New insights into precipitation development as affected by novel investigations on the limitation of large raindrops' sizes

对大雨滴尺寸限制的新研究影响降水发展的新见解

• 批准号: 25482868
• 负责人: Professor Dr. Klaus Dieter Beheng (†)
• 金额: --
• 依托单位: Department Troposphärenforschung (IMK-TRO)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/25482868?language=en
• 关键词: New; insights; into; precipitation; development; New; insights; into; precipitation; development

To the ultimate goal to improve precipitation forecasts a basic mechanism limiting the size of large raindrops (collision-induced breakup), which has been examined in the very past by very few laboratory experiments only, is re-investigated. Its effect is estimated by numerical studies using a cloud-resolving operational weather forecast model of the German Weather Service. The studies are partitioned into two parts: At first numerical experiments with an advanced fluid-dynamics code were performed where the collision and the breakup of colliding large (rain)drops are followed in greatest detail. They will be checked by according laboratory experiments. The results provide characteristics whose values may depend on specific breakup modes if results of the few past experiments are confirmed. The new data will be used in a ID-rainshaft model. Besides equilibrium raindrop size spectra important in many fields related to precipitation physics as, e.g., in radar meteorology, the rainshaft model delivers basic values for deriving a (coarser) parameterization of breakup. Prom the latter values then a new parameterization of breakup is developed for operational applications. It will replace the traditional formulation which actually is part of a bulk cloudmicrophysical scheme running already in a cloud-resolving version of a weather forecast model of the German Weather Service. First sensitivity studies will be undertaken to assess the effect of the new data on the breakup process on precipitation.

为了提高降水预测的最终目标是一种基本机制，限制了大雨滴的大小（碰撞引起的分裂），这在过去的几乎没有实验室实验中已经对此进行了检查。它的效果是通过使用德国气象服务的云解决云的操作天气预测模型来估计的。研究分为两个部分：首先，进行了高级流体动力学代码的数值实验，在此，碰撞和碰撞大（雨）滴的破裂最大的细节遵循。根据实验室实验将检查它们。结果提供了特征，如果证实了过去的几个实验的结果，其值可能取决于特定的分解模式。新数据将用于ID-Rainshaft模型。除了在与降水物理学有关的许多领域中重要的雨滴尺寸光谱外，例如在雷达气象学中，雨轴模型还提供了基本值，以推导A（更粗）的分裂参数化。 PROM后一个值，然后为操作应用开发了新的分解参数化。它将取代传统的配方，这实际上是在德国气象服务的天气预报模型的云分辨率版本中运行的散装云生理方案的一部分。将进行首次敏感性研究，以评估新数据对分解过程对降水的影响。