The file RossSea.nc is a netCDF file containing snapshots of model output from our high-resolution (5 km) model for the Ross Sea. Details on the model can be found in Dinniman et al., 2003 and Smith et al., 2003. This file contains snapshots of model output at 10d intervals for the period: model day 60 - model day 420. The model is initialized on Sept. 15, so this period covers a little over a year (370d) starting on Nov. 14.

The model output is on the original horizontal grid with the full 5 km resolution. The model grid is an Arakawa "C-grid", so the u and v velocities are at different locations from each other and from any tracers (rho-points). Please note that the u and v velocities are with respect to the local grid AND NOT TRUE NORTH. The angle between the grid and true north can be found in the variable "angle".

The model has a terrain following vertical coordinate system, but the output here has been interpolated onto fixed z-depths (19: 0,10,20,30,50,75,100, 125,150,200,250,300,400,500,600,700,800,900,1000) covering the top 1000 m. Interested parties can contact Mike Dinniman should any information below 1000 m (or on the original model layers) be desired.

The available variables are:

Grid Variables:

• 'h' - model depth (m) at all grid points
• 'depth' - depth (m) for each vertical point in this output file
• 'angle' - angle (radians) between the model grid (at rho-points) and true north
• 'mask_rho' - mask (0=land, 1=water) for rho-points
• 'mask_u' - mask for U-points
• 'mask_v' - mask for V-points
• 'lat_rho' - latitude (degrees) for each rho-point
• 'lon_rho' - longitude (degrees) for each rho-point
• 'lat_u' - latitude (degrees) for each U-point
• 'lon_u' - longitude (degrees) for each U-point
• 'lat_v' - latitude (degrees) for each V-point
• 'lon_v' - longitude (degrees) for each V-point
• 'time' - time (days) since the start of the model run (Sept. 15)

3D (x,y,time) Variables:

• 'zeta' - surface height (m)
• 'aice' - ice concentration (% 0-100)
• 'ubar' - barotropic U-velocity (m/s - on U-points)
• 'vbar' - barotropic V-velocity (m/s - on V-points)

4D (x,y,z,time) Variables:

• 'u' - baroclinic U-velocity (m/s - on U-points)
• 'v' - baroclinic V-velocity (m/s - on V-points)
• 'w' - vertical velocity (m/s - w.r.t fixed horizontal layers and not the model layers) (Note that this definition of vertical velocity is not used at all in the model, is purely done for output and is quite variable for several reasons.)
• 'temp' - temperature (deg C)
• 'salt' - salinity (psu)
• 'nitrate' - nitrate (micromole/liter)
• 'silicate' - silicate (micromole/liter)
• 'chlorophyll' - chlorophyll (microgram/liter)

Hofmann, E. E. et al.; U.S. JGOFS Synthesis & Modeling Project - Data. U.S. JGOFS. iPub: November 2003. 'date you accessed the data' http://usjgofs.whoi.edu/las?dset=Model+Results/Ross+Sea+Model+Snapshots

Dinniman, M.S., J.M. Klinck and W.O. Smith, Jr. 2003. Cross shelf exchange in a model of the Ross Sea circulation and biogeochemistry. Deep-Sea Research II, 50(22-26), 3103-3120, doi:10.1016/j.dsr2.2003.07.011

Smith, W.O., Jr., M.S. Dinniman, J.M. Klinck and E.E. Hofmann, 2003. Biogeochemical climatologies of the Ross Sea, Antarctica: seasonal patterns of nutrients and biomass. Deep-Sea Research II, 50(22-26),3083-3101, doi:10.1016/j.dsr2.2003.07.010