The application of a present-day climatic model to the late quaternary in southern Africa

Cockcroft, Matthew; Wilkinson, Mike; Tyson, Peter

doi:10.1007/bf00140253

Cited by 144 publications

(84 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An El Niño produces drier conditions over the summer rainfall region and wetter conditions over the winter; a La Niña results in the opposite (Lindesay, 1988;Mason and Lindesay, 1993;Allan et al, 1996). Likewise, an inverse relationship is obtained over extended spells of wet and dry years (Muller and Tyson, 1988) and over centuries and millennia (Cockcroft et al, 1987;Tyson, 1999). In the all-seasons rainfall region the relationships are more complex, depending on whether in any particular year(s) it is the summer or winter atmospheric circulation that is producing the greatest contribution to the annual rainfall record.…”

Section: Data Methods and Background Climatementioning

confidence: 96%

Millennial to multi‐decadal variability in the climate of southern Africa

Tyson

Cooper

McCarthy

2002

Intl Journal of Climatology

Self Cite

View full text Add to dashboard Cite

Wavelet analysis has been used to determine changes in the variability of southern Africa climate over the last three millennia. The structure of the variability in a 3000-year δ 18 O record has been compared with that in tree ring data for the last 600 years and both to the variability in annual rainfall and runoff during the 20th century. Preferred modes of variability are shown to have occurred in all the data sets. For overlap periods, the variability modes are in phase where the data are for a common seasonal rainfall regime.From the combined proxy and instrumental data it appears that an ∼1500-year oscillation in rainfall variability may have been present during the late Holocene. Considerable variability in South African climate has been shown to reside in the bands 500-800 and 60-120 years. The latter is manifest in stable isotope and tree ring proxy data and in measured rainfall and runoff, and shows a distinctive latitudinal variation over southern Africa. The ∼80-year variability has been present for at least 600 years in the tree ring data and at least 3000 years in the stable isotope data. During the 20th century, the variability in the 60-120-year range was confined south of 20°S in southern Africa.The existence of considerable multi-decadal climate variability in the range 16-20 years has been confirmed south of 15°S. Tree ring data show that the ∼18-year oscillation in climate has been present for at least 600 years. The 500-800-year, ∼80-year and ∼18-year variability has been both frequency-and amplitude-modulated over time, but never to the extent that the variability bands have lost their integrity. Their persistence is a striking feature of southern African climate.The millennial, centennial and multi-decadal variability in climate over southern Africa finds counterparts with temporal variability in similar time ranges reported elsewhere. Spatial teleconnections in variability likewise have been shown to occur. The changes in climate variability over the subcontinent are part of variability changes affecting the Earth system in many other regions.

show abstract

Section: Data Methods and Background Climatementioning

confidence: 96%

Millennial to multi‐decadal variability in the climate of southern Africa

Tyson

Cooper

McCarthy

2002

Intl Journal of Climatology

Self Cite

View full text Add to dashboard Cite

show abstract

“…One aspect of glacial vegetation dynamics in this region has been the question of whether the mediterranean Fynbos Biome expanded into the region as a result of an equatorward shift of the westerly storm track and regional 'winter-rainfall zone' driven by an expanded circumpolar vortex (Chase and Meadows, 2007;Cockcroft et al, 1987;van Zinderen Bakker, 1976). In the absence of long, continuous terrestrial sequences, fossil pollen recovered from marine cores (Shi et al, 2000;Shi et al, 2001;Urrego et al, 2015) has been used to infer vegetation change in southwestern Africa across the last glacial-interglacial cycle, with conclusions generally supporting the early conceptual models (e.g.…”

Section: Accepted M Manuscriptmentioning

confidence: 99%

50,000 years of vegetation and climate change in the southern Namib Desert, Pella, South Africa

Lim

Chase

Chevalier

et al. 2016

Palaeogeography, Palaeoclimatology, Palaeoecology

View full text Add to dashboard Cite

“…periods over the South African subcontinent (see also Cockcroft et al 1987;Tyson 1999). Rainfall is generally derived from moisture transport in the tropical easterlies.…”

Section: Pathway Atmospherementioning

confidence: 99%

Nutrient regime and upwelling in the northern Benguela since the middle Holocene in a global context - a multi-proxy approach

et al. 2011

View full text Add to dashboard Cite

The last 5500 years of climate change and environmental response in the northern Benguela Coastal Upwelling are reconstructed by means of three sediment cores from the inner shelf off central Namibia. The study is based on nutrient (delta(15)N, delta(13)C) and productivity proxies (accumulation rates of total organic carbon; AR(TOC)). Reconstructed sea surface temperatures (alkenone-derived SST) and temperatures at subsurface depths (T(delta 18O); based on tests of planktonic foraminifers) reflect the physical boundary conditions. The selection of proxy indicators proved a valuable basis for robust palaeo-climatic reconstructions, with the resolution ranging from multi-decadal (NAM1) over centennial (core 178) to millennial scale (core 226620). The northern Benguela experienced pronounced and rapid perturbation during the middle and late Holocene, and apparently, not all are purely local in character. In fact, numerous correlations with records from the adjacent South African subcontinent and the northern hemisphere testify to global climatic teleconnections. The Holocene Hypsithermal, for instance, is just as evident as the Little Ice Age (LIA) and the Roman Warm Period. The marked SST-rise associated with the latter is substantiated by other marine and terrestrial data from the South African realm. The LIA (at least its early stages) manifests itself in intensified winds and upwelling, which accords with increased rainfall receipts above the continental interior. It appears that climate signals are transferred both via the atmosphere and ocean. The combined analysis of SST and T(delta 18O) proved a useful tool in order to differentiate between both pathways. SSTs are primarily controlled by the intensity of atmospheric circulation features, reflecting changes of upwelling-favourable winds. T(delta 18O) records the temperature of the source water and often correlates with global ocean conveyor speed due to varying inputs of warm Agulhas Water. It seems as though conveyor slowdown or acceleration not only affected the temperature of the source water but also its nutrient content. This relationship between source water quality and conveyor speed is already known from glacial times

show abstract

The application of a present-day climatic model to the late quaternary in southern Africa

Cited by 144 publications

References 49 publications

Millennial to multi‐decadal variability in the climate of southern Africa

Millennial to multi‐decadal variability in the climate of southern Africa

50,000 years of vegetation and climate change in the southern Namib Desert, Pella, South Africa

Nutrient regime and upwelling in the northern Benguela since the middle Holocene in a global context - a multi-proxy approach

Contact Info

Product

Resources

About