A Review of GNSS/GPS in Hydrogeodesy: Hydrologic Loading Applications and Their Implications for Water Resource Research

Hydrogeodesy, a relatively new field within the earth sciences, is the analysis of the distribution and movement of terrestrial water at Earth's surface using measurements of Earth's shape, orientation, and gravitational field. In this paper, we review the current state of hydrogeodesy with a specific focus on Global Navigation Satellite System (GNSS)/Global Positioning System measurements of hydrologic loading. As water cycles through the hydrosphere, GNSS stations anchored to Earth's crust measure the associated movement of the land surface under the weight of changing hydrologic loads. Recent advances in GNSS‐based hydrogeodesy have led to exciting applications of hydrologic loading and subsequent terrestrial water storage (TWS) estimates. We describe how GNSS position time series respond to climatic drivers, can be used to estimate TWS across temporal scales, and can improve drought characterization. We aim to facilitate hydrologists' use of GNSS‐observed surface deformation as an emerging tool for investigating and quantifying water resources, propose methods to further strengthen collaborative research and exchange between geodesists and hydrologists, and offer ideas about pressing questions in hydrology that GNSS may help to answer.

[1]  Wenjun Cui,et al.  Three-Dimensional Surface Deformation Characteristics Based on Time Series InSAR and GPS Technologies in Beijing, China , 2021, Remote. Sens..

[2]  Topographic Amplification of Crustal Subsidence by the Rainwater Load of the 2019 Typhoon Hagibis in Japan , 2021, Journal of Geophysical Research: Solid Earth.

[3]  H. Martens,et al.  Seasonal hydrological loading in the Great Lakes region detected by GNSS: a comparison with hydrological models , 2021 .

[4]  S. Reed,et al.  Five Decades of Observed Daily Precipitation Reveal Longer and More Variable Drought Events Across Much of the Western United States , 2021, Geophysical Research Letters.

[5]  G. Blewitt,et al.  GPS Constraints on Drought-Induced Groundwater Loss Around Great Salt Lake, Utah, with Implications for Seismicity Modulation , 2021 .

[6]  G. Arhonditsis,et al.  A flow-weighted ensemble strategy to assess the impacts of climate change on watershed hydrology , 2021 .

[7]  Y. Hsu,et al.  Monitoring time-varying terrestrial water storage changes using daily GNSS measurements in Yunnan, southwest China , 2021 .

[8]  M. Belardinelli,et al.  The interaction between displacements and water level changes due to natural and anthropogenic effects in the Po Plain (Italy): The different point of view of GNSS and piezometers , 2021 .

[9]  Phuong D. Dao,et al.  Recent land deformation detected by Sentinel-1A InSAR data (2016–2020) over Hanoi, Vietnam, and the relationship with groundwater level change , 2021 .

[10]  GiRsnow: an open-source software for snow depth retrievals using GNSS interferometric reflectometry , 2021, GPS Solutions.

[11]  C. Simmons,et al.  Review of assimilating GRACE terrestrial water storage data into hydrological models: Advances, challenges and opportunities , 2021 .

[12]  B. Forman,et al.  Assimilation of Ground‐Based GPS Observations of Vertical Displacement into a Land Surface Model to Improve Terrestrial Water Storage Estimates , 2021, Water Resources Research.

[13]  Wyatt Arnold,et al.  Projected Changes in Water Year Types and Hydrological Drought in California’s Central Valley in the 21st Century , 2021, Climate.

[14]  Klaus Scipal,et al.  The International Soil Moisture Network: serving Earth system science for over a decade , 2021, Hydrology and Earth System Sciences.

[15]  Jagat Dwipendra Ray,et al.  Seasonal horizontal deformations obtained using GPS and GRACE data: case study of North-East India and Nepal Himalaya , 2021, Acta Geodaetica et Geophysica.

[16]  G. Blewitt,et al.  Robust estimation of spatially varying common-mode components in GPS time-series , 2021, Journal of Geodesy.

[17]  An Assessment of Global Positioning System Velocity Uncertainty in California , 2020, Earth and Space Science.

