The Systematically Merged Atlantic Regional Temperature and Salinity (SMARTS) Climatology for satellite derived ocean thermal structure

A new oceanic climatology to calculate ocean heat content (OHC) was developed for application during the Atlantic hurricane season. The Systematically Merged Atlantic Regional Temperature and Salinity (SMARTS) Climatology blends temperature and salinity fields from the World Ocean Atlas 2001 (WOA) and Generalized Digital Environmental Model v.3.0 (GDEM) at 1/4º resolution. This higher resolution climatology better resolves features in the Gulf of Mexico (GOM), including the Loop Current and eddy structures, than the previous coarser 1/2º products.

SMARTS was calculated from the monthly GDEM and WOA climatologies by applying a 15-day running average to eliminate discontinuities when transitioning between months. Daily mean isotherm depths of the 20ºC (D20) and 26ºC (D26) (and their mean ratio), reduced gravity, mixed layer depth (MLD), and OHC were estimated from the blended climatology. Using SMARTS with satellite-derived surface height anomaly and SST fields, daily values of D20, D26, MLD, and OHC have been calculated from 1998 to 2009 using a two-layer model approach. Airborne and ship-deployed eXpendable BathyThermographs (XBT), long-term moorings, and Argo profiling floats provide the in-situ data to assess the SMARTS Climatology.

In developing SMARTS, upper ocean drift velocities are estimated regionally from satellite altimetry. Drift velocity can then be included in the objective analysis technique for multiple days of altimetry data, leading to an improved OHC calculation. A better estimation of OHC and ocean thermal structure can be used in hurricane intensity forecasts from the Statistical Hurricane Intensity Prediction Scheme.