7 Modelling/assimilation centres or groups

The GODAE modelling/assimilation centres or groups as they are envisioned now are described. Characteristics of the systems planned for the GODAE operational phases (2003-2007) (input data, model, assimilation method, anticipated products, target applications…) are summarized.

Australia

Background

The Commonwealth Bureau of Meteorology (CBoM), CSIRO (Marine and Atmospheric Research, CMAR) and the Royal Australian Navy (RAN) are collaborating in the development of an ocean forecasting system to support a GODAE Project within Australia. The project was launched in September 2002 under the name of BLUElink – Ocean Forecasting Australia and is scheduled to deliver a global operational system with a focus on the Australasian region by 2007. Both the CBoM and CSIRO provide the scientific expertise and technological infrastructure whereas the RAN is a major funding source and beneficiary of the forecasting system.

BMRC and CMAR developed the first operational coupled ocean-atmosphere model for ENSO prediction (see The ocean component is an Australian version of the MOM code (ACOM, the Australian Community Ocean Model) with enhanced resolution in the tropics but coarse resolution elsewhere. The atmospheric component of the model is a T47L34 version of the BMRC Atmospheric model and the OASIS coupler is used to link the models. Development of a short-range ocean forecasting system will also benefit further improvements of the seasonal-to-interannual prediction system.

Contacts: Neville Smith

Andreas

The BLUElink Forecasting System

1. Input Data

The project has a heavy reliance on data and data products of other Partners in GODAE (e.g., via the Monterey data server and GTS).

  • The Joint Facility (JAFOOS) was established in 1999 to support the collaborative CMAR/Bureau observational program (see JAFOOS is coordinating Australian contributions to GOOS and has a significant effort in assembly and quality control of ocean data. The JAFOOS is likely to be the focus of attempts to enhance Australia’s contribution. Contact: Ann Thresher
  • The forcing fields of the operational systems will come from the Bureau of Meteorology NWP systems. Development and testing has made use of the ECMWF re-analysis fields.
  • The preparations of Bureau NWP fluxes have included comparisons of analysed and forecast winds with QuikSCAT and the extension of the analysis system to include QuikSCAT observations.
  • Near real-time profile observations are being ftp pulled into the Bureau from the GTS, USGODAE and Coriolis.
  • The BLUElink forecast system is dependent on the fast delivery processed satellite altimetry products. BLUElink does not have the infrastructure/resources to process the raw data stream. Most significant limitation to usage is the accuracy of the ocean tidal correction in the continental shelf zone.
  • Near real-time sea surface height anomalies for Jason-1 are being ftp pushed to the Bureau via OCEANIDS. Data availability has been consistent at O(8hrs) behind real-time. The data provided contain values that require local quality control procedures.
  • Near real-time sea surface height anomalies for ENVISAT are being ftp pushed from ESA with a data availability O(3days) behind real-time
  • Near real-time GFO is planned to be retrieved at the Bureau from both USGODAE for the NGDR and NOAA for the IGDR.
  • CMAR presently has a near-real-time altimeter product. This is used initially for the Australian region (T/P, Jason-1, GFO, Envisat, …).
  • BMRC and CMAR are participating in the GHRSST Project. The goal is the development of unique high-resolution SST data sets and products for the Australian region.
  • The data assimilation system (see below) uses SSH data from available satellite systems and from in situ data streams (mainly Argo floats). Assimilation of satellite SST observations is being pursued in research but is not scheduled for implementation in the first version of forecast system.

2. Data serving

The responsibility for operational data and product management as part of this project resides with CBoM. It comprises the following components:

  • A data base and server for incoming data (local, regional, global telecommunications), for provision of data to models, and for provision of data to the Integrated Product Service and scientists involved in the development of components:
  • Argo profiling floats;
  • Ship of Opportunity lines,
  • Surface drifters;
  • Fixed-point time series;
  • Tide gauge data from the National Tidal Centre and other Australian sites; etc.
  • The key satellite data sets include:
  • Altimetry: Topex/Poseidon, Jason 1, GFO, ERS-2, Envisat;
  • SST: NOAA AVHRR, MTSAT/GOES, Envisat, MODIS, AMSR-E;
  • Surface winds: QuikScat and other available remote measurements such as DMSP, and/or NWP;
  • Sea-ice extent (an Antarctic Climate and Ecosystems CRC project).
  • Implementation of an archive and retrieval product database and server for Bluelink fields and delivery of relevant products on the Bureau intranet via the Australian Integrated Forecast System (AIFS). Products will include files in netCDF format delivered by OPeNDAP and graphical products via web images and an interactive graphical user interface
  • Implementation of a data and graphical service for Bluelink products via the Internet and a DODS Server ( Data and file access will is via OPeNDAP and graphical access via a LAS server.
  • To satisfy the requirements of the data and product server the Bureau has implemented the ECMWF Meteorological Archival and Retrieval System (MARS) and this greatly enhances the functionality for ocean applications. In collaboration with ECMWF, MARS is being adapted to handle data types and products common to ocean data assimilation and prediction and interfaces are being established to allow both intranet and internet access to Bureau operational products, including both regional and global systems. An interface is proved between OPeNDAP data retrieval system and MARS data archival server.

