HIGH-LATITUDE OCEAN PROCESSES
High latitude oceans are crucial components of the global climate system. They play a disproportionately large role in the heat balance of the planet, are home to some of the strongest carbon fluxes both into and out of the oceans, and are acting as a canary in the coal mine of climate change. The Arctic is also increasingly a bustling site of human activity, with a delicate balance between the needs of native communities, commercial interests, and national security for surrounding countries. However, there are many facets of high latitude oceanography that are poorly understood, in part due to the historical difficulty in making detailed observations in such inhospitable environments.
One of the primary questions our group is investigating is: How does the heat distribution and mixing rates within the ocean control the rate at which sea or land-fast ice might be melting? Arctic surface waters are generally very cold, close to freezing. However, pockets of substantial heat often lurk at depth, kept their by higher salinity that makes water denser than the surface water, even though it’s warmer. Some of these warm water pockets are tendrils of warmer, lower-latitude oceans that have meandered their way poleward and subducted downward. Other warm water pockets are created by summer heating, but then sequestered below the surface during colder winter months.
Our group is using a variety of tools to investigate the distribution of sub-surface heat and the physical processes that may mix that heat upwards towards the surface. In particular, we are interested in the extent to which that upward heat flux might be increasing in the changing climate, potentially providing a positive feedback for accelerating ice melt rates.