Horizontal km Scale Variability of Arctic Sea Ice and Atmospheric Dynamics, Aerosol, Trace Gases and Radiation for Investigating Interaction Processes of the Earth System Compartments during the Melting Season (HELiPOD4ArtofMelt)

项目HELiPOD 4ArtofMelt的总体目标是帮助了解暖空气入侵对北极大气的影响，并了解决定北极海冰融化开始的空间不均匀性的过程和反馈机制。该方法包括分析2023年5月/6月瑞典破冰船奥登号在北冰洋大西洋部分的融化艺术探险期间获得的空中现场数据。直升机搭载的探测器HELiPOD部署了大量的传感器，用于表征奥登周围100公里范围内的海冰表面、大气动力学、气溶胶、痕量气体和辐射收支的空间分布和特性。奥登探险国际参与者的补充传感器包括在HELiPOD中，例如用于调查水蒸气同位素以研究蒸发，用于确定冰成核粒子以将观测与云特性联系起来，用于测量一氧化碳浓度，烟尘浓度和过滤器采样器用于随后的显微镜实验室分析。在15-20米的低空进行了长距离飞行，以研究海洋-海冰-空气交换过程，并进行了垂直廓线，以研究大气稳定性和参数的垂直分布和变率。不同参数的同步数据集允许量化关系和相互作用，例如，增加的熔池部分的面积可以直接与显热通量和潜热通量的变化、气溶胶颗粒尺寸分布和数量浓度的改变以及随后在小空间尺度上表面能量平衡的改变相关。除了对Oden的连续测量外，HELiPOD数据还提供了空间变异性的信息。在对大型数据集进行最后处理后，确定不同参数的空间变异性，以得出1公里以下至100公里范围内的三维图像。与国际合作伙伴进行的分析的一个特别重点是对所谓的“大气河流”进行表征，即在北极圆顶平流输送暖湿空气团的环流模式，以量化大气边界层的性质和变化，例如垂直温度剖面和热通量的变化，这最终影响融化。此外，过程和相互作用的空间和时间不均匀的海冰融化开始的基础上的空中观测，连续测量奥登，并考虑到泛北极观测站网络在斯瓦尔巴特群岛，格陵兰岛和北方斯堪的纳维亚半岛。

The project HELiPOD4ArtofMelt has the overall aims to contribute to understanding the impact of warm-air intrusions on the Arctic atmosphere, and to understanding processes and feedback mechanisms determining the spatially inhomogeneous onset of Arctic sea ice melt. The method consists in the analysis of airborne field data obtained during the expedition Art of Melt of the Swedish ice breaker Oden in the Atlantic sector of the Arctic Ocean in May/June 2023. The helicopter borne sonde HELiPOD is deployed with a multitude of sensors for characterising the spatial distribution and properties of the sea ice surface, atmospheric dynamics, aerosol, trace gases and radiation budget within a range of up to 100 km around the Oden. Additional complementary sensors of the international participants of the Oden expedition are included in the HELiPOD, e.g. for investigating the water vapour isotopes to study evaporation, for determining ice nucleation particles to relate the observations to cloud properties, for measuring the carbon monoxide concentration, the soot concentration, and filter samplers for subsequent microscopic laboratory analyses. Long flight legs are performed at low altitudes in the range of 15-20 m to study the ocean-sea ice-air exchange processes, and vertical profiles are done to investigate atmospheric stability and the vertical distribution and variability of the parameters. The simultaneous data sets of the different parameters allow quantifying relations and interactions, e.g. an area of increased melt pond fraction can be related directly to changes in sensible and latent heat fluxes, modifications in aerosol particle size distribution and number concentration, and subsequent alteration of the surface energy balance on small spatial scales. In addition to the continuous measurements on the Oden, the HELiPOD data provide information on the spatial variability. After final postprocessing of the large data set, the spatial variability of the different parameters is determined to derive a three-dimensional picture on the scale from below 1 km to 100 km. A special focus of the analyses with the international partners is on the characterisation of so-called „atmospheric rivers“, circulation patterns that advect warm and moist air masses in the Arctic dome, to quantify properties and modification of the atmospheric boundary layer, e.g. changes in the vertical temperatue profiles and heat fluxes, which finally impact melting. Further, the processes and interactions contributing to the spatially and temporally inhomogeneous sea ice melting onset are investigated based on the airborne observations, continuous measurements aboard Oden, and taking into account the pan-Arctic measurement network of observatories in Svalbard, Greenland and northern Scandinavia.