Large-scale state and evolution of the atmosphere and ocean during PISTON 2018
Large-scale state and evolution of the atmosphere and ocean during PISTON 2018
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DOI：
10.1175/jcli-d-20-0517.1
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发表时间：
2021-03
影响因子：
4.9
通讯作者：
A. Sobel;J. Sprintall;E. Maloney;Z. Martin;Shuguang Wang;S. Szoeke;B. C. Trabing;S. Rutledge
中科院分区：
文献类型：
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作者：
A. Sobel;J. Sprintall;E. Maloney;Z. Martin;Shuguang Wang;S. Szoeke;B. C. Trabing;S. Rutledge
季节内热带振荡传播（PISTON）实验于2018年8月至10月进行了一次实地活动。R/V托马斯G.汤普森在帕劳以北和菲律宾以东的西北太平洋地区进行了两次巡航。这项研究利用选定的实地观测和全球观测和再分析数据集，描述了这些航行期间大气和海洋的大规模状态和演变。除了10月有一段时间的对流受到抑制外，现场计划期间的季节内变率很弱。另一方面，热带气旋活动强劲。船所在位置的变化特征是低层东风气流与嵌入式向西传播的天气尺度大气扰动的周期，由强烈的低层西风，既连接到亚洲季风西风带和热带气旋的周期打断。最戏剧性的一次是，在热带气旋杰比从该船北面经过期间及之后，西风持续了数天。在这些时期，由于风混合和大量（约200 Wm −2）的净表面热通量，海洋表面温度降低了几度，这是由于大潜热通量和与广泛的深对流相关的云遮蔽。航行中的电导率-温度断面显示，由于从下面夹带较冷的水，台风山竹通过后，海洋混合层急剧冷却和加深，屏障层受到侵蚀。至少在400米以上观测到的强纬向流可能与近惯性流的产生和传播有关。
The Propagation of Intraseasonal Tropical Oscillations (PISTON) experiment conducted a field campaign inAugust-October 2018. The R/V Thomas G. Thompson made two cruises in thewestern North Pacific region north of Palau and east of the Philippines. Using select field observations and global observational and reanalysis data sets, this study describes the large-scale state and evolution of the atmosphere and ocean during these cruises. Intraseasonal variability was weak during the field program, except for a period of suppressed convection in October. Tropical cyclone activity, on the other hand, was strong. Variability at the ship location was characterized by periods of low-level easterly atmospheric flow with embedded westward propagating synoptic-scale atmospheric disturbances, punctuated by periods of strong low-level westerly winds that were both connected to the Asian monsoon westerlies and associated with tropical cyclones. In the most dramatic case, westerlies persisted for days during and after tropical cyclone Jebi had passed to the north of the ship. In these periods, the sea surface temperature was reduced by a couple of degrees by both wind mixing and net surface heat fluxes that were strongly (~200Wm−2) out of the ocean, due to both large latent heat flux and cloud shading associated with widespread deep convection. Underway conductivity-temperature transects showed dramatic cooling and deepening of the ocean mixed layer and erosion of the barrier layer after the passage of Typhoon Mangkhut due to entrainment of cooler water from below. Strong zonal currents observed over at least the upper 400 meters were likely related to the generation and propagation of near-inertial currents.