Obtaining refined Euro-Mediterranean rainfall projections through regional assessment of CMIP6 General Circulation Models

IF 4 1区地球科学 Q1 GEOGRAPHY, PHYSICAL

Global and Planetary Change Pub Date : 2025-01-22 DOI:10.1016/j.gloplacha.2025.104725

Giovanni-Breogán Ferreiro-Lera, Ángel Penas, Sara del Río

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引用次数: 0

Abstract

Despite the European Mediterranean Region (Euro-Med) being highly vulnerable to climate change the evaluation of General Circulation Models (GCMs) is limited in this region. This research aims to enhance Euro-Med rainfall projections by employing an optimized spatial assessment of 34 CMIP6 GCMs. Firstly, GCMs were interpolated to a common 0.1° grid, matching ERA Land, the reference dataset. Empirical Bayesian Kriging was identified as the most suitable technique, exhibiting the lowest error between raw and interpolated data. After that, annual rainfall interpolated data were compared against ERA5 Land. The performance of GCMs was assessed using five different goodness-of-fit metrics: Normalized Root Mean Squared Error, Nash–Sutcliffe Efficiency, Kling–Gupta Efficiency, Coefficient of Correlation and modified index of agreement. CanESM5, CAS-ESM2-0, UKES-M1-1-LL, HadGEM-GC31-LL, MPI-ESM1-2-HR, and GISS-E2-2-G were identified as the top performers. The Multi-Model Ensemble was created assembling these six GCMs through Random Forest (RFE), since it was found that it discriminates local under or overestimations in GCMs. RFE was used for short-term (2026-2050), medium-term (2051-2075), and long-term (2076-2100) projections under three emission scenarios: SSP1-2.6, SSP2-4.5, and SSP5-8.5. Results indicate a projected decrease in annual rainfall in southern areas, accompanied by more notable declines in summer and autumn. On the contrary, the Alps, particularly the Austrian Alps, show resilience to summer stress, with some regions even showing increases in rainfall. Additionally, there is a noticeable north-south pattern in spring and winter. Finally, anomalies were compared against those reported by IPCC, detecting a potentially drier summer, spring and annual yield, and a wetter winter and autumn. The study provides valuable insights into GCM performance in the Euro-Med, offering a robust foundation for improved future rainfall projections and a reduction in associated uncertainties, crucial for climate change adaptation strategies in the European Mediterranean Region.

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来源期刊

Global and Planetary Change 地学天文-地球科学综合

CiteScore

7.40

自引率

10.30%

发文量

226

审稿时长

63 days

期刊介绍： The objective of the journal Global and Planetary Change is to provide a multi-disciplinary overview of the processes taking place in the Earth System and involved in planetary change over time. The journal focuses on records of the past and current state of the earth system, and future scenarios , and their link to global environmental change. Regional or process-oriented studies are welcome if they discuss global implications. Topics include, but are not limited to, changes in the dynamics and composition of the atmosphere, oceans and cryosphere, as well as climate change, sea level variation, observations/modelling of Earth processes from deep to (near-)surface and their coupling, global ecology, biogeography and the resilience/thresholds in ecosystems. Key criteria for the consideration of manuscripts are (a) the relevance for the global scientific community and/or (b) the wider implications for global scale problems, preferably combined with (c) having a significance beyond a single discipline. A clear focus on key processes associated with planetary scale change is strongly encouraged. Manuscripts can be submitted as either research contributions or as a review article. Every effort should be made towards the presentation of research outcomes in an understandable way for a broad readership.