[18]  Michael Bevis,et al.  Truncated Singular Value Decomposition Regularization for Estimating Terrestrial Water Storage Changes Using GPS: A Case Study over Taiwan , 2020, Remote. Sens..

[19]  A. Moore,et al.  Atmospheric pressure loading in GPS positions: dependency on GPS processing methods and effect on assessment of seasonal deformation in the contiguous USA and Alaska , 2020, Journal of Geodesy.

[20]  R. Bürgmann,et al.  Assessing seasonal and interannual water storage variations in Taiwan using geodetic and hydrological data , 2020 .

[21]  T. Jin,et al.  Estimation of component contributions to total terrestrial water storage change in the Yangtze river basin , 2020 .

[22]  P. Clarke,et al.  Effect of antenna snow intrusion on vertical GPS position time series in Antarctica , 2020, Journal of Geodesy.

[23]  G. Blewitt,et al.  Rise of Great Lakes Surface Water, Sinking of the Upper Midwest of the United States, and Viscous Collapse of the Forebulge of the Former Laurentide Ice Sheet , 2020, Journal of Geophysical Research: Solid Earth.

[24]  B. Forman,et al.  Comparison of Vertical Surface Deformation Estimates Derived From Space‐Based Gravimetry, Ground‐Based GPS, and Model‐Based Hydrologic Loading Over Snow‐Dominated Watersheds in the United States , 2020, Journal of Geophysical Research: Solid Earth.

[25]  Xiufeng He,et al.  Analysis and combination of multi-GNSS snow depth retrievals in multipath reflectometry , 2020, GPS Solutions.

[26]  F. Silverii,et al.  Hydrologically Induced Deformation in Long Valley Caldera and Adjacent Sierra Nevada , 2020, Journal of Geophysical Research: Solid Earth.

[27]  Pascal Willis,et al.  GipsyX/RTGx, a new tool set for space geodetic operations and research , 2020, 2004.13124.

[28]  K. Heki.  Geodesy in Japan: legends and highlights , 2020, Earth, Planets and Space.

[29]  R. Bennett,et al.  Vertical Displacements of the Amazon Basin From GRACE and GPS , 2020, Journal of Geophysical Research: Solid Earth.

[30]  Y. Djamour,et al.  Water Depletion and Land Subsidence in Iran Using Gravity, GNSS, InSAR and Precise Levelling Data , 2020, International Association of Geodesy Symposia.

[31]  Thomas Fuhrmann,et al.  Surface Deformation from Sentinel-1A InSAR: Relation to Seasonal Groundwater Extraction and Rainfall in Central Taiwan , 2019, Remote. Sens..

[32]  Stefania Bonafoni,et al.  Radio occultation and ground-based GNSS products for observing, understanding and predicting extreme events: A review , 2019 .

[33]  H. McMillan,et al.  A Decade of Water Storage Changes Across the Contiguous United States From GPS and Satellite Gravity , 2019, Geophysical Research Letters.

[34]  E. Small,et al.  Subsurface Water Dominates Sierra Nevada Seasonal Hydrologic Storage , 2019, Geophysical Research Letters.

[35]  J. Kusche,et al.  Evidence of daily hydrological loading in GPS time series over Europe , 2019, Journal of Geodesy.

[36]  Yongxin Liu,et al.  An Improved GPS-Inferred Seasonal Terrestrial Water Storage Using Terrain-Corrected Vertical Crustal Displacements Constrained by GRACE , 2019, Remote. Sens..

[37]  K. Larson.  Unanticipated Uses of the Global Positioning System , 2019, Annual Review of Earth and Planetary Sciences.

[38]  Srinivas Bettadpur,et al.  GRACE-FO: The Gravity Recovery and Climate Experiment Follow-On Mission , 2019, Journal of Spacecraft and Rockets.

[39]  Peng Yuan,et al.  Prospects for Imaging Terrestrial Water Storage in South America Using Daily GPS Observations , 2019, Remote. Sens..

