Forbush decreases are depressions in the galactic cosmic rays (GCRs) that are caused primarily by modulations of interplanetary coronal mass ejections (ICMEs) but also occasionally by stream/corotating interaction reg...Forbush decreases are depressions in the galactic cosmic rays (GCRs) that are caused primarily by modulations of interplanetary coronal mass ejections (ICMEs) but also occasionally by stream/corotating interaction regions (SIRs/CIRs). Forbush decreases have been studied extensively using neutron monitors at Earth;recently, for the first time, they have been measured on the surface of another planet, Mars, by the Radiation Assessment Detector (RAD) on board the Mars Science Laboratory’s (MSL) rover Curiosity. The modulation of GCR particles by heliospheric transients in space is energy-dependent;afterwards, these particles interact with the Martian atmosphere, the interaction process depending on particle type and energy. In order to use ground-measured Forbush decreases to study the space weather environment near Mars, it is important to understand and quantify the energy-dependent modulation of the GCR particles by not only the pass-by heliospheric disturbances but also by the Martian atmosphere. Accordingly, this study presents a model that quantifies both at the Martian surface and in the interplanetary space near Mars the amplitudes of Forbush decreases at Mars during the pass-by of an ICME/SIR by combining the heliospheric modulation of GCRs with the atmospheric modification of such modulated GCR spectra. The modeled results are in good agreement with measurements of Forbush decreases caused by ICMEs/SIRs based on data collected by MSL on the surface of Mars and by the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft in orbit. Our model and these findings support the validity of both the Forbush decrease description and Martian atmospheric transport models.展开更多
Used the ionization theory of the cosmic ray charged particles in the polar ionosphere, the influence of the cosmic ray Forbush decrease on the low ionosphere in the polar region is studied in this paper. The relation...Used the ionization theory of the cosmic ray charged particles in the polar ionosphere, the influence of the cosmic ray Forbush decrease on the low ionosphere in the polar region is studied in this paper. The relationship between the Forbush decrease and the cosmic noise absorption during the polar night is analysed based on the data recorded by a Riometer at Antarctic Zhongshan Station (69° 22'24'S, 76°22'40'E). The relation of between the cosmic ray Forbush decrease and the cosmic noise absorption is well interpreted by means of the ionizaiotn theory.展开更多
The objective of this research is to investigate the effects of cosmic ray Forbush Decreases (FDs) exceeding 7% in magnitude, occurring between 1985 and 2016, on upper atmospheric pressure and temperature at Abha and ...The objective of this research is to investigate the effects of cosmic ray Forbush Decreases (FDs) exceeding 7% in magnitude, occurring between 1985 and 2016, on upper atmospheric pressure and temperature at Abha and Tabouk. Employing the super epoch analysis method, the study concentrated on altitudes of 5 km and 10 km, uncovering significant variations. Seasonal and synoptic-scale variations were considered and excluded when necessary across eight 9-day periods. Both locations showed considerable fluctuations in pressure and temperature before and after the events. At 5 km altitude (21 events), Abha experienced more pressure increases both before (9 vs. 7) and after (12 vs. 11) the events compared to Tabouk. For temperature, Abha recorded more increases before the events (5 vs. 1), while Tabouk showed more decreases (19 vs. 15). Post-event, Tabouk had more temperature increases (13 vs. 10). At 10 km altitude (20 events), both regions experienced more decreases than increases in pressure and temperature before the events and more increases afterward. Notably, Abha experienced more pressure increases both 4 days before (9 vs. 7) and after the events (12 vs. 11) than Tabouk. For temperature, Abha recorded more increases before the events (5 vs. 1), while Tabouk showed more decreases (19 vs. 15). Post-event, Tabouk had more temperature increases (13 vs. 10). These findings underscore both similarities and differences in atmospheric responses to FDs between Abha and Tabouk. Both locations exhibited cooling trends before and warming trends after the events, with Tabouk demonstrating a more pronounced warming trend post-event. These results enhance our understanding of the atmospheric dynamics linked to FDs and assist in predicting weather patterns associated with these phenomena.展开更多
