Analysis of haline channel formed in the East China Sea and the Atlantic Ocean using the T-S gradient diagram
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In case of any coastal ocean near the mouth of huge rivers, low salinity water can be formed dueto its large amount of freshwater discharge. For the acoustic analysis on the low salinity environment, someoceanographic data of the East China Sea and the Atlantic Ocean were collected through KODC (KoreaOceanographic Data Center) and NODC (National Oceanographic Data Center) online service. In this paper, theT-S gradient diagram is introduced to show a relation between the gradients of temperature and salinity inview of acoustic surface channel formation. Existence of haline channel, quantitative contribution of gradientsof salinity and temperature, effectiveness of the channel formation can be known by the T-S gradient diagram. After applying the collected data into the diagram, tropical regions of the Atlantic Ocean show strong halinechannel due to its nearly invariant temperature and drastic change of salinity with depth. The averaged transmissionloss in the channel is about 5.7 ~ 7.5 dB less than that out of the channel by the results of acousticpropagation model (RAM: Range independent Acoustic Model). On the other hand, the East China Sea andtemperate region of the Atlantic ocean have weaker haline channel with less difference of the averaged transmissionloss between in and out of the channel as 3.2 ~ 6.0 dB. Although data samples used in this studyhave limitation to represent the general physical structures of the three ocean regions, the T-S gradient diagramis shown to be useful and acoustic field affected by low salinity environment is investigated in this study.
Abstract
In case of any coastal ocean near the mouth of huge rivers, low salinity water can be formed dueto its large amount of freshwater discharge. For the acoustic analysis on the low salinity environment, someoceanographic data of the East China Sea and the Atlantic Ocean were collected through KODC (KoreaOceanographic Data Center) and NODC (National Oceanographic Data Center) online service. In this paper, theT-S gradient diagram is introduced to show a relation between the gradients of temperature and salinity inview of acoustic surface channel formation. Existence of haline channel, quantitative contribution of gradientsof salinity and temperature, effectiveness of the channel formation can be known by the T-S gradient diagram. After applying the collected data into the diagram, tropical regions of the Atlantic Ocean show strong halinechannel due to its nearly invariant temperature and drastic change of salinity with depth. The averaged transmissionloss in the channel is about 5.7 ~ 7.5 dB less than that out of the channel by the results of acousticpropagation model (RAM: Range independent Acoustic Model). On the other hand, the East China Sea andtemperate region of the Atlantic ocean have weaker haline channel with less difference of the averaged transmissionloss between in and out of the channel as 3.2 ~ 6.0 dB. Although data samples used in this studyhave limitation to represent the general physical structures of the three ocean regions, the T-S gradient diagramis shown to be useful and acoustic field affected by low salinity environment is investigated in this study.
참고문헌 (14)
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