Scholarlink

<p>Oceans are key components in the global climate and hydrological systems. The water vapour transport to land is the main impetus to precipitation on land surface. The ocean-atmospheric oscillations or teleconnections influence precipitation regimes across different areas and are among the key drivers to drought evolution. This study analysed the impact of teleconnections i.e., Oceanic Nino Index—El Nino Southern Oscillation (ONI ENSO), Indian Ocean dipole (IOD) and North Atlantic Oscillation (NAO) on the drought events (1984, 1985, 1999, 2000, 2001, 2004, 2016, 2018) in the Upper Indus Basin (UIB) over 1980–2020 period. The results revealed a significant positive relationship between ONI ENSO and standardized precipitation index (SPI) for spring season with correlations varying from 0.33 to 0.65 signifying the role of the Pacific Ocean in modulating spring precipitation across UIB. The summer precipitation of the Jammu region was found to be in a mild negative correlation with the ONI ENSO, which weakens with North latitude. A positive correlation averaging 0.30 for the UIB is found between autumnal peak IOD and SPI exhibiting its role in controlling precipitation of the autumn season. Interestingly, in the spring season, there exists an insignificant positive correlation between NAO and SPI of 0.2. In winter, the UIB except Ladakh, shows mild positive relationship between NAO and SPI, implying the minimum influence of NAO on Ladakh’s winter precipitation. The extreme drought years of 1999 and 2000 are mainly associated with negative ONI ENSO i.e., La Nina. The drought years of 1984 and 1985 have the moderate influence of negative phases of both ONI ENSO and IOD. The 2004 drought occurred in the ENSO positive&#xa0;phase but it was also influenced by weak positive NAO in winter. The 2016 drought was modulated by the strong summer/autumn positive IOD. We infer that drought conditions in the UIB are driven by different ocean-atmospheric teleconnections; the deliverable of this work can be reliable for projections of precipitation regimes and drought early warning in the region.</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

Impact of El Nino Southern Oscillation, Indian Ocean Dipole and North Atlantic Oscillation on the drought scenarios in the Upper Indus Basin

  • 期刊论文

  • 发表日期：

    2025年4月3日

查看全文
  • Taha Shamim,
  • M. Sultan Bhat,
  • Akhtar Alam,
  • Ausra Allaie,
  • Shafkat Ahsan

摘要

Oceans are key components in the global climate and hydrological systems. The water vapour transport to land is the main impetus to precipitation on land surface. The ocean-atmospheric oscillations or teleconnections influence precipitation regimes across different areas and are among the key drivers to drought evolution. This study analysed the impact of teleconnections i.e., Oceanic Nino Index—El Nino Southern Oscillation (ONI ENSO), Indian Ocean dipole (IOD) and North Atlantic Oscillation (NAO) on the drought events (1984, 1985, 1999, 2000, 2001, 2004, 2016, 2018) in the Upper Indus Basin (UIB) over 1980–2020 period. The results revealed a significant positive relationship between ONI ENSO and standardized precipitation index (SPI) for spring season with correlations varying from 0.33 to 0.65 signifying the role of the Pacific Ocean in modulating spring precipitation across UIB. The summer precipitation of the Jammu region was found to be in a mild negative correlation with the ONI ENSO, which weakens with North latitude. A positive correlation averaging 0.30 for the UIB is found between autumnal peak IOD and SPI exhibiting its role in controlling precipitation of the autumn season. Interestingly, in the spring season, there exists an insignificant positive correlation between NAO and SPI of 0.2. In winter, the UIB except Ladakh, shows mild positive relationship between NAO and SPI, implying the minimum influence of NAO on Ladakh’s winter precipitation. The extreme drought years of 1999 and 2000 are mainly associated with negative ONI ENSO i.e., La Nina. The drought years of 1984 and 1985 have the moderate influence of negative phases of both ONI ENSO and IOD. The 2004 drought occurred in the ENSO positive phase but it was also influenced by weak positive NAO in winter. The 2016 drought was modulated by the strong summer/autumn positive IOD. We infer that drought conditions in the UIB are driven by different ocean-atmospheric teleconnections; the deliverable of this work can be reliable for projections of precipitation regimes and drought early warning in the region.