Aerosol-Cloud-Radiation Interactions in Northern regions

冰和混合相云在北极天气和气候系统中起着重要作用。因此，有必要了解它们的性质，特别是它们的形成过程。北极地区的遥感观测显示冬季存在两种类型的冰云（TIC）。第一类是TIC-1，其特点是小冰晶浓度高，通常在无污染地区观察到。另一方面，TIC-2的特点是低浓度的大沉淀冰晶。在这项研究中，人们假设TIC-2与高度污染的环境有关。过去的野外试验表明，在春冬季北极污染期，大多数气溶胶呈累积模式被硫酸包裹。最近的实验室实验表明，酸涂层可以改变冰核粒子（INP）成核冰晶的效率。在本研究中，我们假设污染空气团中In浓度的降低导致冰晶浓度的降低。由于对可用水分的竞争较少，冰晶达到沉淀大小，导致TIC-2的形成。本研究旨在利用化学输运模型（WRFCHEM和GEM MACH）结合冰微物理学的最新进展，更好地了解这两种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.