[40]  Y. Bock,et al.  Regional Global Navigation Satellite System Networks for Crustal Deformation Monitoring , 2019, Seismological Research Letters.

[41]  L. Rivera,et al.  LoadDef: A Python‐Based Toolkit to Model Elastic Deformation Caused by Surface Mass Loading on Spherically Symmetric Bodies , 2019, Earth and space science.

[42]  R. Betts,et al.  Global glacier volume projections under high-end climate change scenarios , 2019, The Cryosphere.

[43]  R. Bendick,et al.  Downscaling Vertical GPS Observations to Derive Watershed‐Scale Hydrologic Loading in the Northern Rockies , 2019, Water Resources Research.

[44]  J. Avouac,et al.  Identification and Extraction of Seasonal Geodetic Signals Due to Surface Load Variations , 2018, Journal of Geophysical Research: Solid Earth.

[45]  C. Ndehedehe,et al.  Space-based observations of crustal deflections for drought characterization in Brazil. , 2018, The Science of the total environment.

[46]  G. Blewitt,et al.  Harnessing the GPS Data Explosion for Interdisciplinary Science , 2018, Eos.

[47]  David Bekaert,et al.  Tracking the weight of Hurricane Harvey’s stormwater using GPS data , 2018, Science Advances.

[48]  Frédéric Frappart,et al.  Monitoring Groundwater Storage Changes Using the Gravity Recovery and Climate Experiment (GRACE) Satellite Mission: A Review , 2018, Remote. Sens..

[49]  Weiping Jiang,et al.  Effect of removing the common mode errors on linear regression analysis of noise amplitudes in position time series of a regional GPS network & a case study of GPS stations in Southern California , 2018 .

[50]  Alex Hall,et al.  Increasing precipitation volatility in twenty-first-century California , 2018, Nature Climate Change.

[51]  Adrian A. Borsa,et al.  Accuracy of Snow Water Equivalent Estimated From GPS Vertical Displacements: A Synthetic Loading Case Study for Western U.S. Mountains , 2018 .

[52]  A. Moore,et al.  Sustained Water Loss in California's Mountain Ranges During Severe Drought From 2012 to 2015 Inferred From GPS , 2017 .

[53]  N. Krakauer,et al.  Global change in streamflow extremes under climate change over the 21st century , 2017 .

[54]  Shin‐Chan Han,et al.  GPS Recovery of Daily Hydrologic and Atmospheric Mass Variation: A Methodology and Results From the Australian Continent , 2017 .

[55]  Jianguo Yan,et al.  Regional characteristics and influencing factors of seasonal vertical crustal motions in Yunnan, China , 2017 .

[56]  Wang Li,et al.  A comparison of hydrological deformation using GPS and global hydrological model for the Eurasian plate , 2017 .

[57]  Axel Timmermann,et al.  Multi-year predictability of climate, drought, and wildfire in southwestern North America , 2017, Scientific Reports.

[58]  Nico Sneeuw,et al.  Annual variations of monsoon and drought detected by GPS: A case study in Yunnan, China , 2017, Scientific Reports.

[59]  R. Bürgmann,et al.  Seasonal water storage, stress modulation, and California seismicity , 2017, Science.

[60]  Niko E. C. Verhoest,et al.  A review of spatial downscaling of satellite remotely sensed soil moisture , 2017 .

[61]  K. Stahl,et al.  Catchment water storage variation with elevation , 2017 .

[62]  Xianghong Hua,et al.  Review of current GPS methodologies for producing accurate time series and their error sources , 2017 .

[63]  Shin-Chan Han,et al.  Elastic deformation of the Australian continent induced by seasonal water cycles and the 2010–2011 La Niña determined using GPS and GRACE , 2017 .

[64]  A. Kääb,et al.  Snow depth from ICESat laser altimetry - A test study in southern Norway , 2017 .

[65]  Luca Brocca,et al.  Soil Moisture for Hydrological Applications: Open Questions and New Opportunities , 2017 .

