Models, Regression & Outliers, Oh My !
The tropical cyclone heat potential (hereafter TCHP), is defined as a measure of the integrated vertical temperature from the sea surface to the depth of the 26°C isotherm. This parameter is computed globally from the altimeter-derived vertical temperature profiles estimates in the upper ocean (Shay et al., 2000). Different methods have been developed to calculate this vertical thermal structure of the upper ocean. Up to three different procedures have been developed at NOAA/AOML for this purpose. In chronological order, the first TCHP fields were obtained using a reduced-gravity model (Version 1.0). In May 2005, a second algorithm based on linear regression analysis (Version 2.0) was implemented and all the fields available through this website were updated accordingly. Finally, in October 2008, a third approach was put into service, in order to provide better agreement with observations and remove outliers mainly affecting the Gulf of Mexico and Central Pacific regions (Version 2.1).
Comparing El Ninos, or, apples and oranges ?