Preliminary on-ice remote sensing measurements during the MOSAiC expedition

Several different remote sensing instruments were deployed on the sea ice floe next to RV Polarstern during the MOSAiC expedition (mosaic-expedition.org). Here, preliminary data from nine instruments for two observation periods (Nov 2019 and Sep 2020) is provided. Initial calibration was performed but data might change for the final datasets. Outliers were filtered and some time series smoothed. Data from Figure 10 in Nicolaus et al. (2021), "Overview of the MOSAiC expedition – Snow and Sea Ice", Elementa: Results from co-located active and passive remote sensing instruments (Table 2) looking at similar ice and snow conditions (Figure S4). (left) Measurements during a warming and storm event in November 2019 and (right) during a melting event in September 2020. (A) Air temperature and wind speed from the Polarstern weather station and snow surface temperature from the IR camera at the Remote Sensing Site (dashed blue line shows time periods with potential icing on the lens). (B) Radar backscatter at VV polarization from 2145 microwave scatterometers L-SCAT at 1.3 GHz and Ku/Ka-radar at 15 and 35 GHz (note the different y-scales). (C) Brightness temperature at V polarization from microwave radiometers: ELBARA at 1.4 GHz, ARIEL at 1.4 GHz looking at thin ice on a lead, HUTRAD at 7 and 11 GHz, SSMI at 19, 37, 89 GHz (not all available data shown). (D) Reflected GNSS data, i.e., reflectivity at the Remote Sensing Site (blue) and for sea ice next to Polarstern (red). In the plot titles the used incidence angle range is given. Vertical dashed lines mark the start of warming and/or storm events. (E) Exemple photographs of the remote sensing site during winter and summer.在MOSAiC科考（MOSAiC-expedition.org）期间，多台不同型号的遥感仪器被布设至极星号科考船（RV Polarstern）旁的海冰浮冰块区域。本数据集提供了2019年11月与2020年9月两个观测时段内，9台仪器的初步观测数据。已完成初始校准，但最终数据集的相关数据或存在更新调整。已完成异常值剔除与部分时间序列平滑处理。 本数据集所用数据取自Nicolaus等（2021）发表于《Elementa》的"Overview of the MOSAiC expedition – Snow and Sea Ice"（《MOSAiC科考概览——积雪与海冰》）一文中的图10，该研究针对相似冰雪环境下的共置主动遥感与被动遥感仪器开展观测（详见表2，相关补充结果见图S4）。（左图为2019年11月一次升温与风暴事件期间的观测数据，右图为2020年9月一次融冰事件期间的观测数据） （A）极星号气象站获取的气温与风速数据，以及遥感站点红外相机测得的积雪表面温度（蓝色虚线代表镜头存在结霜风险的时段）。 （B）1.3GHz频段的L-SCAT 2145型微波散射计以及15GHz、35GHz频段的Ku/Ka雷达在VV极化下的雷达后向散射系数（注意纵轴刻度存在差异）。 （C）VV极化下微波辐射计测得的亮温数据：包括1.4GHz频段的ELBARA辐射计、观测冰间水道薄冰的1.4GHz频段ARIEL辐射计、7与11GHz频段的HUTRAD辐射计，以及19、37、89GHz频段的SSMI辐射计（未展示全部可用数据）。 （D）反射式全球导航卫星系统（GNSS）数据，即遥感站点（蓝色曲线）与极星号旁海冰区域（红色曲线）的反射率数据。各图题中标注了所用的入射角范围，垂直虚线代表升温及/或风暴事件的起始时刻。 （E）冬季与夏季遥感站点的典型影像。