TITAM (v1.0): Time Independent Tracking Algorithm forMedicanes

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 in a major threat. Even though their similarities with tropical cyclones have been studied in terms of genesis mechanisms and structure, the fact that the former ones appear in baroclinic environments make them prone to temporarily lose their warm-cored and symmetric structure. Thus, the usage of a measure for the warm-core nature of the cyclone, namely the Hart conditions, stands as a key factor for a successful identification of the 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 of a medicane basing on its location at previous time steps seems to be fundamental when facing situations of cyclones 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 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 pre and post processing tools, is available as a free software extensively documented and prepared for its deployment. As a final remark, this algorithm sheds some light on the medicanes understanding, regarding the medicane structure, the warm-core nature and the existence of tilting.