南海盐致环流对台风降水的响应特征分析
刘娜(1994—), 女, 甘肃省武威市人, 硕士研究生, 主要从事卫星遥感与海气相互作用的研究。E-mail: liunavip666@163.com |
Copy editor: 林强
收稿日期: 2018-10-16
要求修回日期: 2018-11-27
网络出版日期: 2019-06-17
基金资助
国家自然科学基金(91428206)
国家自然科学基金(41576022)
国家自然科学基金(41811530301)
国家自然科学基金(91528304)
国家自然科学基金(41621064)
国家重点研发计划重点专项课题(2017YFC1404103)
"全球变化与海气相互作用"专项(GASI-IPOVAI-04)
上海市优秀学术/技术带头人计划(17XD1400600)
版权
An analysis of response characteristics of saline circulation to typhoon precipitation in South China Sea
Copy editor: LIN Qiang
Received date: 2018-10-16
Request revised date: 2018-11-27
Online published: 2019-06-17
Supported by
The National Natural Science Foundation of China(91428206)
The National Natural Science Foundation of China(41576022)
The National Natural Science Foundation of China(41811530301)
The National Natural Science Foundation of China(91528304)
The National Natural Science Foundation of China(41621064)
The National Key Research and Development Program of China(2017YFC1404103)
The National Programme on Global Change and Air-Sea Interaction(GASI-IPOVAI-04)
Program of Shanghai Academic/Technology Research Leader(17XD1400600)
Copyright
本文采用多源卫星遥感数据通过统计分析的方法研究了17年间(2000—2016年)南海夏季(6—9月)台风对该海域降水、淡水通量的贡献及其可能导致的环流异常。主要结论如下: 1) 台风是南海中北部降水的重要影响因子, 可导致日平均降水量增加12mm, 约占南海夏季日平均降水(25mm·d -1)的一半, 且西北太平洋台风和南海“土台风”产生的降水分布存在显著的区域和强度差异; 2) 夏季, 南海由淡水通量引起的盐致环流表现为以海南岛东南部海域为中心的弱气旋式, 其流量量级约为-0.15Sv, 约占同期风生环流流量(约为-1.5Sv)的10%; 3) 夏季, 台风带来的降水使得南海中北部的气旋式盐致环流增强, 且西北太平洋台风降水导致的淡水通量变化引起的盐致环流强度要强于南海“土台风”。
刘娜 , 王桂华 , 巩远发 , 刘磊 . 南海盐致环流对台风降水的响应特征分析[J]. 热带海洋学报, 2019 , 38(3) : 13 -21 . DOI: 10.11978/2018107
By using various satellite remote sensing data and statistical analysis method, the contribution of typhoons in summer (from June to September) to the precipitation and freshwater flux in the South China Sea (SCS) and their possible influences on circulation anomalies in the SCS in the past 17 years (2000-2016) were studied. The main conclusions are as follows. Typhoon is one of the crucial factors that impact the precipitation in both northern and middle SCS, and the daily mean precipitation can be increased by 12 mm, which accounts for half of the daily mean rainfall in the SCS during summer. Besides, there are significant differences in the location and intensity of the rainfall distributions between the Northwest Pacific Ocean typhoons (NWP TYs) and SCS typhoons(SCS TYs). In summer, the saline circulation in the SCS induced by freshwater flux shows a weak cyclone that centers in the southwestern part of Hainan island with its magnitude of about -0.15 Sv, which is approximately 10% of wind-induced circulation (about -1.5 Sv) during the corresponding period. Precipitation induced by typhoons can intensify cyclonic saline circulation in the northern-central part of the SCS in summer. And the intensity of the saline circulation caused by NWP typhoons is stronger compared to that by SCS typhoons.
Key words: typhoon; freshwater flux; saline circulation; South China Sea
图1 南海台风的季节变化(a)和夏季每24h台风中心位置(b)a、b中蓝色代表西北太平洋台风, 红色代表南海“土台风”; b中A: 台湾岛; B: 海南岛; C: 吕宋岛 Fig. 1 Seasonal variation of TYs in the SCS (a) and 24h locations of TYs in summer (b). The blue triangles represent NWP TYs, and red dots represent SCS TYs. A: Taiwan Island; B: Hainan Island; C: Luzon Island |
图2 夏季南海气候态(a—c)和台风期间(d—f)的蒸发(a、d)、降水和风场(b、e)以及淡水通量(c、f)分布b、e中的等值线表示风速 Fig. 2 Average distribution maps of evaporation (a, d), rainfall and wind (b, e), and freshwater flux (c, f) in summer. (a-c): Evaporation, rainfall and wind, and freshwater flux of the original forcing, respectively. (d-f): Evaporation, rainfall and wind, and freshwater flux of the forcing with all TYs, respectively. The isobaths in (b, e) represent wind speed |
图3 夏季南海西北太平洋台风(a—c)和南海“土台风”期间(d—f)的蒸发(a、d)、降水和风场(b、e)以及淡水通量(c、f)分布b、e中的等值线表示风速 Fig. 3 Average distribution maps of evaporation (a, d), rainfall and wind (b, e), and freshwater flux (c, f) in summer. (a-c): Evaporation, rainfall and wind, and freshwater flux of the forcing only with NWP TYs, respectively. (d-f): Evaporation, rainfall and wind, and freshwater flux of the forcing only with SCS TYs respectively. The isobaths in (b, e) represent wind speed |
图4 夏季南海所有台风(a、d)、西北太平洋台风(b、e)和南海“土台风”(c、f)引起的降水及海表面风异常(a—c)、淡水通量异常(d—f)Fig. 4 Differences of rainfall, wind field (a-c) and freshwater flux (d-f) in summer between the original forcing and the forcing with all TYs (a, d); between the original forcing and the forcing only with NWP TYs (b, e); and between the original forcing and the forcing only with SCS TYs (c, f) |
图5 夏季气候态Sverdrup流函数(a)和气候态(b)、所有台风(c)、西北太平洋台风(d)以及南海“土台风”(e)的G-S正压流函数(单位: Sv) 1Sv=10-6m3·s-1。负值代表气旋式环流, 黑色粗实线代 Fig. 5 Stream function of the original wind forcing calculated from the Sverdrup theory (a) and G-S barotropic stream function of the original rainfall forcing (b). Also shown are the rainfall forcing with all TYs (c); the rainfall forcing only with NWP TYs (d); the rainfall forcing only with SCS TYs (e) (units: Sv; 1 Sv=10-6 m3·s-1). The negative values represent cyclonic circulation, and the thick black line represents zero |
The authors have declared that no competing interests exist.
作者已声明无竞争性利益关系。
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