美国太平洋海洋环境实验室Cronin Meghan F研究团队近日取得一项新成果。他们报道了热带太平洋日间变暖校正与海面温度锋有关。相关论文于2024年3月25日发表于国际顶尖学术期刊《自然—地球科学》杂志上。
据研究人员介绍，与锋面和日循环相关的海表温度（SST）的急剧和快速变化，可以驱动大气边界层稳定性和环流的变化。
研究人员展示了如何用高分辨率或日平均表面通量作用于一维表面海洋模型，以区分从无人机水面飞行器观测到的日间与锋面的SST异常。该模型利用卫星日通量进行模拟，结果显示，赤道太平洋冷舌范围内SST的日增温最大。在海洋和大气边界层稳定性尺度中，冷舌以北强烈持续的SST锋很明显，因此在日间海洋变暖的幅度上也很明显。
使用SST、大气压和在0°、95°W和2°N，95°W时锚定设备的表面风测量值，研究人员发现，SST日变暖的锋面导致下午SST锋面减弱，相应的气压经向梯度减小，这似乎有助于地面经向风的日脉动。在一定程度上，这些调节了哈德利环流的表面分支，这些日间变化可能具有远程的影响。
附：英文原文
Title: Diurnal warming rectification in the tropical Pacific linked to sea surface temperature front
Author: Cronin, Meghan F., Zhang, Dongxiao, Wills, Samantha M., Reeves Eyre, J. E. Jack, Thompson, LuAnne, Anderson, Nathan
Issue&Volume: 2024-03-25
Abstract: Sharp and rapid changes in the sea surface temperature (SST) associated with fronts and the diurnal cycle can drive changes in the atmospheric boundary-layer stability and circulation. Here we show how a one-dimensional surface ocean model forced with either high-resolution or daily averaged surface fluxes can be used to distinguish diurnal versus frontal SST anomalies observed from an uncrewed surface vehicle. The model, forced with daily satellite fluxes, shows that the diurnal warming is largest within the equatorial Pacific cold tongue of SST. The strong persistent SST front north of the cold tongue is evident in both the oceanic and atmospheric boundary-layer stability scales and, as a consequence, in the magnitude of the diurnal ocean warming. Using SST, barometric pressure and surface wind measurements from moorings at 0°, 95°W and 2°N, 95°W, we show that the front in the SST diurnal warming results in a weakened SST front in the afternoon and a corresponding reduced meridional gradient in the barometric pressure that appears to contribute to a diurnal pulsing of the surface meridional winds. To the extent that these modulate the surface branch of the Hadley cell, these diurnal variations may have remote impacts.
DOI: 10.1038/s41561-024-01391-8
Source: https://www.nature.com/articles/s41561-024-01391-8