Artículo de revista
Climate dynamics along the arid northern coast of Chile: The 1997–1998 Dinámica del Clima de la Región de Antofagasta (DICLIMA) experiment
Fecha
2003Registro en:
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 108, NO. D17, 4538, 2003
doi:10.1029/2002JD003357
Autor
Rutllant Costa, José
Fuenzalida Ponce, Humberto
Aceituno Gutiérrez, Patricio
Institución
Resumen
The DICLIMA field experiment was designed to test and quantify the hypothesis of an
afternoon enhancement of the coastal subsidence in the extremely arid northern Chile
because of solar heating over the west slope of the Andes. Ten-day campaigns near
Antofagasta (23 S) were carried out in January 1997, July 1997, and January 1998.
Significant diurnal cycles in temperature, mixing ratio, and wind from about 1000 to 4000m
above sea level were observed. This layer was decoupled from the marine boundary layer
circulation below by the subsidence inversion when its base was under the average height of
the coastal mountain range. The solar heating cycle over the Andes and associated
circulation resulted in a mean afternoon zonal divergence above the subsidence inversion
base of about 30 10 6 s 1, exceeding by a factor of 5 typical subtropical west coast
divergences. The corresponding early morning convergence was particularly intense during
the austral winter experiment. In spite of the very strong El Nin˜o conditions that prevailed
during the July 1997 and January 1998 experiments, the overwhelming control that
radiation exerts on the daily cycles of the atmospheric circulation over the west slope of the
Andes seems to guarantee the general validity of the results.