Wind Energy — Cross-Event Overview

Cross-event analysis and diagnostics for the Wind Energy category. These plots compare scenarios across the full simulation period rather than focusing on a single event.
Wind Speed Scenario Differences — Top Months Diagnostic

Wind Speed Scenario Differences — Top Months Diagnostic

1.0° monthly Europe (35–72°N, 25°W–45°E) 2017–2025

Diagnostic identifying the months and regions with the largest wind speed differences between scenarios. Shows the top-6 months by spatial-RMS difference for each scenario pair, plus a time series of monthly RMS differences with 12-month running means.

Key Findings

  • +2K − Historical: Top months are Jan 2017 (RMS 0.253), Jan 2025 (0.246), Feb 2021 (0.222). Predominantly winter months.
  • Historical − Counterfactual: Larger signal overall. Top months are Feb 2017 (RMS 0.366), Jan 2017 (0.361), Mar 2017 (0.333). Early 2017 dominates.
  • Spatial hotspot for +2K−Hist: Norwegian/Barents Sea (~72°N, 45°E), mean |diff| = 0.53 m/s.
  • Spatial hotspot for Hist−Cont: North Atlantic (~54°N, 23°W), mean |diff| = 0.77 m/s.
  • The 12-month running mean shows the Hist−Cont difference is persistently larger than +2K−Hist throughout the entire period.
  • These diagnostics motivated the Phase 2 focus on the Norwegian Sea (winter 2025) and North Atlantic (winter 2017) for hourly analysis.
Methodology

Ranking Metric: Spatial RMS of the wind speed difference field, area-weighted by cos(latitude).

Hotspot Detection: Temporal mean of absolute differences per grid cell, plus search for the 10°x10° box with the highest integrated signal.

Monthly 10m Wind Speed — Storyline Scenario Comparison (2017–2025)

Monthly 10m Wind Speed — Storyline Scenario Comparison (2017–2025)

1.0° monthly Europe (35–72°N, 25°W–45°E) 2017–2025

Seasonal mean wind speed maps and pairwise scenario differences across all three storyline experiments, using monthly mean 10m wind speed over Europe for the full simulation period.

Key Findings

  • Wind speed differences between scenarios are small (a few percent of the mean), consistent with large-scale flow being nudged.
  • The Historical − Counterfactual difference is larger than +2K − Historical, suggesting the 1950→present change in surface winds exceeds the present→2K change over Europe.
  • Differences are strongest over ocean and coastal areas (North Atlantic, Norwegian Sea, Mediterranean) — likely driven by changed SSTs and boundary layer stability.
  • Winter (DJF) shows the largest signal; summer (JJA) the weakest.
  • The time series of all three scenarios track closely due to nudging, but persistent offsets are visible.

Scientific Context

Since the jetstream is forced to be similar across scenarios, surface wind differences arise from thermodynamic changes: different SSTs alter boundary layer stability and surface drag, different sea ice extent changes surface roughness, and modified temperature gradients affect local pressure patterns. These are the 'residual' climate signals that survive despite identical large-scale atmospheric circulation.

Methodology

Nudging: All three experiments use spectral nudging towards observed winds at jetstream height (wavenumbers below T60 truncation, ~330 km). Surface winds and all other variables evolve freely, constrained only by boundary conditions.

Scenarios:

  • cont: Counterfactual: boundary conditions from ~1950 climate (pre-industrial SSTs, sea ice extent).
  • hist: Historical: boundary conditions matching observed climate.
  • plus2K: +2K Warming: boundary conditions from a world 2K warmer than present.

Analysis: Seasonal means computed over DJF/MAM/JJA/SON across all available years. Differences are simple arithmetic (experiment A minus experiment B). Time series show spatial-mean wind speed over the full Europe domain.