Contact: Graham Warren

3. Model

The forecasting component of the Bluelink project is based on a nested modeling system.

  • The global ocean data assimilation and prediction model (OFAM) is based on the latest GFDL MOM4 code. It has a horizontal resolution of (1/10)º within a “rectangular” box between 90ºE and 180ºE and 17Nº and 75ºS. Within the remaining parts of the Equatorial and Southern Pacific and IndianOceans the minimum resolution is 0.9º. Outside this area the resolution is as coarse as 2º. The model has 47 vertical levels with 35 levels in the upper 1000m. This model will be implemented and run operationally by the CBoM (2006/2007). Contact for global model: Andreas Schiller
  • A regional model, nested within the eddy-resolving region of the global model is being designed as a relocatable model which will require only minimum user input. The regional ocean model MECO is based on an in-house development by CMAR (Model of the Estuaries and CoastalOceans). It is one-way coupled to a nested relocatable atmospheric model (Colorado State University RAMS model); RAMS is nested with CBoM’s GASP/LAPS atmospheric models. This model will be implemented at the operational centre of the RAN (2006/2007). Further details are:
  • Automatic implementation via visual interface of hydrodynamic model with minimum user input
  • Forecasts of ocean and atmosphere state out to 3 days
  • Ocean domains of scales down to 100 km x 100 km with resolution down to 2km
  • Surface atmospheric data for ocean from RAMS (currently just one-way coupling)
  • Contact for regional model: Peter Craig
  • A regional ocean model is being developed as an experimental tropical forecasting system to explore impacts on forecast skill. The ocean model is based directly on OFAM and will use initial and boundary conditions from the forecasting system. Contact Gary Brassington

4. Assimilation method

  • The stand-alone operational analysis system run by the Bureau will be continued with enhanced global and regional versions, with fine resolution in the Australian region, and capable of ingesting both in situ temperature and salinity profiles and altimeter data (via pseudo-XBTs).
  • A daily-updated nowcast of the three-dimensional temperature, salinity and current velocity field for the Australasian region based on in situ and satellite data has been developed and is run by CSIRO. Contact: David Griffin (
  • The forecasting system is based on a multivariate assimilation scheme (Ensemble Optimal Interpolation) that combines a model forecast with available in situ and satellite derived observations into the global ocean model to provide improved short-range model predictions with forecast skill of up to 4-6 days. The system assimilates altimeter data, subsurface Argo, SOOP and XBT data (assembled into a single data set) and has an option for assimilation of SST data.
  • An enhanced data assimilation method will be developed in collaboration with the Bluelink project. It will be based on the ensemble Kalman filter but is unlikely to be implemented in the operational ocean forecasting system before 2008. Additional work will be done within the Antarctic and Climate Ecosystems CRC for assimilation of Antarctic data.

Contacts: Oscar Alves , Peter Oke

5. Prototype systems and transition to global systems

The initial configuration for the trial forecast system is specified in the OceanMAPS Science and Technical Implementation Plan and reviewed in a workshop summary report both available online ( The system is scheduled for completion end of 2005. This system will target a reduced configuration that is focused on robust delivery. The robust and subsequent extended configurations will be trialed in the first half of 2006. The operational configuration will be finalised mid-2006. The second half of 2006 will be reserved to transfer the trial system to the operational infrastructure, monitor the system performance and establish system product streams. Operational certification is planned for end 2006/early 2007.

The initial configuration will be based on:

  • OFAM with trials for parameter tuning and optimisation for operational infrastructure
  • BODAS configured for near real-time analyses and extended quality control
  • Argo, XBT, TAO profile observations from GTS, USGODAE and Coriolis
  • Jason-1, ENVISAT and GFO from OCEANIDS, ESA, USGODAE and NOAA
  • The forecast system is being designed to perform two analysis cycles. The first is a delayed mode cycle to provide a “best analysis” and a near real-time analysis from which a forecast is initiated.
  • The delayed mode cycle will be performed 3 to 6 days behind real-time. The precise delay will be determined during the trials based on resources and impacts to forecast skill.
  • The near real-time analysis will be performed approximately 1-2 days behind real-time.
  • The initial service level will target a 7day forecast, which will be performed twice weekly but with a capability of up to daily forecasts.

Contacts: Gary Brassington , Peter Oke

6. Assimilation products and dissemination

The principal source for products from the operational trials and fully operational systems will be the external access point to the MARS server. The Partnership with the Navy potentially allows for expanded requirements in terms of product serving, proper treatment of oceanographic fields, ingestion and serving of data products, and modes for internal and external access. The OPenDAP server DODS.bom.gov.au will be used for intercomparisons and product exchange.

