共查询到20条相似文献,搜索用时 31 毫秒
1.
K. N. Iyer R. M. Jadav A. K. Jadeja P. K. Manoharan Som Sharma Hari Om Vats 《Journal of Astrophysics and Astronomy》2006,27(2-3):219-226
This paper describes the space weather effects of a major CME which was accompanied by extremely violent events on the Sun.
The signatures of the event in the interplanetary medium (IPM) sensed by Ooty Radio Telescope, the solar observations by LASCO
coronagraph onboard SOHO, GOES X-ray measurements, satellite measurements of the interplanetary parameters, GPS based ionospheric
measurements, the geomagnetic storm parameter Dst and ground based ionosonde data are used in the study to understand the
space weather effects in the different regions of the solar-terrestrial environment. The effects of this event are compared
and possible explanations attempted. 相似文献
2.
Cui-Lian Zhu Jia-Long WangNational Astronomical Observatories Chinese Academy of Sciences Beijing 《中国天文和天体物理学报》2003,3(6):563-568
We present a verification of the short-term predictions of solar Xray bursts for the maximum phase (2000-2001) of Solar Cycle 23, issued by two prediction centers. The results are that the rate of correct predictions is about equal for RWC-China and WWA; the rate of too high predictions is greater for RWC-China than for WWA, while the rate of too low predictions is smaller for RWC-China than for WWA. 相似文献
3.
P. Vanlommel P. Cugnon R. A. M. Van Der Linden D. Berghmans F. Clette 《Solar physics》2004,224(1-2):113-120
Since January 1981, the Royal Observatory of Belgium (ROB) has operated the Sunspot Index Data Center (SIDC), the World Data
Center for the Sunspot Index. From 2000, the SIDC obtained the status of Regional Warning Center (RWC) of the International
Space Environment Service (ISES) and became the “Solar Influences Data analysis Center”. As a data analysis service of the
Federation of Astronomical and Geophysical data analysis Services (FAGS), the SIDC collects monthly observations from worldwide
stations in order to calculate the International Sunspot Number, R
i
. The center broadcasts the daily, monthly, yearly sunspot numbers, with middle-range predictions (up to 12 months). Since
August 1992, hemispheric sunspot numbers are also provided.
Deceased. 相似文献
4.
The organization and activities of the international initiative named Electronic Geophysical Year (eGY), promoted by the International Union for Geodesy and Geophysics (IUGG) are outlined as synergetic to the other initiatives as the International Heliophysical Year (IHY). 相似文献
5.
Life In Space: An Introduction To Space Life Sciences And The International Space Station 总被引:1,自引:0,他引:1
The impact of the space environment upon living organisms is profound. Its effects range from alterations in sub-cellular
processes to changes in the structure and function of whole organ systems. As the number of astronaut and cosmonaut crews
flown in space has grown, so to has our understanding of the effects of the space environment upon biological systems. There
are many parallels between the physiology of space flight and terrestrial disease processes, and the response of astronaut
crews themselves to long-duration space deployment is therefore of central interest.
In the next 15 years the International Space Station (ISS) will serve as a permanently manned dedicated life and physical
sciences platform for the further investigation of these phenomena. The European Space Agency's Columbus module will hold
the bulk of the ISS life science capability and, in combination with NASA's Human Research Facility (HRF) will accommodate
the rack mounted experimental apparatus. The programme of experimentation will include efforts in fundamental biology, human
physiology, behavioural science and space biomedical research.
In the four decades since Yuri Gagarin first orbited the Earth, space life science has emerged as a field of study in its
own right. The ISS takes us into the next era of human space exploration, and it is hoped that its programme of research will
yield new insights, novel therapeutic interventions, and improved biotechnology for terrestrial application.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
6.
