法国克莱蒙奥弗涅大学
研究收集的测量数据来源于部署在西南太平洋的船载海气界面储罐,测量数据确定了夜间与浮游生物群落组成相关新颗粒的形成(NPF)之间的关系。研究人员在其主持的半控制实验中发现,硝酸盐离子是唯一可以支持 NPF 速率的类型。硝酸盐离子在自然原始海洋大气中也普遍存在,并在 10nm 以下的粒子、浓度较高的情况下升高。
该团队成员假设这些成核事件是由复杂的、短期的生物地球化学循环(包括微生物循环)推动的。这些发现为以前未知的海洋生物地球化学来源的硝酸盐,在气溶胶成核中的作用提供了新的视角。
据悉,研究者们对海洋—云的相互作用及其对气候的影响的理解,缺乏对一个关键途径的认识,即海洋生物排放物是否会在开阔的海洋大气中形成新的颗粒。
附:英文原文
Title: Evidence of nitrate-based nighttime atmospheric nucleation driven by marine microorganisms in the South Pacific
Author: Chamba, Guillaume, Rissanen, Matti, Barthelme, Theresa, Saiz-Lopez, Alfonso, Rose, Clémence, Iyer, Siddharth, Saint-Macary, Alexia, Rocco, Manon, Safi, Karl, Deppeler, Stacy, Barr, Neill, Harvey, Mike, Engel, Anja, Dunne, Erin, Law, Cliff S., Sellegri, Karine
Issue&Volume: 2023-11-22
Abstract: Our understanding of ocean–cloud interactions and their effect on climate lacks insight into a key pathway: do biogenic marine emissions form new particles in the open ocean atmosphere ?Using measurements collected in ship-borne air–sea interface tanks deployed in the Southwestern Pacific Ocean, we identified new particle formation (NPF) during nighttime that was related to plankton community composition. We show that nitrate ions are the only species for which abundance could support NPF rates in our semicontrolled experiments. Nitrate ions also prevailed in the natural pristine marine atmosphere and were elevated under higher sub-10 nm particle concentrations. We hypothesize that these nucleation events were fueled by complex, short-term biogeochemical cycling involving the microbial loop. These findings suggest a new perspective with a previously unidentified role of nitrate of marine biogeochemical origin in aerosol nucleation.
DOI: 10.1073/pnas.2308696120
Source: https://www.pnas.org/doi/abs/10.1073/pnas.2308696120