Heat extremes in Western Europe increasing faster than simulated due to atmospheric circulation trends

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Oct. 26, 2023

Over the last 70 years, extreme heat has been increasing at a disproportionate rate in Western Europe, compared to climate model simulations. This mismatch is not well understood. Here, we show that substantial fraction (0.8 °C [0.2°-1.4 °C] of 3.4 per global warming degree) extremes trend induced by atmospheric circulation changes, through more frequent southerly flows over Europe. In 170 available simulations from 32 different models analyzed, including 3 large ensembles, none have circulation-induced as observed. can be due underestimated response external forcing, or systematic underestimation low-frequency variability, both. The former implies future projections are too conservative, latter left with deep uncertainty regarding pace summer calls for caution when interpreting view adaptation waves.

Language: Английский

---

Climate change exacerbates snow-water-energy challenges for European ski tourism

Nature Climate Change, Journal Year: 2023, Volume and Issue: 13(9), P. 935 - 942

Published: Aug. 28, 2023

Language: Английский

---

Exacerbated summer European warming not captured by climate models neglecting long-term aerosol changes

Communications Earth & Environment, Journal Year: 2024, Volume and Issue: 5(1)

Published: April 6, 2024

Abstract In much of western-central Europe, summer temperatures have surged three times faster than the global mean warming since 1980, yet this is not captured by most climate model simulations. Here we disentangle into thermodynamic and circulation-induced contributions, show that latter main reason why numerically simulated weaker observed. Crucially, regional models from Coordinated Regional Downscaling Experiment with constant aerosol forcings systematically strongest discrepancies observations: in these simulations, brightening associated due to reductions represented. We estimate an effect ~0.5 °C over Europe for our ensemble, discrepancy evolving aerosols increases future projections. To better reap benefits high-resolution it thus imperative represent relevant external responses across entire chain.

Language: Английский

---

Performance-based sub-selection of CMIP6 models for impact assessments in Europe

Earth System Dynamics, Journal Year: 2023, Volume and Issue: 14(2), P. 457 - 483

Published: April 21, 2023

Abstract. We have created a performance-based assessment of CMIP6 models for Europe that can be used to inform the sub-selection this region. Our covers criteria indicative ability individual capture range large-scale processes are important representation present-day European climate. use study provide examples how may applied multi-model ensemble (a) filter performance against these climatological and processed-based (b) create smaller subset based on also maintains model diversity filtered projection as far possible. Filtering by excluding least-realistic leads higher-sensitivity remaining in an emergent consequence assessment. This results both 25th percentile median projected temperature being shifted towards greater warming set models. weight unfiltered global trends. In contrast, shifts distribution less warming. highlights tension regional selection terms climate versus mean trend.

Language: Английский

---

Response of the sea surface temperature to heatwaves during the France 2022 meteorological summer

Ocean science, Journal Year: 2023, Volume and Issue: 19(3), P. 629 - 647

Published: May 12, 2023

Abstract. The summer of 2022 was memorable and record-breaking, ranking as the second hottest in France since 1900, with a seasonal surface air temperature average 22.7 ∘C. In particular, experienced multiple record-breaking heatwaves during meteorological summer. As main heat reservoir Earth system, oceans are at forefront events this magnitude which enhance oceanic disturbances such marine (MHWs). study, we investigate sea (SST) French maritime basins using remotely sensed measurements to track response waters atmospheric determine intensity feedback. Beyond direct relationship between SSTs temperatures, explore leading parameters affecting upper-layer ocean budget. Despite some gaps data availability, measured were mean SST 1.3 2.6 ∘C above long-term (1982–2011), studied areas 4 22 d where basin-averaged exceeded maximum recorded from 1982 2011. We found significant heatwave periods temperatures locally 30.8 north-western Mediterranean Sea. Our results show that August (31 July 13 August), above-average solar radiation correlated below-average total cloud cover negative wind speed anomalies. attribution analysis based on simplified mixed-layer budget highlights critical role ocean–atmosphere fluxes initiating abnormally warm SSTs, while mixing plays crucial cessation periods. find 2 m specific humidity consistently linked advection moist masses key variables across all regions. reveal influence is variable secondary importance. Moreover, observe incident has effect only Bay Biscay (BB) English Channel (EC) areas. study findings consistent previous research demonstrate vulnerability Sea increasing frequency extreme weather resulting climate change. Furthermore, our investigation reveals recurring episodes had an undeniable impact surveyed France. therefore provides valuable insights into complex mechanisms underlying interaction demonstrates need for efficient sustainable operational system combining polar-orbiting geostationary satellites monitor alterations threaten context

Language: Английский

---

Mapping the race between crop phenology and climate risks for wheat in France under climate change

Scientific Reports, Journal Year: 2024, Volume and Issue: 14(1)

