The importance of ice nucleating particle types and modes for the initiation of the ice phase and precipitation: Model simulations based on laboratory measurements.

在这个项目中，模型模拟将使用COSMO-SPECS进行，这是一种3D云模型，其中包括气溶胶粒子和水流星的光谱面元微物理方案。由于微物理包与因纽特-1号期间使用的航空包裹模型中包含的相同，因此因纽特-1号的所有新开发和修改都将转移到宇宙规范中。首先，将模拟一个人工测试案例，即平坦地形上的热泡，敏感性研究将显示在冰核粒子类型和分布的真实变化下冰相和降水的发展。敏感性研究的另一个重点将放在所谓的小触发因素的影响上，即冰核粒子类型(如生物粒子)或冻结模式(如接触冻结)，它们乍一看不会显示出明显的影响，但可能会影响云的动力学，最终加强冰的形成。最后，将与Rp5联合开展以因纽特人实地实验为基础的真实案例研究。不同的结冰模式的贡献将被量化，从而将估计因纽特实验室和实地项目中调查的冰成核制度的大气相关性。同时，将开发在因纽特-2期间研究的新粒子类型的参数，并将其纳入微物理方案。现有的参数化将不断修改和改进。作为该项目的一部分，将利用美因茨垂直风洞和声学悬浮器进行一些实验室实验，以调查接触和浸泡冻结。这里的重点在于改进接触冻结实验。它们将在美因茨垂直风洞中进行，过冷液滴自由漂浮在携带潜在接触冰核粒子的气流中。因此，可以计算液滴和粒子之间的碰撞次数，并且可以确定冻结效率，即一个液滴-粒子碰撞的冻结概率。

In this project model simulations will be performed with COSMO-SPECS, a 3D cloud model which includes a spectral bin microphysical scheme for aerosol particles and hydrometeors. As the microphysics package is the same contained in the air parcel model used during INUIT-1, all new developments and modifications from INUIT-1 will be transferred into COSMO-SPECS. First an artificial test case, i.e. a heat bubble over a flat terrain, will be simulated and sensitivity studies will show the development of the ice phase and precipitation under realistic variations of ice nucleating particle types and distributions. Another focus of the sensitivity studies will lie on the effects of so-called small triggers, i.e. ice nucleating particle types (e.g., biological particles) or freezing modes (such as contact freezing) which do not show significant effects on the first sight but might influence the dynamics of the cloud in the way that in the end ice formation is enhanced. Finally a real case study based on INUIT field experiments will be performed in joint cooperation with RP5. The contributions of the different ice forming modes will be quantified and, thus, the atmospheric relevance of the ice nucleation regimes which are investigated in INUIT laboratory and field projects will be estimated. Simultaneously, parameterizations of new particle types studied during INUIT-2 will be developed and included into the microphysical scheme. Existing parameterizations will continuously be modified and improved. As part of the project a number of laboratory experiments will be performed to investigate contact and immersion freezing by means of the Mainz vertical wind tunnel and an acoustic drop levitator. Here the focus lies on the improvement of contact freezing experiments. They will be conducted at the Mainz vertical wind tunnel with supercooled drops freely floated in an air stream which carries the potential contact ice nucleating particles along with. Thus, the number of collisions between drops and particles can be calculated and the freezing efficiency, i.e. the freezing probability for one drop-particle collision can be determined.