IP核的测试时间与其加载测试封装后的最大输入/输出扫描链长度有直接关系,为了降低测试成本,减少测试时间,必须对IP核内的扫描链进行平衡设计.最为经典的扫描链平衡方法是BFD(Best Fit Decrease)方法,它具有实现简单、算法复杂度低等优...IP核的测试时间与其加载测试封装后的最大输入/输出扫描链长度有直接关系,为了降低测试成本,减少测试时间,必须对IP核内的扫描链进行平衡设计.最为经典的扫描链平衡方法是BFD(Best Fit Decrease)方法,它具有实现简单、算法复杂度低等优点,但是其分配的结果尚有待提高之处.本文提出一种基于差值的二次分配的扫描链平衡方法,其主要思想是选择IP核内部的某一条扫描链作为基准扫描链,将其长度记为L,将所有长度超过L的扫描链与之做差,并将差值记为di.在第一次分配中,只将长度大于L的扫描链按照长度为L的基准扫描链进行分配;然后将长度小于L的扫描链与差值di重新排序后,按照从大到小的顺序,依次将其放置在可以放置的最小的测试封装扫描链上进行第二次分配.该方法简单易实现,通过在ITC’02 SOC标准测试集上实验,数据表明,基于差值二次分配的扫描链平衡方法与现有方法相比,能得到更好的平衡结果.展开更多
A cosmic-ray muon telescope the telescope was built in the Zhongshan has been collecting data since the end Station of Antarctica. The telescope of 2014, which was shortly after is the first observation device to be b...A cosmic-ray muon telescope the telescope was built in the Zhongshan has been collecting data since the end Station of Antarctica. The telescope of 2014, which was shortly after is the first observation device to be built by Chinese scientists in Antarctica. The pressure change is very strong in Zhongshan station. The count rate of the pressure correction results shows that the large variations in the count rate are likely caused by pressure fluctuations. During the period from 18 June to 22 June 2015, four halo coronal mass ejections （CMEs） were ejected from the Sun. These CMEs initiated a series of Forbush decreases （FD） when they reached the Earth. We conducted a comprehensive study of the intensity fluctuations of galactic cosmic rays recorded during FDs. The intensity fluctuations used in this study were collected by cosmic ray detectors of multiple stations （Zhongshan, McMurdo, South Polar, and Nagoya）, and the solar wind measurements were collected by ACE and WIND. The profile of the FD of 22 June demonstrated a four-step decrease. The traditional one- or two-step FD classification method does not adequately explain the FD profile results. The interaction between the faster CME that occurred on 21 June 2015 and the two slow CMEs of the earlier few days should be considered. The cosmic ray intensities of the South Pole, McMurdo, and Zhongshan stations have similar hourly variations, whereas the galactic cosmic rays recorded between polar and non-polar locations are distinct. The FD pre-increase of 22 June 2015 for the Nagoya ninon telescope （non-polar location） lags those of the McMurdo and Zhongshan stations （polar locations） by 1 h. The FD onset of 22 June 2015 for the Nagoya muon telescope lags those of the polar locations by 1 h.展开更多
Major solar flare events have been utilised to study the latitudinal frequency distribution of solar flares in northern and southern hemispheres for the period of 1986 to 2003. A statistical analysis has been performe...Major solar flare events have been utilised to study the latitudinal frequency distribution of solar flares in northern and southern hemispheres for the period of 1986 to 2003. A statistical analysis has been performed to obtain the correlation between Coronal Mass Ejections (CMEs) and Forbush decrease (Fds) of cosmic ray intensity. Almost the same flares distribution in both hemispheres is found in association with CMEs. In a further analysis, it is noted that a larger number of CME-associated solar flares located in the northern hemisphere are found to be more effective in producing Forbush decreases.展开更多
The Earth is continually exposed to the cosmic radiation of both solar and galactic origin. Solar eruption and solar ac- tivity may affect cosmic radiation flux density which has a secondary effect on the flux of part...The Earth is continually exposed to the cosmic radiation of both solar and galactic origin. Solar eruption and solar ac- tivity may affect cosmic radiation flux density which has a secondary effect on the flux of particles in the atmosphere as well. Such one event was recorded in the last week of October 2003, where the measured dose rate of the cosmic radia- tion in the aircraft ATR 42 was 1.8 times higher than the average value of the other measurements. Later we found the data on an unusual solar activity in the mentioned time interval. Analysis of the increasing solar proton flux during the solar flare, as well as the decreasing neutron flux in the atmosphere (representing the galactic radiation), on May 14 and 15, 2005, showed a nonlinear correlation with the exponential equation of regression;this one described galactic ray modulation by solar flux during the short term variation of cosmic radiation.展开更多
