Upwelling and downwelling visible radiation measurements of the autonomous ice-tethered OptiCAL 'gg' buoy deployed during MOSAiC in the Monster Bay area

Three ice-tethered / floating systems measuring sub - sea-ice Photosynthetic Active Radiation (PAR) were deployed within the MOSAiC ice camp from February 2020, and recorded hourly data through to later summer 2020. These Optical Chain And Logger (OptiCAL) systems capture PAR-like data at 12 logarithmically-spaced levels down to 50 m depth, and, along with positional data, transmit these data hourly via Iridium. The PAR sensors have a wide dynamic range, able to detect PAR from 5x10⁻⁵ µMol s⁻¹ m⁻² to 100 µMol s⁻¹ m⁻² and thereby graph a wide range of light behaviour from winter to summer and from surface to depth. Sampling at the 12 levels is accomplished by resin-containment 'nodes' located along a power and communication cable that hangs vertically from the underside of the surface spar-buoy. The nodes are at nominal depths of 1, 2, 3, 4, 5, 6, 7, 9, 14, 21, 32, and 50m. Each node has six 'PAR' sensors, three detecting downwelling light and three upwelling light. Two of each set of three sensor sets have simple optical filters: one transmitting 'orange' the other 'blue'. The third sensor, being unfiltered, is 'white'. PAR data are archived in CSV files as 'counts' from the sensors, and are in units of millihertz (mHz). The detail of the CSV format is provided in this directory (see "OptiCAL 'gg' buoy: Detail of the CSV format" under Documentation), but to convert from mHz to the expected SI unit of µMol s⁻¹ m⁻² requires a conversion function. Details of this conversion are provided in this directory (see "OptiCAL 'gg' buoy: Data description" under Documentation). The 'gg' unit was deployed in the "Monster Bay" area some 20-m away from the upward looking AZFP on level ice surrounded by SYI old ridges of the main floe. Access via the road to the Dark site with a junction to the buoy area right before the crossing of Allis ridge. Its drift started at N 88.029858, E 80.206014 on 14th Feb 2020 and last data transmission was on 12th August at 05:44 UTC due to battery power being exhausted. Intended recovery was not possible before positional data were lost. […]

自2020年2月起，在MOSAiC冰营内部署了三个冰锚定/浮动物理系统，用以测量海底冰的叶绿素活性辐射（PAR），直至2020年夏末。这些光学链与记录仪（OptiCAL）系统在12个对数级分布的深度（至50米）处捕捉PAR相似的数据，并连同位置数据，每小时通过铱星系统传输。这些PAR传感器具有宽广的动态范围，能够检测从5x10⁻⁵ µMol s⁻¹ m⁻²至100 µMol s⁻¹ m⁻²的PAR，从而描绘出从冬季至夏季，从水面至深度的广泛光照行为。在12个层级上的采样是通过位于垂直悬挂于表面桁架浮标下方的电力和通信电缆上的树脂封装‘节点’完成的。这些节点位于1、2、3、4、5、6、7、9、14、21、32米和50米的标称深度。每个节点配备六个‘PAR’传感器，其中三个用于检测下行光，另外三个用于检测上行光。每组三个传感器中，有两个配备了简单的光学滤波器：一个传输‘橙色’，另一个传输‘蓝色’。第三个传感器未经过滤，因此为‘白色’。PAR数据以CSV文件格式归档，作为传感器的‘计数’，并以毫赫兹（mHz）为单位。CSV格式的详细信息提供在本目录中（参见“OptiCAL ‘gg’ 浮标：CSV格式详细说明”下的文档），但要将毫赫兹转换为预期的SI单位µMol s⁻¹ m⁻²，需要使用转换函数。该转换的详细信息也提供在本目录中（参见“OptiCAL ‘gg’ 浮标：数据描述”下的文档）。‘gg’单位部署在“巨湾”区域，距离向上观测的AZFP水平冰上的旧脊约20米。通过通往黑暗地点的道路，在越过Allis脊之前，即可到达浮标区域。其漂移始于2020年2月14日的N 88.029858，E 80.206014，最后的数据传输发生在2020年8月12日05:44 UTC，由于电池电量耗尽。在位置数据丢失之前，无法进行预期的回收。