question about RUNOFF cpp flag ...

[turuncu]

Hi,

I just want to ask you about the usage of RUNOFF cpp flag for the model configuration. In the varinfo.dat file you can find the definition of it like "Fresh water runoff from land" but what happened if i set both river runoff using UV_PSOURCE and TS_PSOURCE and RUNOFF. Are they same? What is the logic behind it? If you give me detailed information about that it would be helpful for me.

Regards,

--ufuk

[kate]

The purpose of RUNOFF is to distribute fresh water over more points - some farther offshore. It is implemented like rain, a taking of salt from the surface without change in volume.

The logic of it comes from the climate models, where there is some closed hydrologic cycle without having to gauge all rivers and other poorly known fresh water inputs. Also, our experience has been that rivers applies as UV_PSOURCE can cause trouble when there's too little explicit vertical mixing right at the surface - we get a pool of fresh water that is too stable to mix down properly. We're missing a surface wave mixing parameterization and we're not explicitly resolving everything in a coastal estuary where that mixing would happen. So perhaps the answer is to use RUNOFF for basin-scale domains and the PSOURCE for estuary-scale domains.

[turuncu]

Thanks, Kate. Now, it makes sense. Sometimes, it might be very hard to keep the volume in the range (especially for the lakes). I just try different combination of configurations. Some of them increase volume and some others decreases. Anyway, thanks again.

Regards,

--ufuk

[Pysh]

Hi,

We have some problems with salinity distribution from the river runoff

turuncu some times ago (21 May 2012) wrote

I just want to ask you about the usage of RUNOFF cpp flag for the model configuration

and Kate answered

The purpose of RUNOFF is to distribute fresh water over more points - some farther offshore. It is implemented like rain, a taking of salt from the surface without change in volume.

I can't find cpp flag RUNOFF in my latest version (Jun 25 2012) of cppdefs.h. Is there this flag in some other version or this flag is in some another place? (My attempts to include this flag into compilation process have appeared ineffectual) Or now is reasonable convert river runoff of fresh water into "additional rain" in the forcing as indicated Kate in her post?

Thanks in advance,
Boris

[kate]

RUNOFF is in my branch only. It is applied exactly like rain in the bulk flux code, though I believe some use RUNOFF to add iron to the ecosystem part of the simulation.

[Pysh]

Thank you, Kate.

We should repeat your way

Regards,
Boris