Intraannual fog variability and its relationship with spatio-temporal gradients in northern Chilean Atacama Desert

Abstract

<p>The coastal regions of the Atacama Desert comprise some of the driest areas of the world, with average annual precipitation mostly less than 1 mm per year. It is in these environments where the ocean-atmosphere interconnected system determines the spatio-temporal dynamic of an advective coastal fog, providing moisture out stratocumulus clouds from the Pacific Ocean to an hyper-arid environment and allowing the development of fog ecosystems and high biodiversity along the Atacama coast.<br />Studies about fog has been done in this region since the middle of the 20th century. However, there is a high quality knowledge gap about spatio-temporal fog dynamics on a local scale and its interaction of climate variables with topography. The study on fog climatology and its variability will be the basis for the analysis of complex biosphere-atmosphere interactions, in which the local ecosystems can act as bio-indicators for fog water availability and climate change.<br />The study area is situated in the Chilean coastal desert of Atacama in the Tarapacá region (20° S), where a transect of seven climatological stations located between 518 m and 1,354 m altitude, from the coast to 10.7 km inland, records a high temporal (hourly/10-minutes) atmospheric data. The climate stations measurement it is based on Standard Fog Collectors (SFC) and a broad set of atmospherical variables that allows determine the relationship between the spatio-temporal variability of the fog and its driving parameters.<br />First results show a significant local intraannual fog variability with marked spatial differences in fog water collected and its atmospherical parameters along longitudinal and altitudinal gradient. The fog dynamic could provide a test bed for analyzing, assess and modeling biosphere-atmospheric interactions and relating them to meso-climate regimes.</p>