Characterization of bacteria emission over the North-Eastern Atlantic using mesocosm experiments

Airborne bacteria play an important role in the Earths climate system, by acting as ice-nucleating particles and thus influencing cloud phase. As 70 percent of the Earth is covered by oceans, quantifying and characterizing bacteria emissions over these waters are key to the enhancement of climate models. Furthermore, airborne bacteria can have adverse effects on human health.To investigate the aerosolization of bacteria in conjunction with sea spray aerosols (SSA), we conducted mesocosm experiments in the Azores archipelago in the North-Eastern Atlantic. We used a plunging jet sea spray simulation chamber filled with coastal seawater, which allowed us to generate and collect nascent SSA onto filter samples under controlled conditions, excluding any terrestrial sources. 16S rRNA sequencing was employed to investigate the microbial community composition in the seawater and aerosol samples in order to identify taxa that are preferably aerosolized from the North-Eastern Atlantic.

大气悬浮细菌（airborne bacteria）通过充当冰核粒子进而影响云相态，在地球气候系统中发挥着重要作用。鉴于地球70%的地表被海洋覆盖，对海洋上空的细菌排放进行定量分析与特性表征，是改进气候模型的关键所在。此外，大气悬浮细菌还会对人体健康产生不利影响。为探究细菌与海洋飞沫气溶胶（sea spray aerosols, SSA）的气溶胶化过程，我们在东北大西洋的亚速尔群岛开展了中宇宙（mesocosm）实验。我们使用装填沿岸海水的射流冲击式海洋飞沫模拟舱，可在受控条件下生成初生海洋飞沫气溶胶，并将其收集至滤膜样本中，全程排除陆地来源的干扰。为识别东北大西洋海域中更易被气溶胶化的细菌分类群，我们采用16S rRNA测序（16S rRNA sequencing）技术，对海水与气溶胶样本的微生物群落组成进行了分析。