Reynolds and Smith AOI SST Climatology (1971 - 2000)

The AOI SST climatology is an optimum interpolation analysis of sea surface temperature with an adjusted base period of 1971 to 2000, on a global 1 degree by 1 degree by 1 month grid. As of July 23 2002 we have begun using the latest version of the Reynolds and Smith climatology, which formerly had a base period of 1961-1990. Differences between these climatologies are generally small in the tropics, usually below 0.2°C.

For further information, please see:

Smith, T. M. and R. W. Reynolds, 1998: A high resolution global sea surface temperature climatology for the 1961-90 base period. J. Climate, 11, 3320-3323.

Xue, Y., T.M. Smith and R.W. Reynolds, 2002: A new SST climatology for the 1971-2000 base period and interdecadal changes of 30-year SST normals. J. Climate in revision.

Subsurface Temperature Climatology (Tropical Pacific Ocean)

After merging of XBT and CTD data, we further smoothed the climatologies to eliminate unrealistic features related to uneven data distribution in space and time. We then blended this climatology with the Reynolds and Smith SST climatology to ensure consistency between surface anomalies appearing in vertical and horizontal temperature analyses. Blending was done such that surface values were set to Reynolds and Smith and values between 0 and 50 m generated by linear interpolation between SST and Kessler values at 50 m. Any discontinuities across 50 m were smoothed out and any near surface temperature instabilities generated by this blending were eliminated. As a final step, monthly values were smoothed with a 1-2-1 filter in time to eliminate small amplitude month-to-month noise variations.

This climatology is used to compute subsurface temperature anomalies, and to grid temperature data in Longitude-Depth and Latitude-Depth sections. A special exception to this is along 95°W for Latitude-Depth sections. Since we have data at 12°N during the EPIC program, which are located outside the domain of the modified Kessler climatology (extending only to 10°N), we use instead the Bureau of Meteorology Research Center (BMRC) temperature climatology (Smith, 1995) at all latitudes along 95°W so that the anomalies in the 95°W depth-section plots are coherent and extend to 12°N. This introduces a small inconsistency between anomalies shown in the depth-longitude and latitude-depth section plots at 95°W. For more information on how these TAO data are gridded, see the Depth-Longitude Gridding and Latitude-Depth Gridding web pages.

For additional information see:

Kessler, W.S., 1990: "Observations of long Rossby waves in the northern tropical Pacific". J. Geophysical Research, 95(C4), 5183-5217 (abstract),

Kessler, W.S. and J.P. McCreary, 1993: "The annual wind-driven Rossby wave in the subthermocline equatorial Pacific". J. Phys. Oceanogr., 23(6), 1192-1207 (abstract)

Smith, N. R., 1995: "An improved system for tropical ocean sub-surface temperature analyses". J. Atmos. Oceanic Technol., 12, 850-870.

Subsurface Temperature Climatology (Alantic and Indian Oceans)

For additional information see:

Locarnini, R. A., A. V. Mishonov, J. I. Antonov, T. P. Boyer, and H. E. Garcia, 2006. World Ocean Atlas 2005, Volume 1: Temperature. S. Levitus, Ed. NOAA Atlas NESDIS 61, U.S. Government Printing Office, Washington, D.C., 182 pp.

COADS Winds (1946 - 1989)

COADS Relative Humidity (1946 - 1989)

This climatology is used for computing TAO RH anomalies, and for gridding RH in the latitude-longitude maps and latitude-time section plots. For example plots of RH see the "Assorted Plots" on the TAO/TRITON Data Display page. For information on these gridding methods, see the Latitude-Longitude Gridding and Latitude-Time Gridding web pages.

COADS Sea Level Barometric Pressure (1946 - 1989)

20°C Isotherm Depth

Similarly, for the Atlantic and Indian oceans, a 20°C isotherm depth climatology was computed from the World Ocean Atlas 2005 temperature climatology (see above).

These climatologies are used for computing 20°C isotherm depth anomalies, and for gridding 20°C depths in the latitude-longitude maps and latitude-time section plots. To make plots of 20°C depth see the TAO/TRITON Data Display page. For information on these gridding methods, see the Latitude-Longitude Gridding and Latitude-Time Gridding web pages.

Dynamic Height

These climatologies are used to compute dynamic height anomalies, and for gridding dynamic heights in the latitude-longitude maps and time section plots. For example plots of dynamic height see the TAO/TRITON Display and Delivery page. For information on these gridding methods, see the Latitude-Longitude, Time-Logitude, and Latitude-Time gridding pages.

Salinity and Sigma-Theta

Salinity is combined with potential temperature computed from the World Ocean Atlas temperature climatology to compute the potential density anomaly (sigma-theta) defined as sigma-theta = 1/V(S,Theta,P) -1000 kg m-3 where V is specific volume, S is salinity, Theta is potential temperature and P is set to zero. The algorithms used in these calculations are from "Algorithms for computation of fundamental properties of seawater" by Fofonoff and Millard (UNESCO technical papers in marine science, 44, 1983).

For information on how salinity and sigma-theta data are gridded, see the Latitude-Time Gridding and the see the Latitude-Depth Gridding web pages.

For additional information see:

Antonov, J. I., R. A. Locarnini, T. P. Boyer, A. V. Mishonov, and H. E. Garcia, 2006. World Ocean Atlas 2005, Volume 2: Salinity. S. Levitus, Ed. NOAA Atlas NESDIS 62, U.S. Government Printing Office, Washington, D.C., 182 pp.

Shortwave Radiation (1945-1989)

Longwave Radiation (1945-1989)

Xie and Arkin Precipitation Climatology (1979 - 1995)

Sea Surface Ocean Currents