海冰厚度的时间变化特征与海冰再生周期研究

THE TEMPORAL CHANGE CHARACTERISTICS OF SEA ICE THICKNESS AND REGENERATION PERIOD OF SEA ICE IN LIAODONG GULF

认识海冰厚度在气温等因子影响下随时间变化的特征 ,是估算海冰资源量的基础。该文通过室内冻结实验、现场观测实验和历史资料分析 ,探讨了在气温和风的影响下海冰厚度随时间变化的特征 ,并在此基础上给出了海冰的再生周期。室内实验利用 5 0 0L温控冰柜 ,实验温度设为 -2℃、-4℃、-6℃、-8℃、-1 0℃ ,冻结时间 1 1 4h-1 2 0h,冰厚取样间隔 6h。现场观测地点为辽宁省瓦房店市长兴岛北侧海区的潮间带平整冰面 ,在观测冰厚变化的同时 ,测定实验地点的冰面温度、冰上气温和邻近岸上的地面温度、地上气温。历史资料分析使用 1 989年 1 2月 2 5日～ 1 990年 2月 2 3日葫芦岛海洋站观测到的气温、风速和冰厚的资料 ,以及同时期葫芦岛气象站≤ -2℃积温、≤ -4℃积温资料做对比分析。文中得出的结论如下 :随着气温降低或负积温值的增加 ,冰厚逐渐增加 ;风速增加 ,冰厚降低 ,风速减小 ,冰厚增加 ;在气温≤ -4℃条件下 ,渤海海冰再生速率为 1 86cm·d- 1 ,生成厚度为 1 0cm的海冰所需时间为 5 4d ;常冰年渤海各海区工程性开采海冰的可能次数为 :辽东湾 7 4次～ 1 3次 ,渤海湾 3 7次～ 7 4次 ,莱州湾 1 9次～ 3

It is the basis for estimation of the amount of sea ice resources to understand the changing characteristics of sea ice thickness with the effect by some factors, such as temperature. In this paper, a freezing experiment in laboratory, an observation in experimental sites and an analysis by historical data were performed to study the changing characteristics of sea ice thickness affected by temperature and wind with time. Based on that, a reformed cycle for sea ice was proposed. A 500L refrigerator was used in the laboratory, its temperature was controlled at-2℃、-4℃、-6℃、-8℃、-10℃, frozen time was 114～120 hours, the intermission obtained ice thickness was 6 hours. The observed location was northern of sea region of Liaoning Province. Ice surface temperature, temperature above ice surface and surface temperature close to coast were observed while thickness of sea ice was observed at same time. And these data were compared with accumulated temperature with ≤-2℃, ≤-4℃ from Hulu Island meteorological station. The conclusions of this study are as follows. The sea ice thickness increases in accordance with the temperature decrease or the negative accumulated temperature increase; the greater wind speed, the smaller of sea ice thickness formed; the regenerated speed of sea ice in temperature with ≤-4℃ in Bohai region is 1.86m/d, which means that producing the sea ice on the thickness with 10cm needs 5.4 days. The possible times for exploiting sea ice with regenerated period of sea ice in each region of Bohai Sea were 7.4～13 times in Liaodong Gulf, 3.7～4.7 times in Bohai Gulf, 1.9～3.7 times in Lai-zhou Gulf, respectively.