Faculty Candidate Seminar - Ryan Rykaczewski

03/20/2017 - 3:00pm


DATE:  March 20th, Monday, 3 p.m.  

LOCATION: Hubbs Hall 4500
*Additionally, a “chalk talk” presentation will be held in HH4500 on March 21st at 2pm

SPEAKER:  Ryan Rykaczewski, Ph.D.
University of South Carolina

TITLE:  Climate impacts on upwelling and the planktonic prey of anchovy and sardine in eastern boundary currents

ABSTRACT: Relationships among various atmospheric, oceanic, and biological processes in eastern boundary upwelling systems continue to attract the attention of oceanographers from all disciplines, particularly in attempt to explain ecosystem changes evident at decadal and multi-decadal frequencies.  In these systems, anchovy and sardine populations exhibit prominent variability with distinct periods of growth that are associated with differences in the size structure of the planktonic community and the rate of nutrient supply to the euphotic zone.  A number of hypotheses have been offered to describe the impacts of anthropogenic climate change on nutrient supply in upwelling systems, and at least three key components of the upwelling process must be considered: changes in upwelling-favorable winds (including intensification, poleward shifts in atmospheric pressure cells, and altered seasonality), changes in water-column stratification, and modified characteristics of source waters supplied to the upwelling systems.  Testing hypotheses through examination of observational records is hampered by our ability to distinguish the impacts of anthropogenic climate change from those of natural variability, but numerical model projections can offer some insight to changes in the upwelling process over the coming century.  Here, I will describe the current understanding of the upwelling response to anthropogenic climate change, compare projected changes in the major subtropical eastern boundary upwelling systems, and postulate about the impacts of such changes on the communities inhabiting the upwelling regions.  Improving such understanding is critical for anticipating the future evolution of these systems and their ability to sustain productive ecological communities.
Faculty Host:  Ralf Goericke  (rgoericke@ucsd.edu)
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Hubbs Hall 4500