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第 129 回 大気海洋圏物理系セミナー のおしらせ

日　時： 11月 27日(木) 午前 9:30
場　所：低温科学研究所 新棟 3階 講堂

発表者：Shutilin Sergey V. (気候モデリング講座 研究員)
題　目：The mass balance of Arctic sea ice cover

発表者：渡部 雅浩 (大循環力学講座 助教授)
題　目：東アジアの冬の天候変動に影響する2つの要因

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The mass balance of Arctic sea ice cover (Shutilin Sergey V. ) 発表要旨 :

  
 Goal. Investigate mass balance of Arctic sea ice cover during period 
 1948-2001 years. 
  
 Method. Analyses of the mass balance simulation experiment. Comparison 
 results of the simulation and the observation data. Estimation 
 differences of sea ice mass balance component depend on changing the 
 periods of cyclonic and anti cyclonic atmospheric activity in the 
 Arctic. 
  
 Instruments. Sea ice climatic model forced by NCAR/NCEP and climatic 
 data. 
  
 Sea ice cover play an important role in the climate variability 
 because it change energy and impulse exchange between ocean and 
 atmosphere in the high latitudes. Data about ice cover extend are 
 available from the satellite data, but the large scale changing in the 
 ice thickness distribution may be investigated by model simulation 
 only. 
  
 Climatic sea ice model was used for investigation of the mass balance 
 variability of Arctic ice cover. The characteristics of the mass 
 balance of sea ice cover have natural variability connected to the 
 changing of periods of Arctic oscillations. The picture of spatial 
 distributions of these characteristics and thickness and compactness 
 of ice cover changes from period to period, but more sensible 
 modifications happened during 90s years, which resulted in the 
 essential thinning of sea ice, especially in the Canadian and Siberian 
 regions. During summer time these changing were stronger. The sharp 
 decreasing of hummocks volume and area derived from the changing of 
 atmospheric circulation are responsible for the most part of average 
 ice thickness changing during 90s. 
  
 Results of the model simulations were used for analyses the 
 contribution of different processes to the ice forming and long term 
 variability of Arctic ice cover. The influence of vertical and lateral 
 melting, drift pattern, hummocks shape and other processes and factors 
 on simulation results were investigated. 
  

東アジアの冬の天候変動に影響する2つの要因 (渡部 雅浩) 発表要旨 :

  
 今年後半より, 気象庁が3ヵ月予報に続き暖/寒候期予報も,  
 それまでの統計予報から数値モデルを用いた力学予報に変更した 
 ことは記憶に新しい. これに関連して, アジア各国の現業予報 
 機関の間で予報システムおよび今年の季節予報に関する会議が, 
 今月, 気象庁において開かれた. 研究サイドからの最近の 
 (特に長期予報の精度向上に貢献できそうな)成果報告という 
 ことで, この会議に国内から数人の研究者も参加した. セミナーでは 
 そのときの様子を簡単に報告し, 講演内容を紹介する. 
  

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