Article
Engineering, Electrical & Electronic
Zhiwei Chen, Wei Zheng, Wenjie Yin, Xiaoping Li, Meihong Ma
Summary: In order to rationalize the utilization of water resources, it is important to obtain high-resolution products that can accurately estimate the spatiotemporal changes in regional water resources. This study proposes a geographically weighted regression downscaled model (GWRDM) to improve the spatial resolution of terrestrial water storage (TWS) products obtained from the GRACE satellite. The results show that the downscaled TWS based on GWRDM outperforms other downscaled models, and the downscaled groundwater storage (GWS) based on GWRDM agrees well with in situ observations. Therefore, GWRDM provides a practical algorithm for obtaining high-resolution water storage estimates and contributes to small-scale regional water resources management.
IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING
(2023)
Article
Geosciences, Multidisciplinary
Fupeng Li, Juergen Kusche, Nengfang Chao, Zhengtao Wang, Anno Loecher
Summary: The study combines machine learning with statistical decomposition techniques to reconstruct global long-term TWSA fields from 1979 to 2020, showing a good fit with GRACE-FO observations and successfully reproducing strong El Nino signals. Comparisons with Satellite Laser Ranging solutions and observed global mean sea level changes suggest the reconstruction is more reliable than previously published products, providing a viable approach for both past TWSA reconstruction and filling the GRACE data gap at a global scale.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geochemistry & Geophysics
Jianli Chen, Byron Tapley, Mark E. Tamisiea, Himanshu Save, Clark Wilson, Srinivas Bettadpur, Ki-Weon Seo
Summary: A comprehensive error assessment of GRACE and GFO solutions from CSR, JPL, and GFZ was conducted, revealing differences in error levels and suggesting potential underestimation of errors in TCH analysis. The study also found that the OOR and TCH methods offer a means to assess the noise level of estimated mass change in GRACE/GFO.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Bryant D. Loomis, Denis Felikson, Terence J. Sabaka, Brooke Medley
Summary: The GRACE and GRACE-FO gravimetry data are limited in their ability to measure mass changes in smaller drainage basins and individual glacier systems due to their coarse spatial resolution. A new high-resolution mascon product has been developed to improve spatial resolution and signal recovery by estimating trends directly from over 16 years of data. This new product enhances global signal recovery, improves agreement with ICESat/ICESat-2, and helps identify discrepancies between gravimetry and laser altimetry solutions.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Environmental Sciences
Maosheng Zhou, Xin Liu, Jiajia Yuan, Xin Jin, Yupeng Niu, Jinyun Guo, Hao Gao
Summary: The study reveals significant seasonal variations in the ocean tide loading displacement (OTLD) parameters in Hong Kong, with changes in both amplitude and phase parameters. Factors affecting seasonal variations include mass loading and atmospheric loading.
Article
Environmental Sciences
Shanshan Deng, Zhenlong Jian, Yuxin Liu, Chushun Yi, Yi Chen, Wenxi Zhang
Summary: Climate change has led to a decrease in terrestrial water storage and an increase in ocean water mass, resulting in rising sea levels. Understanding the redistribution of land-sea water mass is important for addressing climate change. This study investigates the different physical processes involved in low-frequency land-sea water mass redistribution on a global scale.
Article
Geosciences, Multidisciplinary
Lei Wang, James L. Davis, Ian M. Howat
Summary: The Antarctic Ice Sheet (AIS) is a major contributor to global sea-level change, and its mass balance variability on different scales highlights the need to include stochastic processes in loss rate estimates. Loss from the West AIS shows a multidecadal trend, while variations in the East AIS are dominated by short-term accumulation changes. The analysis shows unexpected high variability in mass-loss rates from all sectors, emphasizing the importance of considering time-dependent parameters in projecting future ice sheet changes.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Environmental Sciences
Zhiwei Chen, Wei Zheng, Wenjie Yin, Xiaoping Li, Gangqiang Zhang, Jing Zhang
Summary: The study developed a new machine learning spatial downscaling method by using modeling windows of different sizes combined with multiple machine learning algorithms. The method successfully improved the spatial resolution of GRACE observations and verified the downscaled accuracy of the model, showing that WS5 had slightly better downscaled accuracy compared to WS3, WS7, and WS9.
