Doppler Radar Studies of Meteorological Phenomena

本研究的目的是：(1)强下沉气流的模拟和观测研究。这将涉及对现有一维模型的扩展，完成和扩展轴对称下沉气流的建模工作，包括详细的微物理。预计将扩展到三维，并在所有模型中包含更完整的微观物理(除了熔化和蒸发之外，还包括液滴、合并和破裂)。各种模型的结果将与雷达，特别是地面气象数据进行比较；(2)将雷达测量的ZDR与从廓线仪观测推断的雨滴尺寸分布计算的ZDR进行比较，并通过廓线仪观测研究雨滴和雨滴振荡的尺寸谱；(3)测量雨水含量和降雨率的双雷达方法的数值模拟和理论研究，以及该方法与观测结果的对比试验；以及(4)在非常缓慢的上升气流中，如在层状云中，通过凝结水滴增长的理论计算。

The objectives of this research are: (1) modeling and observational studies of intense downdrafts. This will involve extensions to the one-dimensional models already in existence, completion and extension of work on the modeling of axially symmetric downdrafts including detailed microphysics. An extension to three dimensions and inclusion of more complete microphysics (drop coalescence and breakup in addition to melting and evaporation) in all the models is anticipated. The results of the various models will be compared with radar and, in particular, surface meteorological data; (2) A comparison of ZDR measured by a radar, with that calculated from the drop size distribution inferred from profiler observations, and studies of the size spectra of raindrops and raindrop oscillations by means of profiler observations; (3) Numerical simulations and theoretical studies of a dual-radar method of measurement of rainwater content and rainfall rate and tests of the method against observations; and (4) A theoretical calculation of the growth of drops by condensation in very slow updrafts, as in stratiform clouds.