Last Glacial Maximum conditions in southern Africa
Tóm tắt
The Last Glacial Maximum (LGM) (21±2 ka) is an important period for which to understand past climatic and environmental conditions. In particular it is a key time-slice for evaluating the performance of numerical climate model simulations of glacial palaeoclimates using palaeoenvironmental data sets. However, our palaeoenvironmental data sets and reconstructions of climatic conditions at the LGM are still debated in certain regions. This is the case for southern Africa, despite more than half a century of research since early conceptual models of palaeoclimate were proposed. The greatest debates are about the spatial patterning of relatively wetter and drier conditions than present and the position of the mid-latitude westerlies at the LGM. Different patterns emerge from: separate syntheses of palaeoenvironmental proxies, from different numerical model simulations and from comparisons of the two. In this review of the progress over half a century of research in southern Africa: (1) a brief historical review of key conceptual models is given, (2) key points of conflict that emerge in synthesis of palaeoenvironmental proxy records are outlined and (3) numerical model simulations are considered. From these, some points for future progress are suggested.
Từ khóa
Tài liệu tham khảo
Brook GA, 1998, Quaternary Deserts and Climatic Change, 239
Brook GA, 1999, Cimbebasia, 15, 29
Burckle LH, Clarke D (1977) Sea surface temperatures and sea-ice distribution around the Antarctic during the last glacial maximum. Paper presented at the X INQUA Congress, Birmingham, 16–24 August.
Butzer KW, 1984, Late Cenozoic Palaeoclimates of the Southern Hemisphere, 235
Charlesworth JK, 1957, The Quaternary Era: With Special Reference to its Glaciation
CLIMAP (1981) Seasonal reconstructions of the Earth’s surface at the last glacial maximum. Map Series, Technical Report MC-36. Boulder, CO: Geological Society of America.
Deacon J, 1988, Late Quaternary Palaeoenvironments of Southern Africa
Flint RF, 1971, Glacial and Quaternary Geology
Giresse P, 1976, Comptes Rendus de l’Academie des Sciences, 283, 1157
Harrison SP, 2013, Climate Dynamics
Hays JD, Lozano J, Irving G (1974) 17,000-year map of the Atlantic and western Indian Ocean sectors of the Antarctic Ocean (60 to 30 S). High southern latitude estimated temperature changes of the last 20,000 years. Mapping the atmospheric and oceanic circulations and other climatic parameters at the time of the Last Glacial Maximum about 17,000 years ago. Abstracts (Norwich), Climatic Research Unit (University of East Anglia) Research Report 2(52–53): 80–81.
Heine K, 1978, Palaeoecology of Africa, 10, 31
Heine K, 1982, Palaeoecology of Africa, 15, 53
Hipondoka MHT, Mauz B, Kempf J, Packman S, Chiverrell RC, Bloemendal J (2014) Chronology of sand ridges and the late Quaternary evolution of the Etosha Pan, Namibia. Geomorphology 204: 553–563.
Jansen EJ, 2007, Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, 433
K-1 Model Developers (2004) K-1 Coupled GCM (Miroc Description). K-1 Technical Report 1. Centre for Climate System Research, University of Tokyo, 34 pp.
Marti O, Braconnot P, Bellier J, Benshila R, Bony S, Brockmann P, Cadule P, Caubel A, Denvil S, Dufresne J-L, Fairhead L, Filiberti M-A, Foujols M-A, Fichefet T, Friedlingstein P, Gosse H, Grandpeix J-Y, Hourdin F, Krinner G, Lévy C, Madec G, Musat I, de Noblet N, Polcher J, Talandier C (2005) The new IPSL climate system model: IPSL-CM4. France, Institut Pierre-Simon Laplace (IPSL), 84 pp. Note du Pole de Modelisation 26.
Randall DA, 2007, Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, 585
Srivastava P, 2004, Zeitschrift fur Geomorphologie, Supplementband, 133, 1
Srivastava P, Brook GA, Marais E (2005) Depositional environment and luminescence chronology of the Hoarusib River Clay Castles sediments, northern Namib Desert, Namibia. Catena 59: 187–204.
Stute M, 1998, Isotope Techniques in the Study of Environmental Change: Proceedings of a Symposium, 307
Tyson PD, 1986, Climatic Change and Variability in Southern Africa
Tyson PD, 1999, South African Journal of Science, 95, 194
Tyson PD, 2000, The Weather and Climate of Southern Africa
Tyson PD, 2001, South African Journal of Science, 97, 139
van Zinderen Bakker EM, 1967, Background to Evolution in Africa, 125
van Zinderen Bakker EM, 1976, Palaeoecology of Africa, 9, 160
van Zinderen Bakker EM, 1982, Palaeoecology of Africa, 15, 77
Wang C, 2005, The Hadley Circulation: Present, Past and Future, 173