Space VLBI is a new observing technique which will be available in the second half of this decade by radio telescopes as interferometer elements in orbit. Besides the main astronomical interests, this new development has some very interesting potential applications in satellite dynamics, geodesy and geodynamical research which qualify space VLBI a potential new technique in space geodesy. A geodesy demostration experiment (GEDEX) is being proposed for the Japanese space VLBI satellite-VSOP, with the main objectives of reference frame interconnections and orbit accuracy improvement of the space radio telescope. The paper gives a review of the special characteristics of space VLBI and a general background of the GEDEX proposal. 相似文献
7.
Halo coronal mass ejections (HCMEs) are responsible of the most severe geomagnetic storms. A prediction of their geoeffectiveness
and travel time to Earth’s vicinity is crucial to forecast space weather. Unfortunately, coronagraphic observations are subjected
to projection effects and do not provide true characteristics of CMEs. Recently, Michalek (Solar Phys.
237, 101, 2006) developed an asymmetric cone model to obtain the space speed, width, and source location of HCMEs. We applied this technique
to obtain the parameters of all front-sided HCMEs observed by the SOHO/LASCO experiment during a period from the beginning
of 2001 until the end of 2002 (solar cycle 23). These parameters were applied for space weather forecasting. Our study finds
that the space speeds are strongly correlated with the travel times of HCMEs to Earth’s vicinity and with the magnitudes related
to geomagnetic disturbances. 相似文献
8.
It is generally appreciated that the September 1859 solar–terrestrial disturbance, the first recognized space weather event, was exceptionally large. How large and how exceptional? To answer these questions, we compiled rank order lists of the various measures of solar-induced disturbance for events from 1859 to the present. The parameters considered included: magnetic crochet amplitude, solar energetic proton fluence (McCracken et al., 2001a), Sun–Earth disturbance transit time, geomagnetic storm intensity, and low-latitude auroral extent. While the 1859 event has close rivals or superiors in each of the above categories of space weather activity, it is the only documented event of the last ~150 years that appears at or near the top of all of the lists. Taken together, the top-ranking events in each of the disturbance categories comprise a set of benchmarks for extreme space weather activity. 相似文献
9.
《Chinese Astronomy and Astrophysics》2023,47(2):376-390
The United States provide Element Sets (ELSET) database in Two-Line Element (TLE) format for public use, which plays an important role in the inversion of atmospheric density in the thermosphere, ballistic coefficient estimation, early-warning and so on. Due to large uncertainties existing in the TLE generation process, space environment changes, and space events, ELSET database contains a large number of abnormal TLE data to be filtered, such as corrected TLE, orbital element outlier, and Bstar outlier. The existing methods to filter out the outliers lack general applicability and are very complicated, which are only applicable to a few space targets in certain orbit regions. To overcome the shortcomings of the existing methods, a filtering method is proposed based on Expectation Maximization (EM) algorithm employing a sliding window and polynomial fitting method, which can detect outliers for different orbital elements and space events. The research shows that the algorithm can effectively single out the outliers in TLE sequences and is suitable for all orbital debris. 相似文献
10.
Masoud Mirmomeni Caro Lucas Babak Nadjar Araabi Behzad Moshiri Mohammad Reza Bidar 《Solar physics》2011,272(1):189-213
The time-varying Sun as the main source of space weather affects the Earth??s magnetosphere by emitting hot magnetized plasma in the form of solar wind into interplanetary space. Solar and geomagnetic activity indices and their chaotic characteristics vary abruptly during solar and geomagnetic storms. This variation depicts the difficulties in modeling and long-term prediction of solar and geomagnetic storms. On the other hand, the combination of neurofuzzy models and spectral analysis has been a subject of interest due to their many practical applications in modeling and predicting complex phenomena. However, these approaches should be trained by algorithms that need to be carried out by an offline data set, which influences their performance in online modeling and prediction of time-varying phenomena. This paper proposes an adaptive approach for multi-step ahead prediction of space weather indices by extending the regular singular spectrum analysis and locally linear neurofuzzy models to adaptive approaches. The combination of these recursive approaches fulfills requirements of long-term prediction of solar and geomagnetic activity indices. The results demonstrate the power of the proposed method in online prediction of space weather indices. 相似文献
11.
