Near-surface wind speed trends and variability over the Antarctic Peninsula, 1979–2022

Abstract

Near-Surface Wind Speed (SWS) is a crucial but less studied climate variable in the northern Antarctic Peninsula (AP). This research evaluates, for the first time, 44 years (i.e., 1979–2022) of SWS trends and variability across the AP using two data sources: (i) observational data from quality-controlled and homogenized meteorological stations, and (ii) reanalysis data from ERA5; the accuracy of this product strongly depends on each station with an overall underestimation of observed SWS. Annual trends in observed SWS exhibit a positive trend, being statistically significant in autumn and spring, with a marked intraanual and spatial variability in the sign and magnitudes across the AP. In addition, the multidecadal variability of observed SWS showed a general positive trend until ∼2001 (varying between 1993 and 2007 depending on each season), followed by a period of slowdown in the last two decades. Over the AP, SWS changes are mainly driven by two principal modes of atmospheric variability: i.e., mainly the Southern Annular Mode (SAM) and, secondarily, by the El Niño-Southern Oscillation (ENSO). Overall, positive trends in SWS could be partly associated with the increase and poleward shift of the westerlies due to the positive trend of the SAM index. However, as previous studies pointed out for air temperature and precipitation, we found a non-stationary and complex relationship of these modes with SWS changes. This research addresses the gap in SWS changes and variability in the AP and surrounding Southern Ocean and the influence of the atmospheric circulation, a hotspot area in climate change research.