# \#DYN

**URL:** https://nemo-ocean.discourse.group/tag/dyn/73.md

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## [The vertical diffusion trend term has issues (utrd\_zdf/vtrd\_zdf)](https://nemo-ocean.discourse.group/t/the-vertical-diffusion-trend-term-has-issues-utrd-zdf-vtrd-zdf/1036)

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**Author:** [@corentingnt](https://nemo-ocean.discourse.group/u/corentingnt)\
**Replies:** 1\
**Last updated:** [2 July 2026 16:50 UTC](https://nemo-ocean.discourse.group/t/the-vertical-diffusion-trend-term-has-issues-utrd-zdf-vtrd-zdf/1036 "2026-07-02T16:50:44Z")

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Hi, We do this message with Véga, trainee with Julie Deshayes and myself at Locean (I am PhD student). We looked at different trends terms in the NEMO.4.0 version. We noticed an issue with utrd\_zdf and vtrd\_zdf, that se…

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## [Bug in the sign convention in the TKE OSBL scheme?](https://nemo-ocean.discourse.group/t/bug-in-the-sign-convention-in-the-tke-osbl-scheme/998)

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**Author:** [@takachanbo](https://nemo-ocean.discourse.group/u/takachanbo)\
**Replies:** 0\
**Last updated:** [6 March 2026 08:29 UTC](https://nemo-ocean.discourse.group/t/bug-in-the-sign-convention-in-the-tke-osbl-scheme/998 "2026-03-06T08:29:52Z")

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I am looking through the turbulent kinetic energy (TKE) ocean surface boundary layer (OSBL) scheme but I am having some confusions pertaining to the term associated with Kolmogorov dissipation. In the snippet of code fro…

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## [Values for lateral mixing coefficients](https://nemo-ocean.discourse.group/t/values-for-lateral-mixing-coefficients/481)

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**Author:** [@atb299](https://nemo-ocean.discourse.group/u/atb299)\
**Replies:** 3\
**Last updated:** [2 May 2023 10:00 UTC](https://nemo-ocean.discourse.group/t/values-for-lateral-mixing-coefficients/481 "2023-05-02T10:00:48Z")

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When selecting one of the ‘nn\_ahm\_ijk\_t’ option to supply 2D or 3D fields for ahm{t,f}, should the values supplied for ‘t’ and ‘f’ be the same (if so why require two variables?), or are there cases when they can or shoul…

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## [QG Leith viscosity implementation](https://nemo-ocean.discourse.group/t/qg-leith-viscosity-implementation/377)

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**Author:** [@tmwilder](https://nemo-ocean.discourse.group/u/tmwilder)\
**Replies:** 7\
**Last updated:** [9 January 2023 14:28 UTC](https://nemo-ocean.discourse.group/t/qg-leith-viscosity-implementation/377 "2023-01-09T14:28:30Z")

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Hi all, I am currently attempting to implement the QG Leith viscous coefficient in nemo v4.0.4. The choice of v4.0.4 is because there is an ORCA025 setup ready to go, which is not yet the case for v4.2. I am also new to…

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## [From v3.6 to v4.2.x on mixing coefficients (missing \`key\_dynspg\_ts\`)](https://nemo-ocean.discourse.group/t/from-v3-6-to-v4-2-x-on-mixing-coefficients-missing-key-dynspg-ts/255)

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**Author:** [@qtqw](https://nemo-ocean.discourse.group/u/qtqw)\
**Replies:** 4\
**Last updated:** [1 April 2022 13:54 UTC](https://nemo-ocean.discourse.group/t/from-v3-6-to-v4-2-x-on-mixing-coefficients-missing-key-dynspg-ts/255 "2022-04-01T13:54:40Z")

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I am transitioning from old NEMO 3.6 to new 4.2. I found that there are minor modifications in namelist\_ref and namelist\_cfg files. For example, in NEMO 3.6 were coefficients rn\_aht\_0 = -5.e+8 ! horizo…