MPAS Fixed SST vs Daily-Updated SST

[Snow_Rain_Cloud]

Dear technical support,

I configured a set of experiments to look at SST differences between two experiments with config_sst_update = true and false.

Please find attached figure F000_sst.png the skintemp difference in one run initialized at 00Z 21 Oct 2021. The second figure, F006_sst.png is the same run but for a 6-h forecast. The differences along the coast and sharp gradients seem to appear, when SST has not been updated yet - which will happen at f024.

Do you have any ideas on why this happens? Apologies for the poor figure quality and colors – our server is under maintenance so I cannot re-create plots.
I am using 60-15 km meshes, 55 levels, mesoscale reference suite, and version 8.2.2.
Thanks so much for your time!

Minghua

 

[Ming Chen]

Hi Minghua,

Thank you for raising this issuee. Would you please upload your namelist.atmopshere ?

Also, please upload sea ice field at the initial time and at 6-h FCST time for me to take a look? Thanks.

 

[Snow_Rain_Cloud]

Hi Ming,

Hoping you are doing well! Please find attached my namelists and the plot (for XICE variables (in shades).

 

[Snow_Rain_Cloud]

&nhyd_model
config_time_integration_order = 2
config_dt = 90.0
config_start_time = '2021-10-21_00:00:00'
config_run_duration = '5_00:00:00'
config_split_dynamics_transport = true
config_number_of_sub_steps = 2
config_dynamics_split_steps = 3
config_horiz_mixing = '2d_smagorinsky'
config_visc4_2dsmag = 0.05
config_scalar_advection = true
config_monotonic = true
config_coef_3rd_order = 0.25
config_epssm = 0.1
config_smdiv = 0.1
/
&damping
config_zd = 22000.0
config_xnutr = 0.2
/
&limited_area
config_apply_lbcs = false
/
&io
config_pio_num_iotasks = 0
config_pio_stride = 1
/
&decomposition
config_block_decomp_file_prefix = 'x4.535554.graph.info.part.'
/
&restart
config_do_restart = false
/
&printout
config_print_global_minmax_vel = true
config_print_detailed_minmax_vel = false
/
&IAU
config_IAU_option = 'off'
config_IAU_window_length_s = 21600.
/
&physics
config_sst_update = true
config_sstdiurn_update = false
config_deepsoiltemp_update = false
config_radtlw_interval = '00:30:00'
config_radtsw_interval = '00:30:00'
config_bucket_update = 'none'
config_physics_suite = 'mesoscale_reference'
/
&soundings
config_sounding_interval = '3:00:00'
/
&physics_lsm_noahmp
config_noahmp_iopt_dveg = 4
config_noahmp_iopt_crs = 1
config_noahmp_iopt_btr = 1
config_noahmp_iopt_runsrf = 3
config_noahmp_iopt_runsub = 3
config_noahmp_iopt_sfc = 1
config_noahmp_iopt_frz = 1
config_noahmp_iopt_inf = 1
config_noahmp_iopt_rad = 3
config_noahmp_iopt_alb = 1
config_noahmp_iopt_snf = 1
config_noahmp_iopt_tksno = 1
config_noahmp_iopt_tbot = 2
config_noahmp_iopt_stc = 1
config_noahmp_iopt_gla = 1
config_noahmp_iopt_rsf = 4
config_noahmp_iopt_soil = 1
config_noahmp_iopt_pedo = 1
config_noahmp_iopt_crop = 0
config_noahmp_iopt_irr = 0
config_noahmp_iopt_irrm = 0
config_noahmp_iopt_infdv = 1
config_noahmp_iopt_tdrn = 0
/

 

[Snow_Rain_Cloud]

The namelist is for the sst updated run. The only difference for fixed sst namelist is config_sst_update = false