Space radiation impact on smallsats during maximum and minimum solar activity

2019 ◽  
Vol 64 (1) ◽  
pp. 239-251 ◽  
Author(s):  
Susan W. Samwel ◽  
Esraa A. El-Aziz ◽  
Henry B. Garrett ◽  
Ahmed A. Hady ◽  
Makram Ibrahim ◽  
...  
Keyword(s):  
Solar Activity ◽  
Space Radiation ◽  
Minimum Solar Activity

Seasonal behavior of H component during solar cycle 24

2021 ◽  
Author(s):  
Yasmina Bouderba ◽  
Ener Aganou ◽  
Abdenaceur Lemgharbi
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Horizontal Component ◽  
Low Latitude ◽  
Seasonal Behavior ◽  
The Earth ◽  
Earth Magnetic Field ◽  
Solar Cycle 24 ◽  
Minimum Solar Activity ◽  
Cycle 24

<p>In this work we will show the behavior of the horizontal component H of the Earth Magnetic Field (EMF) along the seasons during the period of solar cycle 24 lasting from 2009 to 2019. By means of  continuous measurements of geomagnetic components (X, Y) of the EMF, we compute the horizontal component H at the Earth’s surface. The data are recorded with a time resolution of one minute at Tamanrasset observatory in Algeria at the geographical coordinates of 22.79° North and 5.53° East. These data are available from the INTERMAGNET network. We find that the variation in amplitude of the hourly average of H component at low latitude changes from a season to another and it is greater at the maximum solar activity than at the minimum solar activity.</p><p><strong>Keywords:</strong> Solar cycle 24, Season, Horizontal component H. </p>

scholarly journals Exploring the role of ionospheric drivers during the extreme solar minimum of 2008

2013 ◽  
Vol 31 (12) ◽  
pp. 2147-2156 ◽  
Author(s):  
J. Klenzing ◽  
A. G. Burrell ◽  
R. A. Heelis ◽  
J. D. Huba ◽  
R. Pfaff ◽  
...  
Keyword(s):  
Solar Activity ◽  
Solar Minimum ◽  
Wind Model ◽  
Ion Density ◽  
Density Data ◽  
Early Afternoon ◽  
Minimum Solar Activity ◽  
Forecasting System ◽  
Electric Field Instrument

Abstract. During the recent solar minimum, solar activity reached the lowest levels observed during the space age, resulting in a contracted atmosphere. This extremely low solar activity provides an unprecedented opportunity to understand the variability of the Earth's ambient ionosphere. The average E × B drifts measured by the Vector Electric Field Instrument (VEFI) on the Communications/Navigation Outage Forecasting System (C/NOFS) satellite during this period are found to have several differences from the expected climatology based on previous solar minima, including downward drifts in the early afternoon and a weak to non-existent pre-reversal enhancement. Using SAMI2 (Sami2 is Another Model of the Ionosphere) as a computational engine, we investigate the effects of these electrodynamical changes as well as the contraction of the thermosphere and reduced EUV ionization on the ionosphere. The sensitivity of the simulations to wind models is also discussed. These modeled ionospheres are compared to the C/NOFS average topside ion density and composition and Formosa Satellite-3/Constellation Observing System for Meteorology, Ionosphere, and Climate average NmF2 and hmF2. In all cases, incorporating the VEFI drift data significantly improves the model results when compared to both the C/NOFS density data and the F3/C GOX data. Changing the MSIS and EUVAC models produced changes in magnitude, but not morphology with respect to local time. The choice of wind model modulates the resulting topside density and composition, but only the use of the VEFI E × B drifts produces the observed post-sunset drop in the F peak.

scholarly journals Integrity investigation of global ionospheric TEC maps for high-precision positioning

2021 ◽  
Vol 95 (3) ◽  
Author(s):  
Jiaojiao Zhao ◽  
Manuel Hernández-Pajares ◽  
Zishen Li ◽  
Ningbo Wang ◽  
Hong Yuan
Keyword(s):  
Solar Activity ◽  
Geomagnetic Storm ◽  
Precise Point Positioning ◽  
Electron Content ◽  
International Gnss Service ◽  
Total Electron ◽  
Ionospheric Total Electron Content ◽  
Actual Error ◽  
Minimum Solar Activity ◽  
Global Ionospheric Maps

