Regionalization of anthropogenically forced changes in 3 hourly extreme precipitation over Europe

Parisa Hosseinzadehtalaei,Hossein Tabari,Patrick Willems

doi:10.1088/1748-9326/ab5638

Parisa Hosseinzadehtalaei, Hossein Tabari + Show 1 more

Open Access

https://doi.org/10.1088/1748-9326/ab5638

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Abstract

Future extreme precipitation events are expected to be influenced by climate change; however, the robustness of this anthropogenically forced response in respect to projection uncertainty especially for sub-daily extremes is not fully understood. We analyze the impact of anthropogenic climate change on 3 hourly extreme precipitation with return periods ranging between 5 and 50 years over Europe using the RCA4 model ensemble simulations at 0.11° resolution. The robustness of the signals is examined based on a regionalized signal-to-noise (S2N) technique by taking the spatial pooling into account and the efficacy of the regionalization is tested by a sensitivity analysis. The results show an increasing signal in 3 hourly extreme precipitation over Europe for all seasons except summer for which a bipolar pattern (increase in the north and decrease in the south) is discerned. For the business-as-usual scenario RCP8.5, the regionalized winter 3 hourly extreme precipitation signals over 9 × 9 model grid cells are statistically significant in roughly 72%, 65%, 59% and 48% of the European area for 5, 15, 25 and 50 year return periods respectively, while 16%–21% of the area will experience significant changes in summer. The S2N values for 3 hourly extreme precipitation changes rise after the spatial pooling by about a factor of 1.4–1.7 for all seasons except summer when they decline by about a factor of 0.78. The results of sensitivity analysis reveal that the regionalization influence is sensitive—in order of decreasing importance—to season, precipitation time scale, precipitation intensity, emission scenario and model spatial resolution. The precipitation time scale is particularly important seasonally in summer and regionally in south Europe when/where short-duration convective precipitation is dominant.

Highlights

An intensification of extreme precipitation is projected by climate models by the end of the 21st century (e.g., Willems et al 2012, IPCC 2013, Scoccimarro et al 2013, Fischer et al 2013, Pendergrass and Hartmann 2104, Donat et al 2016, Wang et al 2017, Prein et al 2017, Hosseinzadehtalaei et al 2017, Kendon et al 2018)
The results indicate that 3-hourly extreme precipitation is projected to intensify in winter, spring and autumn for most of Europe for both RCP4.5 and RCP8.5 with more pronounced changes for RCP8.5
The results indicate that the 3-hourly extreme precipitation changes are more significant and robust on applying the spatial pooling across all seasons and return periods for both RCPs compared to daily precipitation

Summary

Introduction

An intensification of extreme precipitation is projected by climate models by the end of the 21st century (e.g., Willems et al 2012, IPCC 2013, Scoccimarro et al 2013, Fischer et al 2013, Pendergrass and Hartmann 2104, Donat et al 2016, Wang et al 2017, Prein et al 2017, Hosseinzadehtalaei et al 2017, Kendon et al 2018). This intensification is due to several factors.

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