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2. GENESIS: Co-location of Geodetic Techniques in Space

Author

Delva, Pacôme, Altamimi, Zuheir, Blazquez, Alejandro, Blossfeld, Mathis, Böhm, Johannes, Bonnefond, Pascal, Boy, Jean-Paul, Bruinsma, Sean, Bury, Grzegorz, Chatzinikos, Miltiadis, Couhert, Alexandre, Courde, Clément, Dach, Rolf, Dehant, Véronique, Dell'Agnello, Simone, Elgered, Gunnar, Enderle, Werner, Exertier, Pierre, Glaser, Susanne, Haas, Rüdiger, Huang, Wen, Hugentobler, Urs, Jäggi, Adrian, Karatekin, Ozgur, Lemoine, Frank G., Poncin-Lafitte, Christophe Le, Lunz, Susanne, Männel, Benjamin, Mercier, Flavien, Métivier, Laurent, Meyssignac, Benoît, Müller, Jürgen, Nothnagel, Axel, Perosanz, Felix, Rietbroek, Roelof, Rothacher, Markus, Sert, Hakan, Sosnica, Krzysztof, Testani, Paride, Ventura-Traveset, Javier, Wautelet, Gilles, and Zajdel, Radoslaw

Subjects
Physics - Instrumentation and Detectors, Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Physics - Atmospheric and Oceanic Physics, Physics - Applied Physics, Physics - Geophysics
Abstract

Improving and homogenizing time and space reference systems on Earth and, more directly, realizing the Terrestrial Reference Frame (TRF) with an accuracy of 1mm and a long-term stability of 0.1mm/year are relevant for many scientific and societal endeavors. The knowledge of the TRF is fundamental for Earth and navigation sciences. For instance, quantifying sea level change strongly depends on an accurate determination of the geocenter motion but also of the positions of continental and island reference stations, as well as the ground stations of tracking networks. Also, numerous applications in geophysics require absolute millimeter precision from the reference frame, as for example monitoring tectonic motion or crustal deformation for predicting natural hazards. The TRF accuracy to be achieved represents the consensus of various authorities which has enunciated geodesy requirements for Earth sciences. Today we are still far from these ambitious accuracy and stability goals for the realization of the TRF. However, a combination and co-location of all four space geodetic techniques on one satellite platform can significantly contribute to achieving these goals. This is the purpose of the GENESIS mission, proposed as a component of the FutureNAV program of the European Space Agency. The GENESIS platform will be a dynamic space geodetic observatory carrying all the geodetic instruments referenced to one another through carefully calibrated space ties. The co-location of the techniques in space will solve the inconsistencies and biases between the different geodetic techniques in order to reach the TRF accuracy and stability goals endorsed by the various international authorities and the scientific community. The purpose of this white paper is to review the state-of-the-art and explain the benefits of the GENESIS mission in Earth sciences, navigation sciences and metrology., Comment: 31 pages, 9 figures, submitted to Earth, Planets and Space (EPS)

Published
2022
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3. GENESIS: co-location of geodetic techniques in space

Author

Delva, Pacôme, Altamimi, Zuheir, Blazquez, Alejandro, Blossfeld, Mathis, Böhm, Johannes, Bonnefond, Pascal, Boy, Jean-Paul, Bruinsma, Sean, Bury, Grzegorz, Chatzinikos, Miltiadis, Couhert, Alexandre, Courde, Clément, Dach, Rolf, Dehant, Véronique, Dell’Agnello, Simone, Elgered, Gunnar, Enderle, Werner, Exertier, Pierre, Glaser, Susanne, Haas, Rüdiger, Huang, Wen, Hugentobler, Urs, Jäggi, Adrian, Karatekin, Ozgur, Lemoine, Frank G., Le Poncin-Lafitte, Christophe, Lunz, Susanne, Männel, Benjamin, Mercier, Flavien, Métivier, Laurent, Meyssignac, Benoît, Müller, Jürgen, Nothnagel, Axel, Perosanz, Felix, Rietbroek, Roelof, Rothacher, Markus, Schuh, Harald, Sert, Hakan, Sosnica, Krzysztof, Testani, Paride, Ventura-Traveset, Javier, Wautelet, Gilles, and Zajdel, Radoslaw

Published
2023
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4. Altimetry for the future: Building on 25 years of progress

