SEMINAR: GEOTOPICS Now!!!!!!!!!!!!!!!!!!!!


From: orash sharifi <osharifi@rsmas.miami.edu>
Subject: SEMINAR: GEOTOPICS Now!!!!!!!!!!!!!!!!!!!!
Date: Mon, 24 Oct 2011 14:39:02 -0400







Monday, October 24, 2011
3:15, SLAB Seminar Room, S/A 103
Refreshments at 3:00 PM

Our upcoming speaker is one of our top researchers at MAC: ANGELA KNAPP

The title of her talk is "Testing the sensitivities of marine nitrogen fixation: from culture studies to South Pacific".


ABSTRACT

Over the past decade, chemical oceanographers have vigorously debated whether the marine nitrogen budget is balanced or not; the answer has significant implications for the ability of phytoplankton to remove CO2 from the atmosphere via the biological pump. Over the past 5 years, several indirect lines of evidence have challenged assumptions about the dominant process that adds nitrogen to the ocean, biologically-mediated nitrogen fixation, including where (globally) the largest fluxes are, and what the sensitivities of the organisms carrying out the process are, especially with respect to surface ocean nitrate and trace metal concentrations. I will describe work that directly tests the sensitivities of marine nitrogen fixation, including culture studies focused on how nitrogen fixing cyanobacteria respond to changes in nitrate and phosphate concentrations, as well as preliminary data from a field campaign to quantify the importance of nitrogen fixation in the Eastern Tropical South Pacific using molecular, biological, and geochemical tools.



We hope to see you all there!

Your GEOTOPICS Coordinators,

Keri Vinas and Arash Sharifi
        




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