The Role of Indian Ocean Internal Processes in Generating Decadal Climate Variability

印度洋内部过程在产生年代际气候变化中的作用

• 批准号: 1935279
• 负责人: Weiqing Han
• 金额: $ 55.09万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1935279&HistoricalAwards=false
• 关键词: Role; Indian; Ocean; Internal; Processes

From Indonesia to East Africa, fluctuations of Indian Ocean (IO) sea surface temperature (SST) have been linked to floods, droughts, wildfires, and other disruptive impacts of shifts in rainfall and temperature. These impacts have motivated efforts to characterize IO SST variability and the physical mechanisms that drive it, efforts complicated by the sparsity of observations in the region. A key question in research to date is the extent to which variability of IO SSTs is driven by mechanisms local to the IO and how much is externally forced by El Nino events in the Pacific and other remote influences. Research by the PIs and others has focused on identifying forms of locally-driven IO SST variability and identifying the roles of atmosphere-ocean interactions and subsurface currents and ocean heat storage in generating them.Here the PIs specifically address IO SST fluctuations that take place over a decade or two, which they call the Indian Ocean Decadal Oscillations (IODOs). In its positive phase the IODO features warmer than normal SSTs extending from western Australia to southern Africa accompanied by anomalies in sea level pressure and surface wind. Simulations from the Community Earth System Model (CESM) suggest further anomalies of the subsurface ocean, with higher temperatures to a depth of 200m or so below the region of warm SSTs. The project seeks to investigate the mechanisms of the IODO and explore its impacts on the global climate system through a combination of observational analysis and model simulations.The work is of societal as well as scientific interest given the large populations living in countries surrounding the IO, many of which are quite vulnerable to the impacts of IO variablity as noted above. Results of the work can inform the development of the multi-national IO Observing System (IndOOS) as well as field campaigns organized around it. The project also provides support and training to a graduate student as well as summer support for undergraduates.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

从印度尼西亚到东非，印度洋（IO）海表温度（SST）的波动与洪水、干旱、野火以及降雨和温度变化的其他破坏性影响有关。这些影响促使人们努力表征IO海温变率及其物理机制，而该区域观测的稀疏性使工作变得更加复杂。迄今为止研究中的一个关键问题是，IO海温的变率在多大程度上受到IO本地机制的驱动，以及太平洋厄尔尼诺事件和其他远程影响在多大程度上受到外部强迫。pi和其他机构的研究重点是确定局地驱动的IO海温变率形式，并确定大气-海洋相互作用、地下流和海洋热储存在产生这些变化中的作用。在这里，pi专门研究十年或二十年发生的印度洋海温波动，他们称之为印度洋年代际振荡（IODOs）。在其正相位，IODO表现出比正常海温偏暖的特征，从西澳大利亚延伸到南部非洲，伴随着海平面气压和地面风的异常。来自社区地球系统模式（CESM）的模拟表明，在温暖的海温区域以下200米左右的深度，地下海洋的温度进一步异常。该项目旨在通过观测分析和模式模拟相结合，研究IODO的机制并探讨其对全球气候系统的影响。鉴于居住在IO周边国家的人口众多，这项工作具有社会和科学意义，其中许多国家非常容易受到上文所述IO变化的影响。这项工作的结果可以为多国观测系统的发展以及围绕该系统组织的实地运动提供信息。该项目还为研究生提供支持和培训，并为本科生提供暑期支持。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Inter-basin and Multi-time Scale Interactions in generating the 2019 Extreme Indian Ocean Dipole

2019年印度洋极端偶极子的跨流域和多时间尺度相互作用

• DOI: 10.1175/jcli-d-20-0760.1
• 发表时间: 2021
• 期刊: Journal of Climate
• 影响因子: 4.9
• 作者: Zhang, Lei;Han, Weiqing;Hu, Zeng-Zhen
• 通讯作者: Hu, Zeng-Zhen

Role of Oceanic Internal Instability in the Generation of Low‐Frequency Variability in the Indian Ocean

• DOI: 10.1029/2022gl102489
• 发表时间: 2023-05
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: S. Anjana;A. Chatterjee;W. Han;S. Prerna;C. K. Sajidh

Interannual to Decadal Variability of Tropical Indian Ocean Sea Surface Temperature: Pacific Influence versus Local Internal Variability

• DOI: 10.1175/jcli-d-20-0807.1
• 发表时间: 2021-04
• 期刊: Journal of Climate
• 影响因子: 4.9
• 作者: Lei Zhang;Gang Wang;M. Newman;W. Han

Eastward Shift of Interannual Climate Variability in the South Indian Ocean since 1950

• DOI: 10.1175/jcli-d-21-0356.1
• 发表时间: 2021-10
• 期刊: Journal of Climate
• 影响因子: 4.9
• 作者: Lei Zhang;W. Han;K. Karnauskas;Yuanlong Li;T. Tozuka