Not Just Sea Ice: Other Factors Important to Near-inertial Wave Generation in the Arctic Ocean

Internal wave energy in the Arctic Ocean is often an order of magnitude lower than the midlatitudes. By inhibiting energy input and causing damping, the presence of sea ice is believed to be responsible for low internal wave energy. While a few current studies have shown slightly elevated internal wave energy compared to historical measurements, it has not matched the catastrophic decline in sea ice extent over the same period. We report internal wave energy and mixing estimates that show little difference in the presence of sea ice. To examine possible causes other than sea ice, we adopt the model framework developed in Gill (1984) to explore the importance of previously unexamined factors responsible for the low internal wave energy in the Arctic Ocean. Model results show that low beta and shallow mixed layers can result in significant reductions in horizontal kinetic energy in the pycnocline compared to midlatitudes.

Automated summary

This study reveals that while sea ice may impact internal wave energy in the Arctic Ocean, other factors such as low beta and shallow mixed layers may also play a significant role.