团队使用 Argo 剖面浮标数据，研究发现日本南部的亚热带模态水(其厚度随年代变化)通过随厚度的增加而增加，等温线隆起来全年调节上覆热结构。亚热带模态水引起的年代际温度变化幅度可达约 1 °C，在存在季节性温跃层的暖季变化幅度更大。
此外，50 年的观测数据结合数值模拟表明，海表温度、上层海洋热含量和台风增强率在亚热带模态水较厚的年份明显较低，而在亚热带模态水较薄的年份较高。
据悉，亚热带模态水(STMW)的特点是垂直温度均匀，约17℃，水平分布在北太平洋亚热带 100-500 米深度的 5000 公里处。它的形成和扩散与太平洋年代际振荡和黑潮路径变化有关，但亚热带模态水对海表温度(SST)和上覆大气的反馈尚不清楚。
附：英文原文
Title: Subtropical Mode Water south of Japan impacts typhoon intensity
Author: Eitarou Oka, Shusaku Sugimoto, Fumiaki Kobashi, Hatsumi Nishikawa, Sachie Kanada, Tomoe Nasuno, Ryuichi Kawamura, Masami Nonaka
Issue&Volume: 2023-09-13
Abstract: Subtropical Mode Water (STMW), characterized by vertically uniform temperature of ~17°C, is distributed horizontally over 5000 kilometers at the 100- to 500-meter depths in the subtropical North Pacific Ocean. Its formation and spreading fluctuate in relation to the Pacific Decadal Oscillation and the Kuroshio path variation, but the feedback from STMW on the sea surface temperature (SST) and the overlying atmosphere remains unclear. Using Argo profiling float data, we show that STMW south of Japan, whose thickness varies decadally, modulates the overlying thermal structure throughout the year by increasing isotherm uplift with increasing thickness. The STMW-induced decadal temperature change has a magnitude of up to ~1°C and is large in the warm season in the presence of the seasonal thermocline. Furthermore, 50-year observations, together with numerical simulation, show that SST, upper ocean heat content, and typhoon intensification rate have been significantly lower in years with thicker STMW and higher in years with thinner STMW.
DOI: adi2793
Source: https://www.science.org/doi/10.1126/sciadv.adi2793