Author

Team, International Altimetry, Abdalla, Saleh, Kolahchi, Abdolnabi Abdeh, Ablain, Michaël, Adusumilli, Susheel, Bhowmick, Suchandra Aich, Alou-Font, Eva, Amarouche, Laiba, Andersen, Ole Baltazar, Antich, Helena, Aouf, Lotfi, Arbic, Brian, Armitage, Thomas, Arnault, Sabine, Artana, Camila, Aulicino, Giuseppe, Ayoub, Nadia, Badulin, Sergei, Baker, Steven, Banks, Chris, Bao, Lifeng, Barbetta, Silvia, Barceló-Llull, Bàrbara, Barlier, François, Basu, Sujit, Bauer-Gottwein, Peter, Becker, Matthias, Beckley, Brian, Bellefond, Nicole, Belonenko, Tatyana, Benkiran, Mounir, Benkouider, Touati, Bennartz, Ralf, Benveniste, Jérôme, Bercher, Nicolas, Berge-Nguyen, Muriel, Bettencourt, Joao, Blarel, Fabien, Blazquez, Alejandro, Blumstein, Denis, Bonnefond, Pascal, Borde, Franck, Bouffard, Jérôme, Boy, François, Boy, Jean-Paul, Brachet, Cédric, Brasseur, Pierre, Braun, Alexander, Brocca, Luca, Brockley, David, Brodeau, Laurent, Brown, Shannon, Bruinsma, Sean, Bulczak, Anna, Buzzard, Sammie, Cahill, Madeleine, Calmant, Stéphane, Calzas, Michel, Camici, Stefania, Cancet, Mathilde, Capdeville, Hugues, Carabajal, Claudia Cristina, Carrere, Loren, Cazenave, Anny, Chassignet, Eric P, Chauhan, Prakash, Cherchali, Selma, Chereskin, Teresa, Cheymol, Cecile, Ciani, Daniele, Cipollini, Paolo, Cirillo, Francesca, Cosme, Emmanuel, Coss, Steve, Cotroneo, Yuri, Cotton, David, Couhert, Alexandre, Coutin-Faye, Sophie, Crétaux, Jean-François, Cyr, Frederic, d’Ovidio, Francesco, Darrozes, José, David, Cedric, Dayoub, Nadim, De Staerke, Danielle, Deng, Xiaoli, Desai, Shailen, Desjonqueres, Jean-Damien, Dettmering, Denise, Di Bella, Alessandro, Díaz-Barroso, Lara, Dibarboure, Gerald, Dieng, Habib Boubacar, Dinardo, Salvatore, Dobslaw, Henryk, Dodet, Guillaume, Doglioli, Andrea, Domeneghetti, Alessio, Donahue, David, and Dong, Shenfu

Subjects
Life Below Water, Climate Action, Satellite altimetry, Oceanography, Sea level, Coastal oceanography, Cryospheric sciences, Hydrology, Astronomical and Space Sciences, Aerospace Engineering, Mechanical Engineering, Aerospace & Aeronautics
Abstract

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the “Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion.

