Abstract/Summary

The ERA5 new generation of high-resolution reanalysis provides a possibility to obtain more accurate cyclone tracks in the Southern Ocean. With a commonly used cyclone tracking algorithm, this study evaluates the impact of data resolution on the Southern Ocean cyclone tracks for the period from 1980 to 2020 by pre-processing the ERA5 dataset at different spatial and temporal resolutions. A new track matching method is proposed to assure an accurate comparison of different track data sets, considering the multiple match pairs and best match pair for each track. It is found that the number, distribution, and characteristics of cyclones are considerably different for various resolution scenarios. The higher spatial resolution captures more tracks, while the increased temporal resolution will decrease the number, as well as the lifetime and moving distance of tracks. The shared cyclones of different track data sets show different characteristics, influenced by both spatial and temporal resolutions. The additional track points of shared cyclones obtained by higher resolution are mainly at the end of the tracks and they have a consistent distribution pattern among the results of different resolution schemes. These results are a reference to the application of objective tracking algorithms in the Southern Ocean using input data with higher resolution.