Properties of cloud condensation nuclei, ice nucleating particles, and cloud particle residuals in and around clouds of the Southern Ocean (HALO 2024, HALO-South)

南半球（SH），特别是南大洋（SO）是地球上对大气，特别是云相关特性研究不足的地区。此外，在SO上，一般环流模式（GCMs）等模式不能正确地再现云覆盖、云相和大气气溶胶，尽管这些是评估人为气溶胶影响和云对气候反馈的重要参数。与模式相比，卫星数据显示SH云中过冷液态水的比例更高，特别是在SO上空，这造成了辐射偏倚，因此在估算地球-大气系统辐射收支的模式中存在误差。一般来说，气溶胶粒子，特别是云凝结核（CCN）和冰成核粒子（INP），分别影响云的形成和冰川作用，从而影响云的微物理和辐射特性。有关于一般气溶胶颗粒的性质、迹象和假设的资料，特别是南大洋上空的CCN和INP。然而，无论是数据量还是对定量过程的理解，都不足以驱动、评估、甚至更重要的是改进SO区域的大气模式。因此，在本提案的框架内，我们建议联合测量CCN， INP和云粒子残留特性，并对其各自的起源和来源进行全面评估。应用仪器是一个小型的云凝结核计数器（mCCNc），大容量流气溶胶颗粒过滤器采样器（HERA）和逆流虚拟冲击器（HALO-CVI）。

The Southern Hemisphere (SH) and particularly the Southern Ocean (SO) are locations on Earth which are understudied concerning atmospheric and specifically cloud related properties. Furthermore, over the SO, models such as general circulation models (GCMs) cannot correctly reproduce cloud coverage, cloud phase and atmospheric aerosols, although these are important parameters for the assessment of anthropogenic aerosol impacts and cloud feedbacks on climate. Compared to models, satellite data show higher fractions of supercooled liquid water in clouds in the SH, particularly over the SO, causing a radiation bias and hence errors in models estimating the radiation budget of the earth-atmosphere system. Aerosol particles in general, and cloud condensation nuclei (CCN) and ice nucleating particles (INP) in particular, influence cloud formation and glaciation, respectively, thereby affecting cloud microphysical and radiative properties. Information concerning the properties, as well as indications and hypotheses with respect to potential sources of aerosol particles in general, and CCN and INP, in particular, over the Southern Ocean do exits. However, both amount of data and quantitative process understanding are not sufficient for driving, evaluating, and even more important improving atmospheric models over the SO region. Therefore, in the framework of this proposal, we suggest the combined measurement of CCN, INP, and cloud particle residual properties, together with a thorough evaluation of their respective origins and sources. Applied instruments are a miniaturized Cloud Condensation Nucleus Counter (mCCNc), the high-volume flow aerosol particle filter sampler (HERA) and a Counterflow Virtual Impactor (HALO-CVI).