The University of Melbourne Cyclone Detection and Tracking Algorithm

This website hosts the University of Melbourne cyclone detection and tracking algorithm developed by Murray and Simmonds (1991). The code-base has been updated in 2020 by Science IT, and is actively maintained at the University of Melbourne.

• The algorithm is designed to track low-pressure systems mainly in the extratropics, but also some tropical cyclones can be detected.
• The cyclone detection scheme locates maxima in the Laplacian of either mean sea level pressure or geopotential height at any pressure level.
• The average inflection point around the cyclone centre is used to define a cyclone radius, which can be adopted as impact area of a cyclone.
• The scheme can also be used to detect and track anticyclones. This can easily be done by changing the sign of the pressure (or geopotential) field and searching for ‘lows’.

Note that this algorithm is provided without any warranty, any updated manual and is to be used for non-profit applications only. The algorithm can be downloaded here.

The following list of publications either describe the scheme or its application. Please use at least one of these publications, when you are publishing results obtained with the provided algorithm.

Description of scheme

Murray, R.J. and Simmonds, I., 1991a: A numerical scheme for tracking cyclone centres from digital data. Part I: Development and operation of the scheme. Aust. Met. Mag., 39, 155-166.

Murray, R.J. and Simmonds, I., 1991b: A numerical scheme for tracking cyclone centres from digital data. Part II: Application to January and July general circulation model simulations. Aust. Met. Mag., 39, 167-180.

Simmonds, I., Murray, R.J. and Leighton, R.M., 1999: A refinement of cyclone tracking methods with data from FROST. Aust. Met. Mag., Special Edition, 35-49.

Applications

Earl, N., I. Simmonds and I. Rudeva, 2019: Sub-synoptic-scale features associated with extreme surface gusts during the South Australia Storm of September 2016: Part I. Characteristics of the event. Weather, 74, 278-285, doi:10.1002/wea.3385.

Grieger, J., G. C. Leckebusch, C. C. Raible, I. Rudeva and I. Simmonds, 2018: Subantarctic cyclones identified by 14 tracking methods, and their role for moisture transports into the continent. Tellus, 70A, 1454808, doi:10.1080/16000870.2018.1454808.

Kouroutzoglou, J., H. A. Flocas, M. Hatzaki, K. Keay, I. Simmonds and A. Mavroudis, 2015: On the dynamics of a case study of explosive cyclogenesis in the Mediterranean. Meteorology and Atmospheric Physics, 127, 49-73, doi:10.1007/s00703-014-0357-x.

Rudeva, I., and I. Simmonds, 2015: Variability and trends of global atmospheric frontal activity and links with large-scale modes of variability. Journal of Climate, 28, 3311-3330, doi:10.1175/JCLI-D-14-00458.1.

Papritz, L., S. Pfahl, I. Rudeva, I. Simmonds, H. Sodemann and H. Wernli, 2014: The role of extratropical cyclones and fronts for Southern Ocean freshwater fluxes. Journal of Climate, 27, 6205-6224, doi:10.1175/JCLI-D-13-00409.1.

Ulbrich, U., et al., 2013: Are greenhouse gas signals of Northern Hemisphere winter extra-tropical cyclone activity dependent on the identification and tracking algorithm? Meteorologische Zeitschrift, 22, 61-68, doi:10.1127/0941-2948/2013/0420.

Kouroutzoglou, J., H. A. Flocas, K. Keay, I. Simmonds and M. Hatzaki, 2012: On the vertical structure of Mediterranean explosive cyclones. Theoretical and Applied Climatology, 110, 155–176, doi:10.1007/s00704-012-0620-3.

Simmonds, I., and I. Rudeva, 2012: The Great Arctic Cyclone of August 2012. Geophysical Research Letters, 39, L23709, doi:10.1029/2012GL054259.

Screen, J. A., I. Simmonds and K. Keay, 2011: Dramatic interannual changes of perennial Arctic sea ice linked to abnormal summer storm activity. Journal of Geophysical Research, 116, D15105, doi:10.1029/2011JD015847.

Irving, D., I. Simmonds and K. Keay, 2010: Mesoscale cyclone activity over the ice-free Southern Ocean: 1999-2008. Journal of Climate, 23, 5404–5420, doi:10.1175/2010JCLI3628.1.

Simmonds, I., C. Burke and K. Keay, 2008: Arctic climate change as manifest in cyclone behavior. Journal of Climate, 21, 5777-5796, doi:10.1175/2008JCLI2366.1.

Pezza, A. B., I. Simmonds and J. A. Renwick, 2007: Southern Hemisphere cyclones and anticyclones: Recent trends and links with decadal variability in the Pacific Ocean. International Journal of Climatology, 27, 1403-1419, doi:10.1002/joc.1477.

Simmonds, I., 2000: Size changes over the life of sea level cyclones in the NCEP reanalysis. Monthly Weather Review, 128, 4118-4125, doi:10.1175/1520-0493(2000)129%3C4118:SCOTLO%3E2.0.CO;2.

Simmonds, I., and K. Keay, 2000: Mean Southern Hemisphere extratropical cyclone behaviour in the 40-year NCEP-NCAR reanalysis. Journal of Climate, 13, 873-885, doi:10.1175/1520-0442(2000)013<0873:MSHECB>2.0.CO;2.

Simmonds, I., and K. Keay, 2000: Variability of Southern Hemisphere extratropical cyclone behaviour 1958-97. Journal of Climate, 13, 550-561, doi:10.1175/1520-0442(2000)013<0550:VOSHEC>2.0.CO;2.

Many people have contributed to the development of this scheme over the last three decades. These include in alphabetical order:

Ahmad Galea, Damien Irving, David Jones, Murray Keable, Kevin Keay, John Kouroutzoglou, Eun-Pa Lim, Michel Mesquita, Martina Messmer, Ross Murray, Acacia Pepler, Alex Pezza, Irina Rudeva, Petteri Uotila, and many more.