Collaborative Research: P2C2--Reconstructing Holocene Dynamics of the Indo-Pacific Tropical Rain Belt using Australian Stalagmites and Coupled Climate Models

合作研究：P2C2——利用澳大利亚石笋和耦合气候模型重建印度洋-太平洋热带雨带全新世动态

• 批准号: 1602544
• 负责人: Rhawn Denniston
• 金额: $ 10.41万
• 依托单位: Cornell College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-01 至 2022-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1602544&HistoricalAwards=false
• 关键词: Collaborative; Research; P2C2; Reconstructing; Holocene

This collaborative project generally aims to develop a high resolution aragonite stalagmite record of Holocene Indo-Australian Summer Monsoon (IASM) variability from cave KNI-51, located at the southern margin of the Indo-Pacific tropical rain belt (TRB), a region bounded by the austral and boreal summer intertropical convergence zones. Regional monsoons represent the dominant component of low latitude hydroclimate and are sensitive to a wide array of sub-orbital forcings including solar irradiance, ENSO, and volcanic and anthropogenic aerosols. Tropical societies and ecosystems rely heavily on monsoon rainfall, and thus understanding the origin and nature of decadal-scale hydroclimate variability is critical to understanding the dynamics at play in such systems.Recent field studies of Indo-Pacific hydroclimate suggests that over the last millennium, the TRB may have contracted during the Little Ice Age (LIA) thereby producing reduced monsoon rainfall along both the northern and southern margins of the TRB. In contrast, paleohydrologic and modeling studies show that the global TRB shifted southward meridionally at this time, creating anti-phasing (dry/wet) of rainfall between the TRB northern and southern margins. The researchers have developed a sub-decadal resolved (~4 year) late Holocene (the last 3,000 years) IASM reconstruction from cave KNI-51 that, when integrated with paleomonsoon records from Southeast Asia and the Maritime Continent, reveal not only TRB contraction during the LIA, but expansion and contraction at multi-decadal to centennial time scales over the entirety of the late Holocene. The specific research goals of the project are to extend the KNI-51 stalagmite record through the middle and early Holocene (9,000-3,000 years ago) to examine the nature of TRB dynamics during conditions distinct from those of the late Holocene, including elevated contrasts between summer insolation in the Northern and Southern Hemispheres, lower eustatic sea level (and increased exposure of Indo-Pacific continental shelf), intervals of reduced Atlantic meridional overturning circulation, and the El Nino-Southern Oscillation (ENSO) regime. To better understand atmospheric circulation associated with TRB dynamics, these proxy data will be integrated with climate dynamical analyses of the 6,000 year time slice simulations conducted within the Coupled Model Intercomparison Project phase 5/Paleoclimate Modeling Intercomparison Project phase 3 (CMIP5/PMIP3) framework and with the newly available Last Millennium Ensemble (LME) simulations conducted by the National Center for Atmospheric Research (NCAR).The project involves the potential for a unique view of TRB variability over the last 9,000 years and provides an important test of the skill of CMIP5-class models to accurately reproduce associated Indo-Pacific atmospheric dynamics. As the TRB is closely tied to tropical methane production, this research will help refine estimates of regional tropical methane fluxes during the Holocene. The research will be conducted with extensive involvement of undergraduate students thereby providing experience in advanced paleoclimate research and data analysis techniques.

该协作项目通常旨在开发高分辨率的陆战石stalagmite记录，该记录是印度 - 澳大利亚夏季季风（IASM）的可变性，位于印度太平洋热带雨带（TRB）的南部边缘（TRB）的南部边缘，该地区是由澳大利亚和自卫夏季夏季室内互动式Zones界定的。区域季风代表了低纬度气候的主要成分，并且对包括太阳辐照度，ENSO以及火山和人为气溶胶在内的各种亚轨道弯曲敏感。 热带社会和生态系统在很大程度上依赖于季风降雨，因此理解了十年级级氢化气候变化的起源和性质，对于理解这种系统中的动态至关重要。印度 - 太平洋氢化气候的现场研究表明，在过去的千年中，TRB可能与冰上的降雨相同，这是北方的降雨（Lia），这是Mar的降雨（Lia），这是Mar的范围。 trb。 相比之下，古水力学和建模研究表明，此时全球TRB向南移动，从而产生了TRB北部和南部边缘之间的降雨（干/湿）。 The researchers have developed a sub-decadal resolved (~4 year) late Holocene (the last 3,000 years) IASM reconstruction from cave KNI-51 that, when integrated with paleomonsoon records from Southeast Asia and the Maritime Continent, reveal not only TRB contraction during the LIA, but expansion and contraction at multi-decadal to centennial time scales over the entirety of the late Holocene. The specific research goals of the project are to extend the KNI-51 stalagmite record through the middle and early Holocene (9,000-3,000 years ago) to examine the nature of TRB dynamics during conditions distinct from those of the late Holocene, including elevated contrasts between summer insolation in the Northern and Southern Hemispheres, lower eustatic sea level (and increased exposure of Indo-Pacific continental shelf), intervals of reduced Atlantic meridional推翻循环和埃尔尼诺 - 南方振荡（ENSO）制度。为了更好地理解与TRB动态相关的大气循环，这些代理数据将与气候动力学分析集成，以耦合模型对比计划阶段5/古气候建模项目阶段3（CMIP5/PMIP3）的框架（CMIP5/pmip3）框架（CMIP5/pmip3）框架（CMIP5/pmip3）框架（LMERERION ENDERDERCTION）（LME）ENDENEMERS ENDENEMER（LME）进行的6,000年时间切片模拟（偶联模型之间的模拟）进行了模拟。 （NCAR）。该项目涉及在过去的9，000年中对TRB变异性的独特视图的潜力，并对CMIP5级模型的技能进行了重要的测试，以准确再现相关的印度太平洋大气动力学。 由于TRB与热带甲烷的产生紧密相关，因此这项研究将有助于改进全新世期间区域热带甲烷通量的估计。这项研究将在本科生的广泛参与下进行，从而提供高级古气候研究和数据分析技术的经验。