AbstractAside from the ionospheric total electron content (TEC) information, root-mean-square (RMS) maps are also provided as the standard deviations of the corresponding TEC errors in global ionospheric maps (GIMs). As the RMS maps are commonly used as the accuracy indicator of GIMs to optimize the stochastic model of precise point positioning algorithms, it is of crucial importance to investigate the reliability of RMS maps involved in GIMs of different Ionospheric Associated Analysis Centers (IAACs) of the International GNSS Service (IGS), i.e., the integrity of GIMs. We indirectly analyzed the reliability of RMS maps by comparing the actual error of the differential STEC (dSTEC) with the RMS of the dSTEC derived from the RMS maps. With this method, the integrity of seven rapid IGS GIMs (UQRG, CORG, JPRG, WHRG, EHRG, EMRG, and IGRG) and six final GIMs (UPCG, CODG, JPLG, WHUG, ESAG and IGSG) was examined under the maximum and minimum solar activity conditions as well as the geomagnetic storm period. The results reveal that the reliability of the RMS maps is significantly different for the GIMs from different IAACs. Among these GIMs, the values in the RMS maps of UQRG are large, which can be used as ionospheric protection level, while the RMS values in EHRG and ESAG are significantly lower than the realistic RMS. The rapid and final GIMs from CODE, JPL and WHU provide quite reasonable RMS maps. The bounding performance of RMS maps can be influenced by the location of the stations, while the influence of solar activity and the geomagnetic storm is not obvious.

Forecasting Fire Risk in Forest Ecosystems Using Solar Activity Index

2021 ◽  
Vol 25 (12) ◽  
pp. 60-64
Author(s):  
T.E. Katkova
Keyword(s):  
Solar Activity ◽  
Forest Ecosystems ◽  
Activity Index ◽  
Fire Hazard ◽  
Fire Risk ◽  
Fire Frequency ◽  
Fire Dynamics ◽  
Minimum Solar Activity ◽  
Regional Forest

Improving forest ecosystems protection management based on a long-term fire hazard forecasting has been studied. Fires long-term dynamics in terms of quantity in various forests has been investigated. Fire risk patterns in forest ecosystems have been established conditional to regional characteristics due to solar period. Fire dynamics and solar periods analytics over multi-year period of time have brought to light that conditions contributing to a high fire frequency in Leningrad and Tver regional forest ecosystems arise in years with maximum and minimum solar activity. A long-term forecast of high forest fire danger periods for the next solar cycle has been performed through parameters of solar activity – Wolf numbers.

The Effect of Atmospheric Drag Force on the Elements of Low Earth Orbital Satellites at Minimum Solar Activity

2021 ◽  
Vol 19 (9) ◽  
pp. 24-37
Author(s):  
Najlaa Ozaar Hasan ◽  
Wafaa Hasan Ali Zaki ◽  
Ahmed Kader Izzet
Keyword(s):  
Solar Activity ◽  
Low Earth Orbit ◽  
Atmospheric Drag ◽  
Size Parameter ◽  
Mass Ratio ◽  
Orbital Elements ◽  
Unperturbed Motion ◽  
Minimum Solar Activity ◽  
Low Earth Orbit Satellites ◽  
The Impact

Researching and modeling perturbations is essential in astrodynamics because it gives information on the deviations from the satellite's normal, idealized, or unperturbed motion. Examined the impact of non-conservative atmospheric drag and orbital elements of low-earth-orbit satellites under low solar activity. The study is consisting of parts, the first looks at the effects of atmospheric drag on LEO satellites different area to mass ratios, and the second looks at different inclination values. Modeling the impacts of perturbation is included in each section, and the final portion determines the effects of atmospheric drag at various node values. The simulation was run using the Celestial Mechanics software system's SATORB module (Beutler, 2005), which solves the perturbation equations via numerical integration. The findings were examined using Matlab 2012. Conclusion that the impacts are stronger for retrograde orbits, which is due to the fact that the satellite moves in the opposite direction. The atmospheric drag effects for all orbital elements were increased by increasing the area to mass ratio. When the node value rises, the size parameter changes slightly, but the other orbital elements change. At varying inclinations, it is found that the changes in orbital elements due to atmospheric drug.

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