Projected changes in near-surface wind speed over Iberian Peninsula and associated atmosphere-ocean oscillations.

Near-surface wind speed has been one of the forgotten parts of the climate system due to poor quality of observational data and the challenges in its homogenization.  During the last two decades the interest in near-surface wind variability and trends has increased and two main phenomena have been found: the first one is termed “stilling”, indicating a decline of near-surface wind speed between around 1978 and 2010; the other is related to an interruption in the “stilling” since 2000s, known as a “reversal” of the wind speed trends at global and regional scales like China, Sweden or Iberian Peninsula, among others. There are uncertainties about the plausible causes of the variability of the near-surface wind speed, but last research pointed to the role played by decadal atmosphere-ocean oscillations. Under this assumption and a climate change context, a new “stilling” phase is expected for the 21^st century. In order to advance in the evaluation and attribution of the causes of the “stilling” and the “reversal” phenomena, the main objective of this study is to analyze projected changes in near-surface wind speed at regional scale, e.g. the Iberian Peninsula. The methodology consists in a comparison between observed wind speed data of the Iberian Peninsula and historical simulations from CMIP6 models, followed by a study of wind speed variability and trends of CMIP6 models under low to high greenhouse gas forcing scenarios in the future. The analyses will focus on quantifying the long-term changes in near surface wind speed and their relationship with dominant modes of variability in the Pacific and Atlantic (e.g., the Pacific Decadal Oscillation and the Atlantic Multi-decadal Oscillation).