Practical investigation of climate extremes and IDF curves under climate change with applications of SSP scenarios (case study: Silakhor Plain, Iran)

Abstract

It is necessary to assess climate extremes under conditions of climate change to avoid irreversible damage caused by catastrophic events. This assessment is beneficial for developing mitigation strategies. The Coupled Model Intercomparison Project Phase 6 (CMIP6) models exhibit the latest advancements in climate change modeling. This study aims to project future variations of climate extremes in the Silakhor plain using a single general circulation model (GCM) considering two emission scenarios: SSP2-4.5 and SSP5-8.5. Climate extreme indices were extracted by downscaling outputs from GCMs using LARS-WG. This study incorporates a practical evaluation of climate extremes and intensity duration frequency (IDF) curves. It focuses on identifying peak over threshold temperatures that impact health and agriculture. It also conducts a detailed examination of the characteristics of wet spells. For sub-daily assessment of extreme precipitation, this paper addresses the challenge of extracting IDF curves from daily LARS-WG data by driving Bell’s equation for study aria. The projections suggest a higher intensity across all climate extremes except for frost waves. Heatwaves showed a potential increasing trend in duration and intensity across all scenarios, reaching critical red Lines for health and agriculture. The frequency of wet spells is projected to decline under all scenarios. Nevertheless, the near-future projections showed that the probability and intensity of shorter wet spells have increased by 3.2% and 1.6 \(\left(\mathrm{mm}/\mathrm{day}\right)\) under the SSP5-8.5 scenario, respectively. IDF curves shifted in favor of increasing the intensity of sub-daily extreme precipitation. The results also reinforce the theory that the intensity of all tested climate extreme indices are sensitive to the amount of greenhouse gas emissions in each scenario.