{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,27]],"date-time":"2026-06-27T04:55:29Z","timestamp":1782536129401,"version":"3.54.5"},"reference-count":77,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2020,3,13]],"date-time":"2020-03-13T00:00:00Z","timestamp":1584057600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Science Centre, Poland (NCN)","award":["2018\/31\/N\/ST10\/00209"],"award-info":[{"award-number":["2018\/31\/N\/ST10\/00209"]}]},{"name":"Polish National Agency for Academic Exchange (NAWA)","award":["PPI\/APM\/2018\/1\/00032\/U\/001"],"award-info":[{"award-number":["PPI\/APM\/2018\/1\/00032\/U\/001"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Over the last 15 years, the Gravity Recovery and Climate Experiment (GRACE) mission has provided measurements of temporal changes in mass redistribution at and within the Earth that affect polar motion. The newest generation of GRACE temporal models, are evaluated by conversion into the equatorial components of hydrological polar motion excitation and compared with the residuals of observed polar motion excitation derived from geodetic measurements of the pole coordinates. We analyze temporal variations of hydrological excitation series and decompose them into linear trends and seasonal and non-seasonal changes, with a particular focus on the spectral bands with periods of 1000\u20133000, 450\u20131000, 100\u2013450, and 60\u2013100 days. Hydrological and reduced geodetic excitation series are also analyzed in four separated time periods which are characterized by different accuracy of GRACE measurements. The level of agreement between hydrological and reduced geodetic excitation depends on the frequency band considered and is highest for interannual changes with periods of 1000\u20133000 days. We find that the CSR RL06, ITSG 2018 and CNES RL04 GRACE solutions provide the best agreement with reduced geodetic excitation for most of the oscillations investigated.<\/jats:p>","DOI":"10.3390\/rs12060930","type":"journal-article","created":{"date-parts":[[2020,3,18]],"date-time":"2020-03-18T08:20:44Z","timestamp":1584519644000},"page":"930","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["Evaluating Gravimetric Polar Motion Excitation Estimates from the RL06 GRACE Monthly-Mean Gravity Field Models"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7502-5243","authenticated-orcid":false,"given":"Justyna","family":"\u015aliwi\u0144ska","sequence":"first","affiliation":[{"name":"Space Research Centre, Polish Academy of Sciences, 00-716 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1136-5609","authenticated-orcid":false,"given":"Jolanta","family":"Nastula","sequence":"additional","affiliation":[{"name":"Space Research Centre, Polish Academy of Sciences, 00-716 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1776-3314","authenticated-orcid":false,"given":"Henryk","family":"Dobslaw","sequence":"additional","affiliation":[{"name":"Section 1.3: Earth System Modelling, GFZ German Research Centre for Geosciences, 14473 Potsdam, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9596-267X","authenticated-orcid":false,"given":"Robert","family":"Dill","sequence":"additional","affiliation":[{"name":"Section 1.3: Earth System Modelling, GFZ German Research Centre for Geosciences, 14473 Potsdam, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,3,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Lambeck, K. (1980). The Earth\u2019s Variable Rotation: Geophysical Causes and Consequences, Cambridge University Press.","DOI":"10.1017\/CBO9780511569579"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"e1501693","DOI":"10.1126\/sciadv.1501693","article-title":"Climate\u2013driven polar motion: 2003\u20132015","volume":"2","author":"Adhikari","year":"2016","journal-title":"Sci. Adv."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"126","DOI":"10.1016\/j.epsl.2018.08.059","article-title":"What drives 20th century polar motion?","volume":"502","author":"Adhikari","year":"2018","journal-title":"Earth Planet. Sci. Lett."