Physical Sciences Laboratory, Earth System Research Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO, 80305, USA.
Environmental Research Division, Southwest Fisheries Science Center, National Oceanic and Atmospheric Administration, 99 Pacific St #255A, Monterey, CA, 93940, USA.
Nat Commun. 2023 Mar 13;14(1):1038. doi: 10.1038/s41467-023-36567-0.
Recently, there has been substantial effort to understand the fundamental characteristics of warm ocean temperature extremes-known as marine heatwaves (MHWs). However, MHW research has primarily focused on the surface signature of these events. While surface MHWs (SMHW) can have dramatic impacts on marine ecosystems, extreme warming along the seafloor can also have significant biological outcomes. In this study, we use a high-resolution (~8 km) ocean reanalysis to broadly assess bottom marine heatwaves (BMHW) along the continental shelves of North America. We find that BMHW intensity and duration varies strongly with bottom depth, with typical intensities ranging from ~0.5 °C-3 °C. Further, BMHWs can be more intense and persist longer than SMHWs. While BMHWs and SMHWs often co-occur, BMHWs can also exist without a SMHW. Deeper regions in which the mixed layer does not typically reach the seafloor exhibit less synchronicity between BMHWs and SMHWs.
最近，人们做出了大量努力来理解海洋暖温极端事件的基本特征，即海洋热浪（MHWs）。然而，MHW 的研究主要集中在这些事件的表面特征上。虽然表层海洋热浪（SMHW）会对海洋生态系统产生巨大影响，但海底的极端升温也会产生重大的生物后果。在这项研究中，我们使用高分辨率（约 8 公里）海洋再分析来广泛评估北美的大陆架海底海洋热浪（BMHW）。我们发现，BMHW 的强度和持续时间与海底深度密切相关，典型的强度范围从约 0.5°C-3°C。此外，BMHW 比 SMHW 更为强烈且持续时间更长。尽管 BMHW 和 SMHW 经常同时发生，但 BMHW 也可能在没有 SMHW 的情况下出现。在混合层通常无法到达海底的较深区域，BMHW 和 SMHW 之间的同步性较差。
