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1.
Christoph Förste Roland Schmidt Richard Stubenvoll Frank Flechtner Ulrich Meyer Rolf König Hans Neumayer Richard Biancale Jean-Michel Lemoine Sean Bruinsma Sylvain Loyer Franz Barthelmes Saskia Esselborn 《Journal of Geodesy》2008,82(6):331-346
The recent improvements in the Gravity Recovery And Climate Experiment (GRACE) tracking data processing at GeoForschungsZentrum
Potsdam (GFZ) and Groupe de Recherche de Géodésie Spatiale (GRGS) Toulouse, the availability of newer surface gravity data
sets in the Arctic, Antarctica and North-America, and the availability of a new mean sea surface height model from altimetry
processing at GFZ gave rise to the generation of two new global gravity field models. The first, EIGEN-GL04S1, a satellite-only
model complete to degree and order 150 in terms of spherical harmonics, was derived by combination of the latest GFZ Potsdam
GRACE-only (EIGEN-GRACE04S) and GRGS Toulouse GRACE/LAGEOS (EIGEN-GL04S) mean field solutions. The second, EIGEN-GL04S1 was
combined with surface gravity data from altimetry over the oceans and gravimetry over the continents to derive a new high-resolution
global gravity field model called EIGEN-GL04C. This model is complete to degree and order 360 and thus resolves geoid and
gravity anomalies at half- wavelengths of 55 km at the equator. A degree-dependent combination method has been applied in
order to preserve the high accuracy from the GRACE satellite data in the lower frequency band of the geopotential and to form
a smooth transition to the high-frequency information coming from the surface data. Compared to pre-CHAMP global high-resolution
models, the accuracy was improved at a spatial resolution of 200 km (half-wavelength) by one order of magnitude to 3 cm in
terms of geoid heights. The accuracy of this model (i.e. the commission error) at its full spatial resolution is estimated
to be 15 cm. The model shows a reduced artificial meridional striping and an increased correlation of EIGEN-GL04C-derived
geostrophic meridional currents with World Ocean Atlas 2001 (WOA01) data. These improvements have led to select EIGEN-GL04C
for JASON-1 satellite altimeter data reprocessing.
Electronic Supplementary Material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
2.
J. J. Bommer M. B. Benito M. Ciudad-Real A. Lemoine M. A. Lpez-Menjívar R. Madariaga J. Mankelow P. Mndez de Hasbun W. Murphy M. Nieto-Lovo C. E. Rodríguez-Pineda H. Rosa 《Soil Dynamics and Earthquake Engineering》2002,22(5)
The small Central American republic of El Salvador has experienced, on average, one destructive earthquake per decade during the last hundred years. The latest events occurred on 13 January and 13 February 2001, with magnitudes Mw 7.7 and 6.6, respectively. The two events, which were of different tectonic origin, follow the patterns of the seismicity of the region although neither event has a known precedent in the earthquake catalogue in terms of size and location. The earthquakes caused damage to thousands of traditionally built houses and triggered hundreds of landslides, which were the main causes of fatalities. The earthquakes have clearly demonstrated trends of increasing seismic risk in El Salvador due to rapid population expansion in areas of high shaking and landslide hazard, exacerbated by deforestation and uncontrolled urbanisation. The institutional mechanisms required for the control of land use and building practice are very weak and present a major obstacle to risk mitigation. 相似文献
3.
The impact of accelerometry on CHAMP orbit determination 总被引：6，自引：0，他引：6
The contribution of the STAR accelerometer to the CHAMP orbit precision is evaluated and quantified by means of the following
results: orbital fit to the satellite laser ranging (SLR) observations, GPS reduced-dynamic vs SLR dynamic orbit comparisons,
and comparison of the measured to the modeled non-gravitational accelerations (atmospheric drag in particular). In each of
the four test periods in 2001, five CHAMP arcs of 2 days' length were analyzed. The mean RMS-of-fit of the SLR observations
of the orbits computed with STAR data or the non-gravitational force model were 11 and 24 cm, respectively. If the accelerometer
calibration parameters are not known at least at the few percent level, the SLR orbit fit deteriorates. This was tested by
applying a 10% error to the along-track scale factor of the accelerometer, which increased the SLR RMS-of-fit on average to
17 cm. Reference orbits were computed employing the reduced-dynamic technique with GPS tracking data. This technique yields
the most accurate orbit positions thanks to the estimation of a large number of empirical accelerations, which compensate
for dynamic modeling errors. Comparison of the SLR orbits, computed with STAR data or the non-gravitational force model, to
the GPS-based orbits showed that the SLR orbits employing accelerometer observations are twice as accurate. Finally, comparison
of measured to modeled accelerations showed that the level of geomagnetic activity is highly correlated with the atmospheric
drag model error, and that the largest errors occur around the geomagnetic poles.