基金supported by the Strategic Priority Program of the Chinese Academy of Sciences (Grant No.XDB41000000 and XDA15017300)the Key Research Program of the Chinese Academy of Sciences (Grant No.XDPB11 and QYZDBSSW-DQC015)+3 种基金the CNSA pre-research Project on Civil Aerospace Technologies (Grant No.D020104)National Natural Science Foundation of China (Grant No.41842037)the German Aerospace Center (DLR) and DLR’s Space Administration grants 50QM0501, 50QM1201 and 50QM1701support by the Croatian Science Foundation under the project 7549 (MSOC) and EUH2020 grant agreement No 824135 (project SOLARNET)
文摘Forbush decreases are depressions in the galactic cosmic rays (GCRs) that are caused primarily by modulations of interplanetary coronal mass ejections (ICMEs) but also occasionally by stream/corotating interaction regions (SIRs/CIRs). Forbush decreases have been studied extensively using neutron monitors at Earth;recently, for the first time, they have been measured on the surface of another planet, Mars, by the Radiation Assessment Detector (RAD) on board the Mars Science Laboratory’s (MSL) rover Curiosity. The modulation of GCR particles by heliospheric transients in space is energy-dependent;afterwards, these particles interact with the Martian atmosphere, the interaction process depending on particle type and energy. In order to use ground-measured Forbush decreases to study the space weather environment near Mars, it is important to understand and quantify the energy-dependent modulation of the GCR particles by not only the pass-by heliospheric disturbances but also by the Martian atmosphere. Accordingly, this study presents a model that quantifies both at the Martian surface and in the interplanetary space near Mars the amplitudes of Forbush decreases at Mars during the pass-by of an ICME/SIR by combining the heliospheric modulation of GCRs with the atmospheric modification of such modulated GCR spectra. The modeled results are in good agreement with measurements of Forbush decreases caused by ICMEs/SIRs based on data collected by MSL on the surface of Mars and by the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft in orbit. Our model and these findings support the validity of both the Forbush decrease description and Martian atmospheric transport models.
文摘Used the ionization theory of the cosmic ray charged particles in the polar ionosphere, the influence of the cosmic ray Forbush decrease on the low ionosphere in the polar region is studied in this paper. The relationship between the Forbush decrease and the cosmic noise absorption during the polar night is analysed based on the data recorded by a Riometer at Antarctic Zhongshan Station (69° 22'24'S, 76°22'40'E). The relation of between the cosmic ray Forbush decrease and the cosmic noise absorption is well interpreted by means of the ionizaiotn theory.
文摘The objective of this research is to investigate the effects of cosmic ray Forbush Decreases (FDs) exceeding 7% in magnitude, occurring between 1985 and 2016, on upper atmospheric pressure and temperature at Abha and Tabouk. Employing the super epoch analysis method, the study concentrated on altitudes of 5 km and 10 km, uncovering significant variations. Seasonal and synoptic-scale variations were considered and excluded when necessary across eight 9-day periods. Both locations showed considerable fluctuations in pressure and temperature before and after the events. At 5 km altitude (21 events), Abha experienced more pressure increases both before (9 vs. 7) and after (12 vs. 11) the events compared to Tabouk. For temperature, Abha recorded more increases before the events (5 vs. 1), while Tabouk showed more decreases (19 vs. 15). Post-event, Tabouk had more temperature increases (13 vs. 10). At 10 km altitude (20 events), both regions experienced more decreases than increases in pressure and temperature before the events and more increases afterward. Notably, Abha experienced more pressure increases both 4 days before (9 vs. 7) and after the events (12 vs. 11) than Tabouk. For temperature, Abha recorded more increases before the events (5 vs. 1), while Tabouk showed more decreases (19 vs. 15). Post-event, Tabouk had more temperature increases (13 vs. 10). These findings underscore both similarities and differences in atmospheric responses to FDs between Abha and Tabouk. Both locations exhibited cooling trends before and warming trends after the events, with Tabouk demonstrating a more pronounced warming trend post-event. These results enhance our understanding of the atmospheric dynamics linked to FDs and assist in predicting weather patterns associated with these phenomena.
