Mechanisms for the Northward Displacement of the Pacific Intertropical Convergence Zone (ITCZ)

太平洋热带辐合带（ITCZ）北移机制

• 批准号: 0104468
• 负责人: Shang-Ping Xie
• 金额: $ 28.2万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-15 至 2005-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0104468&HistoricalAwards=false
• 关键词: Mechanisms; Northward; Displacement; Pacific; Intertropical

The project will investigate the causes for the off-equatorial location of the Inter-Tropical Convergence Zone (ITCZ). The confluence of northeast and southeast trade winds generates the moisture flux convergence that feeds deep tropical convection. The convection shows up as a bright cloud band in satellite pictures, and helps identify the ITCZ. Although solar forcing is nearly symmetric in the annual-mean, the ITCZ in the central/eastern Pacific remains northward of the equator throughout much of the year. Recent studies have revealed the role of ocean-atmosphere interactions in equatorial and coastal zones, and of geographical asymmetries of continents (e.g., the Americas) in producing the Northern hemisphere location of the ITCZ, but many key questions remain unanswered. Not surprisingly, the ITCZ remains a poorly simulated feature in current climate models. Drs. Shang-Ping Xie and Tim Li will identify the key climate interactions that control ITCZ location from modeling analysis, using a pair of coupled climate models. The PIs will decompose the geographical asymmetries of the Americas into several elements and investigate their "symmetry-breaking" potential in context of ITCZ's meridional position. They will also investigate the interaction of the eastern Pacific ITCZ and the North American monsoon. This research will advance the understanding of how ocean, land, and the atmosphere interact to shape the eastern Pacific climate. In so doing, it will provide the large-scale interpretive framework for NSF's Eastern Pacific Investigation of Climate (EPIC) field program, and also contribute to the Pan American/Pacific research goals of the U.S. CLIVAR program.

该项目将研究热带融合区（ITCZ）的赤道位置的原因。东北和东南贸易风的汇合产生了进食深度热带对流的水分通量收敛。对流显示为卫星图片中的明亮云带，并有助于识别ITCZ。尽管在年度公平的太阳能强迫几乎是对称的，但整个一年中的大部分时间，中部/东太平洋中部/东太平洋的ITCZ仍然是赤道的北部。最近的研究揭示了海洋 - 大气相互作用在赤道和沿海地区以及大陆（例如美洲）的地理不对称区域中的作用，在产生ITCZ的北半球位置中的作用，但许多关键问题仍然没有被提及。毫不奇怪，在当前气候模型中，ITCZ仍然是模拟不良的功能。博士。 Shang-Ping Xie和Tim Li将使用一对耦合气候模型来确定从建模分析中控制ITCZ位置的关键气候相互作用。 PIS将使美洲的地理不对称分解为几个要素，并在ITCZ的子午线立场上研究其“对称性的”潜力。他们还将调查东太平洋ITCZ和北美季风的相互作用。这项研究将促进对海洋，陆地和大气如何相互作用以塑造东部太平洋气候的理解。这样一来，它将为NSF的东部太平洋气候（EPIC）现场计划提供大规模的解释框架，并为美国Clivar计划的PAN American/Pacific Research目标做出贡献。