Vertical Turbulent Aerosol Particle Transport above open Water and Ice in the central Arctic during Summertime (APAICA) -Aerosol particle sources and transformation in the Arctic marine boundary layer

由于气候变化，目前在北极观察到最强烈的温度上升。这一事实是基于一个非常复杂的过程和反馈链，其中气溶胶粒子通过影响辐射平衡和云的形成而发挥重要作用。为了评估冰盖变化的影响，还需要更好地了解海洋以及冰与大气之间的相互作用。总的来说，缺乏大气测量，特别是在北冰洋，这是迫切需要了解的过程，也是预测预期的变化。在这些地区，目前对海洋/冰与大气之间的交换过程知之甚少。在该项目中，RV Polarstern将用于详细研究水和冰上方的垂直交换过程，并定位相关的气溶胶颗粒源。为此，计划在船上进行一系列连续的气溶胶测量，包括数量尺寸分布，光学参数（散射，吸收），含有黑碳（BC）的颗粒的混合比，冰成核颗粒（INP）的浓度，以及气溶胶颗粒的化学成分。此外，将在夏季经常出现的雾期收集雾水样本，以及在整个活动期间每天从海洋中收集水样。在测量活动后，将分析这些样品的INP和BC浓度。首次采用激光白炽法测量空气和水样中的BC-浓度。将采用一种新的高矿化度水样预处理方法。通过对空气和水中组分的平行调查，应量化这些气溶胶颗粒的输送和交换过程。在船舶平静运动或随冰漂移期间，将在船舶前支腿处使用测量设备，以确定垂直颗粒通量。这将用于获取风矢量和颗粒浓度的时间序列，随后将用于通过涡动协方差法确定垂直湍流颗粒通量。结合这些测量，记录INP的浓度，以便能够指定其起源和来源。另一个测量系统，包括一维风测量和颗粒计数器，连接到起重机吊钩，位于前支腿下方，并确定颗粒浓度的垂直分布，由此也可以估计垂直颗粒通量。这些方法已经得到证实和确立，但从未在北冰洋上以这种方式应用过。

The strongest temperature increase due to climate change is currently observed in the Arctic. This fact is based on a very complex chain of processes and feedbacks, in which aerosol particles play an essential role through their influence on radiation balance and cloud formation. In order to assess the impact of changing ice cover, the interactions between ocean as well as ice and the atmosphere also need to be better understood. In general, there is a lack of atmospheric measurements especially in the Arctic Ocean, which are urgently needed to understand the processes but also to predict the expected changes. Exchange processes between ocean/ice and atmosphere are currently poorly understood in these regions. In this project, the RV Polarstern will be used to study vertical exchange processes above water and ice in detail and to localize associated sources of aerosol particles. For this purpose, a series of continuous aerosol measurements on board the ship are planned, including number size distributions, optical parameters (scattering, absorption), the mixing ratio of particles containing black carbon (BC), the concentration of ice nucleating particles (INP), and the chemical composition of aerosol particles. Furthermore, samples of fog water will be collected during fog phases that occur frequently in summer, as well as daily water samples from the ocean throughout the campaign. These samples will be analyzed for the concentration of INP and BC after the measurement campaign. For the first time, BC- concentrations in airborne and water samples will be measured for the using laser incandescence. A novel method for pre-treatment of water samples with high salinity will be applied. By this combination of parallel investigation of components in air and water, transport and exchange processes of these aerosol particles shall be quantified.In the periods with calm movement of the ship or drift with the ice, measurement equipment for the determination of vertical particle fluxes will be employed at the frontal outrigger of the ship. This will be used to acquire time series of the wind vector and particle concentration, which will subsequently be used to determine the vertical turbulent particle flux by the eddy covariance method. Combined with these measurements, the concentration of the INP is recorded in order to be able to assign their origin and sources. Another measuring system, consisting of a one-dimensional wind measurement and a particle counter, is attached to the crane hook below the frontal outrigger and determines the vertical profiles of the particle concentration from which an estimation of the vertical particle flux is also possible. These methods are proven and established, but have never been applied in this way over the Arctic Ocean.