Tropical Upper-Ocean Thermal Structure Variability during the Atlantic Hurricane Season

Climatological profiles of temperature are key to studying variability of the world's oceans. Accurate climatology provides a baseline representation of the ocean thermal structure, and variance shows areas where departure from climatology is typically large or small. Understanding how the upper-ocean thermal structure changes, particularly in the top 300 meters, provides insight into potential coupled effects of the ocean and atmosphere during events such as tropical cyclone passage. However, at present, basin-specific temperature climatologies are incomplete or outdated despite hundreds of thousands of upper-ocean point observations since 1950.

To take advantage of these observations, a gridded 1^o x 1^o vertical temperature profile climatology is created for the Gulf of Mexico, western Atlantic Ocean and Caribbean Sea from historical observations archived in the Master Oceanographic Observation Data Set. The individual temperature profile observations were collected between 1960 -2009, and the resultant gridded climatology is organized by month. Linear interpolation was used to construct temperature versus depth profiles with 1-m vertical resolution at every grid point. From those temperature profiles, key oceanographic parameters were calculated, including ocean heat content, depth of the 26^oC isotherm, and temperatures at 50-, 100-, 150- and 300-m depths. Variance of ocean heat content within each grid box was calculated, revealing large variances in sub-surface areas. Results are compared to observations from case studies of Hurricanes Ernesto and Isaac (2012).