台风对西北太平洋叶绿素a浓度的影响

发布时间：2018-01-15 19:34

本文关键词：台风对西北太平洋叶绿素a浓度的影响　出处：《广东海洋大学》2016年硕士论文　论文类型：学位论文

【摘要】：台风Sinlaku与Jangmi分别于2008年9月11日和27日先后经过台湾岛东部海域。本文利用卫星遥感数据观测到两次连续台风在不同初始环境条件下诱发了两次不同程度的浮游植物增长。相对于强度更强移动速度更快的台风Jangmi,慢移动的弱台风Sinlaku在台湾岛东部诱发了一次更强的浮游植物增长(Sinlaku:Chl-a0.3 mg?m-3;Jangmi:Chl-a0.2 mg?m-3)。该结果显示,移动速度是影响浮游植物增长的因素之一。其次,Sinlaku经过前存在的气旋涡为上层海洋提供相对不稳定的热力学结构,Sinlaku经过后富含营养盐的深层冷水更容易涌升到表层。而且,Sinlaku引起的混合层加深以及较深的真光层厚度为Jangmi经过后的浮游植物增长提供了不利条件。厚的混合层阻碍了Jangmi过后富含营养盐的冷水上翻过程,从而产生了较弱的浮游植物增长。研究表明风的强迫作用(包括强度和移动速度)和台风前的上层海洋环境条件(混合层深度、涡、营养盐)在浮游植物增长过程中发挥重要作用。为了衡量台风强迫作用和初始海洋环境条件对浮游植物增长的作用大小,文中我们介绍了一个影响参数。参数化结果表明,Sinlaku过后风的强迫作用更大。基于上述研究,我们进一步调查了2015年首个登陆粤西的强台风彩虹在南海西北部诱发了大范围浮游植物水华。研究结果表明,在粤西离岸海域,Ekman抽吸将次表层富含营养盐的冷水输送到上层海洋,促使真光层的营养盐得到大量补充,诱发海洋表层浮游植物水华。海南岛东部近岸海域,台风彩虹引起的陆源营养盐的地表径流、近惯性振荡、潮汐及离岸平流输送的共同作用可能导致了该区域叶绿素a浓度的增加。通过统计分析海洋上层对2002到2009年夏季(6-9月)16个途经西北太平洋海域的热带气旋的响应发现叶绿素浓度增长与Ekman抽吸和风应力时间积分呈正相关,相关系数分别达到0.87和0.76。混合层深度的变化与热带气旋经过前混合层深度呈负相关,相关系数为0.46。该结果表明混合层的加深主要是风场强迫作用的结果。
[Abstract]:Typhoon Sinlaku and Jangmi passed through the eastern waters of Taiwan Island on September 11th 2008 and 27th respectively. In this paper, two successive typhoons were observed in different initial rings using satellite remote sensing data. Two times of phytoplankton growth were induced under environmental conditions. Typhoon Jangmi, which moved faster than the intensity of the typhoon. The slow-moving weak typhoon Sinlaku induced a stronger phytoplankton growth in the eastern part of the island, Sinlaku: Chl-a 0.3 mg? M-3 Jangmi: Chl-a 0.2 mg? The results show that the moving velocity is one of the factors that influence the growth of phytoplankton. Secondly, the gas vortex of Sinlaku provides a relatively unstable thermodynamic structure for the upper ocean. Deep cold water, which is rich in nutrients after Sinlaku passes, is more likely to surge to the surface. And. The deepening of the mixing layer caused by Sinlaku and the depth of the eoluminescent layer provide a disadvantage for the phytoplankton growth after the Jangmi passes. The thick mixed layer hinders the rich nutrition after the Jangmi. The cold water overturning of salt. This resulted in weak phytoplankton growth. Studies have shown that the forcing of wind (including intensity and moving velocity) and the conditions of the upper marine environment prior to typhoon (mixing layer depth, vortex). Nutrients) play an important role in phytoplankton growth. In order to measure the effect of typhoon forcing and initial marine environmental conditions on phytoplankton growth. In this paper, we introduce an influence parameter. The parameterization results show that the force of wind after Sinlaku is stronger. In 2015, we investigated the first strong typhoon rainbow landing in western Guangdong and induced a large range of phytoplankton Shui Hua in the northwestern part of the South China Sea. Ekman pumped the cold water rich in nutrients in the subsurface layer to the upper ocean, which promoted the nutrient supplement in the eoluminescent layer and induced the marine surface phytoplankton Shui Hua near the east coast of Hainan Island. Typhoon rainbow causes terrestrial nutrient surface runoff, near inertial oscillation. The combination of tide and offshore advection may lead to the increase of chlorophyll a concentration in the region. The response of 16 tropical cyclones passing through the Northwest Pacific Ocean showed that the increase of chlorophyll concentration was positively correlated with the Ekman suction and the time integral of wind stress. The correlation coefficients are 0.87 and 0.76 respectively. The variation of mixing layer depth is negatively correlated with the depth of the mixed layer before the tropical cyclone passes through. The correlation coefficient is 0.46. The results show that the deepening of the mixed layer is mainly the result of wind forcing.
【学位授予单位】：广东海洋大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P732.6

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