Ice Nuclei and Ice Formation Processes in Tropical Cumulus Clouds

热带积云中的冰核和冰形成过程

• 批准号: 1036028
• 负责人: Paul DeMott
• 金额: $ 42.69万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-11-01 至 2013-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1036028&HistoricalAwards=false
• 关键词: Ice; Nuclei; Formation; Processes; Tropical

This award will provide researchers the opportunity to improve our understanding of the sources, physical and chemical nature, and number concentrations of atmospheric ice nuclei (IN). The measurements and modeling involved to be conducted are important in order to elucidate the roles of primary and secondary ice formation processes in determining microphysical composition and precipitation formation in cumulus clouds. The main aspect of this study is participation in the Ice in Clouds Experiment - Tropical Field Campaign (ICE-T). ICE-T is focused on improved understanding of the role of primary and secondary ice production in developing towering cumulus clouds through access to measurements to be collected during June-July 2011 by the NSF/NCAR C-130 aircraft. Research flights will be based out of St. Croix, in the U.S. Virgin Islands, with a target data collection region over the Western Tropical Atlantic and adjacent Caribbean Sea. Work supported under this award will provide IN measurements using the Colorado State University continuous flow diffusion chamber (CFDC) instrument, which is a annular flow diffusion chamber employing axial thermal gradients for real time ice nuclei measurements. The specific objectives are to perform airborne measurements aboard the C-130 to constrain the concentration of aerosols available to initiate ice by primary ice nucleation processes within the clouds being investigated, and to determine contributions of dust versus associated or unassociated biological aerosol toward ice formation at temperatures warmer than -20 degC. These investigators will then collaborate with other members of the ICE-T science team to analyze in-cloud ice formation processes a combination of via observational data and detailed numerical simulations. This support will also allow the investigative team to continue efforts to advance the technology for making atmospheric measurements of IN, including specialized implementations for ICE-T and participation in the proposed Instrument Development and Education in Airborne Sciences project.The intellectual merit of the award rests in expected improvements in understanding ice formation processes tropical cumuli, which are ubiquitous at near-equatorial latitudes, and in defining the role of different classes (inert vs. biological) of natural ice nuclei in triggering the initial formation of ice (and ultimately, precipitation) in such clouds.The broader impact of the research will include postdoctoral scientist training, collaborations with scientists in other institutions and disciplines, and enhancing U.S. research infrastructure. The obtained will be important for addressing such topics as aerosol-cloud-climate interactions and tropical storm formation. Additionally, a number of public outreach and educational activities are planned during the ICE-T field campaign.

该奖项将为研究人员提供机会，以提高我们对大气冰核（IN）的来源，物理和化学性质以及数量浓度的理解。 所进行的测量和模拟对于阐明初级和次级冰形成过程在确定积云的微物理组成和降水形成方面的作用是重要的。 这项研究的主要方面是参加云中冰实验-热带实地活动。 ICE-T的重点是通过获取NSF/NCAR C-130飞机在2011年6月至7月期间收集的测量数据，进一步了解初级和次级冰生成在形成高耸积云方面的作用。 研究飞行将以美属维尔京群岛的圣克鲁瓦为基地，目标数据收集区在热带大西洋西部和邻近的加勒比海。 该奖项支持的工作将使用科罗拉多州立大学的连续流扩散室（CFDC）仪器提供IN测量，该仪器是一种环形流扩散室，采用轴向热梯度进行真实的时间冰核测量。 具体目标是在C-130上进行空中测量，以限制可用于通过正在研究的云中的初级冰成核过程引发冰的气溶胶的浓度，并确定灰尘与相关或非相关生物气溶胶在温度高于-20 ℃时对冰形成的贡献。 然后，这些研究人员将与ICE-T科学团队的其他成员合作，通过观测数据和详细的数值模拟相结合来分析云中冰的形成过程。 这一支持也将使调查小组能够继续努力，以推进技术，使大气测量的IN，包括专门的实施ICE-T和参与拟议的仪器开发和教育在空中科学项目。该奖项的智力价值在于预期改善理解冰的形成过程热带积云，这是无处不在的近赤道纬度，并定义不同类别（惰性与生物）的天然冰核在触发此类云中冰的初始形成（并最终形成降水）中的作用。该研究的更广泛影响将包括博士后科学家培训、与科学家的合作其他机构和学科，以及加强美国的研究基础设施。 所获得的结果对于解决气溶胶-云-气候相互作用和热带风暴形成等问题将是重要的。 此外，还计划在移民、教育和培训局实地运动期间开展一些公共宣传和教育活动。