Central Asian modulation of Northern Hemisphere moisture transfer over the Late Cenozoic

Earth's climatic evolution over the last 5 million years is primarily understood from the perspective of marine mechanisms, however, the role of terrestrial feedbacks remains largely unexplored. Here we reconstruct the last 5 million years of soil moisture variability in Central Asia using paleomagnetism data and isotope geochemistry of an 80 m-thick sedimentary succession at Charyn Canyon, Kazakhstan. We identify a long-term trend of increasing aridification throughout the period, along with shorter-term variability related to the interaction between mid-latitude westerlies and the Siberian high-pressure system. This record highlights the long-term contribution of mid-latitude Eurasian terrestrial systems to the modulation of moisture transfer into the Northern Hemisphere oceans and back onto land via westerly air flow. The response of Earth-surface dynamics to Plio-Pleistocene climatic change in Central Asia likely generated terrestrial feedbacks affecting ocean and atmospheric circulation. This missing terrestrial link elucidates the significance of land-water feedbacks for long-term global climate. Late Cenozoic variation in Central Asian hydroclimate resulted from the interaction between mid-latitude westerlies and the Siberian high-pressure system and may have driven terrestrial feedbacks, according to analyses of sediments from Charyn Canyon, Kazakhstan.

Automated summary

Analyzing sediments from Charyn Canyon, Kazakhstan, researchers found that late Cenozoic variation in Central Asian hydroclimate was driven by the interaction between mid-latitude westerlies and the Siberian high-pressure system, potentially leading to terrestrial feedbacks affecting ocean and atmospheric circulation, highlighting the significance of land-water feedbacks for long-term global climate.