To facilitate access to products via the intranet (e.g., for the RAN) and internet, a web-based interface to an internal MARS client has been constructed. This interface operates from an external proxy server for security reasons. A system is being developed to automatically query and catalogue new entries to the database and expose these to for browsing. We anticipate this functionality will satisfy our requirement for ingesting large data and product sets from outside and providing our own data and products for the GODAE Partners.

It is also anticipated that several products, particularly those from the experimental system, will be available directly from the Australian Partnership, either through CSIRO or BMRC (see “Data Serving”).

The following products have been included or are scheduled to appear before the end 2005:

Daily global and regional surface wind products from the NWP systems

SST data products based on locally retrieved SST

Regional and global SST and subsurface analyses (no model assimilation)

Various coupled model climate forecasts fields

Other products that will be exposed as they become available include:

Global model assimilation estimates (u, v, η, T, S), probably on reduced space-time grids

Global and regional model forecasts, again on reduced space-time grids

Various ocean state diagnostics and statistics as determined by GODAE metrics

Contacts: Graham Warren , Neville Smith

7. Systems

Seasonal-to-interannual prediction

The BMRC coupled seasonal prediction model has been running operationally since 2002. The application of climate products occurs through the Bureau's National Climate Centre and its Climate Analysis Section. The monthly Seasonal Climate Outlook meetings provide and interpretation of Bureau and other climate monitoring and prediction information. An internal forum involving operational and research personnel provides advice on the performance of systems and on the implementation of new systems.

The Climate Analysis Section, and contacts in the regions, provides a conduit from climate product to application (consumption). There are direct links into many sectors but agriculture is the dominant user. Other groups (e.g., the Queensland Department of Primary Industry) also provide value adding of Bureau climate information.

Contacts: Oscar Alves

Short-range ocean forecasts

The Navy will be the principal customer for the new Ocean Forecasting System. The project is linked to an effort to develop improved acoustical model systems for the Navy. Links to regional users are being established through WAGOOS, a consortium of industry, private sector and Government users in Western Australia, regional research initiatives (e.f., SRFME), and the regional Offices of the Bureau of Meteorology. The Great Barrier Reef Marine Park Authority has expressed an interest in temperature forecast products to assist their management strategies to mitigate the impact of Coral Bleaching. The Bureau is developing an experimental regional modelling system for a coupled tropical cyclone forecasting system (see “Model”)

Coastal forecasting

The regional forecasting model will be operated at a resolution that permits useful ocean state estimates and forecasts for the coastal region. Discussions have been initiated with private and public sector groups in Western Australia with the aim of developing several value-adding projects that use the products of the ocean forecasting and data assimilation system.

8. Links with GODAE pilot projects (Argo, GHRSST)

Data from Argo floats are central to the data assimilation system. Australia (CBoM, CSIRO, ACE CRC) is deploying an increasing number of floats in its regional oceans, which will benefit the forecasting system. Research on how to optimize information derived from Argo floats in the data assimilation system is a core activity.

Both CBoM and CSIRO actively participate in the GHRSST pilot project. Apart from calibration and validation activities the goal is the provision of real-time regional SST products with order 10 km spatial resolution within 6 hours of data reception. The products will be based on both satellite and in situ measurements. Satellite data will come from both infrared and microwave instruments and the processing system will blend all data sources in to skin, sub-skin and bulk (depths of 1 to 5 m) temperature estimates.

Contacts: Helen Beggs: , Ian Barton:

9. Internal metrics and intercomparison plans

The forecasting system will be subject to ongoing validation with independent (non-assimilated) observations and with products provided by other agencies (e.g. NAVOCEANO).

The Bluelink research partners have agreed to lead an intercomparison effort for the Australian region. A set of metrics for the Australian region, including the Indian Ocean and Antarctic sector, has been developed. The standards and formats for presentation of data on servers will follow that developed by the MERSEA project. The Bluelink partners have produced a tentative schedule of activities noting dates/times of (i) Agreement on metrics/classes, (ii) participation, (iii) set up of servers and formats, (iv) planned/needed workshops, and (v) any other milestones. Initial focus will be on metrics based on MERSEA class 1 and class 2 data sets. Expected participants are: Aust, NRL, FOAM (W IO), MERCATOR.

Contacts: Peter Oke , Gary Brassington

10. Targeted Users and envisioned external metrics

Initially, the Navy and research scientists will be the main users of the forecasting system. There is potentially considerable interest by the marine user community such as offshore industries, fisheries, marine transport, marine management and search and rescue. Within Australia’s Ocean Policy, the Bureau, CSIRO and Navy, among others are actively pursuing the concepts of marine environmental prediction and operational ocean services, with activities and actions during 2004-2007 that will enable engagement of a broader user base. It is anticipated that once the system is fully operational many national and regional users will incorporate data from the Bluelink system in their services.