158 / 2022-04-11 10:42:57
Northern poleward edge of regional Hadley cell over western Pacific during boreal winter: Year-to-year variability, influence factors and associated winter climate anomalies
Regional Hadley cell; Interannual variability; El Niño-Southern Oscillation Modoki; North Pacific Oscillation; North Atlantic Oscillation; East-Asian climate
全文录用
黄汝萍 / 中国气象局广州热带海洋气象研究所
陈尚锋 / 中国科学院大气物理研究所
Compared to the zonal-mean Hadley cell (HC), our knowledge of the characteristics, influence factors and associated climate anomalies of the regional HC remains quite limited. Here, we examine interannual variability of the northern poleward HC edge over western Pacific (WPHCE) during boreal winter. Results suggest that interannual variability of the WPHCE is impacted by the El Niño-Southern Oscillation (ENSO) Modoki, North Pacific Oscillation (NPO) and North Atlantic Oscillation (NAO). The WPHCE tends to shift poleward during negative phase of the ENSO Modoki, and positive phases of the NPO and NAO, which highlights not merely the tropical forcing but also the extratropical signals that modulate the WPHCE. ENSO modoki, NPO and NAO modulate the WPHCE via inducing atmospheric anomalies over the western North Pacific. We further investigate the climatic impacts of the WPHCE on East Asia. The poleward shift of the northern descending branch of the WPHC results in anomalous upward (downward) motions and upper-level divergence (convergence) anomalies over south-central China (northern East-Asia), leading to increased (decreased) rainfall there. Moreover, pronounced cold surface air temperature anomalies appear over south-central China when the sinking branch of the WPHC moves poleward. Based on the temperature diagnostic analysis, negative surface temperature tendency anomalies over central China are mostly attributable to the cold zonal temperature advection and ascent-induced adiabatic cooling, while the negative anomalies over South China are largely due to the cold meridional temperature advection. These findings could improve our knowledge of the WPHCE variability and enrich the knowledge of forcing factors for East Asian winter climate.
重要日期
  • 会议日期

    07月27日

    2022

    07月28日

    2022

  • 06月30日 2022

    初稿截稿日期

  • 07月19日 2022

    注册截止日期

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