GODAE OceanView Inter-comparison for the Australian Region

Abstract

This paper compares the performance of short-range operational ocean forecasts, using 'observational space' metrics developed under GODAE OceanView (GOV). Best estimates (behind the real-time analysis) and forecasts are intercompared for the Australian region (0-50S, 90-180E) for 2013. Systems considered include those developed in Australia, France, Canada, United Kingdom and USA. Each system is compared to observations of along-track sea level anomaly, sea surface temperature observations from surface drifters and sub-surface Argo profiles of temperature and salinity. The UK operational system generally has the smallest errors for sea surface temperature and sea level anomaly for the Australian region. However, the French systems outperform others in sub-surface temperature and salinity for the region. Of the two products provided by the Australian centre, an ensemble based approach is found to perform better than the deterministic system, having higher skill and lower root mean square errors. Some of the 'better' results of systems can be attributed in part to the lack of independence of the reference observations; however the study does demonstrate the feasibility and robustness of GOV global ocean inter-comparison efforts for regional applications.

Verification of the mixed layer depth in the OceanMAPS operational forecast model for Austral autumn

“…Commonly, climatology is used as a reference, with typical skill scores for operational ocean forecast models in the range 0.2 to 0.7 for parameters such as temperature, salinity and sea surface height (e.g. Divakaran et al, 2015;.…”

An introduction to GODAE OceanView

“…The GOV task team for intercomparison and validation (ICV-TT) has developed protocols for controlled comparison of model predictions against carefully selected sets of observations which enable statistics of the differences between observations and predictions from a number of operational centres to be regularly calculated and rigorously intercompared. Two papers in this edition describe recently obtained results Divakaran et al 2015). Results from similarly careful intercomparisons of long period hindcasts (assimilating data) carried out by the observing system experiment task team (OSE-TT) jointly with the CLIVAR Global Synthesis and Observations Panel (GSOP) are presented in a third paper .…”

The Regional Ice Ocean Prediction System v2: a pan-Canadian ocean analysis system using an online tidal harmonic analysis

“…GIOPS analyses and forecasts are also used by the Canadian navy for marine operations (e.g., sonar range prediction). Building on the availability of ocean analyses from GIOPS, a higher-grid-resolution Regional Ice Ocean Prediction System (RIOPS) was developed (Dupont et al, 2015;Lemieux et al, 2016a) to support marine operations in Canadian ice-infested waters, in particular over two Arctic METAREAs (17 and 18) for which Canada has the responsibility to provide warnings regarding ice hazards and marine weather predictions as part of the Global Marine Distress and Safety System.…”

“…OPA is a primitive-equation model on an Arakawa C-grid employing the non-Boussinesq and hydrostatic approximations. A detailed description and evaluation of the model are provided in Dupont et al (2015). The particular parameterization details and settings used are described in Tables 1 and 2. The RIOPSv2 numerical grid is constructed from the 1/12 • tripolar ORCA grid (Madec and Imbard, 1996), whereby grid points from the Pacific section have been remapped to the top of the grid to eliminate the north fold from the ORCA grid (see Dupont et al, 2015, for details).…”