Inquiring whether HYCOM can output the components of the heat budget

[Mengli Zhang]

Dear Alan,

I hope this message finds you well.

I would like to know whether the model can output daily-mean vertical heat flux calculated online, or other components of the heat budget. I have checked the archive files, but I could only find the variable "surflx".

If this is possible, could you please advise how to modify the settings to enable such outputs? Any guidance would be greatly appreciated.

Thank you for your time and assistance.

Best regards,

Mengli Zhang

[Alan Wallcraft]

HYCOM writes out the northward (actually y-ward) heat flux in ovrtn_out (a text file), which is calculated in overtn.F90.

The relatively new option 'mstrcr' can be used to write fields to the surface archive file.  These can be any 2-d field on the p-grid.  So far we have:

! --- 'mstrcr' = number of surface tracers
! --- 'strflg' = surface tracer flag (one per tracer, 701-799)
! ---              701: disp_ld
! ---              702: disp_qd
! ---              703: oneta
! ---              704: pbavg
! ---              705: hntide
! ---              706: pbavg_a
! ---              707: htide
! ---              708: ns_ssh
! ---              721: efold_cb
! ---              722: spdbot
! ---              723: spdtid

You could add heat budget fields, and if you do so please make a pull request to add them to the standard model code.  At present these are always snapshots, but you could do time averaging as part of their calculation (i.e. replace snapshots with the time mean since last write).

The 3-D archm files a for means over time.  Once again there is an option to add new tracers:

! --- 'mtracr' = number of diagnostic tracers
! --- 'dtrflg' = diagnostic tracer flag (one per tracer, 801-899)
! ---              801: change in layer thickness   due to hybgen (m/day)
! ---              802: change in layer temperature due to hybgen (degC/day)
! ---              803: change in layer salinity    due to hybgen (psu/day)

In this case you would add layer by layer heat terms to the archv and archm files and calculate the vertical means off-line.  Note that this is only accurate for p-grid fields because we don't write out the u and v grid dp means.

Alan.