Development and Assessment of the Systematically Merged Pacific Ocean Regional Temperature and Salinity (SPORTS) Climatology for Ocean Heat Content Estimations

Abstract

Systematically Merged Pacific Ocean Regional Temperature and Salinity (SPORTS) climatology was created to estimate ocean heat content (OHC) for tropical cyclone (TC) intensity forecasting and other applications. A technique similar to the creation of the Systematically Merged Atlantic Regional Temperature and Salinity (SMARTS) climatology was used to blend temperature and salinity fields from the Generalized Digital Environment Model and World Ocean Atlas 2001 at a 0.25° resolution. The weights for the blending of these two climatologies were estimated by minimizing residual covariances across the basin. Drift velocities associated with eddy variability were accounted for using a series of 3-yr sea surface height anomalies (SSHA) to ensure continuity between the periods of different altimeters. In addition to producing daily estimates of the 20° and 26°C isotherm depths, mixed-layer depth, and OHC, the model produces mapping errors from the optimal interpolation of the SSHA due to gaps in altimeter track coverage and sensor uncertainties.Using SPORTS with satellite-derived sea surface temperature (SST) and SSHA fields from radar altimetry, daily OHC was estimated from 2000 to 2011 using a 2.5-layer model approach. Argo profiling floats, expendable probes from ships and aircraft, long-term Tropical Atmosphere Ocean (TAO) moorings, and drifters provide more than 267 000 quality controlled in situ thermal profiles to assess uncertainty in estimates from SPORTS. This carefully constructed climatology creates an accurate estimation of OHC from satellite-based measurements, which can then be used in TC intensity forecasts in the North Pacific Ocean and analysis of ocean thermodynamics. The SPORTS time and space series extends from 1998 to 2016, forming a 19-yr dataset by the end of 2016.