Solar modulation of Little Ice Age climate in the tropical Andes.
The underlying causes of late-Holocene climate variability in the tropics are incompletely understood. Here we report a 1,500-year reconstruction of climate history and glaciation in the Venezuelan Andes using lake sediments. Four glacial advances occurred between anno Domini (A.D.) 1250 and 1810, coincident with solar-activity minima. Temperature declines of -3.2 +/- 1.4 degrees C and precipitation increases of approximately 20% are required to produce the observed glacial responses. These results highlight the sensitivity of high-altitude tropical regions to relatively small changes in radiative forcing, implying even greater probable responses to future anthropogenic forcing.
Polissar
P J
PJ
Department of Geosciences, Morrill Science Center, University of Massachusetts, Amherst, MA 01003, USA. ppolissa@geosc.psu.edu
Abbott
M B
MB
Wolfe
A P
AP
Bezada
M
M
Rull
V
V
Bradley
R S
RS
D002980:Climate; D019015:Geologic Sediments; D046448:Ice Cover; D008962:Models, Theoretical; D013472:Sunlight; D013696:Temperature; D014329:Tropical Climate; D014687:Venezuela