Collaborative research: The WArming and irRadiance Measurement (WARM) buoy: Assessing the role of solar energy in heating, photosynthesis, and photo-oxidation in the upper Arctic

WARM浮标收集北极海冰下的光、温度、盐度和浮游植物丰度的测量数据。北极冰盖持续变薄，季节性范围不断缩小，导致穿透冰层并进入下面海洋的阳光量发生变化，对物理和生物环境产生影响。阳光被冰下的海洋吸收，导致气候变暖，这可能导致冰融化加速，从而导致更多的阳光到达海洋。此外，温暖的海水也影响生物，影响北极适应物种的生存能力，并可能促进亚北极物种向北推进。更薄的冰也增加了光合作用所需的光线，影响了浮游植物大量繁殖的时间。如果浮游植物生长在这个季节的早期，那么浮游动物，以它们为食的生物可能会错过开花时间，对北极的整个食物网造成后果。该项目旨在提供观测数据，通过使用自主浮标来帮助确定冰下环境是如何变化的，该浮标克服了船舶观测的局限性。这些浮标已被证明非常坚固，可以存活大约一年，为研究界和感兴趣的公众团体提供几乎实时的每小时观测。这些浮标将于早春部署在波弗特海西部，预计将向西漂过楚科奇大陆架。该项目将继续WARM浮标倡议，改进现有的设计，包括提高温度和光测量的垂直分辨率，增加盐度测量以确定水团，以及第二个荧光计以确定下沉的浮游植物生物量。收集的数据将在一个完整的季节周期内提供重要的物理和生物地球化学特性的时间序列。它将使我们能够处理与更薄和更开阔的冰层对太阳辐射吸收、海洋加热、远洋初级产品物候学和碳循环的影响有关的问题。这些浮标已被证明非常坚固，可以存活大约一年，为研究界和感兴趣的公众团体提供几乎实时的每小时观测。这些浮标将于早春部署在波弗特海西部，预计将向西漂过楚科奇大陆架。北极的浮冰就像一道屏障，控制着紫外线和可见光进入水柱的可能性。季节性北极冰的持续变薄和减少导致太阳辐射穿透北冰洋上部的时间和强度发生了变化。海洋对太阳辐射吸收的扩大使表层变暖并分层，这可以引起进一步的冰退缩和延迟下降冻结。由此产生的热分层通过限制营养物质的垂直补充而影响生态系统，直接影响初级生产的规模。温暖的水柱也可以在浮游生物群落丰度和分布的阈值设定、影响营养效率和促进亚北极物种向北推进方面发挥根本作用。较薄的冰增加了光合作用和净初级生产的可用光，影响了初级生产的时间。浮游植物繁殖和浮游动物繁殖周期之间的微小时间不匹配可能会对整个脂质驱动的北极海洋生态系统产生影响。通过更长的开放水域暴露在紫外线下的时间的变化，有可能增加陆地和海洋有机物的光化学再矿化和可被微生物利用的不稳定有机物质的生产。确定太阳辐射变化对变暖、初级生产和光化学的影响对于评估和预测气候变化对海洋碳循环的影响至关重要。由于船舶观测的局限性，测量季节性浮冰内部和下方的这些变量具有挑战性，但这可以通过使用部署在冰内的自主WARM浮标来解决，这些浮标的设计可以在冰融化时幸存下来。

The WARM buoy collects measurements of light, temperature, salinity and phytoplankton abundance under the Arctic sea ice. The Arctic ice pack has suffered continued thinning and reduction in seasonal extent, resulting in changes to the amount of sunlight penetrating through the ice and into the ocean beneath, having consequences for the physical and biological environment. Sunlight absorbed by the ocean under the ice causes warming, which can lead to accelerated ice melt resulting in even more sunlight reaching the ocean. In addition, warmer water also affects living organisms, influencing the ability of Arctic adapted species to survive, and possibly promoting the northward advancement of sub-Arctic species. Thinner ice also increases light available for photosynthesis, affecting the timing of phytoplankton blooms. If phytoplankton growth occurs early in the season then zooplankton, the organisms that feed on them can miss the bloom with consequences for the entire food web of the Arctic. This project aims to provide observations to help determine how the under-ice environment is changing by using autonomous buoys which overcome the limitations of ship-based observations. The buoys have proven to be very robust and can survive for approximately one year, providing hourly observations which will be available in near-real time to the research community and interested public parties. The buoys will be deployed in early spring in the western Beaufort Sea, with anticipated drift west over the Chukchi Shelf. This project will continue the WARM buoy initiative by improving the existing design to include increased vertical resolution of temperature and light measurements, the addition of salinity measurement to enable water mass identification, and a second fluorometer to identify sinking phytoplankton biomass. The data collected will provide a time series of important physical and biogeochemical properties over a complete seasonal cycle. It will enable us to address questions related to the effects of a thinner and more open ice pack on the absorption of solar radiation, ocean heating, the phenology of pelagic primary production, and carbon cycling. The buoys have proven to be very robust and can survive for approximately one year, providing hourly observations which will be available in near real time to the research community and interested public parties. The buoys will be deployed in early spring in the western Beaufort Sea, with anticipated drift west over the Chukchi Shelf. The Arctic ice pack acts as a barrier controlling the availability of UV and visible light to the water column. Continued thinning and reduction of seasonal Arctic ice has resulted in alterations in the timing and magnitude of solar radiation penetrating the upper Arctic Ocean. Amplification of solar radiation absorption into the ocean acts to warm and stratify the surface layer, which can induce further ice retreat and delay fall freeze-up. Resulting thermal stratification affects the ecosystem by limiting vertical replenishment of nutrients with a direct consequence on the magnitude of primary production. A warmer water column can also play a fundamental role in setting thresholds for the abundance and distribution of plankton communities, affecting trophic efficiency and promoting the northward advancement of sub-Arctic species. Thinner ice increases the light available for photosynthesis and net primary production, affecting the timing of primary production. Small timing mis-match between phytoplankton blooms and zooplankton reproductive cycles can have consequences for the entire lipid-driven Arctic marine ecosystem. Changes in the duration of UV exposure through longer open water periods has the potential to increase photochemical remineralization of terrestrial and marine organic matter and production of labile organic material that can be used by microbes. Determining the impact of solar radiation changes on warming, primary production, and photochemistry are all critical in assessing and predicting the effects of climate change on the marine carbon cycle. The measurement of these variables within and beneath the seasonal ice pack is challenging due to the limitations of ship based observations, but this can be resolved by using the autonomous WARM buoys deployed within the ice and designed to survive ice melt.