Article
Geography, Physical
Pengao Li, Haiyang Yu, Peng Zhou, Ping Zhang, Ruili Wang
Summary: This study introduces a novel ensemble learning-based model using meteorological and topographical data to enhance spatial resolution of groundwater storage monitoring. The results demonstrate that this approach improves downscaling accuracy and reduces the Root Mean Square Error (RMSE) by up to 18.95%. Furthermore, the model achieves an R-Square (R-2) value of 0.7924 and shows enhanced accuracy when restricting the downscaling inversion to June-August data, with an R-2 value of 0.8247 in a holdout dataset test. The variation in groundwater storage exhibits distinct patterns throughout the year, influenced by meteorological, topographical, and human factors.
INTERNATIONAL JOURNAL OF DIGITAL EARTH
(2023)
Article
Environmental Sciences
Emad Hasan, Aondover Tarhule, Pierre-Emmanuel Kirstetter
Summary: This research evaluates the changes in total water storage in the Nile River Basin over the past century and future projections. The study shows significant transitions in water storage in the basin, with decreases during dry seasons and increases during wet seasons. Future projections indicate a positive increase in water storage during rainy seasons but an overall reduction in total water storage.
Article
Geosciences, Multidisciplinary
Wei Wang, Yunzhong Shen, Qiujie Chen, Tianyi Chen
Summary: In this study, a regional mascon method is developed to analyze the mass changes of the Antarctic Ice Sheet. The results show that the mass loss is most significant in the Antarctic Peninsula Ice Sheet, while East AIS, West AIS, and APIS have positive, negative, and negative mass changes, respectively. The mascon solutions demonstrate a high correlation with the cumulated surface mass balance from the regional atmospheric climate model.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Environmental Sciences
Longwei Xiang, Hansheng Wang, Holger Steffen, Liming Jiang, Qiang Shen, Lulu Jia, Zhenfeng Su, Wenliang Wang, Fan Deng, Baojin Qiao, Haifu Cui, Peng Gao
Summary: Glacier-mass losses were observed in the Nyainqentanglha Mountains and Eastern Himalayas, while small increases were found in the Karakoram and West Kunlun. Water basins in the north and south of the TP showed negative terrestrial water storage (TWS) changes, while the endorheic region and the Qaidam basin exhibited positive TWS signals. These findings have implications for water resource management, disaster prevention, and global change studies.
Article
Meteorology & Atmospheric Sciences
M. Mathis, K. Logemann, J. Maerz, F. Lacroix, S. Hagemann, F. Chegini, L. Ramme, T. Ilyina, P. Korn, C. Schrum
Summary: ICON-Coast is a global ocean-biogeochemistry model that uses high-resolution telescoping technology to improve the representation of coastal carbon dynamics. By combining regional grid refinement and enhanced process representation, the model seamlessly incorporates the global coastal ocean. ICON-Coast provides a new tool to deepen our mechanistic understanding of the role of the land-ocean transition zone in the global carbon cycle and reduce uncertainties in global future projections.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2022)
Article
Environmental Sciences
Biao Jin, Yuqiang Li, Kecai Jiang, Zhulian Li, Shanshan Chen
Summary: Precise knowledge of the phase center of a GNSS antenna is crucial for POD of LEO satellites. PCV corrections using IF carriers and AR methods significantly improve orbit accuracy. SD AR solutions show an average 18.3% improvement over FA orbits and 6.3% over DD AR, enhancing LEO orbit accuracy effectively.