[66]  Venkat Lakshmi,et al.  Soil Moisture Remote Sensing: State‐of‐the‐Science , 2017 .

[67]  Lei Wang,et al.  Plate Boundary Observatory and related networks: GPS data analysis methods and geodetic products , 2016 .

[68]  F. Silverii,et al.  Transient deformation of karst aquifers due to seasonal and multiyear groundwater variations observed by GPS in southern Apennines (Italy) , 2016 .

[69]  Tongqing Wang,et al.  Detecting seasonal and long-term vertical displacement in the North China Plain using GRACE and GPS , 2016 .

[70]  Shuanggen Jin,et al.  Terrestrial Water Storage Anomalies Associated with Drought in Southwestern USA from GPS Observations , 2016, Surveys in Geophysics.

[71]  Yibin Yao,et al.  Potential Seasonal Terrestrial Water Storage Monitoring from GPS Vertical Displacements: A Case Study in the Lower Three-Rivers Headwater Region, China , 2016, Sensors.

[72]  Yehuda Bock,et al.  Physical applications of GPS geodesy: a review , 2016, Reports on progress in physics. Physical Society.

[73]  Yunfeng Tian,et al.  Extracting the regional common‐mode component of GPS station position time series from dense continuous network , 2016 .

[74]  Enrico Serpelloni,et al.  Blind source separation problem in GPS time series , 2016, Journal of Geodesy.

[75]  Yehuda Bock,et al.  National Weather Service Forecasters Use GPS Precipitable Water Vapor for Enhanced Situational Awareness during the Southern California Summer Monsoon , 2015 .

[76]  Wujiao Dai,et al.  Spatiotemporal analysis of GPS time series in vertical direction using independent component analysis , 2015, Earth, Planets and Space.

[77]  R. Dach,et al.  Bernese GNSS Software Version 5.2 , 2015 .

[78]  P. Rasch,et al.  Increasing water cycle extremes in California and in relation to ENSO cycle under global warming , 2015, Nature Communications.

[79]  R. Bendick,et al.  Monsoonal loading in Ethiopia and Eritrea from vertical GPS displacement time series , 2015 .

[80]  Michael D. Dettinger,et al.  On Critiques of “Stationarity is Dead: Whither Water Management?” , 2015 .

[81]  Z. Martinec,et al.  Applying local Green's functions to study the influence of the crustal structure on hydrological loading displacements , 2015 .

[82]  M. Watkins,et al.  Improved methods for observing Earth's time variable mass distribution with GRACE using spherical cap mascons , 2015 .

[83]  Felix W. Landerer,et al.  GPS as an independent measurement to estimate terrestrial water storage variations in Washington and Oregon , 2015 .

[84]  Matt A. King,et al.  On the Rebound: Modeling Earth's Ever-Changing Shape , 2015, Eos.

[85]  Eiichi Sato,et al.  Estimation of Local-Scale Precipitable Water Vapor Distribution Around Each GNSS Station Using Slant Path Delay: Evaluation of a Severe Tornado Case Using High-Resolution NHM , 2015 .

[86]  Duncan Carr Agnew,et al.  Ongoing drought-induced uplift in the western United States , 2014, Science.

[87]  E. Small,et al.  Terrestrial water storage response to the 2012 drought estimated from GPS vertical position anomalies , 2014 .

[88]  G. Blewitt,et al.  Uplift and seismicity driven by groundwater depletion in central California , 2014, Nature.

[89]  D. Wuebbles,et al.  Severe Weather in United States Under a Changing Climate , 2014 .

[90]  Felix W. Landerer,et al.  Seasonal variation in total water storage in California inferred from GPS observations of vertical land motion , 2014 .

[91]  Petra Döll,et al.  Seasonal Water Storage Variations as Impacted by Water Abstractions: Comparing the Output of a Global Hydrological Model with GRACE and GPS Observations , 2014, Surveys in Geophysics.

[92]  Valery U. Zavorotny,et al.  Effects of Near-Surface Soil Moisture on GPS SNR Data: Development of a Retrieval Algorithm for Soil Moisture , 2014, IEEE Transactions on Geoscience and Remote Sensing.

