Abstract
This paper brings a new perspective on the large scale dynamics of severe heat wave (HW) events that commonly affect southern Australia. Through an automatic tracking scheme, the cyclones and anticyclones associated with HWs affecting Melbourne, Adelaide and Perth are tracked at both the surface and upper levels, producing for the first time a synoptic climatology that reveals the broader connections associated with these extreme phenomena. The results show that a couplet (or pressure dipole) formed by transient cyclones and anticyclones can reinforce the HW similarly to what is observed in cold surges (CS), with an obvious opposite polarity. Our results show that there is a large degree of mobility in the synoptic signature associated with the passage of the upper level ridges before they reach Australia and the blocking is established, with HW-associated surface anticyclones often initiating over the west Indian Ocean and decaying in the eastern Pacific. In contrast to this result the 500 hPa anticyclone tracks show a very small degree of mobility, responding to the dominance of the upper level blocking ridge. An important feature of HWs is that most of the cyclones are formed inland in association with heat troughs, while in CS the cyclones are typically maritime (often explosive), associated with a strong cold front. Hence the influence of the cyclone is indirect, contributing to reinforce the blocking ridge through hot and dry advection on the ridge’s western flank. Additional insights are drawn for the record Adelaide case of March 2008 with fifteen consecutive days above 35°C breaking the previous record by 7 days. Sea surface temperatures suggest a significant air-sea interaction mechanism, with a broad increase in the meridional temperature gradient over the Indian Ocean amplifying the upstream Rossby waves that can trigger HW events. A robust cooling of the waters close to the Australian coast also contributes to the maintenance of the blocking highs locally, which is a fundamental ingredient to sustain the HWs.
Similar content being viewed by others
References
Anderson CA (1987) Temperature and aggression: effects on quarterly, yearly, and city rates of violent and nonviolent crime. J Personal Soc Psychol 52(6):1161–1173
Ashcroft L, Pezza AB, Simmonds I (2009) Cold events over southern Australia: synoptic climatology and hemispheric structure. J Clim 22:6679–6698
Black E, Blackburn M, Harison G, Hoskins B, Methven J (2004) Factors contributing to the summer 2003 heatwave. Weather 59:217–223
Cai WJ, Cowan TD (2008a) Evidence of impacts from rising temperature on inflows to the Murray-Darling Basin. Geophys Res Lett 35:L07701. doi:10.1029/2008GL033390
Cai WJ, Cowan TD (2008b) Dynamics of late autumn rainfall reduction over southeastern Australia. Geophys Res Lett 35:L09708. doi:10.1029/2008GL033727
Cai WJ, Cowan TD, Raupach MR (2009) Positive Indian Ocean Dipole events precondition southeast Australia bushfires. Geophys Res Lett 36:L19710. doi:10.1029/2009GL039902
Carril AF, Gualdi S, Cherchi A, Navarra N (2008) Heatwaves in Europe: areas of homogeneous variability and links with the regional to large-scale atmospheric and SSTs anomalies. Clim Dyn 30:77–98
De Bono A, Giuliani G, Kluser S, Peduzzi P (2004) Impacts of summer 2003 heat wave in Europe. UNEP/DEWA/GRID Eur Environ Alert Bull 2:1–4
Della-Marta PM, Luterbacher J, von Weissenfluh H, Xoplaki E, Brunet M, Wanner H (2007) Summer heat waves over western Europe 1880–2003, their relationship to large-scale forcings and predictability. Clim Dyn 29:251–275
Egger J (1978) Dynamics of blocking highs. J Atmos Sci 35:1788–1801
Fink A, Brucher T, Kruger A, Leckebusch G, Pinto J, Ulbrich U (2004) The 2003 European summer heatwaves and drought–synoptic diagnosis and impacts. Weather 59:209–216
Fischer EM, Seneviratne SI, Luthi D, Schär C (2007) Contribution of land-atmosphere coupling to recent European summer heat waves. Geophys Res Lett 34:L06707. doi:10.1029/2006GL029068
Fouillet A, Rey G, Laurent F, Pavillon G, Bellec S, Guihenneuc-Jouyaux C, Clavel J, Jougla E, Hémon D (2006) Excess mortality related to the August 2003 heat wave in France. Int Arch Occup Environ Health 80:16–24
