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141.
Peter Creola 《Space Policy》1999,15(1):41
Is it possible for small nations to get their concerns aired or improve their industries and economies in the field of space activities? In this edited version of a speech to the international symposium on ‘The History of the European Space Agency’, held in London, 11–13 November 1998, the author demonstrates that, through judicious cooperative endeavour within the framework of ESA, and a willingness to put forward solutions rather than harping on problems, it is. Switzerland’s role in the foundation of ESA is discussed, along with various successful initiatives taken by the country. The particular difficulties presented by the country’s constitution – and how they have been overcome – are also examined. The author concludes with some thoughts on the present and futute state of space affairs in Europe. 相似文献
142.
Nicolas Peter 《Space Policy》2004,20(3):9554
There is a growing realisation of the increasingly varied and interesting possibilities for the use of Earth observation data to ensure compliance with international obligations generally, and treaty obligations in particular. Most examinations of the application of Earth observation data to monitoring states’ compliance with international obligations focus on the environmental sector. This paper proposes the use of remote sensing satellites for the support of multilateral environmental agreements (MEAs), especially land monitoring MEAs such as the Convention on Biological Diversity (1992) and the Kyoto Protocol (1997). It discusses the uses of remote sensing for treaty implementation or enforcement in general, and the admissability of satellite imagery as legal proof, before examining how Earth observation-derived data could be of benefit to specific MEAs. As sensors become increasingly sophisticated the use of remote sensing in this area should grow but it needs to be supported by its more widespread legal recognition as proof. 相似文献
143.
144.
Remote sounding of atmospheric gravity waves with satellite limb and nadir techniques 总被引:4,自引:0,他引:4
Dong L. Wu Peter Preusse Stephen D. Eckermann Jonathan H. Jiang Manuel de la Torre Juarez Lawrence Coy Ding Y. Wang 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2006,37(12):2269-II
Recent advances in satellite techniques hold great potential for mapping global gravity wave (GW) processes at various altitudes. Poor understanding of small-scale GWs has been a major limitation to numerical climate and weather models for making reliable forecasts. Observations of short-scale features have important implication for validating and improving future high-resolution numerical models. This paper summarizes recent GW observations and sensitivities from several satellite instruments, including MLS, AMSU-A, AIRS, GPS, and CLAES. It is shown in an example that mountain waves with horizontal wavelengths as short as 30 km now can be observed by AIRS, reflecting the superior horizontal resolution in these modern satellite instruments. Our studies show that MLS, AMSU-A and AIRS observations reveal similar GW characteristics, with the observed variances correlated well with background winds. As a complementary technique, limb sounding instruments like CRISTA, CLAES, and GPS can detect GWs with better vertical but poorer horizontal resolutions. To resolve different parts of the broad GW spectrum, both satellite limb and nadir observing techniques are needed, and a better understanding of GW complexities requires joint analyses of these data and dedicated high-resolution model simulations. 相似文献
145.
Peter J. Cargill Loukas Vlahos Rim Turkmani Klaus Galsgaard Heinz Isliker 《Space Science Reviews》2006,124(1-4):249-259
Particle acceleration in large-scale turbulent coronal magnetic fields is considered. Using test particle calculations, it
is shown that both cellular automata and three dimensional MHD models lead to the production of relativistic particles on
sub-second timescales with power law distribution functions. In distinction with the monolithic current sheet models for solar
flares, particles gain energy by multiple interactions with many current sheets. Difficulties that need to be addressed, such
as feedback between particle acceleration and MHD, are discussed. 相似文献
146.
Atmospheric gaseous constituents play an important role in determining the surface temperatures and habitability of a planet. Using a global climate model and a parameterization of the carbonate-silicate cycle, we explored the effect of the location of the substellar point on the atmospheric CO(2) concentration and temperatures of a tidally locked terrestrial planet, using the present Earth continental distribution as an example. We found that the substellar point's location relative to the continents is an important factor in determining weathering and the equilibrium atmospheric CO(2) level. Placing the substellar point over the Atlantic Ocean results in an atmospheric CO(2) concentration of 7 ppmv and a global mean surface air temperature of 247 K, making ~30% of the planet's surface habitable, whereas placing it over the Pacific Ocean results in a CO(2) concentration of 60,311 ppmv and a global temperature of 282 K, making ~55% of the surface habitable. 相似文献
147.
