Calendar of Daily Circulation Types for the northern Antarctic Peninsula (2012–2024)

This repository contains a calendar of circulation types, created using an objective classification scheme centered on 57.972°W, 63.569°N, based on the method proposed by Jenkinson and Collison (1977). The classification scheme used mean daily 850 hPa geopotential height fields from the ERA5 reanalysis (Hersbach et al. 2020) to calculate flow strength, flow direction, and vorticity. This approach enables a comprehensive understanding of the variable nature of lower-tropospheric pressure field in terms of both the airflow direction and (anti-)cyclonic character of the circulation type. In total, nine anticyclonic (A, AN, ANE, AE, ASE, ASW, AW, ANW) and nine cyclonic (C, CN, CNE, CE, CSE, CS, CSW, CW, CNW) circulation types were defined; unclassified days were attributed to type U. References: Jenkinson A, Collison F (1977) An initial climatology of gales over the north sea. Synoptic climatology branch memorandum. Meteorol Off 62. Hersbach H, Bell B, Berrisford P, Hirahara S, Horányi A, Muñoz-Sabater J, Nicolas J, Peubey C, Radu R, Schepers D, Simmons A, Soci C, Abdalla S, Abellan X, Balsamo G, Bechtold P, Biavati G, Bidlot J, Bonavita M, De Chiara G, Dahlgren P, Dee D, Diamantakis M, Dragani R, Flemming J, Forbes R, Fuentes M, Geer A, Haimberger L, Healy S, Hogan RJ, Hólm E, Janisková M, Keeley S, Laloyaux P, Lopez P, Lupu C, Radnoti G, De Rosnay P, Rozum I, Vamborg F, Villaume S, Thépaut J-N (2020) The ERA5 global reanalysis. Q J R Meteorol Soc 146(730):1999–2049. https://doi.org/10.1002/qj.3803