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1016\/j.jog.2017.01.008","article-title":"Ice and groundwater effects on long term polar motion (1979\u20132010)","volume":"106","author":"Youm","year":"2017","journal-title":"J. Geodyn."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"358","DOI":"10.1038\/s41558-019-0456-2","article-title":"Contributions of GRACE to understanding climate change","volume":"9","author":"Tapley","year":"2019","journal-title":"Nat. Clim. Chang."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Sneeuw, N., Nov\u00e1k, P., Crespi, M., and Sans\u00f2, F. (2015). Theory of earth rotation variations. VIII Hotine-Marussi Symposium on Mathematical Geodesy, Springer.","DOI":"10.1007\/978-3-319-30530-1"},{"key":"ref_7","unstructured":"Brzezi\u0144ski, A., Nastula, J., Ko\u0142aczek, B., and Ponte, R.M. (July, January 30). Oceanic excitation of polar motion from interannual to decadal periods. Proceedings of the International Association of Geodesy, IAG General Assembly, Sapporo, Japan."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"235","DOI":"10.1016\/j.jog.2009.09.021","article-title":"Seasonal excitation of polar motion estimated from recent geophysical models and observations","volume":"48","author":"Nastula","year":"2009","journal-title":"J. Geodyn."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2370","DOI":"10.1029\/2002JB002143","article-title":"Atmospheric and oceanic excitation of the Earth\u2019s wobbles during 1980\u20132000","volume":"108","author":"Gross","year":"2003","journal-title":"J. Geophys. Res. Solid Earth"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1046\/j.1365-246X.1999.00930.x","article-title":"Further evidence for oceanic excitation of polar motion","volume":"139","author":"Nastula","year":"1999","journal-title":"Geophys. J. Int."},{"key":"ref_11","unstructured":"Dick, S., McCarthy, D., and Luzum, B. (2000). Regional signals in atmospheric and oceanic excitation of polar motion. Polar Motion: Historical and Scientific Problems, Astronomical Society of the Pacific."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1029\/2006GL028983","article-title":"Comp on excitation series derived from GRACE and from analyses of geophysical fluids","volume":"34","author":"Nastula","year":"2007","journal-title":"Geophys. Res. Lett."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"B04407","DOI":"10.1029\/2008JB005605","article-title":"Patterns of atmospheric excitation functions of polar motion from high\u2013resolution regional sectors","volume":"114","author":"Nastula","year":"2009","journal-title":"J. Geophys. Res."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"561","DOI":"10.2478\/s11600-011-0008-2","article-title":"Comparison of the geophysical excitations of polar motion from the period 1980.0\u20132007.0","volume":"59","author":"Nastula","year":"2011","journal-title":"Acta Geophys."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1016\/j.jog.2019.01.014","article-title":"Hydrological signals in polar motion excitation\u2014Evidence after fifteen years of the GRACE mission","volume":"124","author":"Nastula","year":"2019","journal-title":"J. Geodyn."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Seoane, L., Nastula, J., Bizouard, C., and Gambis, D. (2011). Hydrological excitation of polar motion derived from GRACE gravity field solutions. Int. J. Geophys.","DOI":"10.1155\/2011\/174396"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1007\/s11600-018-0227-x","article-title":"Terrestrial water storage variations and their effect on polar motion","volume":"67","author":"Nastula","year":"2019","journal-title":"Acta Geophys."},{"key":"ref_18","first-page":"7110","article-title":"Hydrological excitation of polar motion by different variables from the GLDAS model","volume":"17","author":"Nastula","year":"2017","journal-title":"J. Geod."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"615","DOI":"10.1007\/s10712-006-9008-1","article-title":"The rotational and gravitational signature of the December 26, 2004 Sumatran earthquake","volume":"27","author":"Gross","year":"2006","journal-title":"Surv. Geophs."