Atmospheric and Oceanic Sciences Seminar

“Impacts of Climate Change and Extreme Weather Events on Coastal Oceans” presented by Ming Li, Horn Point Laboratory, University of Maryland

Wednesday, March 13, 2013
3:30 PM - 5:00 PM
Room MSB 7124

This seminar highlights a faculty search candidate. Sign up to meet with Ming Li on March 13th and 14th by e-mailing melisl@atmos.ucla.edu or dawnz@atmos.ucla.edu directly.

Abstract

“Coastal oceans around the world have suffered from hypoxia, harmful algal blooms, and altered ecosystem productivity. These problems have primarily been attributed to anthropogenic nutrient enrichment, i.e., eutrophication. However, there is increasing evidence that climate variability has overwhelmed eutrophication in coastal ecosystems over the past 2 decades, particularly in developed countries. There is also evidence that extreme weather events can cause dramatic disruptions with long-term impacts. To address these challenging interdisciplinary topics, a fundamental understanding of coastal ocean responses to meteorological forcing, such as winds and precipitation, is essential. In this talk, I will describe recent investigations of several coastal systems, including semi-enclosed bays on the U.S. East Coast and shelf seas in Asia. I will show how the competition between river flow and tidal mixing shapes the gravitational circulation under different tidal regimes. I will discuss how the dynamics of wind-driven circulation change for coastal oceans at different horizontal and vertical scales. Two case studies of long-term climatic effects will be presented. First, I will show how sea level rise and changing river flow affect salt intrusion and circulation in two neighboring coastal bays with contrasting stratification conditions. Second, I will use a coupled hydrodynamic-biogeochemical model to diagnose physical and biogeochemical mechanisms driving interannual variability of hypoxia in Chesapeake Bay. For extreme weather, I describe research on two events: a windy storm (Hurricane Isabel) that caused destratification and restratification of the water column, leading to a fall phytoplankton bloom of unprecedented magnitude and the temporary relief of hypoxia; a wet storm (Tropical Storm Lee) that generated a large flood and extensive sediment plume with long-term implications for water quality and geology. These case studies demonstrate that changing climate and extreme weather events have become predominant drivers in the coastal ocean, requiring an increased focus in oceanographic research.”
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SEMINAR at 3:30 PM
Room MSB 7124
SEMINAR TEA:  4:30-5:00PM (MSB 7124B)