摘要
冰间湖内存在强烈的海-气相互作用和结冰析盐过程,在极区以及全球气候系统中起着重要作用。本文基于数字图像处理技术,从AMSR-E高分辨卫星遥感海冰密集度数据中提取了长时间序列的冰间湖变化信息,研究北极冰间湖内的净水面积、净水表面的净热通量(向上为正)、产冰量和产盐量的季节和年际变化,比较不同冰间湖区域之间的差异。研究结果表明:总净水面积分别在结冰初期和末期存在极大值,而由于总净水面积季节变化幅度不是很大,总产冰量和产盐量的季节变化主要受净热通量影响,在1月份存在极大值;在不同冰间湖区域内净水面积的季节变化中,进入结冰期越早的冰间湖内净水面积越快达到首次极大值;净热通量的年际变化趋势总体上是减小的,总净水面积是增加大的,其中靠近太平洋和大西洋入流口的冰间湖内净热通量减小的速率要比其他区域快,靠近亚欧大陆的冰间湖内净水面积增长速率要比其他区域大;总产冰量的年际变化同总净水面积基本一致,也是呈增加趋势。最后通过研究冰间湖的年际变化信息同海冰范围变化的相关性,发现如果连续多年冰间湖内年平均净热通量为负的异常,那么海冰范围将出现一次极小值。
Arctic polynyas are significant sites of ocean-atmosphere heat exchange and high winter sea ice production resulting in brine rejection,and play a critical role in local and regional climate variability.In this study,the net water area within Arctic polynyas is obtained using image-processing technology.The net heat flux and sea ice production in the surface of the net water area are also estimated.We analyzed the seasonal and interannual variability of the polynyas.Then,dividing the Arctic into eight domains,we studied the differences in the variability between the different domains.The results show that the total net water area has maximum at the beginning and at the end of the freezing period,and the total ice and salt production are mainly affected by the net heat flux and have a maximum in January.Based on the analysis of the seasonal variability of the net water areas in different polynya domains,the timing of the first net water area maximum is related to the time when polynyas begin to freeze.The interannual variability of the net heat flux has a decreasing trend and the net water area has an increasing trend.The interannual variability of the total ice production is very similar to that of the total net water area,also with an increasing trend.Finally,we discuss the correlation of interannual variability between the sea ice extent and the annual mean net heat flux in all polynyas.
出处
《极地研究》
CAS
CSCD
北大核心
2014年第2期244-253,共10页
Chinese Journal of Polar Research
基金
中国极地科学战略研究基金(20100209)
国家自然科学基金(41206178,41106005)
国家科技支撑计划(2011BAC03B02-01-04)资助
关键词
冰间
湖净水面积
净热通量
产冰量
北极
polynyas
net water area
net heat flux
ice production
Arctic