Received: 7 May 2002 / Accepted: 18 November 2002
Correspondence to: S. Bruinsma
Acknowledgments. The TIGCM results were obtained from the CEDAR database. This study was supported by the Centre National d'Etudes Spatiales
(CNES). The referees are thanked for their helpful remarks and suggestions. 相似文献
4.
Coseismic and post-seismic signatures of the Sumatra 2004 December and 2005 March earthquakes in GRACE satellite gravity 总被引：2，自引：0，他引：2
Isabelle Panet Valentin Mikhailov Michel Diament Fred Pollitz Geoffrey King Olivier de Viron Matthias Holschneider Richard Biancale Jean-Michel Lemoine 《Geophysical Journal International》2007,171(1):177-190
The GRACE satellite mission has been measuring the Earth's gravity field and its temporal variations since 2002 April. Although these variations are mainly due to mass transfer within the geofluid envelops, they also result from mass displacements associated with phenomena including glacial isostatic adjustment and earthquakes. However, these last contributions are difficult to isolate because of the presence of noise and of geofluid signals, and because of GRACE's coarse spatial resolution (>400 km half-wavelength). In this paper, we show that a wavelet analysis on the sphere helps to retrieve earthquake signatures from GRACE geoid products. Using a wavelet analysis of GRACE geoids products, we show that the geoid variations caused by the 2004 December ( M w = 9.2) and 2005 March ( M w = 8.7) Sumatra earthquakes can be detected. At GRACE resolution, the 2004 December earthquake produced a strong coseismic decrease of the gravity field in the Andaman Sea, followed by relaxation in the area affected by both the Andaman 2004 and the Nias 2005 earthquakes. We find two characteristic timescales for the relaxation, with a fast variation occurring in the vicinity of the Central Andaman ridge. We discuss our coseismic observations in terms of density changes of crustal and upper-mantle rocks, and of the vertical displacements in the Andaman Sea. We interpret the post-seismic signal in terms of the viscoelastic response of the Earth's mantle. The transient component of the relaxation may indicate the presence of hot, viscous material beneath the active Central Andaman Basin. 相似文献
5.
Ch. Reigber P. Schwintzer W. Barth F. H. Massmann J. C. Raimondo A. Bode H. Li G. Balmino R. Biancale B. Moynot J. M. Lemoine J. C. Marty F. Barlier Y. Boudon 《Surveys in Geophysics》1993,14(4-5):381-393
On the basis of the GRIM4-S1 satellite-only Earth gravity model, being accomplished in a common effort by DGFI and GRGS, a combination solution, called GRIM4-C1, has been derivcd using 1° × 1° mean gravity anomalies and 1° × 1° Seasat altimeter derived mean geoid undulations. In the meantime improvements could be achieved by incorporating more tracking data (GEOSAT, SPOT2-DORIS) into the solution, resulting in the two new parallel versions, the satellite-only gravity model GRIM4-S2 and the combined solution GRIM4-C2p (preliminary). All GRIM4 Earth gravity models cover the spectral gravitational constituents complete up to degree and order 50.In this report the emphasis is on the discussion of the combined gravity models: combination and estimation techniques, capabilities for application in precise satellite orbit computation and accuracies in long wavelength geoid representation. It is shown that with the new generation of global gravity models general purpose satellite-only models are no longer inferior to combination solutions if applied to satellite orbit restitution. 相似文献
6.
7.
