Particle Precipitation

The particles precipitating from the magnetosphere into the ionosphere during space weather events are mainly electrons with energies of a few keV. They are spiralling around the geomagnetic field lines and interact with neutrals and ions by collisions. Neutrals are ionised by these collisions and the ion production as a function of particle energy and altitude can be described with the relation Fig. 2. Flow chart of space weather effects in the ionosphere and atmosphere. Fig. 2. Flow chart of...

Magnetic Storms

Large solar flares or CME's lead to strong perturbations of the terrestrial magnetosphere for long periods of time (days). Typically the dynamic solar wind pressure is strongly enhanced for many hours leading to a considerable compression of the entire magnetosphere. The effects of a CME can be amplified if in addition the IMF is very large and southward. In this cases it is possible to have several substorms over the course of a magnetic storm. Typically electric fields in the magnetosphere...

Phr

Closed magnetic boundary, there is no plasma flow across the boundary, and the total pressure is balanced p + Bf (2 ,0) _ 0. For the rotational discontinuity the normal magnetic field is nonzero such that the geomagnetic field is connected to the IMF. In the deHoffmann-Teller frame (E _ v x B _ 0 or v B) the velocity normal to the discontinuity satisfies un _ u n with UAn _ Bn p0p. Other important relations for the rotational discontinuity are Btd _ Btu Pd _ Pu and ut _ vAt where the last...

Info

Schematic representation of the main auroral forms as a function of local time for latitudes > 60 . The shaded area characterises diffuse aurora, the thick line a quiet arc which transforms into folded bands after about 21 00 LT. In the morning hours patchy aurora can often be found at the southern rim of the auroral oval. The short thin lines around local noon at about 75 latitude are daylight aurora (Akasofu, 1970 1 ). Fig. 17. Four auroral displays with different colours and...

IphVsIa Vsisvs ItVs

When equilibrium has been reached, the satellite surface potential Vs has a value giving the total current It 0. In (1), Ie and Ii are the currents due to incident plasma electrons and ions, respectively. Since the density and kinetic energy of electrons and positively charged ions are approximately the same, and because the mass of the electrons is much smaller than that of the ions, the electrons move much faster, and the negative electron current is greater than the positive ion current. The...

The Magnetosphere

Geophysical Institute, University Alaska Fairbanks, AK 99775-7320, USA Abstract. First, a brief history of magnetospheric research and a description of the basic structure of the magnetosphere is given. Following are detailed discussions of the major magnetospheric structures, i.e. the bow shock, the magnetosheath, the magnetopause, and the magnetotail. Finally, the role of the inner magnetosphere for geomagnetic storms, which are important mainfestations of space weather, is explained. The...

References

Radio Eng., 16, 297-347, 1928 2. Anderson, C.N., Proc. Inst. Radio Eng., 17, 1528-1535, 1929 3. Bauske, R., and G.W. Pr lss, Adv. Space. Res., 22, No.1, 117-121, 1998 4. Bauske, R., S.Noel, and G.W.Pr lss, Ann. Geophys, 15, 300-305, 1997 5. Bencze, P., I. Almar, and E. Illes-Almar, Adv. Space Res., 13, No.1, 303306, 1992 6. Berger, C., and F. Barlier, J. Atmos. Terr. Phys., 43, 121-133, 1981 7. Blumen, W., and R.G. Hendl, J. Atmos. Sci, 26, 210-217, 1969 8. Bremer,...

Conclusion

Solar non-thermal radio radiation is a valuable tool for studying solar activity, in particular with respect to the solar eruptive phenomena (flares and CMEs) that are the main drivers of space weather. Observations at shorter wavelengths (microwaves to meter waves) provide information on the primary energy release and particle acceleration in flares, as well as on the initial development of CMEs and smaller-scale ejecta (i.e. plasmoids) and associated phenomena, such as shock waves. Type III...

Mit

Then the magnetopause is identified as a sudden large change of the magnetic field orientation (and magnitude) in the direction tangential to the boundary. On the Earthward side of the boundary the magnetic field turns predominantly into the northward z direction. At the magnetopause the density may decrease slightly and the plasma consists of a mixture of magnetospheric (energetic) and magnetosheath (cold) particles. At the same time the plasma velocity changes...

Introduction to Space Weather

Laboratory for Atmospheric and Space, University of Colorado, Boulder, CO 80303, USA Abstract. Adverse space weather is one of the principal threats to modern human technology. Solar coronal mass ejections, large solar flares, and high-speed solar wind streams often lead to sequences of damaging disturbances within the Earth's magnetosphere, in the atmosphere, and even on the Earth's surface. Powerful and long-lasting geomagnetic storms can develop following solar disturbances and enhancements...

Year

An example of degradation of the solar array output power (upper panel) and silicon detector leakage current (lower panel) due to displacement damage SOHO ERNE experiment. Four major space weather events are indicated, with inset images from the SOHO LASCO and SOHO EIT. Degradations in solar array power output and increases in detector leakage current are evident coinciding with the solar events, and are most probably due to displacement damage caused by high-energy protons in the...

Contents

Daniel N. 2 Space Weather Effects 3 Energetic Electrons and Space Weather 4 Magnetospheric Substorms 5 Space Weather Effects on the Electric Power System 13 6 Future Directions in Space Weather The Sun and Its Restless Magnetic Field Manfred 2 The Structure of the 3 Solar Magnetic 3.2 Active 3.3 Global Transport of Magnetic Flux 3.4 The Solar Cycle and Its Long-Term 4 Origin of the Magnetic 4.1 Models of the Solar 4.2 Origin of the Long-Term The Application of Radio Diagnostics to the Study of...

Surface Charging

In a comprehensive study of space environment effects on space systems (Koons et al., 1999 67 ), surface charging was found to be the most significant cause of spacecraft anomalies leading to mission failures. Surface charging is the process of electric charge accumulation on surfaces exposed to space environment. It is produced by interactions between satellite surfaces and space plasma, geomagnetic fields, and solar electromagnetic radiation (Leach and Alexander, 1995 68 ). Due to changing...