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1333","DOI":"10.5636\/jgg.45.1333","article-title":"Decade Variations of the Earth\u2019s Rotation and Geomagnetic Core-Mantle Coupling","volume":"45","year":"1993","journal-title":"J. Geomagn. Geoelectr."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1016\/S0031-9201(99)00089-8","article-title":"Influence of possible inner\u2013core motions on the polar motion and the gravity field","volume":"117","author":"Jochmann","year":"2000","journal-title":"Phys. Earth Planet. Inter."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1029\/2004GL019920","article-title":"The gravity recovery and climate experiment: Mission overview and early results","volume":"31","author":"Tapley","year":"2004","journal-title":"Geophys. Res. Lett."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"562","DOI":"10.1046\/j.1365-246x.2001.01550.x","article-title":"Glacial isostatic adjustment on a rotating earth","volume":"147","author":"Mitrovica","year":"2001","journal-title":"Geophys. J. Int."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1029\/2004GL020461","article-title":"Preliminary observations of global ocean mass variations with GRACE","volume":"31","author":"Chambers","year":"2004","journal-title":"Geophys. Res. Lett."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"658","DOI":"10.1126\/science.1128661","article-title":"Crustal dilatation observed by GRACE after the 2004 Sumatra\u2013Andaman earthquake","volume":"313","author":"Han","year":"2006","journal-title":"Science"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"B02403","DOI":"10.1029\/2009JB006635","article-title":"Hydrological and oceanic effects on polar motion from GRACE and models","volume":"115","author":"Jin","year":"2010","journal-title":"J. Geophys. Res."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1016\/j.jog.2012.01.009","article-title":"Assessment of terrestrial water contributions to polar motion from GRACE and hydrological models","volume":"62","author":"Jin","year":"2012","journal-title":"J. Geodyn."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1016\/j.jog.2011.12.002","article-title":"Seasonal excitation of polar motion","volume":"62","author":"Chen","year":"2012","journal-title":"J. Geodyn."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Nastula, J., Salstein, D.A., and Popi\u0144ski, W. (2016). Hydrological excitations of polar motion from GRACE gravity field solutions. Int. Assoc. Geod. Symp., 513\u2013519.","DOI":"10.1007\/1345_2015_85"},{"key":"ref_30","first-page":"1","article-title":"Assessment of the global and regional land hydrosphere and its impact on the balance of the geophysical excitation function of polar motion","volume":"64","author":"Nastula","year":"2016","journal-title":"Acta Geophys."},{"key":"ref_31","unstructured":"Bettadpur, S. (2019, December 24). UTCSR Level\u20132 Processing Standards Document for Level\u20132 Product Release 0006. Technical Report GRACE 2018. Available online: http:\/\/icgem.gfz-potsdam.de\/GRACE_CSR_L2_Processing_Standards_Document_for_RL06.pdf."},{"key":"ref_32","unstructured":"Dahle, C., Flechtner, F., Murb\u00f6ck, M., Michalak, G., Neumayer, H., Abrykosov, O., Reinhold, A., and K\u00f6nig, R. (2019, December 24). GFZ Level-2 Processing Standards Document for Level-2 Product Release 06. Scientific Technical Report STR-Data. Available online: http:\/\/icgem.gfz-potsdam.de\/GRACE_GFZ_L2_Processing_Standards_Document_for_RL06.pdf."},{"key":"ref_33","unstructured":"Yuan, D. (2019, December 24). JPL level\u20132 Processing Standards Document for Level\u20132 Product Release 06. Technical Report GRACE, 327\u2013744. Available online: http:\/\/icgem.gfz-potsdam.de\/GRACE_JPL_L2_Processing_Standards_Document_for_RL06.pdf."},{"key":"ref_34","unstructured":"Petit, G., and Luzum, B. (2010). IERS Conventions, Bureau International Des Poids et Mesures Sevres."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"263","DOI":"10.1093\/gji\/ggx302","article-title":"A new high\u2013resolution model of non\u2013tidal atmosphere and ocean mass variability for de\u2013aliasing of satellite gravity observations: AOD1B RL06","volume":"211","author":"Dobslaw","year":"2017","journal-title":"Geophys. J. Int."