Relations Between Ice Nuclei and Ice Formation in Clouds

摘要/大卫C.罗杰斯/9714177 云中冰核与冰形成的关系 这项研究将研究大气中的气溶胶粒子之间的关系，启动冰的成核（Imown作为冰核，或IN）和冰晶在云中的形成冰如何开始在云中形成的问题是一个长期存在的问题在大气科学。在过去40年的科学评论中已经指出了对这一主题进行研究的必要性。 为此目的，许多实地研究已经进行了使用仪表飞机检查云结构和微观物理。以前试图将冰缺失和冰晶浓度联系起来的尝试依赖于在一个位置和时间的云观测，在不同的位置和时间收集气溶胶，然后在实验室处理气溶胶收集。 在某些情况下，测量解决了温度依赖性，但不包括同样重要的湿度变化。诸如此类的问题，加上冰浓度的广泛自然变化，使得难以评估冰核浓度是否与云的给定部分中的冰晶浓度有很好的相关性。这项研究对这个问题提出了一种新的看法。气溶胶和云的同时观测，在真实的时间，选择和调整的温度和湿度的IN测量的能力，现在有可能与一个新的仪器，快速响应的机载连续流扩散室（CFD）。冰核将在同一时间和同一架飞机上进行微物理观测。将确定IN浓度的温度和湿度依赖性，并收集IN气溶胶进行电子显微镜检查，以确定尺寸和元素组成。这项工作包括在研究飞机上安装仪器，获得气溶胶加上云微物理和其他特性的测量结果，并在三年内进行分析和数值模拟。 观测将在NSF支持的美国五大湖地区的冬季风暴和科罗拉多和怀俄明州的地形波云的实地研究中进行。分析将包括将IN测量值与飞机微物理数据进行比较。还将进行冰形成和云微物理学的数值过程模拟，以帮助解释这些数据。初级冰成核（与次级过程）和降水形成之间的关系，在冬季风暴将使用微物理和遥感观测收集的其他研究人员谁是参与现场方案进行调查。

Abstract/David C. Rogers/9714177 Relations between Ice Nuclei and Ice Formation in Clouds This research will examine the relationship between the aerosol particles in the atmosphere that initiate nucleation of ice (Imown as Ice Nuclei, or IN) and the formation of ice crystals in clouds The question of how ice begins to form in clouds is a long-standing problem in atmospheric science. The need for research on this topic has been pointed out in scientific reviews over the past 40 years. To this end, many field studies have been performed using instrumented aircraft to examine cloud stnucture and microphysics. Previous attempts to correlate Ice Nulclci and ice crystal concentrations oflen depended on cloud observations at one location and time, collecting aerosols at a different location and time, and processing the aerosol collections still later, at a laboratory. In some cases, measurements addressed temperature dependencies but did not include equally important variations in humidity. Problems such as this, together with the wide natural variability of ice concentrations, have made it difficult to evaluate whether concentrations of ice nuclei are well correlated with concentrations of ice crystals in a given part of a cloud. This research embraces a new approach to this question. Simultaneous observations of aerosols and clouds, in real time, with the capability to select and adjust the temperature and humidity of IN measurements are now possible with a new instrument, a fast-response airborne continuous flow difflision chamber (CFD). Ice nuclei will be measured at the same time and in the same aircraft making microphysical observations. The temperature and humidity dependence of IN concentration will be determined, and IN aerosols will be collected for electron microscope examination to determine size and elemental composition. The work involves installing instrumentation on research aircraft, obtaining measurements of aerosols plus cloud microphysical and other prope rties, and performing analyses and numerical modeling over a three-year period. Observations will be made in NSF-supported field studies ofwinter storms in the Great Lakes region of the U.S. and in orographic wave clouds in Colorado and Wyoming. The analyses will involve comparing IN measurements with aircraft microphysical data. Numerical process-modeling of ice formation and cloud microphysics will also be performed to aid the interpretation of these data. The relation between primary ice nucleation (versus secondary processes) and precipitation formation in winter storms will be investigated using microphysical and remote-sensing observations collected by other investigators who are participating in the field programs.