Continental water storage in GGP and satellite signals
Water mass variations in the global hydrological cycle can be identified as time variable gravity field signals derived from the satellite mission GRACE.Further, they are consistent with independent observations provided by terrestrial gravity measurements.The deployment of ground based observations helps to achieve a maximum of reliability and information gain by comparison with the gravity field variations derived from the GRACE satellite mission.Thus, the data of the network of superconducting gravimeters (SG) of the ” Global Geodynamics Project” (GGP) are of particular interest.Since the distribution of such instruments is very dense inCentral Europe, this study is focused on this SG network with its long-term gravity observations.But, in order to separate the wanted signal it is necessary for some terrestrial stations to reduce local hydrological effects in the SG observations especially for subsurface stations.Then, the time-variable gravity signals from GRACE agree well with the terrestrial observations from the SG station cluster.The station stability of the SG sites with respect to vertical deformations was checked by GNSS based observations.Most of the variability can be explained by loading effects due to changes in continental water storage.In general, the stability of all stations has been confirmed.Different statistical tools were applied to retrieve the information content of both data sets and to allow for comparison: Correlation and coherence analyses in combination with the root mean square (RMS) variability as well as Empirical Orthogonal Functions (EOF) analysis, contributed by our colleagues from GFZ Potsdam.The results show that the maximum correspondence between the SG and GRACE time series is achieved when filtering the GRACE data with Gaussian filters of about1000 km filter length.With the EOF analyses it was possible to identify common characteristic spatial and temporal patterns:The high correspondence of the first modes for GRACE and SG data implies that the first EOF mode represents a large-scale (Central European) time variable gravity signal seen by both the GRACE and the SG cluster.In this work, an overview is given over the results obtained for the European SG-network.
Gerhard Jentzsch Thomas Jahr Corinna Kroner Adelheid Weise
Retired chair of Applied Geophysics at the Institute of Geosciences,University of Jena Institute of Geosciences,University of Jena Physikalisch-Technische Bundesanstalt,Braunschweig
国内会议
武汉
英文
660-668
2014-04-22（万方平台首次上网日期，不代表论文的发表时间）