The influence of negative emission technologies and technology policies on the optimal climate mitigation portfolio 总被引：1，自引：1，他引：0
Derek M. Lemoine Sabine Fuss Jana Szolgayova Michael Obersteiner Daniel M. Kammen 《Climatic change》2012,113(2):141-162
Combining policies to remove carbon dioxide (CO2) from the atmosphere with policies to reduce emissions could decrease CO2 concentrations faster than possible via natural processes. We model the optimal selection of a dynamic portfolio of abatement, research and development (R&D), and negative emission policies under an exogenous CO2 constraint and with stochastic technological change. We find that near-term abatement is not sensitive to the availability of R&D policies, but the anticipated availability of negative emission strategies can reduce the near-term abatement optimally undertaken to meet 2°C temperature limits. Further, planning to deploy negative emission technologies shifts optimal R&D funding from ??carbon-free?? technologies into ??emission intensity?? technologies. Making negative emission strategies available enables an 80% reduction in the cost of keeping year 2100 CO2 concentrations near their current level. However, negative emission strategies are less important if the possibility of tipping points rules out using late-century net negative emissions to temporarily overshoot the CO2 constraint earlier in the century. 相似文献
8.
Negulescu Caterina Benaïchouche Abed Lemoine Anne Le Roy Sylvestre Pedreros Rodrigo 《Natural Hazards》2020,104(1):753-793
Natural Hazards - The 2011 Great East Japan earthquake and tsunami remind us once again that these types of cascade event can occur and cause considerable damage. The scientific community realizes... 相似文献
9.
New analysis of Lunar Prospector radio tracking data brings the nearside gravity field of the Moon with an unprecedented resolution 总被引：1，自引：0，他引：1
A new analysis of the Doppler tracking data from the Lunar Prospector mission in 1999 revealed a number of previously-unseen gravity anomalies at spatial scales as small as 27 km over the nearside. The tracking data at low altitudes (50 km or below) were better analyzed to resolve the nearside features without dampening from a power law constraint, by partitioning the gravity parameters concentrated on either the nearside or farside. The resulting model presents gravity anomalies correlated with topography with a correlation coefficient of 0.7 or higher from degree 50 to 150, the widest bandwidth yet. The gravity-topography admittance of ∼70 mGal/km is found from numerous craters of which diameters are 60 km or less. In addition, the new model produces orbits that fit to independent radio tracking data from the Lunar Reconnaissance Orbiter and Kaguya (SELENE) better than previous gravity models. This high-resolution model can be of immediate use to geophysical analysis of small craters. Our technique could be applied to an upcoming mission, the Gravity Recovery And Interior Laboratory and useful to extract short wavelength signals from the MESSENGER Doppler data. 相似文献
10.
Lunar gravity field determination using SELENE same-beam differential VLBI tracking data 总被引：2，自引：0，他引：2
S. Goossens K. Matsumoto Q. Liu F. Kikuchi K. Sato H. Hanada Y. Ishihara H. Noda N. Kawano N. Namiki T. Iwata F. G. Lemoine D. D. Rowlands Y. Harada M. Chen 《Journal of Geodesy》2011,85(4):205-228
A lunar gravity field model up to degree and order 100 in spherical harmonics, named SGM100i, has been determined from SELENE and historical tracking data, with an emphasis on using same-beam S-band differential VLBI data obtained in the SELENE mission between January 2008 and February 2009. Orbit consistency throughout the entire mission period of SELENE as determined from orbit overlaps for the two sub-satellites of SELENE involved in the VLBI tracking improved consistently from several hundreds of metres to several tens of metres by including differential VLBI data. Through orbits that are better determined, the gravity field model is also improved by including these data. Orbit determination performance for the new model shows improvements over earlier 100th degree and order models, especially for edge-on orbits over the deep far side. Lunar Prospector orbit determination shows an improvement of orbit consistency from 1-day predictions for 2-day arcs of 6 m in a total sense, with most improvement in the along and cross-track directions. Data fit for the types and satellites involved is also improved. Formal errors for the lower degrees are smaller, and the new model also shows increased correlations with topography over the far side. The estimated value for the lunar GM for this model equals 4902.80080±0.0009 km3/s2 (10 sigma). The lunar degree 2 potential Love number k 2 was also estimated, and has a value of 0.0255 ± 0.0016 (10 sigma as well). 相似文献