Impact of climate change on extreme temperature events in Australia

  • Orpita Laz

Western Sydney University thesis: Doctoral thesis

Abstract

Due to global climate change, temperature is increasing; however, its spatial and temporal distribution and trend vary across regions. This tendency of warming of the climate system will intensify the extreme temperature events, such as individual events related to heatwaves and droughts, as well as compound events like combined effect of heatwaves and droughts. These changes in extreme temperature events pose a significant challenge to public health policymakers and disaster managers. There has been limited research on extreme temperature events in Australia, in particular on design temperatures in the form of temperature-durationfrequency (TDF) curves. To fill the current knowledge gap, this study focuses on three aspects (i) trend and teleconnection analysis of temperature extremes in New South Wales (NSW), Australia; (ii) assessment of the impacts of climate change and variability on design temperature using data from all over Australia; and (iii) detection of compound heatwave and drought (CHD) hotspots and their trends in Southeast Australia. A total of 26 weather stations were used from NSW region for analysing trends of extreme temperature events (i.e., hot days, hot nights and heatwaves). Mann-Kendall (MK) and Sen's slope estimator were applied to assess trends of extreme days and heatwaves. One of the main aims of this study was to characterise the heatwaves in the NSW region for the period 1971- 2021 for three different durations (1-, 5- and 10-days). It is evident that extreme temperature events, such as hot nights, hot days and heatwaves, exhibited an increasing trend over Australia in the last decade compared to the historical trends. This research also showed similar trends for the compound heatwaves and droughts (CHDs) that occurred throughout southeast Australia. In addition, the first occurrence of the HWs is being shifted towards the onset of the extended summer in Australia. In this research, stationary TDF curves have been constructed for Australia. Also, the importance of considering the nonstationarity in the construction of TDF curves has been highlighted; including non-stationarity led to a better model with more realistic design temperature estimates.
Date of Award2023
Original languageEnglish
Awarding Institution
  • Western Sydney University
SupervisorAtaur Rahman (Supervisor)

Keywords

  • Climatic changes
  • Climatic extremes
  • Heat waves (Meteorology)
  • Droughts
  • Atmospheric temperature

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