Article
Environmental Sciences
F. Sabzehee, A. R. Amiri-Simkooei, S. Iran-Pour, B. D. Vishwakarma, R. Kerachian
Summary: In this study, the drivers behind the decline in water level of Urmia lake in northwest Iran over the past two decades are identified using in-situ and remote sensing data. The study utilizes total water storage (TWS) changes from the GRACE satellite mission and employs three machine learning methods to tackle the coarse resolution of the data. The results reveal that the exploitation of groundwater resources is the main driver of groundwater storage changes, while the impact of precipitation and evapotranspiration is relatively weak.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2023)
Article
Geochemistry & Geophysics
Qiujie Chen, Yunzhong Shen, Juergen Kusche, Wu Chen, Tianyi Chen, Xingfu Zhang
Summary: By proposing a new regularization method, high-resolution spherical harmonic solutions can be developed from GRACE Level-1B data, which have the potential to improve spatial resolution and signal strength. Through evaluating Tongji-RegGrace2019 and global/regional comparisons, it is found to exhibit high consistency with other GRACE solutions.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Stefan Schroeder, Simon Stellmer, Juergen Kusche
Summary: The GRACE and GRACE-FO missions have quantified large-scale changes in the water cycle, while stationary optical clocks continue to improve in stability. This study proposes utilizing a network of clocks to sense large-scale temporal geopotential changes and suggests establishing a European clock network to validate satellite missions like GRACE-FO. Simulation results show that significant hydrological and atmospheric variations over Europe could be observed with clock comparisons even under conservative assumptions for uncertainties.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geosciences, Multidisciplinary
Fupeng Li, Juergen Kusche, Nengfang Chao, Zhengtao Wang, Anno Loecher
Summary: The study combines machine learning with statistical decomposition techniques to reconstruct global long-term TWSA fields from 1979 to 2020, showing a good fit with GRACE-FO observations and successfully reproducing strong El Nino signals. Comparisons with Satellite Laser Ranging solutions and observed global mean sea level changes suggest the reconstruction is more reliable than previously published products, providing a viable approach for both past TWSA reconstruction and filling the GRACE data gap at a global scale.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geochemistry & Geophysics
Eva Boergens, Andreas Kvas, Annette Eicker, Henryk Dobslaw, Lennart Schawohl, Christoph Dahle, Michael Murboeck, Frank Flechtner
Summary: This study uses a spatial covariance model for terrestrial water storage (TWS) data to estimate uncertainties in mean TWS time series, and compares them with formal uncertainties. The results show good agreement between the modeled and formal uncertainties in both spatial and temporal domains, and the appropriateness of the model is further confirmed in arid regions.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Biodiversity Conservation
Irene Wahlstrom, Linus Hammar, Duncan Hume, Jonas Palsson, Elin Almroth-Rosell, Christian Dieterich, Lars Arneborg, Matthias Groger, Martin Mattsson, Lovisa Zillen Snowball, Gustav Kagesten, Oscar Tornqvist, Emilie Breviere, Sandra-Esther Brunnabend, Per R. Jonsson
Summary: This article examines the impacts of climate change on marine environments and ecosystems, and demonstrates how to incorporate climate change into marine spatial planning. The results show that climate change poses a threat to marine environments comparable to existing pressures.
GLOBAL CHANGE BIOLOGY
(2022)
Article
Geochemistry & Geophysics
Matthias O. Willen, Martin Horwath, Andreas Groh, Veit Helm, Bernd Uebbing, Juergen Kusche
Summary: This study presents a globally consistent inversion approach to estimate glacial isostatic adjustment effects, ice sheet mass changes, and firn air content variations in Greenland and Antarctica. The inversion method utilizes data from satellite gravimetry, satellite altimetry, regional climate modeling, and firn modeling, along with the full error-covariance information of all input data. Simulation experiments demonstrate that the proposed GIA parametrization in Antarctica can resolve GIA effects unpredicted by geophysical modeling, despite realistic limitations in input data.
JOURNAL OF GEODESY
(2022)
Article
Engineering, Civil
Helena Gerdener, Juergen Kusche, Kerstin Schulze, Gohar Ghazaryan, Olena Dubovyk
Summary: The availability of freshwater is greatly influenced by climate change, extreme climate events and human activities. Assimilating remote-sensed satellite data into models can help mitigate the limitations of model simulations. The study results show that correlations and signatures in real observations are weaker compared to simulated results, indicating the need for improvement.
JOURNAL OF HYDROLOGY
(2022)
Article
Geochemistry & Geophysics
Fan Yang, ZhiCai Luo, Hao Zhou, Juergen Kusche
Summary: Traditional conversion methods from gravity Stokes coefficients to surface mass may lead to bias in surface mass estimation due to oversimplified assumptions about Earth's shape. An iterative scaling factor method is proposed to more accurately estimate surface mass by considering Earth's actual geometry, reducing bias by at least 80% in simulations. Topography-induced bias is found to be worth considering, especially in regions like Greenland and West Antarctica, where it can exceed other sources of bias in GRACE measurements.
JOURNAL OF GEODESY
(2022)
Review
Geochemistry & Geophysics
Pauline A. Dibi-Anoh, Moussa Kone, Helena Gerdener, Juergen Kusche, Christophe K. N'Da
Summary: West African rainfall significantly impacts the global climate system, including the Atlantic thermohaline circulation, hurricane activities, and dust transport. The region has experienced major climate variability, with extended droughts in recent decades that have had negative effects on people and the economy.
