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151.
The world's first political summit on Earth observation was attended by senior policy makers and expert organizations from a range of scientific disciplines. Its aim was to improve global cooperation in Earth observation and increase its use as a decision-making tool for sustainable development and resource conservation. This article presents a brief survey of the progress made in Earth observation since its birth, along with the specific events driving the convening of the summit. The summit produced a declaration outlining four key areas requiring support, and an ad hoc group was established to produce a 10-year plan and drive implementation of policy. 相似文献
152.
Marina M. Romanova Akshay Kulkarni Min Long Richard V.E. Lovelace Justin V. Wick Galina V. Ustyugova Alexander V. Koldoba 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2006,38(12):2887-2892
We performed 2D and full 3D magnetohydrodynamic simulations of disk accretion to a rotating star with an aligned or misaligned dipole magnetic field. We investigated the rotational equilibrium state and derived from simulations the ratio between two main frequencies: the spin frequency of the star and the orbital frequency at the inner radius of the disk. In 3D simulations we observed different features related to the non-axisymmetry of the magnetospheric flow. These features may be responsible for high-frequency quasi-periodic oscillations (QPOs). Variability at much lower frequencies may be connected with restructuring of the magnetic flux threading the inner regions of the disk. Such variability is specifically strong at the propeller stage of evolution. 相似文献
153.
The transition from research to operations in Earth observation: the case of NASA and NOAA in the US
That basic scientific research often leads to new insights, concepts, and inventions that can have important practical applications and benefits is an established element of the rationale for federal government investment in research and technology. The way in which scientific studies of the Earth from space make their way into practical approaches to environmental measurements and management presents an enlightening case study of the research-to-applications transfer process. This article discusses how fundamental concepts of technology transfer and diffusion are illustrated in the process of transitioning Earth science research into operations at the US National Aeronautics and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA), particularly as it is presented in the National Research Council study, Satellite Observations of the Earth's Environment: Accelerating the Transition of Research to Operations. The authors assert that successful and efficient transitions of this type require not only a detailed understanding of the technologies involved but an appropriately developed social structure to better facilitate those transitions. 相似文献
154.
Following on from IRAS, ISO has provided a huge advancement in our knowledge of the phenomenology of the infrared (IR) emission
of normal galaxies and the underlying physical processes. Highlights include the discovery of an extended cold dust emission
component, present in all types of gas-rich galaxies and carrying the bulk of the dust luminosity; the definitive characterisation
of the spectral energy distribution in the IR, revealing the channels through which stars power the IR light; the derivation
of realistic geometries for stars and dust from ISO imaging; the discovery of cold dust associated with H I extending beyond the optical body of galaxies; the remarkable similarity of the near-IR (NIR)/mid-IR (MIR) SEDs for spiral
galaxies, revealing the importance of the photo-dissociation regions in the energy budget for that wavelength range; the importance
of the emission from the central regions in shaping up the intensity and the colour of the global MIR luminosity; the discovery
of the “hot” NIR continuum emission component of interstellar dust; the predominance of the diffuse cold neutral medium as
the origin for the main interstellar cooling line, [C II] 158 μm, in normal galaxies.
Based on observations with ISO, an ESA project with instruments funded by ESA Member States (especially the PI countries:
France, Germany, The Netherlands, and the United Kingdom), and with the participation of ISAS and NASA. 相似文献
155.
156.
157.
A review of global satellite-derived snow products 总被引:1,自引:0,他引:1
Allan Frei Marco Tedesco Shihyan Lee James Foster Dorothy K. Hall Richard Kelly David A. Robinson 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
Snow cover over the Northern Hemisphere plays a crucial role in the Earth’s hydrology and surface energy balance, and modulates feedbacks that control variations of global climate. While many of these variations are associated with exchanges of energy and mass between the land surface and the atmosphere, other expected changes are likely to propagate downstream and affect oceanic processes in coastal zones. For example, a large component of the freshwater flux into the Arctic Ocean comes from snow melt. The timing and magnitude of this flux affects biological and thermodynamic processes in the Arctic Ocean, and potentially across the globe through their impact on North Atlantic Deep Water formation. 相似文献
158.
Y. Le Coq J.A. Retter S. Richard A. Aspect P. Bouyer 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
We analyze the advantages of using ultra-cold coherent sources of atoms for matter-wave interferometry in space. We present a proof-of-principle experiment that is based on an analysis of the results previously published in Richard et al. (2003) from which we extract the ratio h/m for 87Rb. This measurement shows that a limitation in accuracy arises due to atomic interactions within the Bose–Einstein condensate. Finally we discuss the promising role of coherent-matter-wave sensors, in particular inertial sensors, in future fundamental physics missions in space. 相似文献
159.
Mioara Mandea Richard Holme Alexandra Pais Katia Pinheiro Andrew Jackson Giuliana Verbanac 《Space Science Reviews》2010,155(1-4):147-175
The secular variation of the core field is generally characterized by smooth variations, sometimes interrupted by abrupt changes, named geomagnetic jerks. The origin of these events, observed and investigated for over three decades, is still not fully understood. Many fundamental features of geomagnetic jerks have been the subject of debate, including their origin internal or external to the Earth, their occurrence dates, their duration and their global or regional character. Specific tools have been developed to detect them in geomagnetic field or secular variation time series. Recently, their investigation has been advanced by the availability of a decade of high-quality satellite measurements. Moreover, advances in the modelling of the core field and its variations have brought new perspectives on the fluid motion at the top of the core, and opened new avenues in our search for the origin of geomagnetic jerks. Correlations have been proposed between geomagnetic jerks and some other geophysical observables, indicating the substantial interest in this topic in our scientific community. This paper summarizes the recent advances in our understanding and interpretation of geomagnetic jerks. 相似文献
160.