Climatic role of Southern Hemisphere extratropical cyclones and their relationship with sea ice

• Published in: Papers and Proceedings of the Royal Society of Tasmania
• Main Author: Simmonds, I
• Format: Article in Journal/Newspaper
• Language: English
• Published: 1996
• Subjects: Royal Society of Tasmania; RST; Van Diemens Land; natural history; science; ecology; taxonomy; botany; zoology; geology; geography; papers & proceedings; Australia; UTAS Library; Antarctic; The Antarctic; Antarc*; Sea ice
• Online Access: https://eprints.utas.edu.au/14437/; https://eprints.utas.edu.au/14437/4/1996-Simmonds-Southern_cyclones.pdf

Transient atmospheric systems play a central role in determining the climate of the high southern latitudes. Accordingly, the variability of these features and the mechanisms which cause it are important considerations for the (palaeo)climatologist. One element which might have been expected to be intimately tied up with cyclonic activity is the extent of sea ice encircling the Antarctic continent. We refer to studies which suggest relationships between sea ice and cyclones on synoptic time-scales, but in which these become very weak when interannual relationships are considered. We have analysed the reasons for this apparently contradictory behaviour. It is suggested that the intuitive appeal of an ice-cyclone connection has an implicit and characteristic time-scale (of a few hours or days) associated with it. However, the same reasoning cannot be applied to longer periods, because of the nonlinearities in the links between the two factors. This, in particular, cautions against the use of simplistic arguments when trying to estimate the locations of storm tracks during epochs when seaicc coverage was very different from that obtaining during the insttumental record.