SURVEYS IN GEOPHYSICS
(2023)
Article
Geosciences, Multidisciplinary
Pacome Delva, Zuheir Altamimi, Alejandro Blazquez, Mathis Blossfeld, Johannes Boehm, Pascal Bonnefond, Jean-Paul Boy, Sean Bruinsma, Grzegorz Bury, Miltiadis Chatzinikos, Alexandre Couhert, Clement Courde, Rolf Dach, Veronique Dehant, Simone Dell'Agnello, Gunnar Elgered, Werner Enderle, Pierre Exertier, Susanne Glaser, Rudiger Haas, Wen Huang, Urs Hugentobler, Adrian Jaggi, Ozgur Karatekin, Frank G. Lemoine, Christophe Le Poncin-Lafitte, Susanne Lunz, Benjamin Maennel, Flavien Mercier, Laurent Metivier, Benoit Meyssignac, Juergen Mueller, Axel Nothnagel, Felix Perosanz, Roelof Rietbroek, Markus Rothacher, Harald Schuh, Hakan Sert, Krzysztof Sosnica, Paride Testani, Javier Ventura-Traveset, Gilles Wautelet, Radoslaw Zajdel
Summary: Improving time and space reference systems on Earth is critical for scientific and societal endeavors. The Terrestrial Reference Frame (TRF) accuracy of 1 mm and long-term stability of 0.1 mm/year are necessary for various applications in geophysics and navigation sciences. The GENESIS mission aims to achieve these goals by combining and co-locating space geodetic techniques on one satellite platform.
EARTH PLANETS AND SPACE
(2023)
Article
Geosciences, Multidisciplinary
Armin Corbin, Juergen Kusche
Summary: Neutral thermospheric density is a critical parameter for satellite technology, and utilizing accelerometer data can help calibrate and optimize global thermosphere models, enhancing the accuracy of thermospheric density prediction.
EARTH PLANETS AND SPACE
(2022)
Article
Oceanography
Sophie Stolzenberger, Roelof Rietbroek, Claudia Wekerle, Bernd Uebbing, Juergen Kusche
Summary: This study explores the visibility of Greenland melting signatures in observations. It finds that Greenland freshwater flux affects temperature and salinity, especially in the vicinity of Greenland, and the melting signatures are particularly visible in steric heights in Baffin Bay and Davis Strait.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Geosciences, Multidisciplinary
Matthias Groeger, Manja Placke, H. E. Markus Meier, Florian Boergel, Sandra-Esther Brunnabend, Cyril Dutheil, Ulf Graewe, Magnus Hieronymus, Thomas Neumann, Hagen Radtke, Semjon Schimanke, Jian Su, Germo Vali
Summary: This study established the Baltic Sea Model Intercomparison Project to systematically compare and analyze different Baltic Sea models. The results showed that there were differences among the models, especially with larger uncertainties at extreme temperatures. These differences were influenced by factors such as season, water depth, and sea ice. However, there was still a certain level of correlation in the simulation of sea surface temperature and water salinity.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Josef Vojtech, Lada Altmannova, Vladimir Smotlacha, Radek Velc, Rudolf Vohnout, Harald Schnatz, Tara Cubel Liebisch, Vincenzo Capone, Tryfon Chiotis, Guy Roberts, Domenico Vicinanza, Artur Binczewski, Wojbor Bogacki, Krzysztof Turza, Paul-Eric Pottie, Philip Tuckey, Davide Calonico, Ronald Holzwarth, Benjamin Sprenger, Ondrej Cip, Lenka Pravdova, Simon Rerucha, Javier Diaz Alonso, Eduardo Ros Vidal, Trinidad Garcia, Jan Kodet, Ulrich Schreiber, Juergen Kusche, Dieter Meschede, Stefan Schroeder, Simon Stellmer, Pawel Nogas, Robert Urbaniak, Przemyslaw Krehlik, Lukasz Sliwczynski, Anne Amy-Klein, Nicolas Quintin, Alwyn Seeds, Bruno Desruelle, Jean Lautier-Gaud, Vincent Menoret, Martin Rabault
Summary: Long-distance time and frequency transfer methods based on optical fibre links have rapidly evolved in recent years, showing excellent performance for frequency transfer and considerable promise for accurate time transfer. The CLONETS-DS project aims to establish a sustainable pan-European optical fibre network for precise time and frequency reference dissemination.
2021 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)
(2021)