search

pedrocol / basal_mom5-collaborative-project

4 stars 0 forks source link

Potential vs conservative temperature input #23

Closed pedrocol closed 2 years ago

pedrocol commented 2 years ago

Check if the Tbasal is correct in the sense of being an insitu temperature or a potential temperature

pedrocol commented 2 years ago

@StephenGriffies I just checked the code and the way Tfreezing is calculated assumes the temperature variable to be potential temperature (see below). This function was imported from NEMO, at that time I didn't find a function to calculate Tfreezing(i,j,k) as a function of pressure and salinity. . Screenshot from 2022-09-07 21-45-52

StephenGriffies commented 2 years ago

The ACCESS model uses Conservative Temp as its prognostics temp field. Conservative Temp and potential temp differ especially in regions of relatively fresh water. See Figure 7 in McDougall (2003)

https://journals.ametsoc.org/view/journals/phoc/33/5/1520-0485_2003_033_0945_peacov_2.0.co_2.xml

Although I am doubtful this detail matters much, I suggest we do the right thing.

So if Tfreeze is in coded for potential temp, then we simply need to have an option in MOM5 to convert from pot temp to Conservative Temp. That conversion is available in MOM5 in the routine "contemp_from_pottemp", which is inside ocean_tempsalt.F90.

pedrocol commented 2 years ago

I have included the correction mentioned by Steve

Screenshot from 2022-10-05 14-46-23

I'm closing the issue, we can re-open it if there is any extra comment