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Variabilidad atmosférica de alta frecuencia en el borde oriental del anticiclón del pacífico sureste

Ciencia y Tecnología del Mar 01/2006;
Source: DOAJ

ABSTRACT La variabilidad de alta frecuencia en la cobertura estrato-cumuliforme sobre el margen oriental del anticiclón subtropical del Pacífico sureste, constituye un elemento central del clima regional al modular profundamente fluctuaciones de mayor período. Esta variabilidad es particularmente marcada sobre la franja costera debido al ciclo diario de insolación y al fenómeno genéricamente conocido como depresiones costeras. Sobre la base de cartas meteorológicas (Reanálisis) y datos de superficie y altura obtenidos durante el crucero CIMAR 6 Islas Oceánicas, se documenta y discute el efecto de la variabilidad de escala sinóptica en la nubosidad asociada a la capa límite marina y en la inversión térmica que la limita por arriba. Esta variabilidad fue más marcada durante la primera mitad del CIMAR 6, debido a la proyección de perturbaciones de latitudes medias sobre el sector subtropical del Pacífico sur-oriental. La amplitud de estas perturbaciones resultó ser más pronunciada en la costa, posiblemente debido a ascensos y descensos realzados por los Andes. El flujo cálido del este y el descenso de la inversión térmica asociados a la entrada de dorsales cálidas en altura que siguieron a estas perturbaciones se extendió hasta unos 800 km mar afuera, aunque una delgada capa superficial mantuvo la dirección sur (hacia el ecuador) en los vientos. Se puede concluir que a nivel local no existe una relación simple entre subsidencia de gran escala y espesor de la capa límite marina, probablemente debido a la advección cálida que produce el viento del este al descender sobre la ladera andina.

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  • Monthly Weather Review 01/2002; 130. · 2.76 Impact Factor
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    Bulletin of The American Meteorological Society - BULL AMER METEOROL SOC. 01/2001; 82(10):2193-2208.
  • Diurnal cycles of the circulation and low-cloud cover over the subtropical southeastern Pacific. R Garreaud . 699-1710.

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