Scholarlink

<p>Exploring the sources of atmospheric predictability plays an important role in enhancing our understanding and improving the level of practical simulation and prediction. El Niño and the Southern Oscillation (ENSO), a prominent external forcing, exerts a profound influence on the global atmospheric system. Under the theoretical guidance of the nonlinear local Lyapunov exponent (NLLE) method and the conditional nonlinear local Lyapunov exponent (CNLLE) method, this work applied the optimal local dynamic analog (OLDA) algorithm to quantify the PLs of geopotential height, air temperature, and wind on a seasonal-to-interannual time scale, while explicitly isolating ENSO’s influence on their predictability. Our analysis reveals that the OLDA algorithm yields superior PL estimates. Specifically, the zonal-mean PLs of tropical mid-upper tropospheric geopotential height reach about 17&#xa0;months, significantly extending previous estimations. While tropospheric predictability outside the tropics is generally low, notable exceptions exist, with localized low-level wind predictability in Antarctica exceeding 11&#xa0;months. Through a more clearly response from predictability contributions, ENSO’s impact on the predictability of different variables and at different levels also varies. For example, the zonal averages of ENSO’s predictability contributions to mid-upper tropospheric geopotential height and air temperature have strong positive double peaks at the tropical margins of both hemispheres, while in the lower troposphere, a positive single peak is observed at the equator. Moreover, lower-tropospheric predictability contributions display differing east–west hemispheric asymmetries in geopotential height and temperature patterns. In terms of vertical distribution, the tropical zonal-height high-value distributions of ENSO’s predictability contributions to tropical geopotential height and air temperature present distinctive X-shaped and Y-shaped patterns, respectively. Additionally, ENSO’s predictability influence on wind fields remains constrained in non-divergent layers, such that the characteristics are similar to wind predictability. These results are conducive to enhancing the understanding of atmospheric system’s predictability and providing a helpful reference for practical prediction applications.</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

Quantifying the ENSO’s multifaceted influence on atmospheric predictability across variables and vertical levels

  • 期刊论文

  • 发表日期：

    2025年11月3日

查看全文
  • Houbin Song,
  • Jianping Li,
  • Ruize Li,
  • Zhaolu Hou,
  • Shixin Zhen,
  • Hao Li

摘要

Exploring the sources of atmospheric predictability plays an important role in enhancing our understanding and improving the level of practical simulation and prediction. El Niño and the Southern Oscillation (ENSO), a prominent external forcing, exerts a profound influence on the global atmospheric system. Under the theoretical guidance of the nonlinear local Lyapunov exponent (NLLE) method and the conditional nonlinear local Lyapunov exponent (CNLLE) method, this work applied the optimal local dynamic analog (OLDA) algorithm to quantify the PLs of geopotential height, air temperature, and wind on a seasonal-to-interannual time scale, while explicitly isolating ENSO’s influence on their predictability. Our analysis reveals that the OLDA algorithm yields superior PL estimates. Specifically, the zonal-mean PLs of tropical mid-upper tropospheric geopotential height reach about 17 months, significantly extending previous estimations. While tropospheric predictability outside the tropics is generally low, notable exceptions exist, with localized low-level wind predictability in Antarctica exceeding 11 months. Through a more clearly response from predictability contributions, ENSO’s impact on the predictability of different variables and at different levels also varies. For example, the zonal averages of ENSO’s predictability contributions to mid-upper tropospheric geopotential height and air temperature have strong positive double peaks at the tropical margins of both hemispheres, while in the lower troposphere, a positive single peak is observed at the equator. Moreover, lower-tropospheric predictability contributions display differing east–west hemispheric asymmetries in geopotential height and temperature patterns. In terms of vertical distribution, the tropical zonal-height high-value distributions of ENSO’s predictability contributions to tropical geopotential height and air temperature present distinctive X-shaped and Y-shaped patterns, respectively. Additionally, ENSO’s predictability influence on wind fields remains constrained in non-divergent layers, such that the characteristics are similar to wind predictability. These results are conducive to enhancing the understanding of atmospheric system’s predictability and providing a helpful reference for practical prediction applications.