Average Pleistocene Climatic Patterns in the Southern Central Andes: Controls on Mountain Glaciation and Paleoclimate Implications

2002 ◽  
Vol 110 (2) ◽  
pp. 211-226 ◽  
Author(s):  
Kirk Haselton ◽  
George Hilley ◽  
Manfred R. Strecker
2016 ◽  
Author(s):  
Julie C. Fosdick ◽  
◽  
Barbara Carrapa ◽  
Barbara Carrapa ◽  
Ellen J. Reat ◽  
...  

2017 ◽  
Author(s):  
José Luis Antinao ◽  
◽  
Rachel Tiner ◽  
Rachel Tiner ◽  
Rachel Tiner ◽  
...  

2001 ◽  
Vol 171 (3-4) ◽  
pp. 213-237 ◽  
Author(s):  
Wolfgang Siebel ◽  
Wolfgang B.W. Schnurr ◽  
Knut Hahne ◽  
Bernhard Kraemer ◽  
Robert B. Trumbull ◽  
...  

2011 ◽  
Vol 7 (1) ◽  
pp. 41-46 ◽  
Author(s):  
R. Zech ◽  
J. Zech ◽  
Ch. Kull ◽  
P. W. Kubik ◽  
H. Veit

Abstract. The latitudinal position of the southern westerlies has been suggested to be a key parameter for the climate on Earth. According to the general notion, the southern westerlies were shifted equatorward during the global Last Glacial Maximum (LGM: ~24–18 ka), resulting in reduced deep ocean ventilation, accumulation of old dissolved carbon, and low atmospheric CO2 concentrations. In order to test this notion, we applied surface exposure dating on moraines in the southern Central Andes, where glacial mass balances are particularly sensitive to changes in precipitation, i.e. to the latitudinal position of the westerlies. Our results provide robust evidence that the maximum glaciation occurred already at ~39 ka, significantly predating the global LGM. This questions the role of the westerlies for atmospheric CO2, and it highlights our limited understanding of the forcings of atmospheric circulation.


2017 ◽  
Vol 43 (2) ◽  
pp. 697 ◽  
Author(s):  
J. Zech ◽  
C. Terrizzano ◽  
E. García-Morabito ◽  
H. Veit ◽  
R. Zech

The arid Central Andes are a key site to study changes in intensity and movement of the three main atmospheric circulation systems over South America: the South American Summer Monsoon (SASM), the Westerlies and the El Niño Southern Oscillation (ENSO). In this semi-arid to arid region glaciers are particularly sensitive to precipitation changes and thus the timing of past glaciation is strongly linked to changes in moisture supply. Surface exposure ages from study sites between 41° and 22°S suggest that glaciers advanced: i) prior to the global Last Glacial Maximum (gLGM) at ~40 ka in the mid (26°- 30°S) and southern Central Andes (35°-41°S), ii) in phase with the gLGM in the northern and southern Central Andes and iii) during the late glacial in the northern Central Andes. Deglaciation started synchronous with the global rise in atmospheric CO2 concentration and increasing temperature starting at ~18 ka. The pre-gLGM glacial advances likely document enhanced precipitation related to the Southern Westerlies, which shifted further to the North at that time than previosuly assumed. During the gLGM glacial advances were favored by decreased temperatures in combination with increased humidity due to a southward shifted Intertropical Convergence Zone (ITCZ) and SASM. During the late-glacial a substantial increase in moisture can be explained by enhanced upper tropospheric easterlies as response to an intensified SASM and sustained La Niña-like conditions over the eastern equatorial Pacific that lead to glacial advances in the northern Central Andes and the lake level highstand Tauca (18-14 ka) on the Altiplano. In the southernmost Central Andes at 39º-41°S, further north at 31°S and in the northernmost Central Andes at 22°S glacial remnants even point to precipitation driven glaciations older than ~115 ka and 260 ka.


2020 ◽  
Vol 102 ◽  
pp. 102697 ◽  
Author(s):  
Bruno Colavitto ◽  
Lucía Sagripanti ◽  
Lucía Jagoe ◽  
Carlos Costa ◽  
Andrés Folguera

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