Publications by authors named "Carlos Le Quesne"

Linked to major volcanic eruptions around 536 and 540 CE, the onset of the Late Antique Little Ice Age has been described as the coldest period of the past two millennia. The exact timing and spatial extent of this exceptional cold phase are, however, still under debate because of the limited resolution and geographical distribution of the available proxy archives. Here, we use 106 wood anatomical thin sections from 23 forest sites and 20 tree species in both hemispheres to search for cell-level fingerprints of ephemeral summer cooling between 530 and 550 CE.

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The species (Caprifoliaceae), new to science and endemic to the Ñuble Region, Central Chile, is formally described. Morphological data support its placement in a new species, clearly different from . A detailed description, insights about its habitat and ecology, distribution map and illustration are provided.

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Article Synopsis
  • South American societies are vulnerable to climatic changes due to insufficient long-term climate data, but recent advancements in tree ring chronologies have created a comprehensive network of 286 records that track hydroclimate variability since 1400 CE.
  • The South American Drought Atlas (SADA) has been developed using this data alongside the self-calibrated Palmer Drought Severity Index, providing the most detailed hydrological reconstruction for the region and correlating well with historical climate events.
  • The SADA reveals that El Niño-Southern Oscillation (ENSO) and Southern Annular Mode (SAM) strongly influence droughts and rainfall variability, with the analysis indicating an increasing trend towards severe droughts and extreme rainfall in South America linked to climate change and greenhouse
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Article Synopsis
  • * The incorrect URL given was 'https://www.ams.ethz.ch/research.html', which has been corrected to 'http://www.ams.ethz.ch/research/published-data.html'.
  • * The correction has been updated in both the PDF and HTML formats of the article.
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Though tree-ring chronologies are annually resolved, their dating has never been independently validated at the global scale. Moreover, it is unknown if atmospheric radiocarbon enrichment events of cosmogenic origin leave spatiotemporally consistent fingerprints. Here we measure the C content in 484 individual tree rings formed in the periods 770-780 and 990-1000 CE.

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