P2C2: Positive Feedback between Dust, Radiation, Precipitation and Temperature as a Driver for Abrupt Climate Change

气溶胶反馈是地球系统动力学中最不确定的因素之一(气专委，2007年)。古气候记录显示，与气候变化相关的尘埃波动很大。然而，尘埃对过去和未来气候变化的反馈作用仍然非常不确定。提出的工作假设是，尘埃、辐射、降水和温度之间的正反馈是气候突然变化的重要驱动因素。迈阿密大学的研究人员将重点研究大西洋气候突然变化的两个时期：海因里希事件1和非洲湿润时期的结束。这是两个气候突变的时期，气候突变的根源仍是一个有争议的问题。PIS将使用国家大气研究中心(NCAR)社区地球系统模型(CESM)和交互式尘埃模型进行瞬时古气候模拟，合成古尘埃和干旱记录，并测试其结果对尘埃光学性质变化的敏感性。智力价值拟议中的研究将增进我们对过去气候突变时期与沙漠沙尘相关的强迫和反馈的理解和知识，并确定当沙尘是一个相互作用的组成部分时，气候变化是否更加突然。通过模型数据合成，PI将分析在古气候模拟中包括沙尘气候反馈是否会使模型与观测更好地一致。瞬变古气候模拟的结果将在网上公布，以促进古气候模型与数据的相互比较。更广泛的影响该项目将通过使用CESM和参加CESM古气候工作组，在迈阿密大学、NCAR和康奈尔大学之间建立联系。研究活动将在科学会议、研讨会和社区推广活动中介绍，如科学咖啡馆(http://www.rsmas.miami.edu/info/seminar-archive/msg01683.html).从这项工作中获得的知识将用于为迈阿密大学教授的本科生和研究生课程准备课程材料。PIs参加了地球科学妇女网络(ESWN)，这是一个促进与其他从事科学和技术工作的妇女一起进行指导、支持、专业合作和职业发展的团体。此外，PIs还参加一年一度的RSMAS妇女参与科学日活动。该计划的目标是六年级和七年级的女孩，罗森斯蒂尔学院的女科学家在他们的科学领域领导实践活动，以吸引年轻参与者。

Aerosol feedbacks represent one of the highest uncertainties in the dynamics of the Earth system (IPCC, 2007). Paleoclimate records show significant fluctuations in dust associated with changes in climate. However, the role of dust as a feedback to climate change in the past and into the future remains highly uncertain. The proposed working hypothesis is that a positive feedback between dust, radiation, precipitation and temperature is an important driver for abrupt climate change. Researchers from the University of Miami will focus on two periods of abrupt climate change in the Atlantic: Heinrich Event 1 and the termination of the African Humid Period. These are two periods of abrupt climate change for which the source of the abruptness is still a matter of debate. PIs will run transient paleoclimate simulations using the National Center for Atmospheric Research (NCAR) Community Earth System Model (CESM) coupled to an interactive dust model, synthesize paleo-dust and drought records, and test the sensitivity of their results to changes in dust optical properties. Intellectual MeritThe proposed research will advance our understanding and knowledge of forcing and feedbacks associated with desert dust in past periods of abrupt climate change, and determine if climate change is more abrupt when dust is an interactive component. Through model-data synthesis, the PIs will analyze if the inclusion of dust climate feedback in paleoclimate simulations bring models into better agreement with observations. Results from the transient paleoclimate simulations will be made available online to facilitate paleoclimate model-data intercomparisons. Broader ImpactsThe project will establish linkages between the University of Miami, NCAR, and Cornell University through the use of CESM and the participation in the CESM Paleoclimate Working Group. Research activities will be presented at scientific conferences, workshops, and community outreach events, such as the science café (http://www.rsmas.miami.edu/info/seminar-archive/msg01683.html). Knowledge gained from this work will be used to prepare curriculum material for undergraduate and graduate courses taught at the University of Miami. The PIs participate in the Earth Science Women's Network (ESWN), a group that promotes mentoring, support, professional collaborations, and career development with other women working in science and technology. In addition, the PIs participate in the annual RSMAS Women in Science day. This program targets sixth and seventh grade girls, and female scientists from the Rosenstiel School lead hands-on activities in their scientific field to engage the young participants.