Decomposing kinetic energy along Line P in the Pacific Ocean
| dc.contributor.author | Wang, Manman | |
| dc.contributor.supervisor | Klymak, Jody Michael | |
| dc.date.accessioned | 2016-08-18T18:58:19Z | |
| dc.date.available | 2016-08-18T18:58:19Z | |
| dc.date.copyright | 2016 | en_US |
| dc.date.issued | 2016-08-18 | |
| dc.degree.department | School of Earth and Ocean Sciences | en_US |
| dc.degree.level | Master of Science M.Sc. | en_US |
| dc.description.abstract | The upper ocean is host to overlapping vortical and internal waves dynamics over the submesoscales (10-100km), both of which are poorly represented in eddy-resolving ocean models. We analyze upper-ocean (0-200 m) horizontal-wavenumber spectra along Line P in the North Pacific subpolar gyre from shipboard ADCP measurements in February and June (2013-2015), and compare them to spectra from a 1/36th degree numerical simulation output. At scales between 10 and 100 km, the ADCP along-track (Cv) and across-track (Cv) kinetic energy spectra approximately follow power laws of k-2 and have a ratio R = Cv/Cu - 1. For purely non-divergent motions, the order of the power law and R should be the same, so divergent motions are evident. A Helmholtz decomposition estimates the fraction total kinetic energy that is contributed by internal-wave and vortex components. Vortex components follow a power law of k-2 with ratio R-2, consistent with predictions for a non-divergent flow, while internal waves are mostly consistent with the Garrett and Munk internal wave model. There are modest seasonal changes; vortical motions are slightly stronger in February than in June, whereas the amplitudes of the internal wave component increases in June. Depth variability of non-divergent vortical flows shows that at low wave-numbers energy decreases and that the kinetic energy spectra are bluer with depth, inconsistent with predictions from surface quasi-geostrophic theory of redder spectra with depth. Conversely, in the simulation the depth variability of the decomposed vortex components is in agreement with predictions of surface quasi-geostrophic theory. The simulations had very weak internal waves fields. | en_US |
| dc.description.proquestcode | 0415 | en_US |
| dc.description.proquestemail | manmanw@uvic.ca | en_US |
| dc.description.scholarlevel | Graduate | en_US |
| dc.identifier.uri | http://hdl.handle.net/1828/7460 | |
| dc.language | English | eng |
| dc.language.iso | en | en_US |
| dc.rights | Available to the World Wide Web | en_US |
| dc.rights.uri | http://creativecommons.org/licenses/by-sa/2.5/ca/ | * |
| dc.subject | Kinetic energy spectra, Line P, decomposition | en_US |
| dc.title | Decomposing kinetic energy along Line P in the Pacific Ocean | en_US |
| dc.type | Thesis | en_US |