Investigation of Convective Cloud Processes as Part of the North Dakota Tracer Experiment

计划于1993年夏季进行的北达科他州示踪试验将集中于继续研究活跃的对流云和风暴中的运输、扩散、结冰和冰雹胚胎发育过程。科学目标将是增加对自然云和种子云中这些过程的了解，以及它们与降水（包括冰雹）后续发展的关系。主要的实验技术将使用飞机释放的示踪材料，包括气态SF6、雷达箔条和荧光珠（用于冰雹胚胎研究）。1993年的项目将强调示踪材料的脉冲释放（典型持续时间30秒），以便于研究输运和扩散过程以及水成物的时间演变。只要有机会，将在支线云中发布，以研究支线云和主云之间的传输，以及其他可用的云类型。南达科他州矿业与技术学院T-28和北达科他州引文大学将对SF6以及运动学和微物理特征的云进行采样。c波段多普勒雷达将提供降水来源的单多普勒监测，并确定风暴是否具有馈线单元特征。一个移动类系统将提供当地环境的及时探测。

The North Dakota Tracer Experiment planned for the summer of 1993 will focus on continued study of transport, dispersion, ice initiation, and hail embryo development processes in active convective clouds and storms. The scientific goal will be to increase understanding of these processes in natural and seeded clouds, and their relation to the subsequent development of precipitation (including hail). The primary experimental techniques will employ tracer materials released from aircraft, including gaseous SF6, radar chaff, and fluorescent beads (for hailstone-embryo studies). The 1993 project will emphasize pulsed releases (typical duration 30 s) of the tracer materials to facilitate studying the time evolution of transport and dispersion processes and of the hydrometeors. Releases will be made in feeder clouds whenever opportunities arise, to study transport between feeder and main cell, and in other cloud types as available. The South Dakota School of Mines and Technology T-28 and University of North Dakota Citation will sample the clouds for SF6 as well as for kinematic and microphysical characteristics. C-band Doppler radar will provide one Doppler surveillance of the origin of precipitation, and determine whether the storms have feeder cell characteristics. One mobile CLASS system will provide timely soundings of the local environment.