Published
2021

11. Altimetry for the future: Building on 25 years of progress

Author

Abdalla, Saleh, Abdeh Kolahchi, Abdolnabi, Ablain, Michaël, Adusumilli, Susheel, Aich Bhowmick, Suchandra, Alou-Font, Eva, Amarouche, Laiba, Andersen, Ole Baltazar, Antich, Helena, Aouf, Lotfi, Arbic, Brian, Armitage, Thomas, Arnault, Sabine, Artana, Camila, Aulicino, Giuseppe, Ayoub, Nadia, Badulin, Sergei, Baker, Steven, Banks, Chris, Bao, Lifeng, Barbetta, Silvia, Barceló-Llull, Bàrbara, Barlier, François, Basu, Sujit, Bauer-Gottwein, Peter, Becker, Matthias, Beckley, Brian, Bellefond, Nicole, Belonenko, Tatyana, Benkiran, Mounir, Benkouider, Touati, Bennartz, Ralf, Benveniste, Jérôme, Bercher, Nicolas, Berge-Nguyen, Muriel, Bettencourt, Joao, Blarel, Fabien, Blazquez, Alejandro, Blumstein, Denis, Bonnefond, Pascal, Borde, Franck, Bouffard, Jérôme, Boy, François, Boy, Jean-Paul, Brachet, Cédric, Brasseur, Pierre, Braun, Alexander, Brocca, Luca, Brockley, David, Brodeau, Laurent, Brown, Shannon, Bruinsma, Sean, Bulczak, Anna, Buzzard, Sammie, Cahill, Madeleine, Calmant, Stéphane, Calzas, Michel, Camici, Stefania, Cancet, Mathilde, Capdeville, Hugues, Carabajal, Claudia Cristina, Carrere, Loren, Cazenave, Anny, Chassignet, Eric P., Chauhan, Prakash, Cherchali, Selma, Chereskin, Teresa, Cheymol, Cecile, Ciani, Daniele, Cipollini, Paolo, Cirillo, Francesca, Cosme, Emmanuel, Coss, Steve, Cotroneo, Yuri, Cotton, David, Couhert, Alexandre, Coutin-Faye, Sophie, Crétaux, Jean-François, Cyr, Frederic, d’Ovidio, Francesco, Darrozes, José, David, Cedric, Dayoub, Nadim, De Staerke, Danielle, Deng, Xiaoli, Desai, Shailen, Desjonqueres, Jean-Damien, Dettmering, Denise, Di Bella, Alessandro, Díaz-Barroso, Lara, Dibarboure, Gerald, Dieng, Habib Boubacar, Dinardo, Salvatore, Dobslaw, Henryk, Dodet, Guillaume, Doglioli, Andrea, Domeneghetti, Alessio, Donahue, David, Dong, Shenfu, Donlon, Craig, Dorandeu, Joël, Drezen, Christine, Drinkwater, Mark, Du Penhoat, Yves, Dushaw, Brian, Egido, Alejandro, Erofeeva, Svetlana, Escudier, Philippe, Esselborn, Saskia, Exertier, Pierre, Fablet, Ronan, Falco, Cédric, Farrell, Sinead Louise, Faugere, Yannice, Femenias, Pierre, Fenoglio, Luciana, Fernandes, Joana, Fernández, Juan Gabriel, Ferrage, Pascale, Ferrari, Ramiro, Fichen, Lionel, Filippucci, Paolo, Flampouris, Stylianos, Fleury, Sara, Fornari, Marco, Forsberg, Rene, Frappart, Frédéric, Frery, Marie-laure, Garcia, Pablo, Garcia-Mondejar, Albert, Gaudelli, Julia, Gaultier, Lucile, Getirana, Augusto, Gibert, Ferran, Gil, Artur, Gilbert, Lin, Gille, Sarah, Giulicchi, Luisella, Gómez-Enri, Jesús, Gómez-Navarro, Laura, Gommenginger, Christine, Gourdeau, Lionel, Griffin, David, Groh, Andreas, Guerin, Alexandre, Guerrero, Raul, Guinle, Thierry, Gupta, Praveen, Gutknecht, Benjamin D., Hamon, Mathieu, Han, Guoqi, Hauser, Danièle, Helm, Veit, Hendricks, Stefan, Hernandez, Fabrice, Hogg, Anna, Horwath, Martin, Idžanović, Martina, Janssen, Peter, Jeansou, Eric, Jia, Yongjun, Jia, Yuanyuan, Jiang, Liguang, Johannessen, Johnny A., Kamachi, Masafumi, Karimova, Svetlana, Kelly, Kathryn, Kim, Sung Yong, King, Robert, Kittel, Cecile M.M., Klein, Patrice, Klos, Anna, Knudsen, Per, Koenig, Rolf, Kostianoy, Andrey, Kouraev, Alexei, Kumar, Raj, Labroue, Sylvie, Lago, Loreley Selene, Lambin, Juliette, Lasson, Léa, Laurain, Olivier, Laxenaire, Rémi, Lázaro, Clara, Le Gac, Sophie, Le Sommer, Julien, Le Traon, Pierre-Yves, Lebedev, Sergey, Léger, Fabien, Legresy, Benoı̂t, Lemoine, Frank, Lenain, Luc, Leuliette, Eric, Levy, Marina, Lillibridge, John, Liu, Jianqiang, Llovel, William, Lyard, Florent, Macintosh, Claire, Makhoul Varona, Eduard, Manfredi, Cécile, Marin, Frédéric, Mason, Evan, Massari, Christian, Mavrocordatos, Constantin, Maximenko, Nikolai, McMillan, Malcolm, Medina, Thierry, Melet, Angelique, Meloni, Marco, Mertikas, Stelios, Metref, Sammy, Meyssignac, Benoit, Minster, Jean-François, Moreau, Thomas, Moreira, Daniel, Morel, Yves, Morrow, Rosemary, Moyard, John, Mulet, Sandrine, Naeije, Marc, Nerem, Robert Steven, Ngodock, Hans, Nielsen, Karina, Nilsen, Jan Even Øie, Niño, Fernando, Nogueira Loddo, Carolina, Noûs, Camille, Obligis, Estelle, Otosaka, Inès, Otten, Michiel, Oztunali Ozbahceci, Berguzar, P. Raj, Roshin, Paiva, Rodrigo, Paniagua, Guillermina, Paolo, Fernando, Paris, Adrien, Pascual, Ananda, Passaro, Marcello, Paul, Stephan, Pavelsky, Tamlin, Pearson, Christopher, Penduff, Thierry, Peng, Fukai, Perosanz, Felix, Picot, Nicolas, Piras, Fanny, Poggiali, Valerio, Poirier, Étienne, Ponce de León, Sonia, Prants, Sergey, Prigent, Catherine, Provost, Christine, Pujol, M-Isabelle, Qiu, Bo, Quilfen, Yves, Rami, Ali, Raney, R. Keith, Raynal, Matthias, Remy, Elisabeth, Rémy, Frédérique, Restano, Marco, Richardson, Annie, Richardson, Donald, Ricker, Robert, Ricko, Martina, Rinne, Eero, Rose, Stine Kildegaard, Rosmorduc, Vinca, Rudenko, Sergei, Ruiz, Simón, Ryan, Barbara J., Salaün, Corinne, Sanchez-Roman, Antonio, Sandberg Sørensen, Louise, Sandwell, David, Saraceno, Martin, Scagliola, Michele, Schaeffer, Philippe, Scharffenberg, Martin G., Scharroo, Remko, Schiller, Andreas, Schneider, Raphael, Schwatke, Christian, Scozzari, Andrea, Ser-giacomi, Enrico, Seyler, Frederique, Shah, Rashmi, Sharma, Rashmi, Shaw, Andrew, Shepherd, Andrew, Shriver, Jay, Shum, C.K., Simons, Wim, Simonsen, Sebatian B., Slater, Thomas, Smith, Walter, Soares, Saulo, Sokolovskiy, Mikhail, Soudarin, Laurent, Spatar, Ciprian, Speich, Sabrina, Srinivasan, Margaret, Srokosz, Meric, Stanev, Emil, Staneva, Joanna, Steunou, Nathalie, Stroeve, Julienne, Su, Bob, Sulistioadi, Yohanes Budi, Swain, Debadatta, Sylvestre-baron, Annick, Taburet, Nicolas, Tailleux, Rémi, Takayama, Katsumi, Tapley, Byron, Tarpanelli, Angelica, Tavernier, Gilles, Testut, Laurent, Thakur, Praveen K., Thibaut, Pierre, Thompson, LuAnne, Tintoré, Joaquín, Tison, Céline, Tourain, Cédric, Tournadre, Jean, Townsend, Bill, Tran, Ngan, Trilles, Sébastien, Tsamados, Michel, Tseng, Kuo-Hsin, Ubelmann, Clément, Uebbing, Bernd, Vergara, Oscar, Verron, Jacques, Vieira, Telmo, Vignudelli, Stefano, Vinogradova Shiffer, Nadya, Visser, Pieter, Vivier, Frederic, Volkov, Denis, von Schuckmann, Karina, Vuglinskii, Valerii, Vuilleumier, Pierrik, Walter, Blake, Wang, Jida, Wang, Chao, Watson, Christopher, Wilkin, John, Willis, Josh, Wilson, Hilary, Woodworth, Philip, Yang, Kehan, Yao, Fangfang, Zaharia, Raymond, Zakharova, Elena, Zaron, Edward D., Zhang, Yongsheng, Zhao, Zhongxiang, Zinchenko, Vadim, and Zlotnicki, Victor

