Scholarlink

<p>Northwest China (NWC), an extensive arid and semi-arid region of China, is experiencing a pronounced warming and wetting transition in recent decades. During this shift, both summer precipitation variability and precipitation recycling have intensified, yet how recycling modulates this rising variability remains unclear. Using the Water Accounting Model-2 layers (WAM2layers) driven by MERRA-2 for 1982–2020, we partitioned summer precipitation over NWC into internal recycling and external moisture inflow from four source sectors (northwest, northeast, southwest, southeast). The results indicate that total precipitation variability increases significantly, with external inflow explaining 58.9% of the rise and internal recycling 22.7% as a conditional amplifier. Among external sources, the southwest pathway dominates, contributing 54.1% of the climatological external variability and 58.3% of its upward trend. High-variability summers feature a northward-shifted, intensified South Asian High and a westward-extended Western Pacific Subtropical High, forming a coupled circulation that enhances upper-level divergence, mid-tropospheric moisture transport, and low-level moisture convergence. This configuration increases column moisture and amplifies recycling efficiency. Our results demonstrate that moisture-source pathways exert primary control on hydroclimate variability over NWC. Incorporating pathway-resolved recycling diagnostics with circulation metrics offers a new perspective for understanding regional water-cycle regulation and improving predictability under continued warming.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

The influence of precipitation recycling processes on summer precipitation variability over Northwest China

  • 期刊论文

  • 发表日期：

    2026年3月16日

查看全文
  • Yongli He,
  • Zhen Tang,
  • Chutao Lan,
  • Boyuan Zhang,
  • Jingjing Jia,
  • Haipeng Yu

摘要

Northwest China (NWC), an extensive arid and semi-arid region of China, is experiencing a pronounced warming and wetting transition in recent decades. During this shift, both summer precipitation variability and precipitation recycling have intensified, yet how recycling modulates this rising variability remains unclear. Using the Water Accounting Model-2 layers (WAM2layers) driven by MERRA-2 for 1982–2020, we partitioned summer precipitation over NWC into internal recycling and external moisture inflow from four source sectors (northwest, northeast, southwest, southeast). The results indicate that total precipitation variability increases significantly, with external inflow explaining 58.9% of the rise and internal recycling 22.7% as a conditional amplifier. Among external sources, the southwest pathway dominates, contributing 54.1% of the climatological external variability and 58.3% of its upward trend. High-variability summers feature a northward-shifted, intensified South Asian High and a westward-extended Western Pacific Subtropical High, forming a coupled circulation that enhances upper-level divergence, mid-tropospheric moisture transport, and low-level moisture convergence. This configuration increases column moisture and amplifies recycling efficiency. Our results demonstrate that moisture-source pathways exert primary control on hydroclimate variability over NWC. Incorporating pathway-resolved recycling diagnostics with circulation metrics offers a new perspective for understanding regional water-cycle regulation and improving predictability under continued warming.