Kelebek et al. (2026) Escalating Future Climate Extremes Across the Black Sea Basin Driven by Kilometer-Scale Scenario Simulations

Identification

• Journal: Earth Systems and Environment
• Year: 2026
• Date: 2026-04-06
• Authors: Mehmet Barış Kelebek, Barış Önol, Fulden Batibeniz
• DOI: 10.1007/s41748-026-01144-0

Research Groups

• Aeronautics and Astronautics Faculty, Department of Climate Science and Meteorological Engineering, Istanbul Technical University, Istanbul, Türkiye
• Oeschger Centre for Climate Change Research (OCCR), University of Bern, Bern, Switzerland
• Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland

Short Summary

This study utilizes kilometer-scale convection-permitting simulations to project future climate extremes across the Black Sea Basin under the SSP3-7.0 scenario, revealing significant increases in temperature extremes, accelerated snowmelt, and intensified daily and sub-daily precipitation, particularly in urban and mountainous hotspots.

Objective

• To evaluate the added value of convection-permitting simulations in representing temperature and precipitation extremes across the Black Sea Basin.
• To quantify projected changes in mean climate and extremes at seasonal to sub-daily timescales under a high-emission scenario.
• To diagnose the physical mechanisms driving future changes in regional climate extremes.

Study Configuration

• Spatial Scale: Black Sea Basin (BSB), encompassing 1641 km x 1092 km (547 x 364 grid points) at 3 km horizontal resolution.
• Temporal Scale: Historical period (2005–2014) and future period (2061–2070).

Methodology and Data

• Models used:
  • Weather Research and Forecasting (WRF) model Version 3.9.1 (convection-permitting, 3 km resolution).
  • CMIP6 Max Planck Institute Earth System Model version 1.2 (MPI-ESM1.2-HR) (driving Global Climate Model, 100 km resolution).
• Data sources:
  • Gridded Observations: Climate Hazards Group Infrared Precipitation with Stations (CHIRPS) (daily precipitation), Multi-Source Weighted-Ensemble Precipitation (MSWEP) version 2 (3-hourly and daily precipitation).
  • Reanalysis: ECMWF’s ERA5-Land (hourly data for daily precipitation, daily minimum and maximum temperatures), TerraClimate (monthly gridded minimum and maximum temperatures).
  • Station Observations: Turkish State Meteorological Service (TSMS) station observations (for validation, especially at high-elevation sites).

Main Results

• Convection-permitting simulations (WRFCP) significantly reduce bias in near-surface temperatures (~2 °C) compared to the coarse-resolution MPI-ESM1.2-HR, especially at high-elevation sites.
• WRFCP realistically represents extreme daily and sub-daily precipitation, capturing events exceeding 50 mm/3 h and 100 mm/day, aligning well with gridded observations.
• Future projections indicate a basin-wide warming, with daily maximum temperatures increasing up to 7 °C in March over the Upper Euphrates Basin.
• This warming accelerates snowmelt, leading to a ~20% decline in spring snow cover and a ~10% decrease in surface albedo over Eastern Anatolia, intensifying elevation-dependent warming through snow–albedo feedback.
• The frequency of extremely warm days (TX90P) is projected to increase by up to 28% over Eastern Anatolia, and heatwave duration (HWDI) is amplified to approximately 55 days per year in the same region.
• Precipitation extremes intensify basin-wide, with daily maximums projected to exceed 500 mm in Georgia and Romania, and sub-daily totals reaching up to 100 mm/3 h.
• The Istanbul metropolitan area is identified as a hotspot, where daily maximum precipitation is projected to more than double (from ~210 mm to ~437 mm).
• Winter precipitation increases by nearly 50% along the eastern Black Sea coast and Georgia, and by about 20% along Türkiye's northern coast, primarily driven by enhanced moisture transport and air-sea interactions.
• The contribution of extreme precipitation to total seasonal precipitation (R90PTOT) increases from ~30% to 45% in winter (eastern Black Sea, Georgia) and from 35% to 50% in autumn (broader Black Sea region).

Contributions

• This study provides the first kilometer-scale (3 km) convection-permitting climate simulations for the Black Sea Basin, driven by CMIP6 MPI-ESM1.2-HR outputs under the SSP3-7.0 scenario, covering an extended domain.
• It demonstrates the crucial added value of convection-permitting models in accurately capturing fine-scale climate processes, land–atmosphere interactions, and the intensity and spatial organization of temperature and precipitation extremes over complex terrain and urban areas.
• The research offers robust and consistent projections essential for climate risk assessment, adaptation planning, and enhancing infrastructure resilience across the Black Sea Basin, particularly for vulnerable regions and urban centers like Istanbul.
• It diagnoses key physical mechanisms, such as snow-albedo feedback and changes in atmospheric circulation and moisture transport, that drive future climate extreme changes in the region.

Funding

The authors declare that no funds, grants, or other financial support were received during the preparation of this manuscript.

Citation

@article{Kelebek2026Escalating,
  author = {Kelebek, Mehmet Barış and Önol, Barış and Batibeniz, Fulden},
  title = {Escalating Future Climate Extremes Across the Black Sea Basin Driven by Kilometer-Scale Scenario Simulations},
  journal = {Earth Systems and Environment},
  year = {2026},
  doi = {10.1007/s41748-026-01144-0},
  url = {https://doi.org/10.1007/s41748-026-01144-0}
}