INVESTIGADORES
VILLALBA Ricardo
artículos
Título:
Climate in the Monte Desert: Past trends, present conditions, and future projections
Autor/es:
LABRAGA, J.C.; VILLALBA, R.
Revista:
JOURNAL OF ARID ENVIRONMENTS
Editorial:
Elsevier
Referencias:
Lugar: Berlín; Año: 2009 vol. 73 p. 154 - 163
ISSN:
0140-1963
Resumen:
This paper documents the main features of climate and climate variability across the Monte Desert for
the Last Glacial Maximum, the GlacialInterglacial transition, and the Holocene on the basis of proxy
records and for the 20th century using instrumental observations. The climate in the Monte is determined
by interactions between regional physiography and atmospheric circulation in the 2545S
sectors of South America. Although arid and semi-arid conditions prevail across the Monte, its large
latitudinal extent and complex topography introduce many particularities at local scales. Paleoclimatic
records and model simulations of past climates suggest significant variations in the atmospheric
circulation, temperature and rainfall patterns since the Last Glacial Maximum. High-resolution proxy
records east of the Andes support the existence of complex climatic patterns with similar temperature
changes across the whole region but opposite precipitation variations between subtropical and midlatitude
sectors in the Monte during the past millennium.
The present-day climate is depicted in terms of the space and time variability of the near-surface
temperature, rainfall and tropospheric wind patterns. Uneven temperature trends over the Monte were
recorded for two separate (192044 and 19772001) global warming periods in the 20th century.
Additional warming evidence in the region is provided by extreme temperature records. The nonhomogeneous
regional pattern of precipitation shows a positive long-term increase between 30 and 40S
during the interval 19852001. Ensemble of climate experiments accomplished with general circulation
models provide the most likely changes in temperature and rainfall to occur by the end of this century in
relation to present climate. Temperature increases, larger in summer than in winter, will be concurrent
with more abundant precipitations in summer, but almost no changes or even small reductions in winter
across the Monte.