Radar‐based climatology of damaging hailstorms in Brisbane and Sydney, Australia

Abstract

Severe hailstorms represent some of Australia's most costly natural disasters. In particular, the densely populated east‐coast cities of Brisbane and Sydney have both been impacted by events that individually produced over AU$1 billion in insured losses. In this study, the frequency of damaging hailstorms in these regions is assessed over an eight‐year period using single‐polarisation radar observations. Reflectivity data from multiple radars are carefully calibrated and merged to produce daily grids of MESH (the maximum expected size of hail) at 1 km spatial resolution. Neighbourhood contingency tables are then used to define an optimal MESH threshold for identifying damaging hail events. This analysis makes use of a unique insurance dataset, comprising building‐scale exposure and claim data over a multi‐year period. Overall, damaging hailstorms occur on an average of 26 and 32 days per year in the Brisbane and Sydney regions, respectively. The actual cities of Brisbane and Sydney both experience about five damaging hailstorms annually. In both regions, the highest hail frequencies occur along the coastal slopes of the Great Dividing Range, with more localised maxima highlighting the potential role of mesoscale circulations in storm initiation and intensification. For Brisbane, the seasonal cycle shows a pronounced peak in December, while in Sydney hail frequencies are high throughout the warm season (November–March). This difference reflects the distinct seasonal cycles of convective instability in the two regions. Consistent with previous studies, the combination of CAPE and deep‐layer shear is found to provide reasonable discrimination of environments conducive to severe hailstorms.

An object-based climatology of precipitation systems in Sydney, Australia

“…2). This is in agreement with the previous studies over Australia reporting that severe thunderstorms are most prevalent in the warm seasons (Niall and Walsh 2005;Schuster et al 2005;Davis and Walsh 2008;Warren et al 2020). The extreme summer and spring systems in terms of rainfall intensity are more intense when they are raining over land between 10:00 to 20:00 (AEST; peaking in the afternoon) compared to when they are raining over the ocean, consistent with previous studies looking at thunderstorms (Griffiths et al 1993) and hailstorms (Schuster et al 2005) over Sydney, using weather reports.…”

“…However, this time frame is long enough to conduct climatological studies. Previous researchers have employed these datasets to study the climatology of precipitation systems over specific regions such as the United States (Ghebreyesus and Sharif 2020; Kuo and Orville 1973;Croft and Shulman 1989;Falconer 1984;Cintineo et al 2012;Murillo et al 2021), Europe (Kaltenboeck and Steinheimer 2015;Kreklow et al 2020;Weckwerth et al 2011;Overeem et al 2009;Bližňák et al 2018;Fairman Jr et al 2015;(Junghänel et al 2016;Nisi et al 2016;Fluck et al 2021;Lukach et al 2017;Saltikoff et al 2010), Asia and Australia (Chen et al 2012;Warren et al 2020;Dowdy et al 2020). A limitation of the previous radar-based studies is that they often employed a pixel-based statistical approach which limits the storm properties to rainfall/hail frequency and intensity as a function of position.…”

Hailstorm Detection by Satellite Microwave Radiometers

“…Ground-based approaches are more numerous and dwell on hailpad networks (e.g., [15]), statistics using large-scale environmental conditions [16], or radar data (e.g., [17][18][19]. Recently a physically based stochastic event catalog of hail occurrence over Europe [20] and a radar-based climatology of damaging hailstorms in Brisbane and Sydney [21] were published.…”

Etika Lingkungan Perspektif Hukum Islam

“…Selain itu, ilmu pengetahuan dan teknologi yang dikembangkan dalam bidang antariksa dan militer [20][21] tidak jarang menyebabkan terjadinya eksploitasi energi, sumber daya alam dan lingkungan [22][23] yang dilakukan demi memenuhi berbagai produk yang dibutuhkan manusia. Fenomena memanasnya bola bumi [24] akibat efek rumah kaca [25], menipisnya lapisan ozone [26], meluasnya gurun [27], dan menyusutnya luas hutan tropis [28], serta melumernnya lapisan es di kutub utara dan selatan bumi [29] dapat dijadikan indikasi terjadinya pencemaran lingkungan kerena penggunaan energi dan bahan kimia secara tidak seimbang. Tidak hanya itu, adanya indikasi yang memperlihatkan tidak terkendalinya polusi dan pencemaran lingkungan akibat banyaknya zat buangan dan limbah industri, serta rumah tangga yang memperlihatkan ketidakpedulian terhadap lingkungan sekitar.…”