北冰洋太平洋扇区声学体积后向散射强度和海洋环境噪声研究
发布时间：2018-10-26 10:53
【摘要】：北极水声学的研究是声学研究的热点之一。本文利用中国第六次北极科学考察的数据资料,对北冰洋太平洋扇区的声学体积后向散射强度以及海洋环境噪声进行重点研究。论文主要包括以下五个方面的内容:(1)利用下放式声学多普勒测流仪(LADCP)数据分析白令海水下声体积后向散射强度,发现白令海深散射层生物的昼夜迁移现象。深层水体积后向散射强度在1800m处有一个极大值区。(2)加拿大海盆海冰边缘区是声体积后向散射强度的明显过渡区。无冰海面(海冰密集度小于15%)的海洋深层水的声体积后向散射强度明显大于密集海冰区域的海水(海冰密集度大于50%)。讨论了声体积后向散射强度与海冰融化之间的关系,造成融冰区声体积后向散射强度增大的原因是水下悬浮泥沙、浮游生物等悬浮物质增加。根据海冰密集海域的海水后向散射强度弱的特点,对北极下放式声学多普勒测流仪(LADCP)观测的设置提出建议。(3)楚科奇海台范围内150m以浅的海水体积后向散射强度强于海台周围,对这种差异原因进行解释。在极昼期间,150m以浅的声散射层垂直迁移与当地太阳高度角有关。(4)对北冰洋太平洋扇区的深散射层生物发声进行研究,发现此区域深散射层生物发声频率集中在2000-3000Hz之间。(5)利用变阈值小波变换滤波法对SBE-911CTD配套梅花采水器10L懫水瓶的懫水信号进行提取,并分析懫水声信号的时频特性,懫水时域信号由激发弹扣信号与懫水瓶闭合信号组成;频域信号有双峰结构,峰值分别出现在750Hz与2300Hz,双峰结构的明显程度与时域信号脉冲数量有关。
[Abstract]:The study of Arctic underwater acoustics is one of the hot spots in acoustics research. Based on the data of the sixth Arctic Scientific Survey in China, the acoustic volume backscattering intensity and the environmental noise of the Arctic Ocean sector are studied in this paper. The main contents of this paper are as follows: (1) by using the (LADCP) data of the acoustic Doppler current meter, the backscattering intensity of underwater acoustic volume in Bering Sea is analyzed, and the diurnal migration of organisms in the deep scattering layer in Bering Sea is found. The backscatter intensity of deep water volume has a maximum at 1800 m. (2) the edge of sea ice in the Canadian basin is an obvious transition area of the backscattering intensity of acoustic volume. The sound volume backscattering intensity of deep sea water without sea ice (sea ice density less than 15%) is obviously higher than that of sea water in dense sea ice area (sea ice density is more than 50%). The relationship between the backscattering intensity of acoustic volume and the melting of sea ice is discussed. The reason for the increase of backscattering intensity of acoustic volume in melting ice area is the increase of suspended sediment and plankton. According to the weak backscattering intensity of sea water in the sea ice dense area, Some suggestions for setting up the (LADCP) observations of the arctic acoustic Doppler current meter are given. (3) the backscatter intensity of 150 m in shallow seawater volume is stronger than that around the sea station in the range of 150 m in the Chukchi sea station. The reasons for this difference are explained. During polar day, the vertical migration of 150m in a shallow acoustic scattering layer is related to the local solar height angle. (4) the acoustic sounding in the deep scattering layer in the Arctic Pacific sector is studied. It is found that the frequency of biological sound in the deep scattering layer in this area is between 2000-3000Hz. (5) using the variable threshold wavelet transform filter to extract the water signal from the 10L water bottle of the SBE-911CTD matching plum-blossom water collector. The time-frequency characteristic of the acoustic signal is analyzed. The time-domain signal is composed of the exciting elastic clasp signal and the closing signal of the water bottle. The frequency domain signals have bimodal structure, the peaks occur in 750Hz and 2300Hz, respectively. The obvious degree of bimodal structure is related to the number of time-domain signal pulses.
【学位授予单位】：国家海洋局第一海洋研究所
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P733.2
本文编号：2295481
[Abstract]:The study of Arctic underwater acoustics is one of the hot spots in acoustics research. Based on the data of the sixth Arctic Scientific Survey in China, the acoustic volume backscattering intensity and the environmental noise of the Arctic Ocean sector are studied in this paper. The main contents of this paper are as follows: (1) by using the (LADCP) data of the acoustic Doppler current meter, the backscattering intensity of underwater acoustic volume in Bering Sea is analyzed, and the diurnal migration of organisms in the deep scattering layer in Bering Sea is found. The backscatter intensity of deep water volume has a maximum at 1800 m. (2) the edge of sea ice in the Canadian basin is an obvious transition area of the backscattering intensity of acoustic volume. The sound volume backscattering intensity of deep sea water without sea ice (sea ice density less than 15%) is obviously higher than that of sea water in dense sea ice area (sea ice density is more than 50%). The relationship between the backscattering intensity of acoustic volume and the melting of sea ice is discussed. The reason for the increase of backscattering intensity of acoustic volume in melting ice area is the increase of suspended sediment and plankton. According to the weak backscattering intensity of sea water in the sea ice dense area, Some suggestions for setting up the (LADCP) observations of the arctic acoustic Doppler current meter are given. (3) the backscatter intensity of 150 m in shallow seawater volume is stronger than that around the sea station in the range of 150 m in the Chukchi sea station. The reasons for this difference are explained. During polar day, the vertical migration of 150m in a shallow acoustic scattering layer is related to the local solar height angle. (4) the acoustic sounding in the deep scattering layer in the Arctic Pacific sector is studied. It is found that the frequency of biological sound in the deep scattering layer in this area is between 2000-3000Hz. (5) using the variable threshold wavelet transform filter to extract the water signal from the 10L water bottle of the SBE-911CTD matching plum-blossom water collector. The time-frequency characteristic of the acoustic signal is analyzed. The time-domain signal is composed of the exciting elastic clasp signal and the closing signal of the water bottle. The frequency domain signals have bimodal structure, the peaks occur in 750Hz and 2300Hz, respectively. The obvious degree of bimodal structure is related to the number of time-domain signal pulses.
【学位授予单位】：国家海洋局第一海洋研究所
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P733.2
【参考文献】
相关博士学位论文 前1条
1 原野;基于声学方法的中国近海沉积物和悬浮颗粒物动力过程观测研究[D];中国海洋大学;2009年
，本文编号：2295481
本文链接：https://www.wllwen.com/kejilunwen/haiyang/2295481.html
