Highly active ice-nucleating particles at the summer North Pole
Highly active ice-nucleating particles at the summer North Pole
复制标题
夏季北极高度活跃的冰核颗粒
DOI：
10.1002/essoar.10508073.1
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Porter G
中科院分区：
文献类型：
--
作者：
Porter G
云中冰和过冷水的数量对它们的辐射特性和在气候反馈中的作用很重要。因此，需要了解冰核粒子（INPs）的浓度。一般来说，在偏远的海洋地区发现INPs的浓度非常低，使云水保持过冷状态。考虑到北极与开放海洋和陆地源的距离以及有效的湿清除过程，我们原本预计INPs的浓度会非常低。本研究表明，在2018年夏季（8月和9月），北极偶尔存在高浓度的生物INPs（活跃于bb0 - 20°C）。事实上，与南大洋形成鲜明对比的是，INP浓度有时与受高度活跃的生物INP强烈影响的中纬度地区记录的浓度一样高。此外，使用气球携带的采样器，我们证明了INP浓度通常在地表不同，而在云形成的边界层较高。反轨迹分析表明，俄罗斯海岸附近的INPs来源较强，可能与风驱动的浪花产生有关，而浮冰、开放的铅和边缘冰带不是高度活跃的INPs来源。这些发现表明，原始冰的产生以及北极气候对来自俄罗斯海岸等已经经历了明显气候变化的地区的运输很敏感。
The amount of ice versus supercooled water in clouds is important for their radiative properties and role in climate feedbacks. Hence, knowledge of the concentration of ice‐nucleating particles (INPs) is needed. Generally, the concentrations of INPs are found to be very low in remote marine locations allowing cloud water to persist in a supercooled state. We had expected the concentrations of INPs at the North Pole to be very low given the distance from open ocean and terrestrial sources coupled with effective wet scavenging processes. Here we show that during summer 2018 (August and September) high concentrations of biological INPs (active at >−20°C) were sporadically present at the North Pole. In fact, INP concentrations were sometimes as high as those recorded at mid‐latitude locations strongly impacted by highly active biological INPs, in strong contrast to the Southern Ocean. Furthermore, using a balloon borne sampler we demonstrated that INP concentrations were often different at the surface versus higher in the boundary layer where clouds form. Back trajectory analysis suggests strong sources of INPs near the Russian coast, possibly associated with wind‐driven sea spray production, whereas the pack ice, open leads, and the marginal ice zone were not sources of highly active INPs. These findings suggest that primary ice production, and therefore Arctic climate, is sensitive to transport from locations such as the Russian coast that are already experiencing marked climate change.