Dimensions: Collaborative Research: Research on Airborne Ice-Nucleating Species (RAINS)

微生物在大气中含量丰富，在控制云的发展、云化学和最终的天气模式方面发挥着重要作用。它们主要是通过产生酶来催化冰晶的形成（成核），这种酶在比通常形成冰所需的温度（-2℃vs -36℃）高得多的温度下形成冰晶。尽管有大气层？大气中微生物的丰度、多样性和通量在很大程度上仍然是未知的。冰核微生物在降水事件中显著影响气象学和促进微生物扩散的潜力激发了这项研究。RAINS项目将在地面和低层大气中使用遥控飞机取样雨、雪和空气样本。该项目将：(1)描述微生物分类多样性，包括发生在公元1794年至现在的降水，并保存在冰川冰中；(2)确定微生物组合和单个冰成核细菌的遗传多样性；(3)研究降水和生物冰成核对微生物分布模式的作用的功能多样性。这项工作还将确定哪些微生物被带到地球上？S表面通过降水为影响人类、家畜和植物的疾病提供了可能的接种源。RAINS项目将增加对大气边界层生物多样性的了解，大气边界层是发生降水等重要气象现象的地方。政府间气候变化专门委员会建议更好地了解气溶胶和大气结冰的影响，以便改进气候模式并预测全球气温上升的影响。拟议的研究将增加对大气中最活跃的冰核性质的认识。微生物冰核也可能使微生物和某些植物病原体在大气和地表栖息地之间有效地循环，RAINS将有助于评估冰核微生物在地理尺度上的运动。推广工作将把这些进步以实践研究经验的形式带入高中和大学的课堂，为两个级别的学生提供实践研究经验，并将作为高中教育者开发独特课堂活动的基础。此外，还将建立一个由科学家组成的国际网络，收集旱地地区生物冰核丰度、种植方式和降水之间关系的实地数据。RAINS将赞助一次国际会议，召集该网络中的10名年轻职业科学家，以突出这些研究的进展并确定突出的科学问题。

Microorganisms are abundant in the atmosphere and play an important role in controlling cloud development, cloud chemistry and ultimately weather patterns. They do this primarily by producing enzymes that catalyze the formation (nucleation) of ice crystals at significantly warmer temperatures than would normally be required for ice formation (-2 C vs. -36 C). Despite the atmosphere?s fundamental role in their dispersal, the abundance, diversity and flux of microorganisms in the atmosphere remain largely unknown. The potential of ice-nucleating microorganisms to significantly impact meteorology and promote microbial dispersal during precipitation events motivates this research. The RAINS project will sample rain, snow and air samples at ground level, and in the lower atmosphere using remote-controlled aircraft. The project will: (1) characterize microbial taxonomic diversity, including in precipitation that occurred between 1794 AD and present, and which is preserved in glacial ice; (2) determine the genetic diversity of microbial assemblages and of individual ice nucleating bacteria and (3) examine the functional diversity with respect to the role of precipitation and biological ice nucleation on patterns of microbial distribution. The work will also determine which microbes carried to the Earth?s surface via precipitation present possible inoculum sources for diseases that impact humans, domestic animals, and plants. The RAINS project will increase understanding of biodiversity in the planetary boundary layer of the atmosphere, where important meteorological phenomena such as precipitation occur. The Intergovernmental Panel on Climate Change recommended developing a better understanding of the effect of aerosols and atmospheric ice formation in order to improve climate models and forecast the impact of rising global temperature. The proposed study will increase knowledge on the nature of the most active ice nucleators in the atmosphere. Microbial ice nucleation may also allow microorganisms and certain plant pathogens to efficiently cycle between the atmosphere and surface habitats, and RAINS will contribute to ongoing efforts to assess the movement of ice nucleating microorganisms across geographical scales. Outreach efforts will take these advances into high school and college classrooms in the form of hands-on research experiences for students at both levels and will serve as the basis for high school educators to develop unique classroom activities. In addition, an international network of scientists collecting field data on the relationship between biological ice nucleator abundance, cropping patterns and precipitation in dry land regions will be established. RAINS will sponsor an international conference that brings together 10 young career scientists in the network to highlight the advances of these investigations and identify the outstanding scientific questions.