Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, Villigen, PSI, Switzerland.
Department of Environmental Science & Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden.
Nat Commun. 2020 Oct 1;11(1):4924. doi: 10.1038/s41467-020-18551-0.
In the central Arctic Ocean the formation of clouds and their properties are sensitive to the availability of cloud condensation nuclei (CCN). The vapors responsible for new particle formation (NPF), potentially leading to CCN, have remained unidentified since the first aerosol measurements in 1991. Here, we report that all the observed NPF events from the Arctic Ocean 2018 expedition are driven by iodic acid with little contribution from sulfuric acid. Iodic acid largely explains the growth of ultrafine particles (UFP) in most events. The iodic acid concentration increases significantly from summer towards autumn, possibly linked to the ocean freeze-up and a seasonal rise in ozone. This leads to a one order of magnitude higher UFP concentration in autumn. Measurements of cloud residuals suggest that particles smaller than 30 nm in diameter can activate as CCN. Therefore, iodine NPF has the potential to influence cloud properties over the Arctic Ocean.
在北极中心海域，云的形成及其特性对云凝结核（CCN）的存在情况非常敏感。自 1991 年首次进行气溶胶测量以来，一直未能确定导致新粒子形成（NPF）的潜在蒸汽的成分。在此，我们报告称，2018 年北极海洋考察中的所有观测到的 NPF 事件均由碘酸驱动，硫酸的贡献很小。碘酸在大多数情况下极大地解释了超细颗粒（UFP）的增长。碘酸浓度从夏季到秋季显著增加，可能与海洋冻结和臭氧季节性上升有关。这导致秋季 UFP 浓度增加了一个数量级。云残差的测量结果表明，直径小于 30nm 的颗粒可以作为 CCN 激活。因此，碘 NPF 有可能影响北极海洋的云特性。
