| 冰盖消融的海平面指纹变化及其对GRACE监测结果的影响 |
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| 引用本文： | 王林松,陈超,马险,杜劲松.冰盖消融的海平面指纹变化及其对GRACE监测结果的影响[J].地球物理学报,2018,61(7):2679-2690. |
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| 作者姓名： | 王林松 陈超 马险 杜劲松 |
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| 作者单位： | 中国地质大学(武汉) 地球物理与空间信息学院, 湖北省地球内部多尺度成像重点实验室, 武汉 430074 |
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| 基金项目： | 国家自然科学基金（41504065，41574070，41604060）和中央高校基本科研业务费专项资金资助. |
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| 摘 要： | 全球变暖背景下的冰盖消融以及由此带来海平面上升日益明显，直接影响地球表面的陆地水质量平衡，以及固体地球瞬间弹性响应，研究冰盖质量变化的海平面指纹能够帮助深入了解未来海平面区域变化的驱动因素.本文基于海平面变化方程并考虑负荷自吸效应（SAL）与地球极移反馈的影响，借助美国德克萨斯大学空间研究中心（Center for Space Research，CSR）发布的2003年到2012年十年期间的GRACE重力场月模型数据（RL05），结合加权高斯平滑的区域核函数，反演得到格陵兰与南极地区冰盖质量变化的时空分布，并利用海平面变化方程计算得到了相对海平面的空间变化，结果表明：格陵兰与南极冰盖质量整体呈明显的消融趋势，变化速率分别为-273.31 Gt/a及-155.56 Gt/a，由此导致整个北极圈相对海平面降低，最高可达约-0.6 cm·a-1；而南极地区冰盖质量变化趋势分布不一，导致西南极近海相对海平面下降，而东南极地区近海相对海平面上升，最高可达约0.2 cm·a-1.远离质量负荷区域的全球海平面以上升趋势为主，平均全球相对海平面上升0.71 mm·a-1，部分远海地区相对海平面上升更加突出（例如北美与澳大利亚），高出全球平均海平面上升速率将近30%.此外，本文也重点探讨了GRACE监测冰盖消融结果中由于极地近海海平面变化导致的泄漏影响，经此项影响校正后的结果表明：海平面指纹效应对GRACE监测格陵兰与南极地区2003-2012期间整体冰盖消融速率的贡献分别为约3%与9%，建议在后期利用GRACE更精确地估算研究区冰盖质量变化时，应考虑海平面指纹效应的渗透影响.
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| 关 键 词： | 冰盖消融 海平面指纹 GRACE 泄漏校正 |
| 收稿时间： | 2017-06-01 |
Sea level fingerprints of ice sheet melting and its impacts on monitoring results of GRACE |
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| WANG LinSong,CHEN Chao,MA Xian,DU JinSong.Sea level fingerprints of ice sheet melting and its impacts on monitoring results of GRACE[J].Chinese Journal of Geophysics,2018,61(7):2679-2690. |
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| Authors: | WANG LinSong CHEN Chao MA Xian DU JinSong |
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| Institution: | Hubei Subsurface Multi-scale Imaging Key Laboratory, Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan 430074, China |
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| Abstract: | The sea level contribution from ice sheet melting has been accelerating due to the global warming. Ice sheet mass change can directly pose impacts on terrestrial water mass balance and instantaneous elastic response of the solid earth. Study on sea level fingerprints caused by ice sheets change can help us to understand the drivers of future sea level changes. In this study, we perform forward modeling of the relative sea level (RSL) changes based on sea level equation, self-attraction and loading (SAL) effects. Using monthly GRACE gravity field solution of Release 5 (RL05) products from CSR, spanning 10 years between 2003 and 2012, the spatial and temporal distribution of ice sheets balance in Greenland and Antarctica are estimated by averaging kernel based on weighted Gaussian convolution, and then RSL spatial variation is computed by solving sea level equation. The results indicate that the total ice sheet mass in Greenland and Antarctica has melted significantly, respectively, at change rates of -273.31 and -155.56 Gt/a, which has resulted in RSL decease of the entire Arctic Circle, with maximum negative value about -0.6 cm·a-1. There are mixed trends in ice sheets mass of the Antarctic region, which resulted in RSL decease of West Antarctica but increase of East Antarctica, with a maximum positive value about 0.2 cm·a-1. The far-field peak increase is less dependent on the precise pattern of mass loading and the average global RSL raised by 0.71 mm·a-1. This has a marked effect on the zonal distribution of RSL, resulting in maxima around the coastlines of North America and Australia. In this region the increase is about 30% higher than the eustatic value. In addition, this paper also discusses the influence from sea level changes in coastal areas leakage caused by ice sheet melting estimated by GRACE. The results after leakage effects of offshore sea level are removed show that the sea level fingerprint contributions from ice sheet melting leakage in GRACE detecting mass changes in Greenland and Antarctica are 3% and 9% during 2003 to 2012, respectively. This study suggests that the leakage effects of the sea level fingerprints should be taken into account when using GRACE to accurately estimate ice sheet mass balance in the further work. |
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| Keywords: | Ice sheet melting Sea level fingerprint GRACE Leakage correction |
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