The GRACE(Gravity Recovery and Climate Experiment)space mission recorded temporal variation characteristics of the global gravity field at decadal timescales.The gravity data have been shown to capture the dynamics of...The GRACE(Gravity Recovery and Climate Experiment)space mission recorded temporal variation characteristics of the global gravity field at decadal timescales.The gravity data have been shown to capture the dynamics of flows within the outer core and their effects on the core-mantle boundary.We first aim to remove global surface process gravity signals from the GRACE data.We then construct the global core magnetic field according to the CHAOS-7 model.Finally,we apply the blind source separation method to decompose the processed gravity signals and core magnetic signals and compute the power spectral density of the gravity and magnetic field signals by using the Lomb-Scargle periodogram approach.We have discovered a signal cycle(of~6 years)in the principal components of the core magnetic and gravity signals,potentially as a result of deep Earth processes.The main principal components of the core magnetic and gravity signals reveal that the variation trends in the second-order time derivative of the core magnetic field are similar to those in the gravity field.After 2014,the second-order time derivative of the core magnetic field exhibited linear and rapid change characteristics,which were the same as the change in the gravity field and are consistent with existing research results.展开更多
The primary mission of the Gravity Recovery and Climate Experiment (GRACE) satellite and its successor,GRACE Follow-On (GRACE-FO), is to provide time-variable gravity fields, and its observations have been widely used...The primary mission of the Gravity Recovery and Climate Experiment (GRACE) satellite and its successor,GRACE Follow-On (GRACE-FO), is to provide time-variable gravity fields, and its observations have been widely used in various studies. However, the nearly one-year gap between GRACE and GRACE-FO has affected our ability to obtain continuous time-variable gravity data. In this study, we use the Singular Spectrum Analysis (SSA) method to fill the nearly one-year gap between the GRACE and GRACE-FO missions, as well as the gaps within the GRACE mission itself, to generate a continuous and complete mascon product from April 2002 to December 2022. These products are evaluated at the basin scale in Greenland, Antarctica, and ten river basins worldwide, as well as across oceans. The results show that our filled data can effectively recover seasonal and interannual signals and exhibit good consistency with previous reconstructions. The products provided in this study will benefit GRACE applications related to oceans, glaciers, and terrestrial water storage.展开更多
重力恢复与气候实验(gravity recovery and climate experiment,GRACE)数据解算出的时变重力场模型为陆地水储量的研究提供了一种全新的途径,然而,GRACE数据只能解算出格网点分辨率上总体的水储量变化,包括地表水、土壤水、地下水和植...重力恢复与气候实验(gravity recovery and climate experiment,GRACE)数据解算出的时变重力场模型为陆地水储量的研究提供了一种全新的途径,然而,GRACE数据只能解算出格网点分辨率上总体的水储量变化,包括地表水、土壤水、地下水和植被水等,却无法分离垂直层面上不同深度的水储量成分。采用小波分解方法,将扣除全球陆地数据同化系统水文模型地表水成分的GRACE信号进行分解,利用分解得到的小波子函数结合美国区域内的水井实测数据对地下水成分进行回归分析,并通过二维曲面插值的方法得到全美地区不同小波子函数的回归系数,以此来重构长时间连续的地下水储量变化序列。结果表明,在测试点位中61.84%以上的点位其相关系数达到0.4以上,62.90%的点位其均方根值在1.0 m以下,此方法可以得到地下水时空分布特征,为地下水资源的利用与研究提供数据支撑。展开更多
干旱是全球范围内普遍存在的自然灾害,对环境、生态、经济和社会等多个方面产生深远影响。GRACE(Gravity Recovery and Climate Experiment)重力卫星通过测量地球重力场变化数据可动态监测陆地水储量变化。应用GRACE获得的水储量时空分...干旱是全球范围内普遍存在的自然灾害,对环境、生态、经济和社会等多个方面产生深远影响。GRACE(Gravity Recovery and Climate Experiment)重力卫星通过测量地球重力场变化数据可动态监测陆地水储量变化。应用GRACE获得的水储量时空分布信息,可监测干旱,以研究干旱事件的发生、发展与演变过程。采用文献计量法分析总结了GRACE卫星数据在地下水储量变化、气象与水文干旱演变规律与响应、干旱预警等方面的应用现状及存在数据验证与数据插补重建方面的问题,并展望了变化环境下水储量变化、构建更适合干旱监测的干旱指数、提高GRACE数据精度、提升GRACE数据时空分辨率、干旱预警和决策支持以及区域水循环和生态系统响应等研究方向,可为后续的相关应用研究提供一定参考价值。展开更多
基金the National Natural Science Foundation of China(Grant Nos.42274003,41974007,and 41774019).
文摘The GRACE(Gravity Recovery and Climate Experiment)space mission recorded temporal variation characteristics of the global gravity field at decadal timescales.The gravity data have been shown to capture the dynamics of flows within the outer core and their effects on the core-mantle boundary.We first aim to remove global surface process gravity signals from the GRACE data.We then construct the global core magnetic field according to the CHAOS-7 model.Finally,we apply the blind source separation method to decompose the processed gravity signals and core magnetic signals and compute the power spectral density of the gravity and magnetic field signals by using the Lomb-Scargle periodogram approach.We have discovered a signal cycle(of~6 years)in the principal components of the core magnetic and gravity signals,potentially as a result of deep Earth processes.The main principal components of the core magnetic and gravity signals reveal that the variation trends in the second-order time derivative of the core magnetic field are similar to those in the gravity field.After 2014,the second-order time derivative of the core magnetic field exhibited linear and rapid change characteristics,which were the same as the change in the gravity field and are consistent with existing research results.
基金the National Natural Science Foundation of China(E3ER0402A2,E421040401)the University of Chinese Academy of Sciences Research Start-up Grant(110400M003)the Fundamental Research Funds for the Central Universities(E2ET0411X2).
文摘The primary mission of the Gravity Recovery and Climate Experiment (GRACE) satellite and its successor,GRACE Follow-On (GRACE-FO), is to provide time-variable gravity fields, and its observations have been widely used in various studies. However, the nearly one-year gap between GRACE and GRACE-FO has affected our ability to obtain continuous time-variable gravity data. In this study, we use the Singular Spectrum Analysis (SSA) method to fill the nearly one-year gap between the GRACE and GRACE-FO missions, as well as the gaps within the GRACE mission itself, to generate a continuous and complete mascon product from April 2002 to December 2022. These products are evaluated at the basin scale in Greenland, Antarctica, and ten river basins worldwide, as well as across oceans. The results show that our filled data can effectively recover seasonal and interannual signals and exhibit good consistency with previous reconstructions. The products provided in this study will benefit GRACE applications related to oceans, glaciers, and terrestrial water storage.
文摘干旱是全球范围内普遍存在的自然灾害,对环境、生态、经济和社会等多个方面产生深远影响。GRACE(Gravity Recovery and Climate Experiment)重力卫星通过测量地球重力场变化数据可动态监测陆地水储量变化。应用GRACE获得的水储量时空分布信息,可监测干旱,以研究干旱事件的发生、发展与演变过程。采用文献计量法分析总结了GRACE卫星数据在地下水储量变化、气象与水文干旱演变规律与响应、干旱预警等方面的应用现状及存在数据验证与数据插补重建方面的问题,并展望了变化环境下水储量变化、构建更适合干旱监测的干旱指数、提高GRACE数据精度、提升GRACE数据时空分辨率、干旱预警和决策支持以及区域水循环和生态系统响应等研究方向,可为后续的相关应用研究提供一定参考价值。