[93]  Felipe G. Nievinski,et al.  Forward modeling of GPS multipath for near-surface reflectometry and positioning applications , 2014, GPS Solutions.

[94]  M. Heflin,et al.  Horizontal motion in elastic response to seasonal loading of rain water in the Amazon Basin and monsoon water in Southeast Asia observed by GPS and inferred from GRACE , 2013 .

[95]  Natascha Kljun,et al.  Using High Resolution LiDAR Data and a Flux Footprint Parameterization to Scale Evapotranspiration Estimates to Lower Pixel Resolutions , 2013 .

[96]  R. Dill,et al.  Numerical simulations of global‐scale high‐resolution hydrological crustal deformations , 2013 .

[97]  K. Larson.  A methodology to eliminate snow‐ and ice‐contaminated solutions from GPS coordinate time series , 2013 .

[98]  J. Famiglietti,et al.  Estimating snow water equivalent from GPS vertical site-position observations in the western United States , 2013, Water resources research.

[99]  K. Heki.  Dense Gps Array as a New Sensor of Seasonal Changes of Surface Loads , 2013 .

[100]  J. Wahr,et al.  The use of GPS horizontals for loading studies, with applications to northern California and southeast Greenland , 2013 .

[101]  Geoffrey Blewitt,et al.  Advances in Global Positioning System Technology for Geodynamics Investigations: 1978–1992 , 2013 .

[102]  O. Dauteuil,et al.  Geodetic tools for hydrogeological surveys: 3D-displacements above a fractured aquifer from GPS time series , 2013 .

[103]  D. Argus.  Uncertainty in the velocity between the mass center and surface of Earth , 2012 .

[104]  J. Freymueller,et al.  Seasonal hydrological loading in southern Alaska observed by GPS and GRACE , 2012 .

[105]  Xavier Collilieux,et al.  Hydrological deformation induced by the West African Monsoon: Comparison of GPS, GRACE and loading models , 2012 .

[106]  Duncan Carr Agnew,et al.  SPOTL: Some Programs for Ocean-Tide Loading , 2012 .

[107]  M. Tamisiea,et al.  On seasonal signals in geodetic time series , 2012 .

[108]  F. Nievinski,et al.  GPS snow sensing: results from the EarthScope Plate Boundary Observatory , 2012, GPS Solutions.

[109]  K. Heki,et al.  GPS snow depth meter with geometry-free linear combinations of carrier phases , 2012, Journal of Geodesy.

[110]  J. Genrich,et al.  Modeling deformation induced by seasonal variations of continental water in the Himalaya region: Sensitivity to Earth elastic structure , 2011 .

[111]  R. Sadiq,et al.  A review of drought indices , 2011 .

[112]  Simon D. P. Williams,et al.  Non‐tidal ocean loading effects on geodetic GPS heights , 2011 .

[113]  Jeongho Baek,et al.  Computation of the Load Love Number and the Load Green's Function for an Elastic and Spherically Symmetric Earth , 2011 .

[114]  M. Ek,et al.  Hyperresolution global land surface modeling: Meeting a grand challenge for monitoring Earth's terrestrial water , 2011 .

[115]  J. Thepaut,et al.  The ERA‐Interim reanalysis: configuration and performance of the data assimilation system , 2011 .

[116]  Peter Steigenberger,et al.  Vertical deformations from homogeneously processed GRACE and global GPS long-term series , 2011 .

[117]  Paul Tregoning,et al.  Correction to “Atmospheric effects and spurious signals in GPS analyses” , 2011 .

[118]  S. Bettadpur,et al.  Modeling Earth deformation from monsoonal flooding in Bangladesh using hydrographic, GPS, and Gravity Recovery and Climate Experiment (GRACE) data , 2010 .

[119]  Shuanggen Jin,et al.  GNSS Reflectometry and Remote Sensing: New Objectives and Results , 2010, 1010.2281.

