| 题名 | 联合卫星重力和卫星测高研究全球平均海平面变化 |
| 作者 | 常金龙 |
| 学位类别 | 硕士 |
| 答辩日期 | 2008-06 |
| 授予单位 | 中国科学院测量与地球物理研究所 |
| 授予地点 | 武汉 |
| 导师 | 钟敏 |
| 关键词 | 海平面变化 热容海平面变化 卫星测高 GRACE EOF分析 |
| 学位专业 | 大地测量学与测量工程 |
| 中文摘要 | 海平面变化与人类生活息息相关，特别对于住在沿岸的人们来说具有非常重要的意义。本文利用卫星测高数据、ECCO温盐数据和GRACE时变重力场系数分别计算了平均海平面变化、热容海平面变化、海水质量分布引起的海平面变化，并且联合卫星测高和GRACE数据估算了热容海平面变化。本文的主要研究工作如下： 1. 计算了近全球平均海平面和热容海平面季节变化，结果显示海水热膨胀是大尺度海平面变化的主要贡献者，质量变化只占很小一部分。 2. 利用GRACE系数解算了全球海水质量变化，研究结果表明：低阶项系数（1阶项和 ）对解算结果有较大的影响；不同的平滑半径对平均海平面变化影响不大；在扣除NCEP海平面气压影响后，GRACE得到的海水质量变化与卫星测高扣掉模式热容结果符合的很好。 3. 采用经验正交函数分析方法(EOF)研究了海平面季节变化第一模态，发现估算热容变化与模式热容变化空间分布，在绝大部分海域一致。 4. 给出平均海平面的变化趋势：卫星测高观测最近15年的全球平均海平面变化趋势变化率约3.0～3.3mm/yr，2000～2006年的变化率是3.1±0.2mm/yr；海水质量变化引起全球平均海平面变化的趋势（2003～2006年）约为-0.3±0.2mm/yr，经过PGR修正的值约为1.4±0.2mm/yr；同一时期，全球热容海平面变化趋势约为1.7±0.6 mm/yr。 5. 结合GRACE和ICE-5G模型计算了南极冰雪质量变化趋势，结果显示整个南极冰雪质量呈亏损之势，变化率为-44.5 km3/yr，可导致海平面每年上升0.11mm,，绝大部分质量亏损来自于西部地区 |
| 英文摘要 | Sea level variations affect human life especially for people living in seacoast. In this study, we estimated global mean, steric and eustatic (mass variation) sea level changes respectively using different data resources, including sea level anomalies from satellite radar altimetry, ocean temperature and salinity from ECCO, time-variable gravity observations from GRACE, and combined altimetry and GRACE data to compute the steric sea level variations. The main research works and the results of this thesis are as follows: 1. This study computed global mean and steric seasonal sea level changes , and conformed that thermal expansion is responsible for most of the large-scale seasonal variations observed by altimeter. The eustatic part is a small portion of it. 2. The low degree terms(degree 1 and ) have a considerable effect on the estimation results of global ocean mass variations from GRACE data; The influence of different smoothing radius is weak; After removing NCEP sea level pressure, the ocean mass variation derived from GRACE is in agreement with that derived from the altimetry with the ECCO steric part corrected. 3. Using empirical orthogonal function (EOF) analysis, we examine the leading modes of sea level seasonal variability and find the spatial patterns of the leading ESSL(estimated steric sea level) and SSL(steric sea level) modes are similar in the most region of ocean. 4. Global secular sea level change in recent 15 years is estimated to be rising at 3.0 to 3.3 mm/yr, based on altimetry observations, and the rate is 3.1mm/yr between 2000 and 2005; The estimated trend of global mass sea level variations is -0.4mm/yr without PGR during the period between 2003 and 2006, and the rate is 1.4mm/yr after PGR correction; The trend of global steric sea level variation based on altimetry and GRACE data is 1.7mm/yr over the same period. 5. Using GRACE and ICE-5G ice model ,we computed mass variations of the Antarctic ice/snow .We find that the ice/snow mass decreased, at a rate of -44.5 km3/yr of ice ,equivalent to 0.11mm/yr of global sea level rise. Most of this loss come from the West Antarctic Ice Sheet |
| 公开日期 | 2013-01-25 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.whigg.ac.cn//handle/342008/3702]  |
| 专题 | 测量与地球物理研究所_学生论文_学位论文 |
| 推荐引用方式 GB/T 7714 | 常金龙. 联合卫星重力和卫星测高研究全球平均海平面变化[D]. 武汉. 中国科学院测量与地球物理研究所. 2008. |
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