鉴于卫星测高技术在南极周边海域会受到海面浮冰影响,且在利用测高序列分析海平面周期性动态变化时还会受到潮汐周期混叠效应的影响,为此,本文开展了基于GPS和验潮数据联合的南极大陆附近海域从1994—2014年间海平面的绝对变化研究.研究结果显示:在围绕南极大陆及附近海域的15个验潮站中,海平面绝对变化速度最大的是Diego Ramirez验潮站,达到11.10±0.04mm·a^-1;在西南极南极半岛的德雷克海峡,海平面变化最为活跃,变化均值在8.31±0.05mm·a^-1;在东南极,从Syowa站依次到Casey站,海平面的绝对变化速度相对平稳,四个潮位站海平面变化均值为3.35±0.04mm·a^-1;在罗斯冰架右下侧的罗斯岛附近,由于冰川崩解入海导致Scott Base站处的海平面上升速度较快,达到了9.61±0.07mm·a^-1.综合15个验潮站计算结果可得南极半岛德雷克海峡和罗斯岛附近海域,海平面绝对变化速度要高于同期南大洋海平面绝对变化速度,而东南极4个潮位站海平面绝对变化均值则与其相当.这也进一步反映了南极不同海域间海平面变化的差异性,相比较于对南大洋海平面变化的一个整体研究,分区研究海平面变化更具针对性,能更好地了解南极不同区域冰盖、冰架崩解和消融的情况.
The Antarctic region is the birthplace of global sea level change,and it has great scientific significance to study the sea level change surrounding the Antarctica continent.In view of the effect on precision of altimetry caused by floating sea ice in waters around Antarctica,and the tidal cycle aliasing effect is needed to be taken into account when using satellite altimetry sequence to analyze the sea level periodic dynamic changes.For this reason,this paper carried out a research on the absolute sea level change surrounding the Antarctica continent from 1994to2014 by using GPS tracking stations and tidal gauges.The results showed that the largest absolute sea level change in all 15 tidal gauges around the Antarctic is 11.10±0.04mm·a^-1 at Diego Ramirez station.In the Drake passage adjacent to the Antarctic peninsula,the sea level changes are the most active,where the average change is 8.31±0.05mm·a^-1.In the east Antarctica,the absolute sea level changes of four tidal gauges Syowa,Mawson,Davis and Casey,are relatively stable and slow.The average change rate of above four tidal gauges is 3.35±0.04 mm·a^-1.The absolute sea level change at Scott Base station is as fast as 9.61±0.07mm·a^-1,which is nearby Ross Island in the lower right side of Ross ice shelf.According to the sea level change calculation results,it can be concluded that the sea level change rates of the Drake passage adjacent to the Antarctic peninsula and Ross sea are higher than entire southern ocean sea level change.While the latter is approximately equal to the average change rate of four tidal gauges which are located in the east Antarctica.These reflect the sea level change differences among the different sea areas around the Antarctica.As a consequence,partitioned study of sea level change is more desirable and can better understand the ice shelf collapse and melting situation in different areas.