Preprint Article Version 1 Preserved in Portico This version is not peer-reviewed

Frequency of compound hot-dry weather extremes has significantly increased in Australia since 1889

Version 1 : Received: 29 January 2021 / Approved: 1 February 2021 / Online: 1 February 2021 (11:28:38 CET)

How to cite: Collins, B. Frequency of compound hot-dry weather extremes has significantly increased in Australia since 1889. Preprints 2021, 2021020012 (doi: 10.20944/preprints202102.0012.v1). Collins, B. Frequency of compound hot-dry weather extremes has significantly increased in Australia since 1889. Preprints 2021, 2021020012 (doi: 10.20944/preprints202102.0012.v1).

Abstract

There is high confidence that climate change has increased the probability of concurrent temperature-precipitation extremes, changed their spatial-temporal variations, and affected the relationships between drivers of such natural hazards. However, the extent of such changes has been less investigated in Australia. Daily weather data (131 years, 1889-2019) at 700 grid cells (1◦ × 1◦) across Australia was obtained to calculate annual and seasonal mean daily maximum temperature (MMT) and total precipitation (TPR). A nonparametric multivariate copula framework was adopted to estimate the return period of compound hot-dry (CHD) events based on an ‘And’ hazard scenario (hotter than a threshold ‘And’ drier than a threshold). CHD extremes were defined as years with joint return periods of larger than 25 years. Mann-Kendall nonparametric tests was used to analyse trends in MMT and TPR as well as in the frequency of univariate and CHD extremes. A general cooling-wetting trend was observed over 1889-1989. Significant increasing trends were detected over 1990-2019 in the frequency and severity of hot extremes across the country while trends in dry extremes were mostly insignificant (and decreasing). Results showed a significant increase in the association between temperature and precipitation at various temporal scales. The frequency of CHD extremes was mostly stable over 1889-1989, but significantly increased between 1990 and 2019 at 44% of studied grid cells, mostly located in the north, south-east and south-west. Spatial homogeneity (i.e. connectedness) and propagation of extreme events from one grid cell to its neighbouring cells was investigated across Australia. It can be concluded that this connectedness has not significantly changed since 1889.

Subject Areas

Climate change; Mann-Kendall test; Moran’s I statistic; Nonparametric copula; Spatial homogeneity; Trend analysis.

Comments (0)

We encourage comments and feedback from a broad range of readers. See criteria for comments and our diversity statement.

Leave a public comment
Send a private comment to the author(s)
Views 0
Downloads 0
Comments 0
Metrics 0


×
Alerts
Notify me about updates to this article or when a peer-reviewed version is published.
We use cookies on our website to ensure you get the best experience.
Read more about our cookies here.