Dong Wenhao, Ming Yi, Deng Yi, Shen Zhaoyi
Cooperative Programs for the Advancement of Earth System Science, University Corporation for Atmospheric Research, Boulder, CO, USA.
NOAA/Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA.
Nat Commun. 2024 May 23;15(1):4379. doi: 10.1038/s41467-024-48743-x.
The Taklamakan and Gobi Desert (TGD) region has experienced a pronounced increase in summer precipitation, including high-impact extreme events, over recent decades. Despite identifying large-scale circulation changes as a key driver of the wetting trend, understanding the relative contributions of internal variability and external forcings remains limited. Here, we approach this problem by using a hierarchy of numerical simulations, complemented by diverse statistical analysis tools. Our results offer strong evidence that the atmospheric internal variations primarily drive this observed trend. Specifically, recent changes in the North Atlantic Oscillation have redirected the storm track, leading to increased extratropical storms entering TGD and subsequently more precipitation. A clustering analysis further demonstrates that these linkages predominantly operate at the synoptic scale, with larger contributions from large precipitation events. Our analysis highlights the crucial role of internal variability, in addition to anthropogenic forcing, when seeking a comprehensive understanding of future precipitation trends in TGD.
近几十年来，塔克拉玛干沙漠和戈壁沙漠（TGD）地区夏季降水量显著增加，包括高影响极端事件。尽管已确定大规模环流变化是降水增加趋势的关键驱动因素，但对内部变率和外部强迫的相对贡献的理解仍然有限。在此，我们通过使用一系列数值模拟并辅以多种统计分析工具来解决这一问题。我们的结果提供了有力证据，表明大气内部变化是观测到的这一趋势的主要驱动因素。具体而言，北大西洋涛动最近的变化改变了风暴路径，导致进入TGD的温带风暴增加，进而带来更多降水。聚类分析进一步表明，这些联系主要在天气尺度上起作用，大降水事件的贡献更大。我们的分析强调了在全面理解TGD未来降水趋势时，除了人为强迫外，内部变率的关键作用。
