The Ocean & Glacier Retreat
Ice loss from the continents is a key contributor to glacier retreat, and the ocean plays a lead role in modulating this process in many high latitude regions. There are many potential mechanisms for this modulation, including the supply of warm ocean water to submerged ice bodies, the ocean motion acting to break up or destabilize ice, and the accumulation and removal of sediment in the ocean near the ice. We aim to understand these and other oceanographic and glaciological processes that can help us improve our projections of ice loss and sea-level rise.
In Patagonia, we are conducting a multi-year effort to in the fjord system around the Patagonian Ice Fields, which aims to understand the magnitude, evolution, and impact of the ocean forcing. Our primary study site is Jorge Montt glacier, the fastest-retreating glacier in the fields.
Along the west Antarctic Peninsula shelf, we are analyzing oceanographic data and developing new high-resolution shelf- and fjord-scale numerical models of a number of glacier-fjord systems along this shelf, which spans a large gradient in ocean and atmospheric conditions. We expect this will shed light on the distinct patterns of ocean heat supply and glacier retreat along the Peninsula, one of the fastest-warming regions on earth. This work is a collaborative effort with Dave Sutherland (U. of Oregon), John Klinck and Mike Dinniman (Old Dominion University), and Gene Domack (University of South Florida).
River outflows are a source of freshwater, pollutants, and nutrients to the coastal ocean, and they form coastal currents that can transport these materials for hundreds of kilometers along the coast. Because they can modulate the water properties and circulation of the coastal ocean so effectively, they have also play an important role determining the biological productivity and distribution of marine organisms.
We are interested in understanding the processes than influence the formation, time evolution, along-shore extent, and cross-shelf scale of riverine outflows in the continental shelf. We use a combination of observations, idealized numerical models and theory to study the impact of winds, tides, and other phenomena on the these outflows. We are also interested in how these forcing processes and the riverine outflows themselves impact the distribution and evolution of biochemical properties and population dynamics on the shelf.
Inner-shelf Processes in Upwelling Systems
The upwelling of cold, nutrient-rich water along continental margins - particularly along eastern boundary current systems - is the primary reason why the coastal ocean can sustain a rich biological community and fisheries of economic importance. In the relatively shallow regions near the coast, wind and topography interact creating complex circulation patterns that in turn impact the distribution of heat, salt, and nutrients along the continental shelf.
We are currently conducting studies in the Perú-Chile upwelling system to understand the impact of wind relaxations on the temperature distribution and circulation on the inner-shelf; the role that large submarine canyons have on modulating upwelling; and how the upwelling in the open shelf modulates the supply of oxygen-poor water to semi-enclosed bays and gulfs in central Chile.