摘要: |
由于缺乏长期观测资料,前人对山东半岛邻近海域海水溶解氧的时间变化和空间分布特征的研究较少。本文基于威海刘公岛海洋牧场于2016年7月20日至2017年3月14日期间,利用生态环境实时在线观测系统获得的底层海水的温度、盐度、水深、溶解氧数据,分析了该牧场海水溶解氧浓度的时间变化特征及其影响因素,并探讨了低氧灾害发生的可能性。结果表明在观测期间,该牧场海水溶解氧浓度以季节变化为主,冬季最大、夏季最小,其中2月份平均值最高,约为10.86mg/L,8月份平均值最低,约为5.91mg/L。同时海水溶解氧浓度也存在显著的小时变化和日变化,且变化幅度于8月份最大、3月份最小。影响海水溶解氧浓度变化的主要因素是海水温度,溶解氧浓度随着温度的季节性变化而变化。夏季,水体分层会使溶解氧浓度发生大幅度的降低,大风过程对于溶解氧浓度也有一定的影响,通过打破夏季的季节性温跃层使水体发生垂向混合从而为海底提供氧气,但大风过程之后的几天会出现溶解氧浓度降低的现象。本次研究发现刘公岛海洋牧场在观测期间不存在低氧现象。 |
关键词: 海水溶解氧 刘公岛海洋牧场 时间变化 层结 风致混合 |
DOI:10.11693/hyhz20180300062 |
分类号: |
基金项目:山东省重点研发计划项目,2016ZDJS09A02号;国家自然科学基金项目,41476002号,41776012号,41506008号。 |
附件 |
|
ANALYSIS OF THE TEMPORAL VARIATIONS OF DISSOLVED OXYGEN CONCENTRATION IN SEAWATER IN THE BOTTOM OF THE LIUGONG ISLAND MARINE PASTURE |
LI Zhao-Qin1, LI Xin2, SUN Li-Yuan3, LIU Zi-Zhou1, GU Yan-Zhen1, ZHAI Fang-Guo1, LI Pei-Liang1
|
1.College of Ocean and Atmospheric Sciences, Ocean University of China, Qingdao 266100, China;2.Weifang Marine Environment Monitoring center station in Shandong Province, Weifang 261000, China;3.Shandong Hydrobios Resources Conservation and Management Center, Yantai 264000, China
|
Abstract: |
Due to lace of long-term observation data, there are few studies on the temporal and spatial distribution characteristics of the dissolved oxygen concentration in seawater near Shandong peninsula. Based on observations of the temperature, salinity, depth, and dissolved oxygen of the bottom water obtained by a real-time online observation system deployed in Liugong Island Marin Pasture from July 20, 2016 to March 14, 2017, we investigated the temporal variations of the dissolved oxygen concentration (O2) and contributions from water temperature, salinity, water depth and wind speed. The possibility of the occurrence of hypoxia is also discussed. The results show that during the observation period, the O2 is dominated by its seasonal variation, being largest in winter and lowest in summer. For monthly averaged value, the O2 is lowest in August, being 5.91 mg/L, while highest in February, being 10.83 mg/L. At the same time, the O2 also shows significant diurnal and hourly variabilities, largest in August and lowest in March. The main factors affecting the O2 variations are the seawater temperature,, and the O2 mainly varies with the seasonal variation of the ocean temperature. In summer, the vertical ocean stratification makes the O2 decrease greatly, and the sea surface wind effects the variations of O2, the strong vertical mixing induced by strong sea surface winds could weaken or even break the seasonal thermocline in summer to provide oxygen for the bottom water but there will be a decrease of O2 for several days after the strong wind. The current study indicates that there is no hypoxia in Liugong Island Marine Pasture during the observation period. |
Key words: dissolved oxygen in seawater Liugong Island marine pasture temporal variation stratification wind mixing |