Sudden appearance of katabatic wind in Central-Eastern Europe driven by Scandinavian Ice Sheet dynamics as recorded in Polish loess

Abstract

This study investigates atmospheric circulation changes in Central-Eastern Europe during the Last Glacial Maximum (LGM), with a particular focus on the anisotropy of magnetic susceptibility (AMS) of loess deposits from the Jarosław section in Southeastern Poland. The subject of the study was the sequence of L1LL1 loess, which reaches a depth of approximately 7.5 m. This research integrates new AMS data with optically stimulated luminescence (OSL) dating, granulometric analysis, and spectrophotometric measurements to elucidate the influence of abrupt northern katabatic winds that emerged around 22.7 ka. The appearance of katabatic northern winds in the Scandinavian Ice Sheet's southern foreland correlates well with the time when it covered its maximum area. This change of wind was recorded as a rapid phenomenon without any intercardinal wind directions. Significant shifts in wind patterns corresponded with the major climatic events of the LGM and the end of Heinrich Event 2 (H2). The study documents a pronounced correlation between AMS data and granulometric parameters, indicating dynamic responses of loess deposition to changing wind strengths and directions. The results underscore the sensitivity of the region's paleoclimate to global atmospheric patterns and contribute to the broader understanding of Pleistocene climatic dynamics and their impact on sedimentary processes.