Dust from Patagonia (INSU LEFE/CHAT)
Contact LISA : R. Losno
PI : R. Losno
Participating Laboratories: ARTéHIS (UMR5594), LSCE (UMR8212), IFAECI (UMI3351), LOCEAN (UMR 7159)
The Austral region ranging from about 40° and 65° south is one of the major CO2 sink.Atmospheric dust feeds open ocean surface waters with trace metals and enhance phytoplankton primary productivity and CO2 removal. The South Hemisphere is mainly constituted of oceans and the only possible dust sources are East Patagonia, South Africa and Australia. Patagonia is suspected to be the major dust source for the oceanic region ranging between 40°S and 60°S. The aim of this project is to document as far as possible the chemical properties and the amount of dust exported from Argentinean Patagonia to Southern Ocean to understand and quantify its impacts on these oceanic ecosystems. To achieve these objectives, we measure atmospheric aerosols close to emission zones directly using air filtration and indirectly with lichen chemical composition and wind erodible part of soils. A LIDAR network survey and use of atmospheric dust emission and transportation models give information on the spatial extension of local measurements. We devoted the first year of this project on field experiments and analytical work: soil and lichens collection, set up of an aérosol sampling station, set up of the LIDAR network.
For the next year, we will increase the coverage of soil samplingFor the next year, we will increase the coverage of soil sampling
Picture Left shows a researcher at work on the sampling station at Rio Gallegos. Today one year of continuous sampling is already obtained on a weekly basis. Picture right (from Z. Qu, 2012) shows the iron solubility of an aerosol generated from 4 different Patagonian soil samples at decreasing pH from 7 to 1. Solubility is very low at the higher pHs but increases as pH below 3. One ob the objective of this work is to understand such observed solubility variations.
This project was in its first stage and no reviewed publications are still written. One poster was presented at the SOLAS OSC (Cle Elum, 7-10 may 2012), two PhD (A. Heimburger, 2011-2013; Z. Qu, 2012-2015) and a master degree (Z. Qu, 2012) are involved.