Filters

2018 - 201912020 - 20231

More filters

20232
Reset filters

Settings

Author: Boers, Niklas × End date: 2023 × DDC: 500 ×

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Global vegetation resilience linked to water availability and variability
    ([London] : Nature Publishing Group UK, 2023) Smith, Taylor; Boers, Niklas
    Quantifying the resilience of vegetated ecosystems is key to constraining both present-day and future global impacts of anthropogenic climate change. Here we apply both empirical and theoretical resilience metrics to remotely-sensed vegetation data in order to examine the role of water availability and variability in controlling vegetation resilience at the global scale. We find a concise global relationship where vegetation resilience is greater in regions with higher water availability. We also reveal that resilience is lower in regions with more pronounced inter-annual precipitation variability, but find less concise relationships between vegetation resilience and intra-annual precipitation variability. Our results thus imply that the resilience of vegetation responds differently to water deficits at varying time scales. In view of projected increases in precipitation variability, our findings highlight the risk of ecosystem degradation under ongoing climate change.
  • Thumbnail Image
    Item
    Phase coherence between precipitation in South America and Rossby waves
    (Washington, DC [u.a.] : Assoc., 2018) Gelbrecht, Maximilian; Boers, Niklas; Kurths, Jürgen
    The dominant mode of intraseasonal precipitation variability during the South American monsoon is the so-called precipitation dipole between the South Atlantic convergence zone (SACZ) and southeastern South America (SESA). It affects highly populated areas that are of substantial importance for the regional food supplies. Previous studies using principal components analysis or complex networks were able to describe and characterize this variability pattern, but crucial questions regarding the responsible physical mechanism remain open. Here, we use phase synchronization techniques to study the relation between precipitation in the SACZ and SESA on the one hand and southern hemisphere Rossby wave trains on the other hand. In combination with a conceptual model, this approach demonstrates that the dipolar precipitation pattern is caused by the southern hemisphere Rossby waves. Our results thus show that Rossby waves are the main driver of the monsoon season variability in South America, a finding that has important implications for synoptic-scale weather forecasts.