[120]  Valery U. Zavorotny,et al.  GPS Multipath and Its Relation to Near-Surface Soil Moisture Content , 2010, IEEE J. Sel. Top. Appl. Earth Obs. Remote. Sens..

[121]  Jenni Virtanen,et al.  Crustal loading in vertical GPS time series in Fennoscandia , 2009 .

[122]  Paul Tregoning,et al.  Atmospheric effects and spurious signals in GPS analyses , 2009 .

[123]  F. Nievinski,et al.  Can we measure snow depth with GPS receivers? , 2009 .

[124]  Guillaume Ramillien,et al.  Detecting hydrologic deformation using GRACE and GPS , 2009 .

[125]  Peter Steigenberger,et al.  Annual deformation signals from homogeneously reprocessed VLBI and GPS height time series , 2009 .

[126]  Peter Steigenberger,et al.  Comparison of GMF/GPT with VMF1/ECMWF and implications for atmospheric loading , 2009 .

[127]  Xavier Collilieux,et al.  IGS contribution to the ITRF , 2009 .

[128]  Jan Kouba,et al.  Testing of global pressure/temperature (GPT) model and global mapping function (GMF) in GPS analyses , 2009 .

[129]  J. Kirchner.  Catchments as simple dynamical systems: Catchment characterization, rainfall‐runoff modeling, and doing hydrology backward , 2009 .

[130]  E. Small,et al.  Use of GPS receivers as a soil moisture network for water cycle studies , 2008 .

[131]  Guillaume Ramillien,et al.  Detection of Continental Hydrology and Glaciology Signals from GRACE: A Review , 2008 .

[132]  Peter Steigenberger,et al.  Realization of the Terrestrial Reference System by a reprocessed global GPS network , 2008 .

[133]  P. Axelrad,et al.  Using GPS multipath to measure soil moisture fluctuations: initial results , 2008 .

[134]  R. Stouffer,et al.  Stationarity Is Dead: Whither Water Management? , 2008, Science.

[135]  J. Avouac,et al.  Seasonal variations of seismicity and geodetic strain in the Himalaya induced by surface hydrology as revealed from GPS monitoring, seismic monitoring and GRACE measurements , 2007 .

[136]  F. Sigmundsson,et al.  Discriminating volcano deformation due to magma movements and variable surface loads: Application to Katla subglacial volcano, Iceland , 2007 .

[137]  J. Wahr,et al.  A comparison of annual vertical crustal displacements from GPS and Gravity Recovery and Climate Experiment (GRACE) over Europe , 2007 .

[138]  H. Schuh,et al.  Short Note: A global model of pressure and temperature for geodetic applications , 2007 .

[139]  Geoffrey Blewitt,et al.  GPS and Space-Based Geodetic Methods , 2007 .

[140]  F. Sigmundsson,et al.  Icelandic rhythmics: Annual modulation of land elevation and plate spreading by snow load , 2006 .

[141]  Thomas A. Herring,et al.  Impact of a priori zenith hydrostatic delay errors on GPS estimates of station heights and zenith total delays , 2006 .

[142]  Matt A. King,et al.  Choice of optimal averaging radii for temporal GRACE gravity solutions, a comparison with GPS and satellite altimetry , 2006 .

[143]  Peter Steigenberger,et al.  Reprocessing of a global GPS network , 2006 .

[144]  H. Schuh,et al.  Global Mapping Function (GMF): A new empirical mapping function based on numerical weather model data , 2006 .

[145]  T. Huntington.  Evidence for intensification of the global water cycle: Review and synthesis , 2006 .

[146]  Yehuda Bock,et al.  Spatiotemporal filtering using principal component analysis and Karhunen-Loeve expansion approaches for regional GPS network analysis , 2006 .

[147]  T. Barnett,et al.  Potential impacts of a warming climate on water availability in snow-dominated regions , 2005, Nature.

[148]  D. Alsdorf,et al.  Seasonal fluctuations in the mass of the Amazon River system and Earth's elastic response , 2005 .

[149]  J. Oerlemans.  Extracting a Climate Signal from 169 Glacier Records , 2005, Science.

