Cloud Modeling for Field Experimentation, Including Cloud Modification, and Comparisons with Observations

改变云过程以影响降水的数量和类型仍然是一项科学和技术挑战。虽然提出了许多修正理论，但自然降水产生的复杂性和变异性限制了可预测的应用。人工影响天气的进展不太可能仅靠实地试验来实现。降水过程的数值模式现在已经足够复杂，可以对我们的理解作出很大贡献。这项研究的主要目的是进一步了解冰相播种对雨和冰雹形成的影响。先进的二维和三维时间依赖模型的结果将与有籽和无籽对流云的实际观测结果进行比较，以确定云改变的重要物理过程。次要目标是研究播种材料的运输，并使用二维模型作为预测辅助进行试验。这项研究将作为美国国家科学基金会和美国国家海洋和大气管理局关于改变对流云的联合实验的一部分，该实验被称为北达科他州雷暴项目

The modification of cloud processes to influence quantity and types of precipitation remains a scientific and technical challenge. Although many modification theories have been advanced, the complexity and variability of natural precipitation production has limited predictable application. It is unlikely that advances in weather modification can be made by field experimentation alone. Numerical models of precipitation processes are now of sufficient sophistication that they can contribute much to our understanding. The primary objective of the research is to gain further understanding of the effects of ice-phase seeding on the formation of rain and hail. Results from advanced, time dependent models in two and three spatial dimensions will be used in comparison with actual observations of seeded and unseeded convective clouds to ascertain important physical processes in cloud modification. Secondary objectives are to study the transport of seeding materials and to conduct tests using two-dimensional models as a forecast aid. The Principal Investigators will undertake this research as part of a joint NSF/NOAA experiment on the modification of convective clouds known as the North Dakota Thunderstorm Project.//