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第 50 回 大気海洋圏物理系セミナー のおしらせ

日　時：1998年 9月 24日(木) 午前 9:30 〜 12:00
場　所：地球環境科学研究科 803A

発表者：Jinping Zhao (Institute of Oceanology, Chinese Academy of Sciences, China)
題　目：An analytical study on the mechanism of ice tongues and jets along ice edge

発表者：Glenn Shaw (University of Alaska Geopysical Institute)
題　目：Arctic Air Chemistry

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An analytical study on the mechanism of ice tongues and jets along ice edge (Jinping Zhao) 発表要旨：

 Along ice edge zone in polar region, there are some special phenomena, 
 such as ice tongue, jet, eddy pairs, bands, etc. These phenomena 
 represent some important dynamic processes by which ice melts quite 
 fast and heat exchange stronger. Recent years, the phenomena have been 
 frequently observed by air-borne SAR and satellite SAR. Some theories 
 have been proposed to explain the mechanism of these phenomena. Main 
 point of view for the mechanism of these phenomena is so called 
 dynamic instability. Some numerical models have been used to model the 
 phenomena. 
  
 As the phenomena occurs very frequently and the modeling results are 
 not satisfied, it is suggested that the phenomena might be caused by 
 some stable processes, not by instability. In this study, a new 
 physical model is proposed to address the key action of wind stress, 
 which is considered to be the basic reason to generate such phenomena. 
 With the condition  
 along ice edge, wind can cause these special phenomena. 
  
 An analytical model is established to the ice edge zone and a stable 
 solution is obtained. The result states that the curl of wind stress 
 is the key reason for generating ice tongue and jet with linear 
 theory, and eddy pairs by nonlinear theory. The study gives different 
 flow patterns in different wind conditions, for example, the symmetric 
 ice tongue, asymmetric tongue, jet and its extension, sea level 
 change, complicated under ice flow, etc. By these result,two 
 independent flow patterns are proposed, which can better explain the 
 processes along ice edge. 

Arctic Air Chemistry (Glenn Shaw) 発表要旨：

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