一次层积云发展过程对黑潮延伸体海洋锋强迫的响应研究——观测与机制分析

发布时间：2018-07-05 16:34

本文选题：海洋锋 + 海洋大气边界层　；参考：《大气科学》2017年02期

【摘要】：由于缺乏海上现场观测,对天气尺度扰动下,海表面温度锋(海洋锋)对海洋大气边界层(MABL)垂直结构和MABL内海洋性低云(marine stratus)的影响研究较少。2014年4月12日,中国海洋大学东方红2号科学考察船在黑潮延伸体海区的海洋锋附近捕捉到一次层积云的迅速发展。在比较稳定的天气形势下,由暖水侧向北穿越海洋锋时,云底和云顶高度升高,云区范围迅速扩大。本文利用多种大气—海洋联合观测数据,结合卫星观测和再分析资料,对此次层积云迅速发展的机理进行了综合分析。结果表明,在海上低压后部西北风控制下,在海洋锋的暖水侧(下风方)形成热通量大值中心和低压槽,有助于高空西风动量下传,进而又使得海气界面热通量增加,这种正反馈效应为MABL内混合层厚度加大和云底/顶高度在海洋锋的下风方升高提供有利背景条件。4月12日09:00~12:00(协调世界时),来自日本本州岛陆地的低空暖平流到达该热通量中心上空,暖平流与热通量中心的共同作用,导致该时段近海面暖中心强度异常增加,MABL中静力不稳定层加深和低压槽发展,综合作用的结果使得混合层厚度明显加深,云底高度升高,云区迅速发展。本研究有助于理解在复杂大气背景扰动下MABL对海洋强迫的响应机理。
[Abstract]:Due to the lack of on-site observations at sea, the effects of the sea surface temperature front (ocean front) on the vertical structure of the oceanic and atmospheric boundary layer (MABL) and the oceanic low cloud (marine stratus) in MABL are less studied under synoptic scale disturbances. On April 12, 2014, The Dongfanghong No. 2 scientific research vessel of China Ocean University captured a rapid development of stratified clouds near the sea front of the Kuroshio extensional body. In a relatively stable weather situation, the height of cloud bottom and cloud top increases and the range of cloud area expands rapidly when the warm water crosses the ocean front from the side to the north. In this paper, the mechanism of the rapid development of stratified clouds is comprehensively analyzed by using a variety of atmospheric and oceanic joint observation data and satellite observation and reanalysis data. The results show that under the control of the northwest wind at the back of the sea low pressure, a large heat flux center and a low pressure trough are formed on the warm water side (downwind side) of the ocean front, which is conducive to the downward transmission of the momentum of the westerly wind in the upper air and thus increases the heat flux at the sea and air interface. This positive feedback effect provides a favorable background for increasing the thickness of the mixing layer in MABL and rising the bottom / top height of the cloud below the ocean front. April 12, 09: 00 12: 00 (UTC), the warm advection from the Honshu land in Japan arrived at the lower level. Above the heat flux center, The combined action of warm advection and heat flux center results in an abnormal increase in the intensity of warm center near the sea surface during this period and the deepening of the static unstable layer and the development of the trough of low pressure in MABL. The combined effect results in the thickening of the mixing layer and the elevation of the cloud bottom. The cloud area develops rapidly. This study is helpful to understand the response mechanism of MABL to ocean forcing under complex atmospheric background disturbances.
【作者单位】：中国海洋大学物理海洋教育部重点实验室和海洋—大气相互作用和气候实验室;山东省东营市河口区气象局;
【基金】：国家重大科学研究项目2012CB955600 国家自然科学基金项目41576108 国家自然科学基金委员会—山东省人民政府联合资助海洋科学研究中心项目U1406401 山东省重点研发计划2015GSF120005 青岛市民生科技项目1592114NSH~~
【分类号】：P732.6

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