Chenxi Du Xianzhi Ao Bingxian Luo Jingjing Wang Chong Chen Xin Xiong Xin Wang Gang Li 《天文和天体物理学研究(英文版)》2022,(2):29-44
The solar energetic particle(SEP)event is a kind of hazardous space weather phenomena,so its quantitative forecast is of great importance from the aspect of spa... 相似文献
12.
Badruddin 《Journal of Astrophysics and Astronomy》2006,27(2-3):209-217
We discuss the effects of certain dynamic features of space environment in the heliosphere, the geo-magnetosphere, and the
earth’s atmosphere. In particular, transient perturbations in solar wind plasma, interplanetary magnetic field, and energetic
charged particle (cosmic ray) fluxes near 1 AU in the heliosphere have been discussed. Transient variations in magnetic activity
in geo-magnetosphere and solar modulation effects in the heliosphere have also been studied. Emphasis is on certain features
of transient perturbations related to space weather effects. Relationships between geomagnetic storms and transient modulations
in cosmic ray intensity (Forbush decreases), especially those caused by shock-associated interplanetary disturbances, have
been studied in detail. We have analysed the cosmic ray, geomagnetic and interplanetary plasma/field data to understand the
physical mechanisms of two phenomena namely, Forbush decrease and geomagnetic storms, and to search for precursors to Forbush
decrease (and geomagnetic storms) that can be used as a signature to forecast space weather. It is shown that the use of cosmic
ray records has practical application for space weather predictions. Enhanced diurnal anisotropy and intensity deficit of
cosmic rays have been identified as precursors to Forbush decreases in cosmic ray intensity. It is found that precursor to
smaller (less than 5%) amplitude Forbush decrease due to weaker interplanetary shock is enhanced diurnal anisotropy. However,
larger amplitude (greater than 5%) Forbush decrease due to stronger interplanetary shock shows loss cone type intensity deficit
as precursor in ground based intensity record. These precursors can be used as inputs for space weather forecast. 相似文献
13.
P. K. Manoharan C. R. Subrahmanya J. N. Chengalur 《Journal of Astrophysics and Astronomy》2017,38(1):16
In this paper, we review the results of interplanetary scintillation (IPS) observations made with the legacy system of the Ooty Radio Telescope (ORT) and compare them with the possibilities opened by the upgraded ORT, the Ooty Wide Field Array (OWFA). The stability and the sensitivity of the legacy system of ORT allowed the regular monitoring of IPS on a grid of large number of radio sources and the results of these studies have been useful to understand the physical processes in the heliosphere and space weather events, such as coronal mass ejections, interaction regions and their propagation effects. In the case of OWFA, its wide bandwidth of 38 MHz, the large field-of-view of ~27° and increased sensitivity provide a unique capability for the heliospheric science at 326.5 MHz. IPS observations with the OWFA would allow one to monitor more than 5000 sources per day. This, in turn, will lead to much improved studies of space weather events and solar wind plasma, overcoming the limitations faced with the legacy system. We also highlight some of the specific aspects of the OWFA, potentially relevant for the studies of coronal plasma and its turbulence characteristics. 相似文献
14.
A possibility for using the promising multipurpose Arktika space system for the development and support of situational awareness of Arctic weather and ice conditions based on the network-centric principle is considered. This possibility became a reality when the analysis of synoptic conditions using remote sensing tools progressed from theoretical to practical use. 相似文献
15.
