (1) ◽

pp. 13-23 ◽

Cited By ~ 47

Author(s):

Sharon E. Nicholson ◽

Douglas Klotter ◽

Amin K. Dezfuli

Keyword(s):

Nineteenth Century ◽

Rain Gauge ◽

African Continent ◽

Documentary Evidence ◽

Proxy Data ◽

Data Set ◽

Spatial Reconstruction ◽

Geographical Regions ◽

Gauge Data

AbstractThe article presents a newly created precipitation data set for the African continent and describes the methodology used in its creation. It is based on a combination of proxy data and rain gauge records. The data set is semi-quantitative, with a “wetness” index of − 3 to + 3 to describe the quality of the rainy season. It covers the period AD 1801 to 1900 and includes data for 90 geographical regions of the continent. The results underscore a multi-decadal period of aridity early in the nineteenth century.

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A New 60-year 1940/1999 Monthly-Gridded Rainfall Data Set for Africa

Water ◽

10.3390/w11020387 ◽

2019 ◽

Vol 11 (2) ◽

pp. 387 ◽

Cited By ~ 11

Author(s):

Claudine Dieulin ◽

Gil Mahé ◽

Jean-Emmanuel Paturel ◽

Soundouss Ejjiyar ◽

Yves Tramblay ◽

...

Keyword(s):

Hydrological Modeling ◽

Statistical Tests ◽

Rain Gauge ◽

Climatic Research Unit ◽

Rainfall Regime ◽

Western Coast ◽

African Continent ◽

Data Set ◽

Long Time

The African continent has a very low density of rain gauge stations, and long time-seriesfor recent years are often limited and poorly available. In the context of global change, it is veryimportant to be able to characterize the spatio-temporal variability of past rainfall, on the basis ofdatasets issued from observations, to correctly validate simulations. The quality of the rainfall datais for instance of very high importance to improve the efficiency of the hydrological modeling,through calibration/validation experiments.The HydroSciences Montpellier Laboratory (HSM) has a long experience in collecting andmanaging hydro-climatological data. Thus, HSM had initiated a program to elaborate a referencedataset, in order to build monthly rainfall grids over the African continent, over a period of 60 years(1940/1999). The large quantity of data collected (about 7,000 measurement points were used in thisproject) allowed for interpolation using only observed data, with no statistical use of a referenceperiod. Compared to other databases that are used to build the grids of the Global HistoricalClimatology Network (GHCN) or the Climatic Research Unit of University of East Anglia, UK (CRU),the number of available observational stations (a was significantly much higher, including the end ofthe century when the number of measurement stations dropped dramatically, everywhere.Inverse distance weighed (IDW) was the chosen method to build the 720 monthly grids and amean annual grid, from rain gauges. The mean annual grid was compared to the CRU grid. The gridswere significantly different in many places, especially in North Africa, Sahel, the horn of Africa, andthe South Western coast of Africa, with HSM_SIEREM data (database HydroSciencesMontpellier_Système d’Information Environnementales pour les Ressources en Eau et leurModélisation) being closer to the observed rain gauge values. The quality of the grids computed waschecked, following two approaches—cross-validation of the two interpolation methods, ordinarykriging and inverse distance weighting, which gave a comparable reliability, with regards to theobserved data, long time-series analysis, and analysis of long-term signals over the continent,compared to previous studies. The statistical tests, computed on the observed and gridded data,detected a rupture in the rainfall regime around 1979/1980, on the scale of the whole continent; thiswas congruent with the results in the literature. At the monthly time-scale, the most widely observedsignal over the period of 1940/1999, was a significant decrease of the austral rainy season betweenMarch and May, which has not earlier been well-documented. Thus, this would lead to a furtherdetailed climatological study from this HSM_SIEREM database.

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Threats to the Economic Security of Russia in the Context of Trends in the Development of Africa

Экономическая наука современной России ◽

10.33293/1609-1442-2019-4(87)-112-125 ◽

2020 ◽

pp. 112-125

Author(s):

Alexander I. Selivanov ◽

Vladimir G. Starovoitov ◽

Dmitriy V. Troshin

Keyword(s):

National Economy ◽

Economic Security ◽

Economic Transformation ◽

Economic Crime ◽

African Continent ◽

New Developments ◽

External Threats ◽

National Economic ◽

The World ◽

National Economic Security

Situation and value of the African continent on the economic and social cardmap of the world dynamically changes and will continue to change throughout all the 21st century with strengthening of the Africa positions in the world. In Russia all the complex of threats and problems which arise owing to political and economic transformation of Africa is not adequately estimated. The scientific literature on economic security issues presents an expanded set of internal and external threats to the national economy that goes beyond the traditional areas of the shadow economy, corruption, economic crime and related segments, including the internal economic stability of the national economy and inter-country competition, the quality of state strategic management, studies of the specifics of ensuring economic security in the conditions of the sixth technological order, intercultural communication and their impact on the economic relations between countries, etc. Incomplete use of such approach to strategy for the countries of Africa creates additional threats and risks for Russia. An analysis of security problems in Africa revealed that studies of economic security in the context of African development trends in Russia are conducted in an unsatisfactory volume, not always taking into account the results of new developments in the field of ensuring economic security. Even the large shifts happening on the African continent, forecasts of this dynamics sometimes are poorly known to experts of a profile of economic security, and many experts of an economic profile including working in the African subject often do not accurately distinguish problems of “economic cooperation” and “the Russian – African relations”, on the one hand, and “economic security of Russia” – with another. In this regard the new scientific problem is proved: need for deeper analysis of trends of economic and social development in Africa as an important component of a system of ensuring national economic security of Russia in the current period and in the future into account the new developments in the sphere of economic security. The main directions of activating scientific research and concentration of practical efforts to increase national economic security, neutralize threats and reduce risk for Russia in the designated context are formulated.

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