CGOA model with T, S, and velocity nudging

• NCEP/NCAR Reanalysis winds
• NCEP/NCAR Reanalysis heat flux
• Integrated freshwater input along the coast
• Susitna and Copper River discharge
• Vertical S coordinates manipulated so that top layer is constant depth across the entire domain
• Initial temperature and salinity fields from Levitus data
• Nudging of temperature and salinity to Levitus data
• Nudging of barotropic velocity to output from SEOM
• Simulation of time period August - October, 1996
• Lower vertical background mixing for tracers, higher viscosity, and shorter 2D timestep to improve stability.

Experiment A began 5 days before the end of July when an initialization run was spun up with TS nudging to climatology and subtidal, barotropic U and V nudging to SEOM results over a region that included the entire finely resolved area, and extended to point 10 in the telescoping region, ramping to zero at the western and southern walls. A subsequent 90 day run began on August 1, using the initialization results as initial conditions. This run had a nudging area whose coefficient varied from 0 at walls, max nudgcoft (.1/86400) at point 10, and 0 again at edge of finely resolved area nudging TS and subtidal velocity.

Experiment B was initialized on August 1 the same way that Experiment A was. During this 90 day run, TS was nudged in the nudging zone described above, but subtidal velocity was not. This run was intended as a basis from comparison for the continued nudging to SEOM results.

Nudging area for 90 day subtidal run. Darker grey indicates larger nudging coefficient, and blue denotes land.

General Description of Results