mean instantaneous sea level平均瞬时海平面
mean monthly sea level月平均海平面
mean annual sea level年平均海平面
local mean sea level[测] [海洋] 当地平均海面
mean sea level rise海平面上升
mean sea level change平均海平面变化
Relative mean sea level相对平均海面
above mean sea level平均海拔;平均海平面之上;平均海面之上;[地理] 平均海平面以上
mean sea-level平均海平面
And the systematic difference and its distribution of CNHD85 is analyzed from the difference of height anomalies. At last, the systematic difference of the mean sea level at Qingdao tide gauge is further testified from the sea surface topography model.
然后基于位理论方法求出了1985国家高程基准点的垂直偏差，基于高程异常差分析了1985国家高程基准的系统差及其分布规律，最后基于海面地形模型进一步揭示了青岛验潮站平均海平面的系统差。
参考来源 - 建立高程基准的理论与方法的研究N（名词） (in the UK) the sea level used by the Ordnance Survey as a datum level, determined at Newlyn in Cornwall 平均海平面→see sea level