Indices of Equatorial Pacific Heat Content

As indices of upper ocean heat content in the equatorial Pacific, we compute monthly Warm Water Volume (WWV) and depth averaged temperature over the upper 300 m (T300) from the ocean analyses of the Bureau National Operations Centre (BNOC) at the Australian Bureau of Meteorology. These data are based on temperature profiles from TAO moorings, Argo floats and XBTs. The temperature analyses are available at

Please email the Supervisor for Oceanographic Systems ( for further details, and also see

Smith, N.R., 1995. The BMRC ocean thermal analysis system, Aust. Met. Mag. 44, 93-110.

The monthly WWV and T300 indices are computed for the period beginning January 1980. WWV is defined as the volume of water with temperature above 20°C in oceanic regions of the equatorial Pacific between 5°N to 5°S, 120°E to 80°W. T300 is defined as the average temperature over the same latitude and longitude ranges. Monthly anomalies are computed by removing the mean seasonal cycle for a base period of 1981-2010. Monthly means and anomalies for the eastern (80°W-155°W) and western (155°W-120°E) halves of the basin are also available, as are the mean seasonal cycles for the 1981-2010 base period. The two indices are equivalent for most purposes, with the correlation of monthly means and anomalies > 0.9.

Please acknowledge TAO Project Office, NOAA/PMEL if you use these products in publications or presentations. Also, we would appreciate receiving a preprint and/or reprint of publications utilizing these data for inclusion in the TAO bibliography. Relevant publications should be sent to:
    TAO Project Office
    NOAA/Pacific Marine Environmental Laboratory
    7600 Sand Point Way NE
    Seattle, WA 98115
For further information, contact