Herut, B. Israel Oceanographic & Limnological Research, NIO, barak@ocean.org.il
Zohary, T. Israel Oceanographic & Limnological Research, KLL, tamarz@inter.net.il
Robarts, R. National Hydrology Research Institute, robarts@nhrisv.nhrc.sk.ec.gc.ca
Kress, N. Israel Oceanographic & Limnological Research, NIO, nurit@ocean.org.il

 
DO DUST PARTICLES (USING LOESS AS PROXY) PLAY AN IMPORTANT ROLE IN REMOVING DISSOLVED PHOSPHATE FROM THE EASTERN MEDITERRANEAN?
 
There are still major uncertainties in our understanding of the possible impact of dust on phosphorus dynamics in the oceans in general, and in the Eastern Mediterranean in particular. In this study we examined the potential of loess particles (as dust proxy) to remove dissolved inorganic phosphate (DIP) from the water column in the eastern Mediterranean. In a series of radiolabled experiments, loess from the Negev Desert (Israel), treated in various ways, was added to surface (SSW) and deep (DSW) seawater spiked with radioactive P. It was estimated that when fresh loess enters the SSW approximately 1.3 micromol P/g are released (~11% of the total P concentration). As the loess particles descends through the water column about 0.2 micromol P/g are removed from the seawater and adsorbed onto the loess. Thus, the adsorbed DIP accounts for approximately 15% of the released P and the result is a net addition of dissolved atmospheric phosphorus in seawater. A preliminary quantitative estimate suggests that the process of DIP removal by loess particles can not explain the phosphate 'deficit' in the Eastern Mediterranean DSW characterized by unusually high N:P ratios (~27).
 
Day: Wednesday, Feb. 3
Time: 09:15 - 09:30am
Location: Sweeney Center
 
Code: SS50WE0915S