Published
2021
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18. Study of the atmospheric pressure loading signal in VLBI observations

Author

Petrov, Leonid and Boy, Jean-Paul

Subjects
Physics - Geophysics
Abstract

Redistribution of air masses due to atmospheric circulation causes loading deformation of the Earth's crust which can be as large as 20 mm for the vertical component and 3 mm for horizontal components. Rigorous computation of site displacements caused by pressure loading requires knowledge of the surface pressure field over the entire Earth surface. A procedure for computing 3-D displacements of geodetic sites of interest using a 6-hourly pressure field from the NCEP numerical weather models and the Ponte and Ray [2002] model of atmospheric tides is presented. We investigated possible error sources and found that the errors of our pressure loading time series are below the 15% level. We validated our model by estimating the admittance factors of the pressure loading time series using a dataset of 3.5 million VLBI observations from 1980 to 2002. The admittance factors averaged over all sites are 0.95 -+ 0.02 for the vertical displacement and 1.00 -+ 0.07 for the horizontal displacements. For the first time horizontal displacements caused by atmospheric pressure loading have been detected. The closeness of these admittance factors to unity allows us to conclude that on average our model quantitatively agrees with the observations within the error budget of the model. At the same time we found that the model is not accurate for several stations which are near a coast or in mountain regions. We conclude that our model is suitable for routine data reduction of space geodesy observations., Comment: accepted by the Journal of Geophysical Research

Published
2003
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19. A comparison of the gravity field over Central Europe from superconducting gravimeters, GRACE and global hydrological models, using EOF analysis

Author

Crossley, David, de Linage, Caroline, Hinderer, Jacques, Boy, Jean-Paul, and Famiglietti, James

Subjects
: data assimilation system, time-variable gravity, temporal gravity, energy balances, local hydrology, surface loads, land water, Baltic Sea, variability, metsahovi
Abstract

