Premium
The Seasonality of Submesoscale Energy Production, Content, and Cascade
Author(s) -
Dong Jihai,
FoxKemper Baylor,
Zhang Hong,
Dong Changming
Publication year - 2020
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2020gl087388
Subject(s) - buoyancy , mixed layer , kinetic energy , seasonality , environmental science , cascade , baroclinity , lag , climatology , atmospheric sciences , potential vorticity , energy flux , geology , vorticity , meteorology , physics , mechanics , chemistry , vortex , mathematics , computer network , statistics , chromatography , quantum mechanics , astronomy , computer science
Submesoscale processes in the upper ocean vary seasonally, in tight correspondence with mixed layer thickness variability. Based on a global high‐resolution MITgcm simulation, seasonal evaluation of strong vorticity and spectral analysis of the kinetic energy in the Kuroshio Extension System show the strongest submesoscales occur in March, implying a lag of about a month behind mixed layer thickness maximum in February. An analysis of spectral energy sources and transfers indicates that the seasonality of the submesoscale energy content is a result of the competition between the conversion of available potential energy into submesoscale kinetic energy via a buoyancy production/vertical buoyancy flux associated with mixed layer instability and nonlinear energy transfers to other scales associated with an energy cascade. The buoyancy production is seasonally in phase with the mixed layer depth, but the transfers of energy across scales makes energizing the reservoir of submesoscale kinetic energy lag behind by a month.