Ocean and earth dynamics study by TOPEX/POSEIDON altimeter

卫星上的微波雷达高度计可以测量全球海面高度，精度达到几厘米，被认为对海洋和固体地球的动力学研究非常有用。在目前的研究中，物理海洋学家和固体地球物理学家之间的合作工作已被提出。该计划派出首席调查员和9名联合调查员参加1996年在英国和1997年在法国举行的TOPEX/POSEIDON科学工作组会议，以交流有关国际卫星测高研究的信息。1996年和1997年在东京举行了科学会议，以讨论海拔数据的处理和分析。这些会议邀请了澳大利亚、美国和法国的四名科学家，以促进国际合作。通过这些活动，获得了以下成果：(1)结合卫星测高资料和现场海洋资料，获得了日本南部黑潮的长时间输送序列；(2)结合高程资料和现场海洋资料，揭示了整个北太平洋的地面环流特征；(3)制定了将高程资料同化于海洋数值模式的方案；(4)利用高程资料建立了精确的全球潮汐模型；(5)利用GEOSAT大地测量任务期间发布的高程数据，获得了一幅高分辨率的全球重力异常图，该地图近期未进行分类；(6)将测高资料与重力原位异常资料相结合，获得了日本周边海域高精度大地水准面图。

Micro-wave radar altimeters on board satellites can measure the sea surface hight globally with accuracy of a few centimeters, and are considered to be very useful for studies of dynamics both of the oceans and solid earth. In the present study, cooperative works between physical oceanographers and solid earth geophysicists have been intended. The program sent the Principal Investigator and nine Co-Investigators to TOPEX/POSEIDON Science Working Team meetings held in England in 1996 and in France in 1997, in order to exchange information about international satellite altimetry studies. Scientific meetings were held in Tokyo in 1996 and 1997, in order to discuss about altimetry data processing and analyzes. For those meetings, four scientists of Australia, the United States and France were invited in order to stimulate international cooperation. Through those activities, following results have been obtained : (1) A long time series of transport of the Kuroshio south of Japan was obtained by combined use of satellite altimetry data with in situ oceanographic data ; (2) Features of surface circulations of the whole North Pacific were also revealed through combined use of altimetry data with in situ oceanographic data ; (3) The scheme has been developed to assimilate the altimetrly data to numerical models of the oceans ; (4) A precise global tide model was obtained from altimetry data ; (5) A high-resolution global map of gravity anomaly was obtained through the release of altimetry data during the GEOSAT Geodetic Mission, which has been unclassified recently ; and (6) A high-precision geoid map was obtained for the seas around Japan by combined use of altimetry data with in situ gravity anomaly data.