INVESTIGADORES
MORALES Mariano Santos
congresos y reuniones científicas
Título:
REGIONAL CLIMATE RECONSTRUCTIONS IN SOUTH AMERICA: A CONTRIBUTION FROM THE LOTRED-SA INITIATIVE
Autor/es:
VILLALBA, R; MASIOKAS, M; LARA, A., ; RIVERA, A; GROSJEAN, M; MORALES, M; CHRISTIE, D; URRUTIA, R; DELGADO, S; LUCKMAN, B.H; BONINSEGNA, J.A; PRIETO, M.R.; ESPIZUA, L; ARAVENA, J.C; LE QUESNE, C
Lugar:
Valdivia
Reunión:
Conferencia; II International Symposium Reconstructing Climate Variations in South America and the Antartic Peninsula over the last 2000 years; 2010
Institución organizadora:
PAGES Past Global changes
Resumen:
Recent reviews in the LOTRED-SA
Special Issue (Palaeo 3, 2009) show that
there is a wealth of data sets
available from a large variety of high-resolution
archives across the Andes of
South America. Based on this information, we
provide regional syntheses of
climate variations for the southern tropics (Altiplano),
subtropical Andes (Central Chile
and Argentina),
and the northern
and southern sectors of the
Patagonian Andes during the last four centuries.
Consistency among different
proxy records provide conidence about the major
climate changes recorded at
regional scales. Humid conditions in the Bolivian
Altiplano and the subtropical Andes inferred from tree rings during the
17th and 19th centuries are consistent with glacier
advances in both regions
during the Little Ice Age (LIA,
ca. AD 1600-1850). Across Patagonia, most
glaciers also reached their peak
LIA advances between the 17th and 19th centuries
followed by an accelerated loss
of ice during the past century. Glacier
retreat has been particularly
pronounced in the northern Patagonian Andes
since the mid-1970s, where
tree-ring based temperature estimates have been
the warmest of the past 400
years. This warming has been concurrent with
a marked negative trend in
regional precipitation. Comparisons of long-term
climate variations in the four
selected Andean regions suggest the existence
of coupled interactions between
tropical and extratropical modes of climate
variability. The wet periods in
the southern tropics and the subtropical Andes
around AD 1650 and AD 1820 could
be dynamically associated with a weakening
of the Hadley Cell and a
northward shift of the Westerlies, respectively.
Northward locations of the
Westerlies during the same intervals migth have
enhanced Antarctic inluences
across Patagonia, consistent with the two
coldest
periods reconstructed for the
north and south Patagonian Andes during
the past four centuries.