# Closed budget of T or S using TRD

**URL:** <https://nemo-ocean.discourse.group/t/closed-budget-of-t-or-s-using-trd/524>\
**Category:** Uncategorized\
**Created:** [15 June 2023 15:04 UTC](https://nemo-ocean.discourse.group/t/closed-budget-of-t-or-s-using-trd/524 "2023-06-15T15:04:28Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![robinson](https://avatars.discourse-cdn.com/v4/letter/r/848f3c/32.png) [@robinson](https://nemo-ocean.discourse.group/u/robinson)\
**Post date:** [15 June 2023 15:04 UTC](https://nemo-ocean.discourse.group/t/closed-budget-of-t-or-s-using-trd/524/1 "2023-06-15T15:04:28Z")

</div>

Dear All,

The TRD module in NEMO computes trends in T or S for any grid cell, and for each process (advection, vertical diffusion, horizontal diffusion, bbl etc…), as well as the total trend.

Has anyone managed to compute a locally closed budget using this module AND a non-linear free surface (vvl).  
What I mean is that let’s say you output each trend over for example 1 year of simulation and for each grid cell of and compute a budget error as

epsilon(i,j,k)=| d(T(i,j,k)\*e3t(i,jk))/dt - Trend\_in\_advection\_of\_T(i,j,k) - Trend\_in\_vertical\_diffusion\_of\_T(i,j,k) - etc… |

and then produce a 2D map of this error by integrating over the vertical axis.

Has anyone managed to get an error which is basically of the order of the computer accuracy ?

Thanks for your help,

Robinson

---

<div class="post-metadata">

**Author:** ![jchanut](https://yyz2.discourse-cdn.com/free1/user_avatar/nemo-ocean.discourse.group/jchanut/32/9_2.png) [@jchanut](https://nemo-ocean.discourse.group/u/jchanut)\
**Post date:** [27 June 2023 09:30 UTC](https://nemo-ocean.discourse.group/t/closed-budget-of-t-or-s-using-trd/524/2 "2023-06-27T09:30:25Z")

</div>

Hi Robinson,

A Phd student does actually make such budgets at MOI (Fernand Assene). Here is [a link to a paper](https://egusphere.copernicus.org/preprints/2023/egusphere-2023-418/) (under review) from which you may reach him if needed.

---

<div class="post-metadata">

**Author:** ![robinson](https://avatars.discourse-cdn.com/v4/letter/r/848f3c/32.png) [@robinson](https://nemo-ocean.discourse.group/u/robinson)\
**Post date:** [27 June 2023 10:11 UTC](https://nemo-ocean.discourse.group/t/closed-budget-of-t-or-s-using-trd/524/3 "2023-06-27T10:11:15Z")

</div>

Merci Jérôme, I will contact him.