Circulation and
Biogeochemical Processes in a Numerical Model
of the West Antarctic Peninsula
| Introduction and purpose | |
| Model details | |
| Model results and comparison with observations | |
| Proposed mechanism for cross shelf flow | |
| Summary | |
| Future plans |
| Rutgers/UCLA Regional Ocean Model System (ROMS) | |
| Primitive equation model with free surface | |
| Terrain following vertical coordinate | |
| General surface fluxes | |
| Open boundary conditions | |
| Parallel computer implementation using openmp | |
| Initial fields from World Ocean Data Atlas (1998) | |
| Nitrate and Silicate are included as freely evolving concentrations | |
| Bottom topography based on Sandwell and Smith (ETOPO2) |
| Circulation averaged over winter | |
| Circulation at 200 m compared to ADCP | |
| SST comparison to AVHRR climatology | |
| Vertical section of temperature compared to hydrographic measurements (Jan-Feb, April) | |
| Vertical sections of Nitrate | |
| Temperature at Tmax below 200 m | |
| Analysis of transport across the shelf break |
Surface Temperature Comparison
Temperature Section North
of
Marguerite Bay
Temperature Section North
of
Marguerite Bay
Nitrate Section off Adelaide Island
Nitrate Comparison in Early September
Calculation of Across-shelf-break Flux
| Define the shelf-break section along the 1000 m isobath in the model. Include across-shelf sections at either end to close the box. | |
| At every point, calculate the gradient of bathymetry. Get the component of vertically integrated flow in that direction. | |
| Calculate the curvature, and the change of curvature, along the shelf-break section. | |
| Calculate the lagged correlation of onshelf transport and shelf-break curvature. |
Integrated Cross-shelf
Fluxes
of Volume, Heat and Salt
Persistent Across-shelf-break Transport
Cross Shelf Transport Mechanism
| Flow crosses shelf break if topography turns in front of the flow. | |
| Water penetrates onshore if shelf circulation is towards the coast |
| Circulation shows some comparison with present understanding of circulation | |
| Surface temperature compares well to observations | |
| Mixed layer follows realistic seasonal patterns, although is too deep in winter | |
| Onshore flux of CDW occurs at observed locations | |
| Onshore flux due to combination of bathymetric curvature and shelf circulation |
| Expand comparison of model solutions to observations | |
| Use recent observations to construct more realistic initial conditions for T, S and nutrients | |
| Add forcing for coastal current (ice melt or Gerlache exchange) | |
| Add a dynamic sea-ice model (working on CISE by E. Hunkins) | |
| Add coastal fast ice and ice shelves including George VI sound | |
| Include tidal variability driven at the boundaries by a global model | |
| Add a bio-optical primary production model | |
| Better large scale Southern Ocean model for boundary forcing |