Wind speed stilling and its recovery due to internal climate variability

Abstract

Abstract. Near-surface winds affect many processes on planet Earth, ranging from fundamental biological mechanisms such as pollination to man-made infrastructure that is designed to resist or harness wind. The observed systematic wind speed decline up to around 2010 (stilling) and its subsequent recovery have therefore attracted much attention. While this sequence of downward and upwards trends and good connections to well established modes of climate variability suggest that stilling could be a manifestation of multidecadal climate variability, a systematic investigation is currently lacking. Here, we use the Max Planck Institute Grand Ensemble (MPI-GE) to decompose internal variability from forced changes in wind speeds. We report that wind speed changes resembling observed stilling and its recovery are well in line with internal climate variability, both under current and future climate conditions. Moreover, internal climate variability outweighs forced changes in wind speeds on 20 year timescales by one order of magnitude. Albeit smaller, forced changes become relevant in the long run as they represent alterations of mean states. In this regard, we reveal that land use change plays a pivotal role in explaining MPI-GE ensemble mean wind changes in the representative concentration pathways 2.6, 4.5, and 8.5. Our results demonstrate that multidecadal wind speed variability is of greater relevance than forced changes over the 21st century, in particular for wind related infrastructure like wind energy.

Increases of Offshore Wind Potential in a Warming World

“…While quantitatively attributing historical wind speed changes to specific causes remains a complex challenge (Possner & Caldeira, 2017;Pryor et al, 2020;Shen et al, 2023;Wohland et al, 2021;Zeng et al, 2019;Zha et al, 2021), uncertainties associated with internal variability can be addressed by considering the ensemble mean of CMIP6 simulations (Archer et al, 2014;Lehner et al, 2020). As depicted in Figure 2a, a discernible global trend indicates an increase in the future for the globally averaged annualmean offshore WPD from the Corrected-CMIP6.…”