},{"key":"ref_36","unstructured":"Dobslaw, H., Bergmann-Wolf, I., Dill, R., Poropat, L., and Flechtner, F. (2019, December 24). Product Description Document for AOD1B Release 06. Technical Report GRACE, 327\u2013750. Available online: Ftp:\/\/isdcftp.gfz-potsdam.de\/grace\/DOCUMENTS\/Level-1\/."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"G\u00f6ttl, F., Schmidt, M., and Seitz, F. (2018). Mass\u2013related excitation of polar motion: An assessment of the new RL06 GRACE gravity field models. Earth Planets Space, 70.","DOI":"10.1186\/s40623-018-0968-4"},{"key":"ref_38","first-page":"3","article-title":"Polar motion excitation by variations of the effective angular momentum function: Considerations concerning deconvolution problem","volume":"17","author":"Brzezinski","year":"1992","journal-title":"Manuscr. Geod."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1029\/GD024p0001","article-title":"Variations in the orientation of the Earth","volume":"Volume 24","author":"Smith","year":"1993","journal-title":"Contributions of Space Geodesy to Geodynamics: Earth Dynamics: Geodynamic Series"},{"key":"ref_40","unstructured":"Bizouard, C., Lambert, S., Becker, O., and Richard, J.Y. (2019, December 24). Combined solution C04 for Earth Rotation Parameters consistent with International Terrestrial Reference Frame 2014. IERS Notice. Available online: http:\/\/hpiers.obspm.fr\/eoppc\/eop\/eopc04\/C04.guide.pdf."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"621","DOI":"10.1007\/s00190-018-1186-3","article-title":"The IERS EOP 14C04 solution for Earth orientation parameters consistent with ITRF 2014","volume":"93","author":"Bizouard","year":"2018","journal-title":"J. Geod."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"111","DOI":"10.2151\/jmsj1965.78.2_111","article-title":"Three\u2013dimensional Atmospheric Angular Momentum Simulated by the Japan Meteorological Agency model for the period of 1955\u20131994","volume":"78","author":"Naito","year":"2000","journal-title":"J. Meteorol. Soc. Jpn."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"390","DOI":"10.1111\/j.1365-246X.2005.02694.x","article-title":"Oceanic excitations on polar motion: A cross comparison among models","volume":"162","author":"Zhou","year":"2005","journal-title":"Geophys. J. Int."},{"key":"ref_44","first-page":"51","article-title":"Geophysical fluids, geomagnetic jerks, and their impact on Earth orientation","volume":"96","author":"Vondrak","year":"2017","journal-title":"Publ. Astron. Obs. Belgrade"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"B10406","DOI":"10.1029\/2009JB007127","article-title":"Seasonal polar motion excitation from numerical models of atmosphere, ocean, and continental hydrosphere","volume":"115","author":"Dobslaw","year":"2010","journal-title":"J. Geophys. Res."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"422","DOI":"10.1002\/jame.20023","article-title":"Characteristics of the ocean simulations in MPIOM, the ocean component of the MPI-Earth system model","volume":"5","author":"Jungclaus","year":"2013","journal-title":"J. Adv. Model. Earth Syst."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"6109","DOI":"10.1002\/2016JB013098","article-title":"ITRF2014: A new release of the International Terrestrial Reference Frame modeling nonlinear station motions","volume":"121","author":"Altamimi","year":"2016","journal-title":"J. Geophys. Res. Solid Earth"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"58","DOI":"10.1088\/0004-6256\/150\/2\/58","article-title":"The second realization of the international celestial reference frame by very long baseline interferometry","volume":"2","author":"Fey","year":"2015","journal-title":"Astron. J."