We analyse data from seven superconducting gravimeter (SG) stations in Europe from 2002 to 2007 from the Global Geodynamics Project (GGP) and compare seasonal variations with data from GRACE and several global hydrological models—GLDAS, WGHM and ERA-Interim. Our technique is empirical orthogonal function (EOF) decomposition of the fields that allows for the inherent incompatibility of length scales between ground and satellite observations. GGP stations below the ground surface pose a problem because part of the attraction from soil moisture comes from above the gravimeter, and this gives rise to a complex (mixed) gravity response. The first principle component (PC) of the EOF decomposition is the main indicator for comparing the fields, although for some of the series it accounts for only about 50per cent of the variance reduction. PCs for GRACE solutions RL04 from CSR and GFZ are filtered with a cosine taper (degrees 20–40) and a Gaussian window (350km). Significant differences are evident between GRACE solutions from different groups and filters, though they all agree reasonably well with the global hydrological models for the predominantly seasonal signal. We estimate the first PC at 10-d sampling to be accurate to 1 μGal for GGP data, 1.5 μGal for GRACE data and 1 μGal between the three global hydrological models. Within these limits the CNES/GRGS solution and ground GGP data agree at the 79per cent level, and better when the GGP solution is restricted to the three above-ground stations. The major limitation on the GGP side comes from the water mass distribution surrounding the underground instruments that leads to a complex gravity effect. To solve this we propose a method for correcting the SG residual gravity series for the effects of soil moisture above the station.

Published
2012

22. Lake and reservoir volume variations from laser altimetry and time-variable gravity

Author

Boy, Jean Paul and Carabajal, Claudia

Abstract

Using ICESat-2 ATL13 inland water products, and MODIS imagery, we compute water level variations from various lakes and reservoirs as well as water extent changes. The conversion of the ellipsoidal height into orthometric height requires an accurate geoid model. We show how recent geoid models can improve water level estimates than the classical EGM2008 used in the ATL13 products. We validate our water level estimates with available radar altimetry products and in-situ measurements. Using these two datasets, we derive volume changes. In addition, we derive corresponding mass variations of these water bodies using GRACE and GRACE Follow-On global mascon solutions from NASA GSFC. We show a good agreement between the water volume changes computed from ICESat-2 and MODIS and the mass changes deduced from space gravity missions. The main limitation of the gravimetry products is due to the spatial resolution of the GRACE & GRACE-FO solutions, and the quality of the hydrology models used to correct for the other continental water storage components, e.g. soil moisture and snow.As an independent validation, we compute surface displacements due to the lake/reservoir loading process, and compare them to available GNSS observations., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Published
2023

26. Status of the International Geodynamics and Earth Tide Services (IGETS)

Author

Boy, Jean Paul, Wziontek, Hartmut, Voigt, Christain, Foerste, Christoph, and Barriot, Jean-Pierre

Abstract

The International Geodynamics and Earth Tide Services is one of the newer IAG services under the umbrella of the International Gravity Field Service (IGFS). Its primary objective is to support the monitoring of temporal gravity field variations at the Earth’s surface through long-term records from superconducting and mechanical gravimeters, tiltmeters and other geodynamic sensors.Its main products are the raw and processed data from a worldwide set of superconducting gravimeters (SG), hosted at the main Data Center located at the German Research Centre for Geosciences (GFZ) in Potsdam (Germany).We present here the status of IGETS, the data availability and the different data products:- Level-1: raw gravity and pressure sampled at 1 or 2 seconds and filtered at 1 minute.- Level-2: gravity and pressure data corrected for instrumental perturbations, ready for tidal analysis.- Level-3: gravity residuals after geophysical corrections.The University of French Polynesia (UPF) in Tahiti and the Ecole et Observatoire des Sciences de la Terre (EOST) in Strasbourg (France) are the two current Analysis Centers in charge of producing these higher order level data. While Level-1 products require special knowledge in data pre-processing, the Level-2 and -3 products are intended for analysis and interpretation. In particular, level-2 products are dedicated to the analysis of Earth tides, while level-3 products directly allow further interpretation of small signals after the removal of known components, like water storage changes. &nbsp, The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Published
2023

27. Multi-technique monitoring of climate change signature in Svalbard

Author

Nicolas, Joelle, Verdun, Jérôme, Baltzer, Agnès, Boy, Jean-Paul, Tafflet, Alicia, Durand, Frédéric, Lemoine, Jean-Michel, and Perosanz, Félix