C. Plainaki A. Milillo A. Mura A.M. Di Lellis M.E. Palumbo 《Planetary and Space Science》2009,57(3):384-392
The ion-sputtering (IS) process is active in many planetary environments in the solar system where plasma precipitates directly on the surface (for instance, Mercury, Moon and Europa). In particular, solar wind sputtering is one of the most important agents for the surface erosion of a near-Earth object (NEO), acting together with other surface release processes, such as photon stimulated desorption (PSD), thermal desorption (TD) and micrometeoroid impact vaporization (MIV). The energy distribution of the IS-released neutrals peaks at a few eVs and extends up to hundreds of eVs. Since all other release processes produce particles of lower energies, the presence of neutral atoms in the energy range above 10 eV and below a few keVs (sputtered high-energy atoms (SHEA)) identifies the IS process. SHEA easily escape from the NEO, due to NEO's extremely weak gravity. Detection and analysis of SHEA will give important information on surface-loss processes as well as on surface elemental composition. The investigation of the active release processes, as a function of the external conditions and the NEO surface properties, is crucial for obtaining a clear view of the body's present loss rate as well as for getting clues on its evolution, which depends significantly on space weather.In this work, an attempt to analyze processes that take place on the surface of these small airless bodies, as a result of their exposure to the space environment, has been realized. For this reason, a new space weathering model (space weathering on NEO-SPAWN) is presented. Moreover, an instrument concept of a neutral-particle analyzer specifically designed for the measurement of neutral density and the detection of SHEA from a NEO is proposed. 相似文献
16.
17.
Yue-hua Ma You-wen He Pin-xin Xu Hai-bin Zhao 《Chinese Astronomy and Astrophysics》2008,32(2):186-196
During the first international joint observation of the Leo strong meteor shower, multidisciplinary and multi-media synthetic observation of Leo and Draco strong meteor showers and their catastrophic space weather events were carried out. The comprehensive analysis of the observed and related data of the Leo, Perseus and Draco strong meteor showers obtained for near half a century (from 1957 to 2003) fully verifies that the non-sporadic periodic strong meteor shower may lead to catastrophic space weather events. Preliminary identification is made of the following: the mechanism of formation of strong meteor showers, the law of occurrence of the fbEs abnormal peak and serious safety hazards for astronavigation. Also discussed in this paper are the evolutionary process of cometary dust, the law of occurrence and loss of cosmic dust storm and the mechanism of maintaining cosmic dust in the mid-latitude Es layer. 相似文献
18.
W. H. Jefferys G. F. Benedict P. D. Hemenway P. J. Shelus R. L. Duncombe 《Celestial Mechanics and Dynamical Astronomy》1985,37(3):299-305
The Hubble Space Telescope (HST), a large optical telescope having an aperture of 2.4 meters and a length of 8.8 meters, is being developed by the National Aeronautics and Space Administration. This telescope will be placed into earth orbit by the space shuttle. Astrometric observations with the HST are made using a Fine Guidance Sensor which is capable of measuring the position of one object relative to another with an accuracy of ±0.002 arcseconds. The astrometric user of HST will be provided with an Astrometric Data Reduction Software package (ADRS). The variety of astrometric problems to be investigated with HST is discussed. 相似文献
19.
Michael J. Gaffey 《Icarus》2010,209(2):564-574
Lunar-style space weathering is well understood, but cannot be extended to asteroids in general. The two best studied Asteroids (433 Eros and 243 Ida) exhibit quite different space weathering styles, and neither exhibits lunar-style space weathering. It must be concluded that at this time the diversity and mechanisms of asteroid space weathering are poorly understood. This introduces a significant unconstrained variable into the problem of analyzing asteroid spectral data. The sensitivity of asteroid surface material characterizations to space weathering effects - whatever their nature - is strongly dependent upon the choice of remote sensing methodology. The effects of space weathering on some methodologies such as curve matching are potentially devastating and at the present time essentially unmitigated. On other methodologies such as parametric analysis (e.g., analyses based on band centers and band area ratios) the effects are minimal. By choosing the appropriate methodology(ies) applied to high quality spectral data, robust characterizations of asteroid surface mineralogy can be obtained almost irrespective of space weathering. This permits sophisticated assessments of the geologic history of the asteroid parent bodies and of their relationships to the meteorites. Investigations of the diversity of space weathering processes on asteroid surfaces should be a fruitful area for future efforts. 相似文献