Published: April 8, 2024

Climate change threatens food security by affecting the productivity of major cereal crops. To date, agroclimatic risk projections through indicators have focused on expected hazards exposure during crop's current vulnerable seasons, without considering non-stationarity their phenology under evolving climatic conditions. We propose a new method for spatially classifying risks wheat, combining high-resolution data with wheat's phenological model. The is implemented French wheat involving three GCM-RCM model pairs and two emission scenarios. found that precocity stages allows to avoid periods water deficit in near future. Nevertheless, coming decades emergence heat stress increasing will deteriorate cultivation over territory. Projections show appearance combined up 4 years per decade RCP 8.5 scenario. proposed provides deep level information enables regional adaptation strategies: nature risk, its temporal spatial occurrence, potential combination other risks. It's first step towards identifying sites breeding crop varieties increase resilience agricultural systems.

Language: Английский

---

Simulating record-shattering cold winters of the beginning of the 21st century in France

Weather and Climate Dynamics, Journal Year: 2025, Volume and Issue: 6(1), P. 1 - 15

Published: Jan. 7, 2025

Abstract. Extreme cold winter temperatures in Europe have huge societal impacts. Being able to simulate worst-case scenarios for such events present and future climates is hence crucial short- long-term adaptation. In this paper, we are interested persistent events, whose probability will decrease with climate change. Large ensembles of simulations allow us better analyse the mechanisms characteristics but can require significant computational resources. Rather than simulating very large normal trajectories, rare-event algorithms sampling tail distributions more efficiently. Such been applied extreme heat waves. They emphasized role atmospheric circulation extremes. The goal study evaluate dynamics spells simulated by a algorithm. We focus on that occurred France from 1950 2021. investigate mean (December, January February) identify record-shattering event 1963. find although frequency decreases time, their intensity stationary. apply stochastic weather generator (SWG) approach importance coldest winters could occur factual counterfactual climate. thus worst consistent reanalysis data. few reach colder historical This shows present-day conditions trigger as record spite global warming. prevails during those analysed compared observed record-breaking showing no main change leading type event.

Language: Английский

---

Impact of Climate Change on the Dynamics of the Southern Senegal Upwelling Center

Geophysical Research Letters, Journal Year: 2025, Volume and Issue: 52(2)

Published: Jan. 28, 2025

Abstract The Canary current upwelling System (CCS) is one the most productive marine ecosystems. CMIP5 simulations under RCP8.5 scenario for end of 21st century project a modest upwelling‐favorable wind decrease over CCS southern outpost, that is, senegalese center (SSUC). We explore coastal‐scale physical manifestations climate change in SSUC through dynamical downscaling projected changes from nine models selected their realistic representation present‐day thermohaline structure. find coastal reduction due to be aggravated by geostrophic/pressure adjustments related, large part, upper ocean stratification. could reach 25% rates. intensity poleward boundary offshore decrease. Together with warming this opens vast possibilities ecological evolutions impact on neighboring societies.

Language: Английский

---

Opinion: Why all emergent constraints are wrong but some are useful – a machine learning perspective

Atmospheric chemistry and physics, Journal Year: 2025, Volume and Issue: 25(4), P. 2365 - 2384

Published: Feb. 21, 2025

Abstract. Global climate change projections are subject to substantial modelling uncertainties. A variety of emergent constraints, as well several other statistical model evaluation approaches, have been suggested address these However, they remain heavily debated in the science community. Still, central idea relate future already observable quantities has no real substitute. Here, we highlight validation perspective predictive skill machine learning community a promising alternative viewpoint. Specifically, argue for quantitative approaches which each constraining relationship can be evaluated comprehensively based on out-of-sample test data – top qualitative physical plausibility arguments that commonplace justification new constraints. Building this perspective, review ideas types controlling-factor analyses (CFAs). The principal behind CFAs is use find climate-invariant relationships historical hold approximately under strong scenarios. On basis existing archives, validated perfect-climate-model frameworks. From such three reasons: (a) objectively both past and data, (b) provide more direct and, by design, physically plausible links between observations potential climates, (c) take high-dimensional complex into account functions learned constrain response. We demonstrate advantages two recently published CFA examples form constraints feedback mechanisms (clouds, stratospheric water vapour) discuss further challenges opportunities using example rapid adjustment mechanism (aerosol–cloud interactions). avenues work, including strategies non-linearity, tackle blind spots ensembles, integrate helpful priors Bayesian methods, leverage physics-informed learning, enhance robustness through causal discovery inference.

Language: Английский

---

Using regional warming levels to describe future climate change for services and adaptation: Application to the French reference trajectory for adaptation

Climate Services, Journal Year: 2025, Volume and Issue: 38, P. 100553 - 100553

Published: March 14, 2025

Language: Английский

---