TITAM (v1.0): the Time-Independent Tracking Algorithm for Medicanes

Abstract

Abstract. This work aims at presenting TITAM, a time-independent tracking algorithm specifically suited for medicanes. In the last decades, the study of medicanes has been repeatedly addressed given their potential to damage coastal zones. Their hazardous associated meteorological conditions have converted them to a major threat. Even though medicane similarities to tropical cyclones have been widely studied in terms of genesis mechanisms and structure, the fact that the former appear in baroclinic environments, as well as the limited extension of the Mediterranean basin, makes them prone to maintaining their warm-cored and symmetric structure for short time periods. Thus, the usage of a measure for the warm-core nature of the cyclone, namely the Hart conditions, is a key factor for successful identification of a medicane. Furthermore, given their relatively small spatial extent, medicanes tend to appear embedded in or to coexist with larger lows. Hence, the implementation of a time-independent methodology, avoiding the search for a medicane based on its location at previous time steps, seems to be fundamental when facing situations of cyclone coexistence. The examples selected showcase how the algorithm presented throughout this paper is useful and robust for the tracking of medicanes. This methodology satisfies the requirements expected for a tracking method of this nature, namely the capacity to track multiple simultaneous cyclones, the ability to track a medicane in the presence of an intense trough inside the domain, the potential to separate the medicane from other similar structures by handling the intermittent loss of structure, and the capability to isolate and follow the medicane center regardless of other cyclones that could be present in the domain. The complete TITAM package, including preprocessing and post-processing tools, is available as free software extensively documented and prepared for its deployment. As a final remark, this algorithm sheds some light on medicane understanding regarding medicane structure, warm-core nature, and the existence of tilting.