Genco Brandon M, White Margot E, Koester Irina, Vargas Sonia M, Saunders Jaclyn K, Petras Daniel, Saito Mak A, García-Maldonado José Q, Dorrestein Pieter C, Aluwihare Lihini I, Beman J Michael
Life and Environmental Science and Sierra Nevada Research Institute, University of California, Merced, Merced, CA, USA.
Geosciences Research Division, Scripps Institution of Oceanography, University of California, San Diego, San Diego, CA, USA.
Sci Adv. 2025 Jun 6;11(23):eado8335. doi: 10.1126/sciadv.ado8335.
Tropical cyclones regularly form above the ocean's largest subsurface oxygen minimum zone (OMZ) in the eastern tropical North Pacific Ocean (ETNP), yet how these powerful storms affect this biogeochemically important region remains unknown. We captured multiple direct and potentially interactive oceanographic effects of a Category 4 hurricane (Bud) during a 2018 research cruise in the ETNP. Profiles and samples collected directly beneath Bud's wake revealed rapid OMZ shoaling of 29 to 50 meters, reaching depths as shallow as 41 meters. Untargeted mass spectrometry-based characterization of organic matter, along with elevated particulate organic carbon and chlorophyll concentrations, demonstrated production and accumulation of distinct organic compounds-including phytoplankton biomarkers-within a hurricane-generated phytoplankton bloom. 16 rRNA transcripts from active microbes were dominated by degraders of phytoplankton-derived organic matter near the surface and by anaerobic bacteria (including sulfate-reducing bacteria) within the shoaled OMZ-indicating rapid microbial responses. Tropical cyclones therefore severely disrupt OMZ biogeochemistry through vertical OMZ expansion and altered carbon cycling.
热带气旋经常在东热带北太平洋（ETNP）海洋最大的次表层氧含量最低区域（OMZ）上空形成，但这些强大风暴如何影响这个在生物地球化学方面具有重要意义的区域仍不为人知。在2018年ETNP的一次研究巡航中，我们捕捉到了一场4级飓风（巴德）产生的多种直接且可能相互作用的海洋学效应。在巴德尾流正下方采集的剖面和样本显示，OMZ迅速变浅了29至50米，深度浅至41米。基于非靶向质谱的有机物表征，以及颗粒有机碳和叶绿素浓度的升高，表明在飓风引发的浮游植物大量繁殖过程中，产生并积累了包括浮游植物生物标志物在内的独特有机化合物。来自活跃微生物的16 rRNA转录本在表层附近以浮游植物衍生有机物的降解菌为主，而在变浅的OMZ内则以厌氧细菌（包括硫酸盐还原菌）为主，这表明微生物反应迅速。因此，热带气旋通过垂直扩展OMZ和改变碳循环，严重扰乱了OMZ的生物地球化学。
