Differences between results of ROMS x SODA

[adilsonborges]

Hi all, good?

Dears, I work on Equatorial Atlantic ocean and i would like to share my first result. I started to generate the differences between the ROMS-SODA model data and got this image (attached). I realized that there are differences of positive SST on the Continental Shelf and negative SST near Equatorial range and northwest domain. I would like some suggestions on what might be happening with the integrations. Note that I did a seasonal climatology from 1985 to 2015, both the SODA data and the ROMS data, I'm suspicious that it might be the mixing layer, I used a 50 meter layer. But I did an experiment with a 200 meter mixing layer and I also calculated the differences and the results are similar.

I know I should have calculated the differences with WOA or AVHRR data (I will still do this), but I was curious about this result and would like to know how you evaluate those differences. Thanks in advance!

Best regards!

[kate]

We don't have anywhere near enough information about what you did to know what's going on. 50 m mixed layer? What vertical mixing scheme? What horizontal mixing scheme? What atmospheric forcing?

[adilsonborges]

1. 50 m mixed layer?
Yes

2. What vertical mixing scheme?
AKT_BAK == 1.0d-6 1.0d-6 ! m2/s
ad_AKT_fac == 1.0d0 1.0d0 ! nondimensional

AKV_BAK == 1.0d-5 ! m2/s
ad_AKV_fac == 1.0d0 ! nondimensional

2.1. What horizontal mixing scheme?

TNU2 == 0.1d0 0.1d0 ! m2/s
TNU4 == 5.0d0 5.0d0 ! m4/s
ad_TNU2 == 0.0d0 0.0d0 ! m2/s
ad_TNU4 == 0.0d0 0.0d0 ! m4/s

VISC2 == 10.0d0 ! m2/s
VISC4 == 8.0d+7 ! m4/s
ad_VISC2 == 0.0d0 ! m2/s
ad_VISC4 == 0.0d0 ! m4/s

In my arquive.h

/* vertical mixing */
#ifdef SOLVE3D
# define SOLAR_SOURCE
# undef WTYPE_GRID
# define LMD_MIXING
# ifdef LMD_MIXING
# define LMD_RIMIX
# define LMD_CONVEC
# define LMD_SKPP
# undef LMD_BKPP
# define LMD_NONLOCAL
# define LMD_SHAPIRO
# undef LMD_DDMIX
# endif
# undef GLS_MIXING
# undef MY25_MIXING
# if defined GLS_MIXING || defined MY25_MIXING
# define KANTHA_CLAYSON
# define N2S2_HORAVG
# endif
#endif

3. What atmospheric forcing?
CFSR 6-hourly.

If it helps: Settings I used to configure the grid in get_gridinfo.m:
hmin = 150.;
hmax = 5000;
hmax_coast = 500;
n_filter_deep_topo = 4;
n_filter_final = 2;
rmax = 0.45;
sph = 'T';

I'm sending my .in and .h files in annex.

[adilsonborges]

Someone to give opinions?

[fagundesmo]

Did you add climatology for SST? If not, I would add climatological monthly data for temperature and give it a try. I did that and my results were better. Also, don't forget it's a model and you are comparing with a reanalysis, and therefore, you cannot expect D_sst approximately 0.

Cheers,
Matheus