IANIGLA   20881
INSTITUTO ARGENTINO DE NIVOLOGIA, GLACIOLOGIA Y CIENCIAS AMBIENTALES
Unidad Ejecutora - UE
capítulos de libros
Título:
Dendroclimatology from Regional to Continental Scales: Understanding Regional Processes to Reconstruct Large-Scale Climatic Variations Across theWestern Americas
Autor/es:
VILLALBA, R.; LUCKMAN, B.H.; BONINSEGNA, J.A.; D'ARRIGO, R.D.; LARA, A.; VILLANUEVA-DIAZ, J.; MASIOKAS, M.H.; ARGOLLO, J.; SOLIZ, C.; LE QUESNE, C.; STAHLE, D.W.; ROIG, F.A.; ARAVENA, J.C.; HUGHES, M.K.; WILES, G.C.; JACOBY, G.; HARTSOUGH, P.; WILSON, R.J.S.; WATSON, E.; COOK, E.; CERANO-PAREDES, J.; THERRELL, M.; CLEAVELAND, M.; MORALES, M.; GRAHAM, N.E.; MOYA, J.; PACAJES, J.; MASSACHESI, G.; BIONDI, F.; URRUTIA, R.; MARTINEZ-PASTUR, G.
Libro:
Dendroclimatology
Editorial:
Springer Science+Business Media
Referencias:
Lugar: Jena; Año: 2009; p. 1 - 53
Resumen:
Common patterns of climatic variability across the Western Americas
are modulated by tropical and extra-tropical oscillatory modes operating at different
temporal scales. Interannual climatic variations in the tropics and subtropics of the
Western Americas are largely regulated by El Niño-Southern Oscillation (ENSO),
whereas decadal-scale variations are induced by long-term Pacific modes of climate
variability such as the Pacific Decadal Oscillation (PDO). At higher latitudes,
climate variations are dominated by oscillations in the Annular Modes (the Arctic
and Antarctic Oscillations) which show both interannual and longer-scale temporal
oscillations. Here we use a recently-developed network of tree-ring chronologies
to document past climatic variations along the length of the Western Cordilleras.
The local and regional characterization of the relationships between climate and
tree-growth provide the basis to compare climatic variations in temperature- and
precipitation-sensitive records in the Western Americas over the past 34 centuries.
Upper-elevation records from tree-ring sites in the Gulf of Alaska and Patagonia
reveal the occurrence of concurrent decade-scale oscillations in temperature during
the last 400 years modulated by PDO. The most recent fluctuation from the
cold- to the warm-phase of the PDO in the mid 1970s induced marked changes in
tree growth in most extratropical temperature-sensitive chronologies in the Western
Cordilleras of both Hemispheres. Common patterns of interannual variations in
tree-ring chronologies from the relatively-dry subtropics in western North and
South America are largely modulated by ENSO. We used an independent reconstruction
of Niño-3 sea surface temperature (SST) to document relationships to
tree growth in the southwestern US, the Bolivian Altiplano and Central Chile and
also to show strong correlations between these regions. These results further document
the strong influence of SSTs in the tropical Pacific as a common forcing
of precipitation variations in the subtropical Western America during the past 34
centuries. Common patterns of interdecadal or longer-scale variability in tree-ring
chronologies from the subarctic and subantarctic regions also suggest common forcings
for the annular modes of high-latitude climate variability. A clear separation
of the relative influence of tropical versus high-latitude modes of variability is
currently difficult to establish, discriminating between tropical and extra-tropical
influences on tree growth still remains elusive, particularly in subtropical and temperate
regions along our transect. We still need independent reconstructions of
tropical and polar modes of climate variability to gain insight into past forcing interactions
and the combined effect on climates of the Western Americas. Finally, we
also include a series of brief examples (as boxes) illustrating some of the major
regional developments in dendrochronology over this global transect in the last
10 years