Anticyclone tracks from ERA5, CMIP5, and Australian RCMs

This folder contains anticyclone tracks generated for Pepler (2022) These anticyclones were identified using the Murray and Simmonds (1991) and Simmonds et al. (1999) cyclone tracking scheme, and tracked on 6 hourly MSLP regridded to a constant polar stereographic grid with an approximate resolution of 1.5 degrees at 30S. The source code and documntation is available at https://cyclonetracker.earthsci.unimelb.edu.au/ Tracks are provided for ERA5 during 1979-2021 and for 10 CMIP5 models globally and 12 RCMs for the Australian region (based on CCAM, WRF/NARCliM, and BARPA) from historical simulations for 1979-2005, and rcp85 for 2006-2009 and 2070-2099 For more details on the parameters used for detection and tracking see the files *incycloc and *intrack which are used as inputs for the tracking scheme. A separate track file is provided for each year, beginning on 1 December of the previous year, to allow for the identification of cross-year tracks when relevant. Column headings: ID Track ID Fix Instance within track Date Date* (UTC) Time Time (UTC) Open/closed Is there closed circulation (0) or an "open" ridge. Not used. Lon Longitude Lat Latitude MSLP Central pressure (hPa) Laplacian Laplacian of MSLP (hPa. Deg.lat^2), which represents the curvature of the MSLP. This is a better indicator of the strength of a system Depth Depth of anticyclone (hPa) Radius Radius of anticyclone (degrees) Up Steering velocity (U) Vp Steering velocity (V) *Dates are two digit years, and in some cases are wrong because of the way the tracking scheme works (e.g. 1999-2001). References: Murray, R. J., and I. Simmonds, 1991: A numerical scheme for tracking cyclone centres from digital data. Part I: Development and operation of the scheme. Aust. Meteorol. Mag., 39, 155166. Simmonds, I., R. J. Murray, and R. M. Leighton, 1999: A refinement of cyclone tracking methods with data from FROST. Aust. Meteorol. Mag., (special edition), 3549. Pepler (2022). Projections of synoptic anticyclones for the 21st century. In prep