Employing the Advanced Dvorak Technique to Deduce Historical Trends in Global Tropical Cyclone Intensity

The Advanced Dvorak Technique (ADT) is an objective, satellite-based algorithm principled on the long-standing operational (but somewhat subjective) Dvorak Technique (DT) for estimating tropical cyclone (TC) intensity. The ADT was designed with real-time applications in mind, and normally operates on high space and time resolution imagery. Very recently, the ADT was made operational at the NOAA/NESDIS Satellite Analysis Branch, and is used extensively by the National Hurricane Center and other global TC analysis centers.

While the ADT is primarily an operational tool, the combination of its robust performance in all TC stages, ease of application, and unbiased/objective nature make it attractive for other investigations of TC intensity behavior. For example, analysis of historical tropical cyclone intensities can be used to detect global trends related to climate change. One approach to analyze these trends is to utilize intensity estimates deduced from available observations (imagery) during the geostationary satellite era. And for this, the ADT is a natural candidate.

In this study we apply the ADT to a TC-centric satellite dataset from 1982-2009 that has been subsampled in space and time to be globally homogeneous (referred to as HURSAT). Although the HURSAT imagery has been subsampled to 8km spatial resolution and 3-h spacing, the ADT is found to perform very well in depicting decadal trends of lifetime maximum intensity (LMI) for global tropical cyclones. Examples of the ADT handling of historical cases will be presented in the poster.