Winds with destructive potential across a topographic and seasonal gradient in a Central Amazon forest

Abstract. Winds can exceed the mechanical stability of trees, leading to snapping or uprooting. In large portions of the Amazon, storms propagating winds with destructive potential (WDP) are key drivers of tree mortality, affecting forest structure, biomass stocks, and species composition. Our understanding of WDP primarily comes from tree damage observations, as meteorological records assessing wind patterns exist in few locations and are often made with insufficient time resolution. Consequently, the temporal and spatial patterns of WDP remain poorly understood. Using 24 months of meteorological data recorded at canopy height across a topographic and rainfall gradient, we developed an innovative method for detecting and describing WDP in a central Amazon forest. We assessed the frequency, speed, and critical duration of WDP and possible relationships with local topography and rainfall seasonality/intensity. We recorded 424 WDP events, with speeds ranging from 10 to 17.9 m s^-1 and critical durations from 1 to 90 seconds. WDP occurred approximately 4 % of the analyzed time, representing daily and monthly means (± standard deviation) of 3.1 ± 2.9 and 17.2 ± 9.6 events, respectively. Topography influenced the fastest, longest-lasting, and least frequent gusts but did not affect the more frequent, slower, and shorter ones. Elevated and relatively more exposed areas were particularly vulnerable to the speediest and longest-lasting WDP. The 87th percentile of rainfall rate (~0.7 mm min^-1) correlated most strongly with the frequency and duration of observed events, highlighting the role of extreme rainfall in propagating destructive winds. Our findings indicate that WDP are more common during the transition from the dry to the wet season and confirm previous studies in different Amazon regions that extreme winds are important mechanisms of tree damage and mortality, influencing turbulence and associated processes like gas and energy fluxes.