},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Dahle, C., Murb\u00f6ck, M., Flechtner, F., Dobslaw, H., Michalak, G., Neumayer, K.H., Abrykosov, O., Reinhold, A., K\u00f6nig, R., and Sulzbach, R. (2019). The GFZ GRACE RL06 monthly gravity field time series: Processing details and quality assessment. Remote Sens., 11.","DOI":"10.3390\/rs11182116"},{"key":"ref_50","unstructured":"Mayer-G\u00fcrr, T., Behzadpour, S., Ellmer, M., Kvas, A., Klinger, B., Strasser, S., and Zehentner, N. (2019, December 24). ITSG-Grace2018-Monthly, Daily and Static Gravity Field Solutions from GRACE. GFZ Data Services. Available online: http:\/\/dataservices.gfz-potsdam.de\/icgem\/showshort.php?id=escidoc:3600910."},{"key":"ref_51","unstructured":"Lemoine, J.-M., Bourgogne, S., Biancale, R., and G\u00e9gout, P. (2018, January 4\u201313). The new GRGS\u2013RL04 series of mass variations modelled with GRACE data. Proceedings of the 20th EGU General Assembly, Vienna, Austria."},{"key":"ref_52","unstructured":"Dill, R. (2019, December 24). Hydrological Model LSDM for Operational Earth Rotation and Gravity Field Variations. GFZ Scientific Technical Report STR; 08\/09. Available online: http:\/\/gfzpublic.gfz-potsdam.de\/pubman\/item\/escidoc:8770."},{"key":"ref_53","unstructured":"Dill, R. (2008, January 22\u201324). Hydrological induced Earth rotation variations from standalone and dynamically coupled simulations. Proceedings of the Journ\u00e9es 2008 Syst\u00e8mes de R\u00e9f\u00e9rence Spatio-Temporels, Dresden, Germany."},{"key":"ref_54","unstructured":"Dobslaw, H., and Dill, R. (2019, December 24). Effective Angular Momentum Functions from Earth System Modelling at GeoForschungsZentrum in Potsdam. Technical Report, Revision 1.1 (March 18, 2019), GFZ Potsdam, Germany. Available online: http:\/\/rz-vm115.gfz-potsdam.de:8080\/repository."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.jog.2016.03.011","article-title":"A comparison of interannual hydrological polar motion excitation from GRACE and geodetic observations","volume":"99","author":"Meyrath","year":"2016","journal-title":"J. Geodyn."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1007\/s00190-015-0864-7","article-title":"Elliptic polarisation of the polar motion excitation","volume":"90","author":"Bizouard","year":"2016","journal-title":"J. Geod."},{"key":"ref_57","doi-asserted-by":"crossref","unstructured":"Nastula, J., and \u015aliwi\u0144ska, J. (2020). Prograde and Retrograde Terms of Gravimetric Polar Motion Excitation Estimates from the GRACE Monthly Gravity Field Models. Remote Sens., 12.","DOI":"10.3390\/rs12010138"},{"key":"ref_58","first-page":"27","article-title":"Time Variable Band Pass Filter Spectra of Real and Complex-Valued Polar Motion Series","volume":"30","author":"Kosek","year":"1995","journal-title":"Artif. Satell."},{"key":"ref_59","doi-asserted-by":"crossref","unstructured":"\u015aliwi\u0144ska, J., and Nastula, J. (2019). Determining and Evaluating the Hydrological Signal in Polar Motion Excitation from Gravity Field Models Obtained from Kinematic Orbits of LEO Satellites. Remote Sens., 11.","DOI":"10.3390\/rs11151784"},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1016\/j.geog.2017.04.006","article-title":"Improved geophysical excitations constrained by polar motion observations and GRACE\/SLR time-dependent gravity","volume":"8","author":"Chen","year":"2017","journal-title":"Geod. Geodyn."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1016\/j.jog.2012.02.008","article-title":"Agreement between Earth\u2019s rotation and mass displacement as detected by GRACE","volume":"62","author":"Seoane","year":"2012","journal-title":"J. Geodyn."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1007\/s11200-018-1028-z","article-title":"Assessing hydrological signal in polar motion from observations and geophysical models","volume":"63","year":"2019","journal-title":"Stud. Geophys. Geod."},{"key":"ref_63","unstructured":"Bianchi, G., and Sorrentino, R. (2007). Electronic Filter Simulation & Design, McGraw-Hill Professional."