June 22, 2020
A Stokes drift module is now added in GOTM, providing a way to include the Stokes drift information in GOTM for use in ocean surface boundary layer turbulence closure schemes. Currently it is used to enable Langmuir turbulence parameterizations in KPP via CVMix. But it supports input of the full vertical profile of Stokes drift and its shear, which allows exploration of Langmuir turbulence parameterizations in various forms and other applications. See Li et al., 2019 for some examples.
The Stokes drift module is enabled by default with the Stokes drift set to zero. It provides multiple options to input Stokes drift in GOTM. It introduces the following variables:
vsprof), with input options
dvsdz), with input options
vs0) and a decay scale (
ds), with input options
The figure below shows an example of using the Stokes drift module in comparing different variants of Langmuir turbulence parameterizations in KPP (KPPLT-VR12, KPPLT-LF17) and the original KPP without Langmuir turbulence (KPP-CVMix). The top panel shows the simulated temperature in KPP-CVMix whereas the lower two panels show the differences in KPPLT-VR12 and KPPLT-LF17 from KPP-CVMix. The test case is initialized and forced with conditions during the winter months (Sep. 22, 2012 - Dec. 5, 2012) of the Ocean Surface Mixing, Ocean Submesoscale Interaction Study in the northeast Atlantic (OSMOSIS, 48.7N, 16.2W; Damerell et al., 2016). See more details of this test case in Li et al., 2019.