The magnitude of vertical mixing and advection terms

[HONGWANG]

Hello everyone!

I simulated a tropical cyclone using ROMS model.

When I analyzed the temperature rate, vertical mixing and advection, I found the horizontal/vertical advection terms are far greater than the vertical mixing term. And another strange phenomenon is that the horizontal advection and vertical advection terms are exactly the opposite number. But actually, I learned from others that these terms in most cases are of the same magnitude (i.e., *10^-5). I tried to change some settings in the .h file and .in file and this phenomenon has not been improved (see Figure).

These are the relative parameters in my headfile and inputfile:

/*Physics + numerics*/
#undef LOG_PROFILE
#define UV_ADV
#define UV_COR
#define UV_LOGDRAG
#define SALINITY
#define SOLVE3D
#define SPHERICAL
#define AVERAGES
#define DIAGNOSTICS
#define DIAGNOSTICS_TS
#define DIAGNOSTICS_UV
#undef SEDIMENT

/*Grid and Initial*/
#define MASKING

/*Turbulence closure*/
#undef SPLINES
#undef ANA_VMIX
#define GLS_MIXING
#ifdef GLS_MIXING
# define KANTHA_CLAYSON
# define N2S2_HORAVG
#endif



Hadvection == U3 ! temperature
Vadvection == C4 ! temperature

! Vertical mixing coefficients for tracers in nonlinear model and
! basic state scale factor in adjoint-based algorithms: [1:NAT+NPT,Ngrids]
AKT_BAK == 5.0d-6 5.0d-6 5.0d-6 5.0d-6 ! m2/s
ad_AKT_fac == 1.0d0 1.0d0 ! nondimensional
! Vertical mixing coefficient for momentum for nonlinear model and
! basic state scale factor in adjoint-based algorithms: [Ngrids].
AKV_BAK == 5.0d-5 5.0d-5 ! m2/s

Does anyone know what I should do? I would greatly appreciate your reply and assistance.

Thanks a lot!
Best regards.
Hong

[jcwarner]

those are about the same dynamics that we simulated for H Ivan.
Zambon, J.B., He, R., and Warner, J.C. (2014). Investigation of Hurricane Ivan using the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) Model, Ocean Dynamics, 64, 1535-1554. doi:10.1007/s10236-014-0777-7.

[HONGWANG]

I will study this article carefully. Thank you very much for your reply and the information you provided is very useful to me.

[rduran]

Not related to tropical cyclones, but I also found momentum advection terms that tend to cancel each other in my doctoral thesis on a poleward undercurrent, in case that is of interest:
https://ir.library.oregonstate.edu/conc ... /cj82kf17c

[HONGWANG]

Thanks for your comment and information, rduran. Thank you very much!