Abstract

The Svalbard archipelago is strongly impacted by past and present-day ice melting. This area offers the benefit that several in situ and space datasets are available at different spatial and temporal resolutions. We perform a multi-technique intercomparison for a better understanding of the different processes and extract common climate-related signals, allowing climate change signature analysis. Space geodetic techniques provide time series of daily crustal deformation and monthly gravity field variations over several years at local and regional scales. Seasonal signals included in these time series are mainly caused by the (visco)elastic response of variable mass load due to ice and snow accumulation. GNSS positioning and GRACE equivalent water height time series are compared to geophysical models based on mass redistributions and snow models. For this, we applied specific data analysis methods to accurately separate the different sources and reveal climate change signature from seasonal signals. In addition, ground gravimetry, field datasets, sediment analysis, Sentinel observations, aerial photography, and laser telescan are used to characterize the evolution of the area. These datasets are used to produce maps representing the marine sedimentary facies and glacial environments of different glaciers. We estimate the footprints of glacier retreat and ice thickness loss by monitoring the evolution of the coastline and follow the hydrological network for different glaciers (Kronebreen and Lovenbreen) and fjords to show the contraction of the glacier's drainage during melting. The joint analysis of the maps and space geodesy time series gives the estimation of crustal uplift due to glacier melt., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Published
2023

32. Scientific Committee

Author

Khenchaf, Ali, primary, Frison, Pierre-Louis, additional, Angelliaume, Sébastien, additional, Dubois-Fernandez, Pascale, additional, Touzi, Ridha, additional, Pinel, Virginie, additional, Le-Hegarat, Sylvie, additional, Picot, Nicolas, additional, Seyler, Frédérique, additional, Verron, Jacques, additional, Boutin, Jacqueline, additional, Anterrieu, Eric, additional, Waldteufel, Philippe, additional, Balmino, George, additional, Boy, Jean Paul, additional, Floury, Nicolas, additional, Soulat, François, additional, Botteron, Cyril, additional, Mangiarotti, Sylvain, additional, Laroche, Stéphane, additional, Desroziers, Gérald, additional, Cosme, Emmanuel, additional, Baghdadi, Nicolas, additional, and Zribi, Mehrez, additional

Published
2016
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33. Viscoelastic Love numbers and long-period geophysical effects

Author

Boy, Jean-Paul, Michel, A, Boy, J-P, Institut de physique du globe de Strasbourg (IPGS), and Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010504 meteorology & atmospheric sciences, Laplace transform, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Isotropy, Geophysics, Post-glacial rebound, Deformation (meteorology), 010502 geochemistry & geophysics, 01 natural sciences, Viscoelasticity, Physics::Geophysics, symbols.namesake, Viscosity, Amplitude, Fourier transform, Geochemistry and Petrology, symbols, Astrophysics::Earth and Planetary Astrophysics, Geology, 0105 earth and related environmental sciences
Abstract

SUMMARY Long term deformations strongly depend on the earth model and its rheological parameters, and in particular its viscosity. We give the general theory and the numerical scheme to compute them for any spherically non-rotating isotropic earth model with linear rheology, either elastic or viscoelastic. Although the Laplace transform (LT) is classically used to compute viscoelastic deformation, we choose here instead, to implement the integration with the Fourier transform (FT) in order to take advantage of the fast FT algorithm and avoid some of the LT mathematical difficulties. We describe the methodology to calculate deformations induced by several geophysical signals regardless of whether they are periodic or not, especially by choosing an adapted time sampling for the FT. As examples, we investigate the sensitivity of the displacements due to long period solid Earth tides, glacial isostatic adjustment and present-day ice melting, to anelastic parameters of the mantle. We find that the effects of anelasticity are important for long period deformation and relatively low values of viscosities for both Maxwell and Burgers models. We show that slight modifications in the rheological models could significantly change the amplitude of deformation but also affect the spatial and temporal pattern of the signal to a lesser extent. Especially, we highlight the importance of the mantle anelasticity in the low degrees deformation due to present-day ice melting and encourage its inclusion in future models.

Published
2022

36. Multi-technique monitoring of ocean tide loading in northern France

Author

Llubes, Muriel, Florsch, Nicolas, Boy, Jean-Paul, Amalvict, Martine, Bonnefond, Pascal, Bouin, Marie-Noëlle, Durand, Stéphane, Esnoult, Marie-France, Exertier, Pierre, Hinderer, Jacques, Lalancette, Marie-Françoise, Masson, Frédéric, Morel, Laurent, Nicolas, Joëlle, Vergnolle, Mathilde, and Wöppelmann, Guy

Published
2008
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40. First analyses of the iOSG-type superconducting gravimeter at the low noise underground laboratory (LSBB URL) of Rustrel, France

Author

Rosat Séverine, Hinderer Jacques, Boy Jean-Paul, Littel Frédéric, Boyer Daniel, Bernard Jean-Daniel, Rogister Yves, Mémin Anthony, and Gaffet Stéphane