Hansen A, Bi P, Nitschke M, Ryan P, Pisaniello D, Tucker G (2008) The effect of heat waves on mental health in a temperate Australian city. Environ Health Perspect 116:1369–1375. doi:10.1289/ehp.11339
IPCC (2007) Climate change 2007: the physical science basis. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds) Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, 996 pp
Jones DA, Simmonds I (1993) A climatology of Southern Hemisphere extratropical cyclones. Clim Dyn 9:131–145
Jones DA, Simmonds I (1994) A climatology of Southern Hemisphere anticyclones. Clim Dyn 10:333–348
Kysely J (2007) Implications of enhanced persistence of atmospheric circulation for the occurrence and severity of temperature extremes. Int J Clim 27:689–695. doi:10.1002/joc.1478
Kysely J (2009) Recent severe heat waves in central Europe: how to view them in a long-term prospect? Int J Clim 30:89–109. doi:10.1002/joc.1874
Medina-Ramón M, Zanobetti A, Cavanagh DP, Schwartz J (2006) Extreme temperatures and mortality: assessing effect modification by personal characteristics and specific cause of death in a multi-city case-only analysis. Environ Health Perspect 114:1331–1336
Meehl GA, Tebaldi C (2004) More intense, more frequent, and longer lasting heat waves in the 21st century. Science 305:994–997
Murphy BF, Simmonds I (1993) An analysis of strong wind events simulated in a GCM near Casey in the Antarctic. Mon Weather Rev 121:522–534
Murray RJ, Simmonds I (1991) A numerical scheme for tracking cyclone centres from digital data. Part I: development and operation of the scheme. Aust Meteorol Mag 39:155–166
Nogueira P, Paixão E (2007) Models for mortality associated with heatwaves: update of the Portuguese heat health warning system. Int J Climatol. doi:10.1002/joc.1546
Pezza AB, Ambrizzi T (2003) Variability of Southern Hemisphere cyclone and anticyclone behavior: further analysis. J Clim 16:1075–1083
Pezza AB, Ambrizzi T (2005) Dynamical conditions and synoptic tracks associated with different types of cold surges over tropical South America. Int J Climatol 25:215–241
Reeder M (2010) Contemporary problems in fire weather and fire behaviour. In: AMOS 17th annual conference, Canberra, 27–29 January
Simmonds I, Keay K (2000) Variability of Southern Hemisphere extratropical cyclone behavior, 1958–1997. J Clim 13:550–561
Simmonds I, Murray RJ (1999) Southern extratropical cyclone behavior in ECMWF analyses during the FROST special observing periods. Weather Forecast 14:878–891
Simmonds I, Richter T (2000) Synoptic comparison of cold events in winter and summer in Melbourne and Perth. Theor Appl Climatol 67:19–32
Simmonds I, Murray RJ, Leighton RM (1999) A refinement of cyclone tracking methods with data from FROST. Aust Meteorol Mag 35–49
Sturman A, Tapper N (2008) The weather and climate of Australia and New Zealand, 2nd edn. Oxford Press, 541 pp
Trenberth KE, Jones PD, Ambenje P, Bojariu R, Easterling D, Klein Tank A, Parker D, Rahimzadeh F, Renwick JA, Rusticucci M, Soden B, Zhai P (2007) Observations: surface and atmospheric climate change. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds) Climate change 2007: the physical science basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK and New York, NY, USA
Verdon-Kidd DC, Kiem AS (2009) Nature and causes of protracted droughts in southeast Australia: comparison between the Federation, WWII, and Big Dry Droughts. Geophys Res Lett 36:L22707. doi:10.1029/2009GL041067
Wiedenmann JM, Lupo AR, Mokhov II, Tikhonova EA (2002) The climatology of blocking anticyclones for the Northern and Southern Hemisphere: blocking intensity as a diagnostic. J Clim 15:3459–3473
Acknowledgments
Parts of this work were made possible with funding from the Australian Research Council to Ian Simmonds. We also thank Blair Trewin and the Australian Bureau of Meteorology for making the station data and Fig. 1 available. We also thank two anonymous reviewers for useful comments and discussion.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Pezza, A.B., van Rensch, P. & Cai, W. Severe heat waves in Southern Australia: synoptic climatology and large scale connections. Clim Dyn 38, 209–224 (2012). https://doi.org/10.1007/s00382-011-1016-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00382-011-1016-2