OCEAN ANALYSES

Neville Smith, BMRC

© Copyright Commonwealth of Australia 1996.
Users of these Web pages are deemed to have read and accepted the conditions described in the copyright declaration.

Note: The products referred to here are experimental and not products of the Bureau of Meteorology operational systems, unless otherwise stated. They should not be copied or used for other than research purposes. Contact n.smith@bom.gov.au if you require further information.
Subsurface ocean analyses
SST analyses
BoM NCC analyses
Selection of past analyses
Data server file

Background

BMRC has been running an ocean subsurface analysis system routinely since 1988. The theoretical and experimental background to this system is covered in various publications: Smith, Blomley and Meyers (1991), Smith (1991), Meyers, Phillips, Smith and Sprintall (1991), Smith (1995a) and Smith (1995b).

The data are gathered from the Global Telecommunication System node at the Bureau of Meteorology, through arrangements with the Marine Environmental Data Centre of Canada and the National Oceanographic Data Center of U.S.A., directly from the Pacific Marine Environemental Laboratory (for the Tropical Atmosphere-Ocean mooring array; Note that the TAO Array products can be viewed directly), and from various ocean data archives. The analysis system is run twice weekly to take advantage of the most recent data, using a monthly analysis period and forecasts based on the previous months analysis and the current month climatology (from the World Ocean Atlas). In addition, a separate analysis is run for the depth of the 20C isotherm in the tropical Indian and Pacific Oceans, using an analysis period of 10 days in an attempt to capture more of the higher-frequency variability.

At present the system is being trialled in the Ocean Services Division of the National Meteorological Centre of the Bureau of Meteorology prior to operational implementation. The operational system is likely to be based more on the real-time data stream and less on the various delayed-mode sources. The products presented here are based on the experimental system operated by BMRC. These products form part of the information considered by the National Climate Centre of the Bureau of Meteorology in its monthly climate outlook meetings and in its Monthly Climate Bulletin (text and plots are included below.

A sea surface temperature analysis system, also developed at BMRC and based on a similar methodology to that used for subsurface analyses, has beed running operationally at BoM since 1993. It uses buoy, volunteer observing ship and other in situ data, mapped on very broad scales (around 800 km), to provide an initial (unbiased) estimate of SST. The satellite data are occasionally contaminated by the presence of aerosols and particulates in the atmosphere (e.g., volcanic eruptions) so it is important to have an unbiased in situ analysis to remove such contamination. At BoM, the broadscale in situ analysis is compared with a similar broad-scale analysis of the satellite data; the difference is used to correct all the satellite data and then a fine-scale (O(100km)) analysis is performed using all available SST data. The products displayed here are produced by Wasyl Drosdowsky as part of his research. Other products may be found on the NMC Home Page (under development).

An experimental global ocean model data assimilation system is being developed but, at present, its thermal analyses are not considered sufficiently robust or accurate for operational implementation. However, experimental products including ocean currents will be included here shortly. Experimental trials with a general circulation coupled model, using the BMRC analysis system, indicated the data do have a positive impact on model forecast skill.

A simpler climate forecast model has been developed by Richard Kleeman. This model ingests information from the 400m depth-averaged temperature analysis. The experimental results from this model indicate the ocean data have a positive impact on the model skill in respect of the NINO3 temperature index.

Current subsurface ocean analyses

  • Pacific Ocean 150m depth-averaged temperature analysis
  • Equatorial Pacific Ocean vertical section temperature analysis
  • Global 150m depth-averaged temperature analysis, with data locations
  • Analysis of the monthly mean 20C isotherm depth
  • Hovmoller diagram of the anomaly in the 20C isotherm depth, 2001-present
  • Hovmoller diagram of the anomaly in the 20C isotherm depth, 1980-present
  • Hovmoller diagram of the anomaly in the 20C isotherm depth, 1996-present
  • Hovmoller diagram of the 400m depth-averaged temperature anomaly, 1970-present
  • Hovmoller diagram of the 400m depth-averaged temperature anomaly, 1996-present
  • 4-month sequence of 150m depth-averaged temperature anomalies
  • 4-month sequence of vertical temperature anomaly sections at the equator, Pacific

    Current SST analysis

  • Global SST analysis
  • Global SST anomaly analysis
  • Hovmoller diagram of weekly equatorial SST, week of 28 June 1993 through to present
  • Hovmoller diagram of weekly equatorial SST anomaly, week of 28 June 1993 through to present
  • Hovmoller diagram of monthly equatorial SST, November 1981 through to present
  • Hovmoller diagram of monthly equatorial SST anomaly, November 1981 through to present
  • Plots of Niño1, 2, 3, 4, 1+2 and Indian Ocean SST INDICES, from weekly analyses, 28 June 1993 through to present
  • Plots of Niño1, 2, 3, 4, 1+2 and Indian Ocean SST INDICES, from monthly analyses (CAC + BoM), 1981 through to present 
     Note that for partially completed months, SST values and/or indices are preliminary estimates
based on available data.


    BoM NCC Climate Monitoring Bulletin Text (BoM internal only)

     A commentary on the current ocean climate ( Mar 2008 ) is available. Also available are Black+White versions of
  • 150m depth-averaged temperature analysis,
  • Pacific equatorial temperature section, and
  • 96-present Hovmoller diagram,

    as well as

    Feb 2008
  • 150m depth-averaged temperature analysis,
  • Pacific equatorial temperature section
  • commentary

    Jan 2008
  • 150m depth-averaged temperature analysis,
  • Pacific equatorial temperature section
  • commentary

    and the Mar 2008 monthly NCC OHs (COLOUR)
    (Note that these graphics files are postscript and can be large)

    Past ocean analyses

    A selection of past     SST and subsurface ocean analyses are available.
    Further information is available from n.smith@bom.gov.au