Collaborative Research: Interhemispheric and Zonal Asymmetries of the ITCZ

合作研究：ITCZ 的半球间和区域不对称性

• 批准号: 1934363
• 负责人: Honghai Zhang
• 金额: $ 62.52万
• 依托单位: Columbia University
• 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: 2020-02-01 至 2023-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1934363&HistoricalAwards=false
• 关键词: Collaborative; Research; Interhemispheric; Zonal; Asymmetries

Satellites views of the earth typically show a narrow band of deep precipitating clouds over the tropical oceans where the trade winds converge. This band, known as the inter-tropical convergence zone, or ITCZ, is generally found north of the equator with a mean latitude of about 6N. Many aspects of the ITCZ including its existence, its role in global atmospheric circulation, and its preference for the Northern Hemisphere can be understood by thinking of the ITCZ as a uniform strip of convection with the same width, central latitude, and rainfall intensity at all longitudes. But this longitudinally averaged view of the ITCZ overlooks substantial variations in ITCZ latitude around the tropics. In particular the ITCZ is found south of the equator in the Indian Ocean and it has a southwest to northeast slope across both the Pacific and Atlantic oceans. The latitude of the ITCZ can thus be anywhere from from 4S to 10N depending on the ocean basin, the longitude within that basin, and the time of year.This project uses combination of observational analysis and carefully designed model simulations to study regional variations in ITCZ latitude and other properties. For instance the northward displacement of the ITCZ in the eastern Pacific has been attributed to the geography of the North and South American coastlines, an idea which can be tested through simulations in which the west coasts of the Americas are mirror images of each other. The importance of oceanic processes is tested using simplified ocean configurations which allow some mechanisms but disable others. Ocean model configurations include a simple motionless "slab" ocean, a modified slab ocean which captures near-surface heat transport driven by surface winds, and a "shallow water" ocean model which allows surface cooling due to the upwelling of cold water from the deep ocean. In addition, the project develops a version of the Community Earth System Model (CESM) in which flux corrections are applied to improve the representation of the ITCZ.The work is of practical interest given the importance of the ITCZ for tropical rainfall as well as its outsized effects on the climate and atmospheric circulation of the earth. Despite its importance the ITCZ is not well simulated in models used for weather prediction and climate change projections, thus a better understanding of ITCZ dynamics could be quite useful for model improvement. The work also has value for the broader research enterprise, as model configurations developed for the project will be openly available for adoption by the worldwide research community. In addition, the award provides support and training for two graduate students, thereby contributing to scientific workforce development.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.

卫星对地球的景色通常显示出狭窄的深度沉淀云层，在热带海洋汇聚的热带海洋上。 通常在赤道以北，平均纬度约为6N的北部，该带被称为热带融合区或ITCZ。 ITCZ的许多方面包括其存在，其在全球大气循环中的作用以及其对北半球的偏爱，可以通过将ITCZ视为具有相同宽度，中央纬度和降雨强度的统一对流的理解来理解纵向。 但是，这种纵向平均ITCZ的视图忽略了Tropics周围ITCZ纬度的实质性变化。 特别是在印度洋的赤道南部发现了ITCZ，它在太平洋和大西洋的西北坡上都有西南坡。 因此，ITCZ的纬度可以从4s到10n，具体取决于海盆，该盆地内的经度以及一年中的时间。该项目使用观察性分析和精心设计的模型模拟的组合来研究ITCZ中的区域变化纬度和其他特性。 例如，东太平洋ITCZ的北部位移归因于北美和南美海岸线的地理，这一想法可以通过模拟进行测试，在该模拟中，美洲西海岸是彼此的镜像。 海洋过程的重要性是使用简化的海洋配置测试的，这些海洋配置允许某些机制但禁用其他机制。 海洋模型的配置包括一个简单的静静物“平板”海洋，一种改良的平板海洋，捕获由地面风驱动的近地面热传输和“浅水”海洋模型，该海洋模型由于从深水上升起的冷水而导致表面冷却海洋。 此外，该项目还开发了社区地球系统模型（CESM）的版本，其中应用通量校正来改善ITCZ的表示。鉴于ITCZ对热带降雨及其其重要性的重要性，这项工作具有实践意义。对地球气候和大气循环的巨大影响。 尽管它很重要，但在用于天气预测和气候变化预测的模型中，ITCZ并没有很好地模拟，因此对ITCZ动态的更好理解对于改进可能非常有用。 这项工作还对更广泛的研究企业具有价值，因为为该项目开发的模型配置将由全球研究社区公开采用。 此外，该奖项为两名研究生提供了支持和培训，从而为科学劳动力发展做出了贡献。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的评估标准来评估的。

项目成果

Ocean warming and accelerating Southern Ocean zonal flow

• DOI: 10.1038/s41558-021-01212-5
• 发表时间: 2021-11
• 期刊: Nature Climate Change
• 影响因子: 30.7
• 作者: Jia‐Rui Shi;L. Talley;S. Xie;Qihua Peng;Wei Liu

Persistent Discrepancies between Observed and Modeled Trends in the Tropical Pacific Ocean

热带太平洋观测到的趋势与模拟的趋势之间持续存在差异

• DOI: 10.1175/jcli-d-21-0648.1
• 发表时间: 2022
• 期刊: Journal of Climate
• 影响因子: 4.9
• 作者: Seager, Richard;Henderson, Naomi;Cane, Mark
• 通讯作者: Cane, Mark

How Does Sea Surface Temperature Drive the Intertropical Convergence Zone in the Southern Indian Ocean?

海面温度如何驱动南印度洋热带辐合带？

• DOI: 10.1175/jcli-d-21-0870.1
• 发表时间: 2022
• 期刊: Journal of Climate
• 影响因子: 4.9
• 作者: Zhang, Honghai;Seager, Richard;Xie, Shang-Ping
• 通讯作者: Xie, Shang-Ping

Zonal mean and shift modes of historical climate response to evolving aerosol distribution

• DOI: 10.1016/j.scib.2021.07.013
• 发表时间: 2021-11-05
• 期刊: SCIENCE BULLETIN
• 影响因子: 18.9
• 作者: Kang, Sarah M.;Xie, Shang-Ping;Xiang, Baoqiang
• 通讯作者: Xiang, Baoqiang