Aerosol-Cloud-Radiation Interactions in Northern regions

冰云和混合相云在北极天气和气候系统中发挥着重要作用。因此，了解它们的性质，特别是它们的形成过程是至关重要的。北极上空的遥感观测揭示了冬季存在两种类型的冰云(TIC)。第一种类型为TIC-1，其特点是小冰晶密度高，通常在非污染地区观察到。另一方面，TIC-2的特征是较大的沉淀冰晶浓度较低。在这项研究中，假设TIC-2与高污染环境有关。过去的野外实验表明，在北极春季和冬季的污染时段，积累模式下的大部分气溶胶都被硫酸包裹。最近的实验室实验表明，酸性涂层可以改变冰核颗粒(INP)成核冰晶的效率。在这项研究中，我们假设在受污染的气团中发现的较低的IN浓度会导致冰晶浓度的降低。由于对有效水分的竞争较小，冰晶达到了沉淀大小，导致了TIC-2的形成。本研究旨在通过使用化学输运模型(WRFCHEM和GEM MACH)结合最新的冰微物理来更好地理解这两种类型TIC的形成过程。

Ice and mixed-phase clouds play an important role in the Arctic weather and climate system. Consequently, it is essential to understand their properties and especially their formation process. Remote sensing observations over the Arctic have revealed the existence of two types of ice clouds (TIC) during winter. The first type, TIC-1, is characterized by a high concentration of small ice crystals and is typically observed in non-polluted areas. On the other hand, TIC-2 is characterized by a low concentration of larger precipitating ice crystals. In this study, it is hypothesised that TIC-2 are linked to highly polluted environments. Past field experiments have shown that most aerosols in the accumulation mode are coated by sulphuric acid in polluted episodes in the Arctic during spring and winter. Recent laboratory experiments have shown that acid coating can alter the efficiency of ice nuclei particles (INP) to nucleate ice crystals. In this study, we hypothesize that the resulting lower IN concentration found in polluted air masses leads to the decrease of the ice crystal concentration. Since there is in less competition for the available moisture, ice crystals reach precipitating sizes leading to the formation of TIC-2. This research aims to better understand the formation process of these two types of TIC through the use of chemical transport models (WRFCHEM and GEM MACH) couple with state of the art ice microphysics.