Objective tropical cyclone extratropical transition detection in high-resolution reanalysis and climate model data

The algorithm is based on previous observational studies using phase spaces to define the symmetry and vertical thermal structure of cyclones. Storm tracking is automated, allowing for direct analysis of climate data.

Tracker performance in the North Atlantic is assessed using 23 years of data from the variable-resolution Community Atmosphere Model (CAM) at two different resolutions (Delta X similar to 55 km and 28 km), the Climate Forecast System Reanalysis (CFSR, Delta X similar to 38 km), and the ERA-Interim Reanalysis (ERA-I, Delta X similar to 80 km). The mean spatiotemporal climatologies and seasonal cycles of objectively detected ET in the observationally constrained CFSR and ERA-I are well matched to previous observational studies, demonstrating the capability of the scheme to adequately find events.