river flux

[Aron Nunes]

Dear Alan,

 I am currently running a simulation in the equatorial margin region (see Figure 1 for the domain), which includes significant rivers such as the Amazon. I am striving to accurately represent the Amazon plume in the simulation. Currently, I am using the forcing.rivers file, but I would like to impose a flux at the mouth of the Amazon River to better capture the physical processes.

I've explored some discussions on the forum and found suggestions to use forcing.offlux for this purpose. However, I couldn't find detailed information on generating this file to impose the flux.

Note: Tidal effects are crucial in the region, although they have not been imposed yet.

Best regards.

[Alan Wallcraft]

What we provide is a long term monthly climatology, and it is old (so will not include any recent changes to river flow).  This starts out as a plain text file, so edit it if you have better numbers.

If you have monthly inter-annual river transports, create a rivers.a file for each year and use the appropriate year in your run.

If you have daily (say) transports, then the best approach is to treat these as an anomaly w.r.t. the river climatology.  So keep the climatology but add daily anomalies to the forcing.procip file.This is done with HYCOM-tools/force/src/pcip_riv_hf.

See rivers_daily.tar.gz for an example.

To get a better river plume, set 'epmass'=1 so that E-P is treated as a water flux (rather than a virtual salt flux).  However, we have recently seen issues with this option when used with tides.  It should be OK if the tides are no larger than the depth of the ocean.

Alan.

[Alan Wallcraft]

The latest commit should allow you to use epmass=1 with tides.

For more on rivers and epmass, see https://groups.google.com/a/hycom.org/g/forum/c/owaPLx3aJhs/m/bTma-AnsBAAJ

Alan.

[Aron Nunes]

trank you!

I used epmass=1, worked!

I'm using 2.3.01