3.2 Numerical and observational study of Paracas Wind: Estimation of the dust sources and eolic fluxes toward the ocean using the threshold wind friction velocity required to produce a dust storm in Paracas-Peru

Tuesday, 8 January 2013: 1:45 PM
Room 18B (Austin Convention Center)
Julio Jesus Quijano Vargas Sr., Instituto Geofisico del Peru, Lima, Lima, Peru; and K. Takahashi and F. Velazco Sr.

The Paracas Wind (PW) it's the name of a dust storm of local scale in the desert of Paracas, Ica-Peru, but like the dust storms in all the world, this one requires exceed the threshold wind friction velocity for raising sand and dust upward the surface, particulary that depends of the atmosphere estability and the field of surface wind. This phenomena harms to the main local activities like fishing, aviation,tourism an even human health, but for other hand, the PW it's a input of iron minerals (Fe), that could be produce change in the biogeochemistry ocean and maybe that was the cause to increase the marine productivity in the last years. We studied an event ocurred in the 07th september 2011 and calculated the threshold wind friction velocity required (TFVR) using observational data of the Paracas Sand Experiment-II (ParaSEx-II). The dust sources was identify using a mesoscale model of the atmosphere adapted to the region, this model uses the TFVR as a filter to find the dust sources, then we simulated the eolic flux, toward the ocean and continent, finding the impact areas of PW and estimate the vertical-horizontal flux of dust using a empirical model.This last depends on the diameter of dust particle and the terminal velocity estimated from ParaSEx-II. The figure shows the wind friction velocity (ust,shaded) and the particles trajectories (dots, blue) between 12:00-15:00 Local Time in 07th September 2011.

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