Kuo-Ying Wang Chao-Han Liu Lou-Chuang Lee Peter Braesicke 《Space Science Reviews》2012,168(1-4):261-282
Sudden tropospheric cooling and induced stratospheric warming were found during the 22 July 2009 total solar eclipse. Can the 22 July 2009 hallmark also be seen in other major solar eclipses? Here we hypothesize that the tropospheric cooling and the stratospheric warming can be predicted to occur during a major solar eclipse event. In this work we use the FORMOSAT-3/COSMIC (F3C) Global Positioning System (GPS) radio occultation (RO) data to construct eclipse-time temperature profiles before, during, and after the passages of major solar eclipses for the years 2006–2010. We use four times a day of meteorological analysis from the European Centre for Medium Range Weather Forecast (ECMWF) global meteorological analysis to construct non-eclipse effect temperature profiles for the same eclipse passages. The eclipse effects were calculated based on the difference between F3C and ECMWF profiles. A?total of five eclipse cases and thirteen non-eclipse cases were analyzed and compared. We found that eclipses cause direct thermal cooling in the troposphere and indirect dynamic warming in the stratosphere. These results are statistically significant. Our results show ?0.6 to ?1.2°C cooling in the troposphere and 0.4 to 1.3°C warming in the middle to lower stratosphere during the eclipses. This characteristic stratosphere-troposphere coupling in temperature profiles represent a distinctive atmospheric responses to the solar eclipses. 相似文献
148.
Pia Zacharias Sven Bingert Hardi Peter 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009
We study extreme-ultraviolet emission line spectra derived from three-dimensional magnetohydrodynamic models of structures in the corona. In order to investigate the effects of increased magnetic activity at photospheric levels in a numerical experiment, a much higher magnetic flux density is applied at the photosphere as compared to the Sun. Thus, we can expect our results to highlight the differences between the Sun and more active, but still solar-like stars. We discuss signatures seen in extreme-ultraviolet emission lines synthesized from these models and compare them to observed signatures in the spatial distribution and temporal evolution of Doppler shifts in lines formed in the transition region and corona. This is of major interest to test the quality of the underlying magnetohydrodynamic model to heat the corona, i.e. currents in the corona driven by photospheric motions (flux braiding). 相似文献
149.
William M. Folkner Véronique Dehant Sébastien Le Maistre Marie Yseboodt Attilio Rivoldini Tim Van Hoolst Sami W. Asmar Matthew P. Golombek 《Space Science Reviews》2018,214(5):100
The Rotation and Interior Structure Experiment (RISE) on-board the InSight mission will use the lander’s X-band (8 GHz) radio system in combination with tracking stations of the NASA Deep Space Network (DSN) to determine the rotation of Mars. RISE will measure the nutation of the Martian spin axis, detecting for the first time the effect of the liquid core of Mars and providing in turn new constraints on the core radius and density. RISE will also measure changes in the rotation rate of Mars on seasonal time-scales thereby constraining the atmospheric angular momentum budget. Finally, RISE will provide a superb tie between the cartographic and inertial reference frames. This paper describes the RISE scientific objectives and measurements, and provides the expected results of the experiment. 相似文献
150.
Comets are considered the most primitive planetary bodies in our Solar System, i.e., they should have best preserved the solid components of the matter from which our Solar System formed. ESA’s recent Rosetta mission to Jupiter family comet 67P/Churyumov–Gerasimenko (67P/CG) has provided a wealth of isotope data which expanded the existing data sets on isotopic compositions of comets considerably. In this paper we review our current knowledge on the isotopic compositions of H, C, N, O, Si, S, Ar, and Xe in primitive Solar System materials studied in terrestrial laboratories and how the Rosetta data acquired with the ROSINA (Rosetta Orbiter Sensor for Ion and Neutral Analysis) and COSIMA (COmetary Secondary Ion Mass Analyzer) mass spectrometer fit into this picture. The H, Si, S, and Xe isotope data of comet 67P/CG suggest that this comet might be particularly primitive and might have preserved large amounts of unprocessed presolar matter. We address the question whether the refractory Si component of 67P/CG contains a presolar isotopic fingerprint from a nearby Type II supernova (SN) and discuss to which extent C and O isotope anomalies originating from presolar grains should be observable in dust from 67P/CG. Finally, we explore whether the isotopic fingerprint of a potential late SN contribution to the formation site of 67P/CG in the solar nebula can be seen in the volatile component of 67P/CG. 相似文献