Changes between Initial Version and Version 2 of Ticket #2170
- Timestamp:
- 2019-05-23T18:58:25+02:00 (5 years ago)
Legend:
- Unmodified
- Added
- Removed
- Modified
-
Ticket #2170
- Property Priority changed from low to high
- Property Wp_comment changed from to At 23 May 2019: The OSMOSIS code has been implemented in the v4.0 release of NEMO (presently based on r10833, April 3rd 2019). Work has begun on a range of approaches to reduce the too-deep winter mixed layers. a. Reduction in the effectiveness of the Langmuir mixing in cases where the ratio of the Stokes penetration depth to the boundary layer depth is small. and b. Reduction in effectiveness of shear-turbulent, Langmuir and convective deepening when the respective eddy turnover timescales (hbl/u* etc.) approach the inertial timescale 1/f.
-
Ticket #2170 – Description
initial v2 14 14 ==== Abstract 15 15 16 This section should be completed before starting to develop the code, in order to find agreement with the previewer(s) on the method beforehand. 16 The OSMOSIS OBL code work well in summer conditions, but gives too-deep mixed-layers in winter. It is also written assuming a linear equation of state, and has not yet been applied to passive tracers. 17 Under-ice behaviour has not been checked. All these issues need to be addressed. 17 18 18 19 19 20 ===== Description 20 21 21 ''Describe the goal of development, and the methodology. \\ 22 Add reference documents or publications if relevant.'' 22 he OSMOSIS OBL code has shown promise in giving more realistic, deeper, mixed layers (MLs) in the Southern Ocean in the southern summer. However there are various issues that must be settled before it can be used as an OBL code for global integrations. \\ 23 24 1. ML are too deep in winter, especially over the ACC in southern winter. This problem is being addressed by a) taking account of the effect of the Coriolis force on the turbulence when the eddy-turnover scale approaches the inertial timescale and b) taking account of the lesser effectiveness of Langmuir turbulence in driving mixing when the ML depth becomes very deep relative to the depth to which the Stokes drift penetrates. \\ 25 26 2. Non-local fluxes of passive tracers need to be defined. \\ 27 28 3. The non-linearity of the equation of state needs to be better taken account of. \\ 29 30 4. The behaviour of the model under ice requires detailed examination. \\ 31 32 5. The code has been written for simplicity and ease of understanding rather than performance, and needs to be optimized. 33 23 34 24 35 25 36 ===== Implementation 26 37 27 ''Describe flow chart of the changes in the code. \\ 28 List the .F90 files and modules to be changed. \\ 29 Detailed list of new variables (including namelists) to be defined, give for each the chosen name (following coding rules) and definition.'' 38 Changes will mostly be restricted to the zdfosm.F90 module. \\ 39 40 Namelists will need also to be modified. \\ 41 42 New variables are not fully known yet. 30 43 31 44 32 45 ===== Reference manual and web pages updates 33 46 34 ''Using part 1 and 2, define the summary of changes to be done in reference manuals (tex files), guide (rst files) and in the content of web pages.'' 47 Chapter will be written for reference manual and text for the user guide \\ 35 48 36 49 Once the PI has completed this section, he should send a mail to the previewer(s) asking them to preview the work within two weeks.
