Towards a High-Resolution Global Coupled Navy Prediction System

Abstract

The focus of our recent work has been to complete the global high-resolution ocean and the eddy-permitting coupled ice/ocean simulations using the Los Alamos Parallel Ocean Program (POP) model and the sea ice model (CICE), as well as the first reanalysis using the Simple Ocean Data Assimilation (SODA) and POP (SODA POP 1.2). The high-resolution (0.1degree) global ocean model was run for 25 years (1979-2003) forced with synoptic atmospheric fluxes. The simulated ocean state for the post spin-up period (1994–2002) is examined in terms of its representation of the eddy variability and significant mesoscale processes by comparing energy levels and intrinsic scales with those from satellite altimetry. Also the role of the mesoscale in inter-basin property exchanges is examined with respect to the Indonesian Throughflow (ITF) and the Greenland- Iceland-Norwegian (GIN) Sea. Global coupled seaice/ ocean and stand-alone ice simulations on an eddypermitting 0.4 degree grid were run for the period 1979-2003; both were forced with synoptic atmospheric fluxes. The ice states have been compared statistically with available observations (passive microwave satellite fields, upwardlooking sonar, and ice buoys) in the latter part of the simulation. The results have lead to a suite of sensitivity runs, whose results will guide our final choices for the 0.1° global coupled sea-ice/ocean simulation. The spinup of global stand-alone 0.1 degree CICE is underway. The first reanalysis (SODA POP 1.2) using the 0.4 degree global POP and SODA is complete and is available to the general oceanographic community through Live Access Servers (LAS) at the University of Maryland and at the University of Hawaii. The reanalysis is being used to study various aspects of the global circulation including the Indonesian Throughflow, and the variability of the subtropical cells in the Pacific.