Subjects
Environmental sciences, GE1-350
Abstract

In the last few years, the performance of the cryogenic gravity instruments has been further improved by the development of a new generation of superconducting gravimeter (SG): the so-called iOSG which is a superconducting gravimeter designed for observatory purpose with a heavier sphere than previous SGs. The first iOSG (iOSG-024) has been installed in July 2015 at the LSSB low background noise underground research laboratory in Rustrel (France), funded by the EQUIPEX MIGA (Matter wave-laser based Interferometer Gravitation Antenna) project and by the European FEDER 2006-2013 “PFM LSBB – Développement des qualités environnementales du LSBB”. This instrument is operational since September 2015. We present the first tidal analyses of the 7-month time-varying gravity records of this newly installed instrument as well as the calibration results performed by parallel FG5 absolute gravity measurements. We also show the performances of iOSG-024 in terms of noise levels in the seismic (in the millihertz frequency range) band using a standardized procedure based on the computation of the residual power spectral densities over a quiet time period. The obtained noise levels are compared with other SG sites and with seismological reference noise models. The combination of the instrumental performance of the iOSG with the LSBB site properties makes this gravimetric station one of the quietest in the world, comparable to the lower sensor of the OSG-56 at BFO, at seismic frequencies.

Published
2016
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41. Mezinárodní unie geodézie a geofyziky (IUGG)

Author

Poutanen, Markku, Kotsakis, Christopher, Boy, Jean-Paul, Jaeggi, Adrian, Reguzzoni, Mirko, Bogusz, Janusz, Huang, Cheng-Li, Kealy, Allison, Gikas, Vassilis, Novák, Pavel, Crespi, Mattia, Eicker, Annette, Boening, Carmen, Yang, Yuanxi, Kopp, Heidrun, Mueller, Juergen, Santos, Marcelo, Rozsa, Szabolcs, and Toth, Gyula

Subjects
International Association of Geodesy, Geodesist’s Handbook
Abstract

Příručka geodetů je vydávána Mezinárodní asociací geodézie (IAG) pravidelně po každém Valném shromáždění IUGG / IAG. Cílem je představit současnou strukturu IAG a její specifikace a seznámit širokou geodetickou komunitu s působností a pracovníky složek asociace pro nadcházející legislativní období. Vědecký program a plánované činnosti jsou podrobně popsány. První část příručky 2020 představuje historický vývoj a současné předpisy IAG (stanovy, stanovy a pravidla revidované během Valného shromáždění IUGG / IAG 2019). Druhá část shrnuje výsledky Valného shromáždění IAG konaného ve spojení s 27. Valným shromážděním IUGG v kanadském Montrealu v červenci 2019. Přehled nejdůležitějších výsledků IAG od roku 2015 do roku 2019 je uveden v projevu prezidenta. Publikovány jsou citace vědců vyznamenaných v Montrealu nejvyššími oceněními IAG (Levalloisova medaile, Cena Guy Bomforda a Cena mladých autorů). Tento oddíl uzavírají zprávy generálního tajemníka, zasedání Rady a výkonného výboru IAG a rezoluce IUGG a IAG. Třetí část příručky obsahuje podrobné struktury a programy na období 2019--2023. Všechny komponenty IAG (komise, mezikomisní výbor, komunikační a terénní pobočka, služby a globální geodetický pozorovací systém) jsou prezentovány spolu s jejich dílčími složkami (subkomise, projekty, studijní skupiny a pracovní skupiny). Tato část popisuje plánovanou vědeckou práci IAG v následujících letech. Čtvrtá část doplňuje příručku o některé obecné informace užitečné pro geodetickou komunitu. Zvýrazněno je internetové zastoupení IAG a publikační řada a jsou zde uvedeny národní delegáti a zástupci IAG pro služby a mezinárodní vědecké orgány. The Geodesist’s Handbook is published by the International Association of Geodesy (IAG) periodically after each IUGG/IAG General Assembly. The objective is to present the current IAG structure and its specifications, and to introduce the terms of reference and the officers of the Association’s components for the upcoming legislative period to the broad geodetic community. The scientific program and planned activities are described in detail. The first part of the Handbook 2020 presents the historical developments and current regulations of the IAG (Statutes, Bylaws and Rules as reviewed during the IUGG/IAG General Assembly 2019). The second part summarises the outcome of the IAG General Assembly held in conjunction with the 27th IUGG General Assembly in Montreal, Canada, in July 2019. An overview of the most important IAG results from 2015 to 2019 is given in the presidential address. The citations of thescientists decorated in Montreal with the highest IAG awards (Levallois Medal, Guy Bomford Prize, and Young Authors Award) are published. Reports of the Secretary General, the IAG Council and Executive Committee meetings, and the IUGG and IAG resolutions conclude this section. The third part of the Handbook contains the detailed structures and programs for the period 2019-2023. All IAG components (Commissions, Inter-commission Committee, Communication and Outreach Branch, Services, and the Global Geodetic Observing System) are presented along with their sub-components (Sub-commissions, Projects, Study Groups and Working Groups). This part describes the planed scientific work of IAG during the coming years. The fourth part completes the Handbook with some general information useful for the geodetic community. The IAG Internet representation and the publication series are highlighted, and the IAG national delegates and representatives to services and international scientific bodies are listed.