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"2648","DOI":"10.1002\/2014JB011547","article-title":"Improved methods for observing Earth\u2019s time variable mass distribution with GRACE using spherical cap mascons","volume":"120","author":"Watkins","year":"2015","journal-title":"J. Geophys. Res. Solid Earth"},{"key":"ref_65","unstructured":"Bettadpur, S. (2019, December 24). UTCSR Level-2 Processing Standards Document for Level-2 Product Release 0005. Technical Report GRACE 2012. Available online: http:\/\/icgem.gfz-potsdam.de\/L2-CSR0005_ProcStd_v4.0.pdf."},{"key":"ref_66","unstructured":"Watkins, M.M., and Yuan, D. (2019, December 24). JPL Level-2 Processing Standards Document for Level-2 Product Release 05.1. Technical Report GRACE. Available online: http:\/\/icgem.gfz-potsdam.de\/L2-JPL_ProcStds_v5.1.pdf."},{"key":"ref_67","unstructured":"Lemoine, J.-M., Bourgogne, S., Bruinsma, S., G\u00e9gout, P., Reinquin, F., and Biancale, R. (2018, January 12\u201317). GRACE RL03\u2013v2 monthly time series of solutions from CNES\/GRGS. Proceedings of the 17th EGU General Assembly, Vienna, Austria."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"375","DOI":"10.1007\/s10712-008-9038-y","article-title":"Improvement of global hydrological models using GRACE data","volume":"29","year":"2008","journal-title":"Surv. Geophys."},{"key":"ref_69","first-page":"1","article-title":"A global analysis of temporal and spatial variations in continental water storage","volume":"43","author":"Stuck","year":"2007","journal-title":"Water Resour. Res."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1029\/2010GL044571","article-title":"Global depletion of groundwater resources","volume":"37","author":"Wada","year":"2010","journal-title":"Geophys. Res. Lett."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"8130","DOI":"10.1002\/2014GL061052","article-title":"Regional acceleration in ice mass loss from Greenland and Antarctica using GRACE time-variable gravity data","volume":"41","author":"Velicogna","year":"2014","journal-title":"Geophys. Res. Lett."},{"key":"ref_72","doi-asserted-by":"crossref","first-page":"8459","DOI":"10.1002\/2017JB014555","article-title":"Decadal polar motion of the Earth excited by the convective outer core from geodynamo simulations","volume":"122","author":"Kuang","year":"2017","journal-title":"J. Geophys. Res. Solid Earth"},{"key":"ref_73","unstructured":"Dick, S., McCarthy, D., and Luzum, B. (2000). The Markowitz Wobble. Polar Motion: Historical and Scientific Problems, Astronomical Society of the Pacific."},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"7","DOI":"10.1109\/19.206671","article-title":"A revisited three-cornered hat method for estimating frequency standard instability","volume":"42","author":"Premoli","year":"1993","journal-title":"IEEE Trans. Meas."},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"663","DOI":"10.1007\/s00190-005-0019-3","article-title":"Atmospheric Angular Momentum Time-Series: Characterization of their Internal Noise and Creation of a Combined Series","volume":"79","author":"Koot","year":"2006","journal-title":"J. Geod."},{"key":"ref_76","unstructured":"Dahle, C., Flechtner, F., Gruber, C., K\u00f6nig, D., K\u00f6nig, R., Michalak, G., and Neumayer, K.H. (2019, December 24). GFZ GRACE Level\u20132 Processing Standards Document for Level\u20132 Product Release 0005. Scientific Technical Report STR12\/02\u2013data, Revised Edition. Available online: http:\/\/icgem.gfz-potsdam.de\/L2-GFZ_ProcStds_0005_v1.1-1.pdf."},{"key":"ref_77","unstructured":"Mayer-G\u00fcrr, T., Behzadpour, S., Ellmer, M., Kvas, A., Klinger, B., and Zehentner, N. (2019, December 24). ITSG-Grace2016-Monthly and Daily Gravity Field Solutions from GRACE. GFZ Data Services. Available online: http:\/\/dataservices.gfz-potsdam.de\/icgem\/showshort.php?id=escidoc:1697893."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/12\/6\/930\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T09:06:42Z","timestamp":1760173602000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/12\/6\/930"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,3,13]]},"references-count":77,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2020,3]]}},"alternative-id":["rs12060930"],"URL":"https:\/\/doi.org\/10.3390\/rs12060930","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,3,13]]}}}