title: Solar modulation of Little Ice Age climate in the tropical Andes.
abstract: 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.
authors.affiliation: Department of Geosciences, Morrill Science Center, University of Massachusetts, Amherst, MA 01003, USA. ppolissa@geosc.psu.edu
authors.forename: P J
authors.initials: PJ
authors.lastname: Polissar
authors.forename: M B
authors.initials: MB
authors.lastname: Abbott
authors.forename: A P
authors.initials: AP
authors.lastname: Wolfe
authors.forename: M
authors.initials: M
authors.lastname: Bezada
authors.forename: V
authors.initials: V
authors.lastname: Rull
authors.forename: R S
authors.initials: RS
authors.lastname: Bradley
mesh_terms: D002980:Climate; D019015:Geologic Sediments; D046448:Ice Cover; D008962:Models, Theoretical; D013472:Sunlight; D013696:Temperature; D014329:Tropical Climate; D014687:Venezuela