Published
2020

45. Hydrological Variations in Australia Recovered by GRACE High-Resolution Mascons Solutions

Author

Carabajal, Claudia C, Boy, Jean-Paul, Sabaka, Terence J, Lemoine, Frank G, Rowlands. David, Luthcke, Scott B, and Brown, M. Y

Subjects
Meteorology And Climatology
Abstract

Australia represents a challenging region in which to study hydrological variations as recovered by the GRACE (Gravity Recovery And Climate Experiment) mission data. Much of Australia is characterized by relatively small hydrological signals, with large precipitation gradients between the North and the South. These signals are better recovered using innovative GRACE processing techniques such as high-resolution mascon solutions, which may help overcome the deficiencies in the standard GRACE data processing and filtering methods. We will show the power of using regional and global mas con solutions to recover hydrological variations from 2003 to 2011, as well as the oceanic mass variations in the surrounding regions. We will compare the GRACE signals with state of the art hydrology and ocean general circulation models, precipitation, soil moisture and groundwater data sets. We especially emphasize the gravity signatures observed during the decadal drought in the Murray-Darling river basin and the early 2011 floods in North-Western Australia.

Published
2011

46. Evaluation of the Global Multi-Resolution Terrain Elevation Data 2010 (GMTED2010) Using ICESat Geodetic Control

Author

Carabajal, Claudia C, Harding, David J, Boy, Jean-Paul, Danielson, Jeffrey J, Gesch, Dean B, and Suchdeo, Vijay P

Subjects
Geophysics
Abstract

Supported by NASA's Earth Surface and Interior (ESI) Program, we are producing a global set of Ground Control Points (GCPs) derived from the Ice, Cloud and land Elevation Satellite (ICESat) altimetry data. From February of 2003, to October of 2009, ICESat obtained nearly global measurements of land topography (+/- 86deg latitudes) with unprecedented accuracy, sampling the Earth's surface at discrete approx.50 m diameter laser footprints spaced 170 m along the altimetry profiles. We apply stringent editing to select the highest quality elevations, and use these GCPs to characterize and quantify spatially varying elevation biases in Digital Elevation Models (DEMs). In this paper, we present an evaluation of the soon to be released Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010). Elevation biases and error statistics have been analyzed as a function of land cover and relief. The GMTED2010 products are a large improvement over previous sources of elevation data at comparable resolutions. RMSEs for all products and terrain conditions are below 7 m and typically are about 4 m. The GMTED2010 products are biased upward with respect to the ICESat GCPs on average by approximately 3 m.

Published
2011

47. MSSA Analysis Of Seasonal Loading-Induced Deformation From GNSS Time Series

Author

Berthier, Antoine, Nicolas, Joëlle, Verdun, Jérôme, Boy, Jean-Paul, Laboratoire Géomatique et foncier (GeF), Conservatoire National des Arts et Métiers [CNAM] (CNAM), École supérieure des géomètres et topographes (ESGT-CNAM), Institut de physique du globe de Strasbourg (IPGS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Verdun, Jérôme

Subjects
[SDU] Sciences of the Universe [physics], [SDU]Sciences of the Universe [physics], [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [SDU.STU] Sciences of the Universe [physics]/Earth Sciences, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, [SDU.STU.GP] Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2019

49. The New IERS Special Bureau for Loading (SBL)

Author

vanDam, Tonie, Plag, Hans-Peter, Blewitt, Geoffrey, Boy, Jean-Paul, Francis, Olivier, Gegout, Pascal, Kierulf, Halfdan Pascal, Sato, Tadahiro, Scherneck, Hans-Georg, and Wahr, John

Subjects
Geophysics
Abstract

Currently, the establishment of the International Earth Rotation Service (IERS) Special Bureau for Loading (SBL) is in progress as part of the IERS Global Geophysical Fluids Center (GGFC). The main purpose of the SBL is to provide reliable, consistent model predictions of loading signals that have been thoroughly tested and validated. The products will describe at least the surface deformation, gravity signal and geo-center variations due to the various surface loading processes in reference frames relevant for direct comparison with existing geodetic observing techniques. To achieve these goals, major scientific advances are required with respect to the Earth model, the theory and algorithms used to model deformations of the Earth as well as improvements in the observational data related to surface loading.

Published
2002

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