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）海面温度（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描述IO SST的变化和驱动它的物理机制，在该地区的观测稀疏的努力复杂化。 迄今为止，研究中的一个关键问题是IO SST的变化在多大程度上是由IO的本地机制驱动的，以及有多少是由太平洋厄尔尼诺事件和其他远程影响所造成的。 PI和其他机构的研究主要集中在确定本地驱动的IO SST变化形式，并确定大气-海洋相互作用、次表层海流和海洋热储存在产生这些变化中的作用。在这里，PI特别关注发生在十年或二十年内的IO SST波动，他们称之为印度洋年代际振荡（IODOs）。 在其积极的阶段，IODO的特征是从澳大利亚西部到非洲南部的海温比正常的要高，伴随着海平面气压和表面风的异常。 共同体地球系统模式（CESM）的模拟表明，地下海洋存在进一步的异常，在温暖的SST区域以下200米左右的深度温度更高。该项目旨在通过观测分析和模式模拟相结合的方式，调查IODO的机制，并探索其对全球气候系统的影响。鉴于IODO周边国家的人口众多，其中许多国家很容易受到上述IODO可变性的影响，这项工作具有社会和科学意义。 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NSF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

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

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