文摘IP核的测试时间与其加载测试封装后的最大输入/输出扫描链长度有直接关系,为了降低测试成本,减少测试时间,必须对IP核内的扫描链进行平衡设计.最为经典的扫描链平衡方法是BFD(Best Fit Decrease)方法,它具有实现简单、算法复杂度低等优点,但是其分配的结果尚有待提高之处.本文提出一种基于差值的二次分配的扫描链平衡方法,其主要思想是选择IP核内部的某一条扫描链作为基准扫描链,将其长度记为L,将所有长度超过L的扫描链与之做差,并将差值记为di.在第一次分配中,只将长度大于L的扫描链按照长度为L的基准扫描链进行分配;然后将长度小于L的扫描链与差值di重新排序后,按照从大到小的顺序,依次将其放置在可以放置的最小的测试封装扫描链上进行第二次分配.该方法简单易实现,通过在ITC’02 SOC标准测试集上实验,数据表明,基于差值二次分配的扫描链平衡方法与现有方法相比,能得到更好的平衡结果.
文摘A cosmic-ray muon telescope the telescope was built in the Zhongshan has been collecting data since the end Station of Antarctica. The telescope of 2014, which was shortly after is the first observation device to be built by Chinese scientists in Antarctica. The pressure change is very strong in Zhongshan station. The count rate of the pressure correction results shows that the large variations in the count rate are likely caused by pressure fluctuations. During the period from 18 June to 22 June 2015, four halo coronal mass ejections （CMEs） were ejected from the Sun. These CMEs initiated a series of Forbush decreases （FD） when they reached the Earth. We conducted a comprehensive study of the intensity fluctuations of galactic cosmic rays recorded during FDs. The intensity fluctuations used in this study were collected by cosmic ray detectors of multiple stations （Zhongshan, McMurdo, South Polar, and Nagoya）, and the solar wind measurements were collected by ACE and WIND. The profile of the FD of 22 June demonstrated a four-step decrease. The traditional one- or two-step FD classification method does not adequately explain the FD profile results. The interaction between the faster CME that occurred on 21 June 2015 and the two slow CMEs of the earlier few days should be considered. The cosmic ray intensities of the South Pole, McMurdo, and Zhongshan stations have similar hourly variations, whereas the galactic cosmic rays recorded between polar and non-polar locations are distinct. The FD pre-increase of 22 June 2015 for the Nagoya ninon telescope （non-polar location） lags those of the McMurdo and Zhongshan stations （polar locations） by 1 h. The FD onset of 22 June 2015 for the Nagoya muon telescope lags those of the polar locations by 1 h.
文摘Major solar flare events have been utilised to study the latitudinal frequency distribution of solar flares in northern and southern hemispheres for the period of 1986 to 2003. A statistical analysis has been performed to obtain the correlation between Coronal Mass Ejections (CMEs) and Forbush decrease (Fds) of cosmic ray intensity. Almost the same flares distribution in both hemispheres is found in association with CMEs. In a further analysis, it is noted that a larger number of CME-associated solar flares located in the northern hemisphere are found to be more effective in producing Forbush decreases.
文摘The Earth is continually exposed to the cosmic radiation of both solar and galactic origin. Solar eruption and solar ac- tivity may affect cosmic radiation flux density which has a secondary effect on the flux of particles in the atmosphere as well. Such one event was recorded in the last week of October 2003, where the measured dose rate of the cosmic radia- tion in the aircraft ATR 42 was 1.8 times higher than the average value of the other measurements. Later we found the data on an unusual solar activity in the mentioned time interval. Analysis of the increasing solar proton flux during the solar flare, as well as the decreasing neutron flux in the atmosphere (representing the galactic radiation), on May 14 and 15, 2005, showed a nonlinear correlation with the exponential equation of regression;this one described galactic ray modulation by solar flux during the short term variation of cosmic radiation.
