Arctic summers are now characterized by ever-expanding areas of open water exposed by the declining sea ice. This dramatic decline has input fresh meltwater to the surface ocean and created more openings for direct exchange of heat, freshwater and momentum (i.e. wind energy input) between the ocean and atmosphere. The expected increase in wind energy input into surface ocean currents may disrupt the Arctic Ocean’s stable stratification (cold fresh light water overlying warm salty water from the Atlantic/Pacific) and mix oceanic heat and nutrients to the surface that could contribute to contribute to documented changes in ecosystems and weather. Observations around the Arctic Ocean show no significant trend in wind-driven inertial wave energy in the deep ocean, which implies that excess wind energy input is either trapped or dissipated in near the surface. This project proposes to address the fundamental question: can we quantify any increase in wind energy input to the Arctic ocean? And if so, is this energy dissipated where it can impact the upper ocean stratification and what does this mean for the future Arctic?
To answer these questions, the student will use large data sets of sea ice concentrations and surface winds to produce a new estimate of Arctic ocean ice-concentration-dependent surface stress, and use this to run simple 1D models of wind-driven ocean mixed-layer currents and mixing to evaluate wind impact on Arctic Ocean stratification. These results will be validated against measurements from ice-tethered profilers and used to interrogate state-of-the-art 3D Arctic Ocean and earth system models. The project is based at Bangor University, Wales with co-supervisors in the USA and France and collaborators at the Met Office. This multi-disciplinary project sits at the interface of physical oceanography, sea ice and atmospheric sciences.
Applicants should hold the equivalent of a minimum of a UK Honours Degree at 2:1 level or equivalent in numerate subjects such as Environmental Science, Geography or Natural Sciences. Or alternatively an MSc in Ocean Sciences, Meteorology, Applied Physics, Applied Mathematics or other relevant subject.
Note that UK nationals and residents (continuously resident for 3-years prior to the time of the PhD application) are eligible to receive the full PhD stipend and bursary, while non-resident EU nationals will be eligible to receive the research costs, but not the stipend. Students of other nationalities are ineligible for this PhD funding.
Please contact Dr Yueng-Djern Lenn (y.lenn@bangor.ac.uk) for further information.