title: Persistent drying in the tropics linked to natural forcing.
abstract: Approximately half of the world's population lives in the tropics, and future changes in the hydrological cycle will impact not just the freshwater supplies but also energy production in areas dependent upon hydroelectric power. It is vital that we understand the mechanisms/processes that affect tropical precipitation and the eventual surface hydrological response to better assess projected future regional precipitation trends and variability. Paleo-climate proxies are well suited for this purpose as they provide long time series that pre-date and complement the present, often short instrumental observations. Here we present paleo-precipitation data from a speleothem located in Mesoamerica that reveal large multi-decadal declines in regional precipitation, whose onset coincides with clusters of large volcanic eruptions during the nineteenth and twentieth centuries. This reconstruction provides new independent evidence of long-lasting volcanic effects on climate and elucidates key aspects of the causal chain of physical processes determining the tropical climate response to global radiative forcing.
authors.affiliation: Department of Marine Sciences, University of Puerto Rico, Mayagüez, Puerto Rico 00681-9000, USA.
authors.forename: Amos
authors.initials: A
authors.lastname: Winter
authors.affiliation: 1] The Ocean in the Earth System Department, Max Planck Institute for Meteorology, Bundesstrasse 53, Hamburg 20157, Germany [2] Department of Environmental Sciences, Informatics and Statistics, University of Venice, Dorsoduro 2137, Venice 30123, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Zanchettin
authors.affiliation: Department of Geology, University of Puerto Rico, Mayagüez, Puerto Rico 00681-9000, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Miller
authors.affiliation: Division of Oceans and Climate Physics, Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York 10964, USA.
authors.forename: Yochanan
authors.initials: Y
authors.lastname: Kushnir
authors.affiliation: School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York 11790, USA.
authors.forename: David
authors.initials: D
authors.lastname: Black
authors.affiliation: Division of Climate Sciences and Paleo-climate Dynamics, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven 27570, Germany.
authors.forename: Gerrit
authors.initials: G
authors.lastname: Lohmann
authors.affiliation: Department of Earth Sciences, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: Allison
authors.initials: A
authors.lastname: Burnett
authors.affiliation: Geological Institute, Swiss Federal Institute of Technology, Zurich 8092, Switzerland.
authors.forename: Gerald H
authors.initials: GH
authors.lastname: Haug
authors.affiliation: Department of Marine Sciences, University of Puerto Rico, Mayagüez, Puerto Rico 00681-9000, USA.
authors.forename: Juan
authors.initials: J
authors.lastname: Estrella-Martínez
authors.affiliation: 1] Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK [2] Sediment and Isotope Geology, Ruhr-University Bochum, Universitätsstrasse 150, Bochum 44801, Germany.
authors.forename: Sebastian F M
authors.initials: SF
authors.lastname: Breitenbach
authors.affiliation: Environmental Geosciences, CEREGE (CNRS-Université Aix Marseille), Aix en Provence 13545, France.
authors.forename: Luc
authors.initials: L
authors.lastname: Beaufort
authors.affiliation: Department of Environmental Sciences, Informatics and Statistics, University of Venice, Dorsoduro 2137, Venice 30123, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Rubino
authors.affiliation: 1] Department of Earth Sciences, University of Minnesota, Minneapolis, Minnesota 55455, USA [2] School of Human Settlement and Civil Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
authors.forename: Hai
authors.initials: H
authors.lastname: Cheng