[150]  Martyn P. Clark,et al.  DECLINING MOUNTAIN SNOWPACK IN WESTERN NORTH AMERICA , 2005 .

[151]  Pedro Elosegui,et al.  Climate‐driven deformation of the solid Earth from GRACE and GPS , 2004 .

[152]  Paul R. Houser,et al.  Requirements of a global near-surface soil moisture satellite mission: accuracy, repeat time, and spatial resolution , 2004 .

[153]  M. Watkins,et al.  GRACE Measurements of Mass Variability in the Earth System , 2004, Science.

[154]  J. D. Tarpley,et al.  The multi‐institution North American Land Data Assimilation System (NLDAS): Utilizing multiple GCIP products and partners in a continental distributed hydrological modeling system , 2004 .

[155]  Yehuda Bock,et al.  Error analysis of continuous GPS position time series , 2004 .

[156]  Jeffrey P. Walker,et al.  THE GLOBAL LAND DATA ASSIMILATION SYSTEM , 2004 .

[157]  M. Bevis,et al.  Geodetic measurement of the local elastic response to the changing mass of water in Lago Laja, Chile , 2004 .

[158]  J. Boy,et al.  Study of the atmospheric pressure loading signal in very long baseline interferometry observations , 2003, physics/0311096.

[159]  Michael B. Heflin,et al.  Large‐scale global surface mass variations inferred from GPS measurements of load‐induced deformation , 2003 .

[160]  J. Mitrovica,et al.  Crustal loading near Great Salt Lake, Utah , 2003 .

[161]  G. Blewitt.  Self‐consistency in reference frames, geocenter definition, and surface loading of the solid Earth , 2003 .

[162]  Zuheir Altamimi,et al.  ITRF2000: A new release of the International Terrestrial Reference Frame for earth science applications , 2002 .

[163]  R. Heim.  A Review of Twentieth-Century Drought Indices Used in the United States , 2002 .

[164]  G. Blewitt,et al.  A New Global Mode of Earth Deformation: Seasonal Cycle Detected , 2001, Science.

[165]  Y. Bock,et al.  Anatomy of apparent seasonal variations from GPS‐derived site position time series , 2001 .

[166]  Gerald W. Bawden,et al.  Tectonic contraction across Los Angeles after removal of groundwater pumping effects , 2001, Nature.

[167]  K. Heki.  Seasonal Modulation of Interseismic Strain Buildup in Northeastern Japan Driven by Snow Loads , 2001, Science.

[168]  Jean-François Crétaux,et al.  Annual vertical crustal motions predicted from surface mass redistribution and observed by space geodesy , 2001 .

[169]  Geoffrey Blewitt,et al.  Crustal displacements due to continental water loading , 2001 .

[170]  D. Easterling,et al.  Observed variability and trends in extreme climate events: A brief review , 2000 .

[171]  M. Meier,et al.  Twentieth century climate change: evidence from small glaciers. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[172]  J. Wahr,et al.  Modeling environment loading effects: a review , 1998 .

[173]  Yehuda Bock,et al.  Southern California permanent GPS geodetic array: Spatial filtering of daily positions for estimating coseismic and postseismic displacements induced by the 1992 Landers earthquake , 1997 .

[174]  M. K. Cheng,et al.  Geocenter variations caused by atmosphere, ocean and surface ground water , 1997 .

[175]  James L. Davis,et al.  GPS APPLICATIONS FOR GEODYNAMICS AND EARTHQUAKE STUDIES , 1997 .

[176]  J. Zumberge,et al.  Precise point positioning for the efficient and robust analysis of GPS data from large networks , 1997 .

[177]  Pedro Elosegui,et al.  Geodesy Using the Global Positioning System: The Effects of Signal Scattering , 1995 .

[178]  C. Ropelewski,et al.  Global and Regional Scale Precipitation Patterns Associated with the El Niño/Southern Oscillation , 1987 .

[179]  W. Farrell.  Deformation of the Earth by surface loads , 1972 .