HPGE at sea cliff

[cyltby]

Hi all，

I run the HPGE(Horizontal Pressure Gradient Error) test: 1)without any forcing; 2)closed boundaries; 3)initial Temparature of stable stratification, and constant Salinity; 4)10 days simulation.

The running log attacehd as runningfile.txt. The bottom velocity maganitude of final snapshot is shown as Fig1(unit m/s). It seem OK at shelf region with HPGE ~0.01 m/s(shown as Fig2). However, It ocurrence ~0.4 m/s at the bottom of the sea cliff(Fig3). As I plan to do a ten years simulation, the HPGE will be the problem.

I tried to use 1) different topography data(e.g. etopo1 etopo5 gebco_2014),
2) different stretching (theta_s theta_b hc), actually the RX1 will change but the HPGE not at the sea cliff
3) different smoonthing function(GRID_SmoothPositive_rx0, GRID_SmoothNegative_rx0, GRID_LinProgHeuristic_rx0 )
4) different horizontal mixing cofficient( VIS2 = 0,100,1000), it did work slightly.

How can I controll the HPGE at that sea cliff?

Thanks,
Yong