Mixing Processes and their Influence on Drop Size Distribution in Florida Cumuli

在这个项目中，我们将研究负责扩大小积云中云滴大小分布的因素，特别注意混合和夹带在这个过程中的作用。主要的预算项目是支持研究生Richard Igau，他将在博士的指导下工作。德州农工大学的Ed Zipser和国家大气研究中心的W. A. Cooper。主要数据来源将是小积云微物理研究（SCMS），这是佛罗里达州的一个实地项目，使用NCAR CP2双波长雷达和三架仪器研究飞机。在该项目期间，在该雷达10-20公里范围内形成了许多小积云，三架仪器研究飞机对这些积云进行了很好的研究。所有飞机上都使用了传统的前向散射光谱仪探针（FSSP）和King液态水探针，此外，Brenguier等人（1996）的Fast FSSP (FFSSP)， Lawson和Cormack（1995）的云滴光谱仪（CDS）， Baumgardner等人（1993）的液滴间距监测器（DSM），以及Gerber等人（1994）的ppm -100液态水含量探针都在SCMS中使用。这些新仪器大大提高了液滴大小和空间的分辨率，因此应该有助于克服标准FSSP的局限性，这些局限性已经损害了许多过去的研究，因此应该有助于克服标准FSSP的局限性，这些局限性已经损害了许多过去的液滴大小分布研究。在本研究过程中，我们将评估用于测量液滴尺寸分布的新仪器的特性和价值，将描述云的非混合和混合区域的典型液滴尺寸分布，并将这些尺寸分布的宽度与理论预测进行比较。我们还将研究夹带和混合过程，作为一个主题本身以及它对液滴尺寸分布的影响。与过去的类似研究相比，新仪器应该能更好地描述液滴的大小，而由非常灵敏的雷达进行的良好的同步观测应该能更好地解释云的生活史和动力学方面的微物理观测。因此，应该有可能对理论预测进行严格的检验，从而更好地了解积云中液滴大小分布的发展情况。

Zipser/Abstract ATM-9707301 In this project we will examine factores responsible for broadening the size distributions of cloud droplets in small cumulus clouds, with special attention to the roles of mixing and entrainment in that process. The main budget item is support for a graduate student, Richard Igau, who will work under the guidance of Drs. Ed Zipser of Texas A&M University and W. A. Cooper of the National Center or Atmospheric Research. The primary data source will be the Small Cumulus Microphysics Study (SCMS), a field program in Florida that used the NCAR CP2 dual-wavelength radar and three instrumented research aircraft. Many small cumulus clouds developed witin 10-20 km of this rdar during the project, and a good sample of these were studied by the three instrumented research aircraft. Conventional Forward Scattering Spectrometer Probes (FSSPs) and King liquid water probes were present on all aircraft, and in addition the Fast FSSP (FFSSP) of Brenguier et al. (1996), the Cloud Droplet Spectrometer (CDS) of Lawson and Cormack (1995), the Droplet Spaceing Monitor (DSM) of Baumgardner et al. (1993), and the PVM-100 liquid water content probe of Gerber et al. (1994) were all used in the SCMS. These new instruments provide much improved resolution in droplet size and in space, and so should help overcome the limitations of the standard FSSP which have compromised many past studies, and so should help overcome the limitatins of the standard FSSP which have compromised many past studies of droplet size distributions. In the course of this resesarch, we will assess ofthe characteristics and value of the new instruments for measuring droplet size distributions, will characterize typical droplet size distribuions in unmixed and mixed regions of cloud, and will compare the widths of these size distributions to theoretical predicitions. We will also study the entrainment and mixing process, as a topic in itself as well as for its influence on droplet size distributions. The new instruments should provide better characterization of droplet sizes than has been available to similiar studies in the past, and the goood simultaneous observations by a very sensitive radar should support better interpretation of the microphysical observations in terms of the life history and dynamics of the clouds. It should therefore be possible to test theoretical predictions critically, and so to develop an improveed understanding of how droplet size distributions develop in cumulus clouds.