Negative value in initial netcdf file

[tony1230]

Hi,

1. Can the ROMS now tolerant negative values? Primary for temperature in cold winter in initial condition.

2. Why the ROMS always produces negative values to biology variables like NH4,NO3, etc.(under some kind of conditions, also to salinity, say if i add river point sources)?

Thank you and welcome any comments.

- steve

[kate]

ROMS can handle negative temperatures, no problem. Temperatures can get down around -2C before water will freeze at typical oceanic salinities.

ROMS will produce tracer values outside the initial range through the advection operation. For salinity this can cause troubles for the equation of state so there is now this code:

Code: Select all

            Tt=MAX(-2.5_r8,t(i,j,k,nrhs,itemp))
            Tt=MIN(40.0_r8,Tt)
#  ifdef SALINITY
            Ts=MAX(0.0_r8,t(i,j,k,nrhs,isalt))
            Ts=MIN(100.0_r8,Ts)

I see we have a limiter on the temperature too. Limiters can also be applied to bio tracers to keep things well-behaved.