scostep 2010 (stp12) - Leibniz-Institut für Atmosphärenphysik an der ...

More documents

Recommendations

Info

STP12 Abstracts Berlin, 12 - 16 July 2010 SCOSTEP Symposium 2010 Kinetic instabilities in the solar wind plasma with suprathermal Kappa anisotropies Lazar Marian Ruhr University Bochum, Germany The kinetic instabilities are presently actively invoked in a large variety of astrophysical scenarios because of a wide-spread existence of kinetic anisotropies in space plasmas. The present abundance of data from observations and in-situ measurements in the solar wind reveal not only deviations from isotropy in the velocity space of plasma particles but also a constant presence of suprathermal populations. These are non-Maxwellian distributions with high-energy (suprathermal) tails very well fitted by the Kappa functions. Moreover, the intense electromagnetic fluctuations of the interplanetary fields are traces of the kinetic instabilities which arise in the solar wind and compete with other constraints (adiabatic expansion, Coulomb collisions) for maintaining a relatively small anisotropy. Here we present the main results of the stability analysis for anisotropic distributions modeled with Kappa functions. The new threshold conditions are shown and the growth rates are plotted numerically for typical conditions encountered in the solar wind. The essential phyiscal properties of the kinetic instabilities are retained but both the thresholds and the growth rates are markedly changed by the presence of suprathermal populations. Such analysis including nonequilibrium plasmas is the first step for developing a new transport theory and providing better estimates for the physical parameters characterizing the solar wind plasma.
STP12 Abstracts Berlin, 12 - 16 July 2010 SCOSTEP Symposium 2010 Short term variability of the high and mid latitude ionosphere as a result of coupling between the solar wind and magnetosphere Lester Mark , Milan Stephen University of Leicester Ionospheric variability occurs on a range of time scales from days to years and probably centuries. In this talk we focus on the variability which is introduced by the coupling between the solar wind and magnetosphere. This coupling introduces variability on time scales of hours, due to magnetospheric substorms, and days, due to magnetic storms. The changes in the ionosphere are due to enhanced energy deposition into the ionosphere in the form of particle precipitation which results in heating of the plasma and also enhanced electric field resulting in Joule heating of the plasma. At high latitudes the changes in the ionospheric plasma result from the enhanced ionisation from particle precipitation, which can lead to enhanced absorption of radio waves should the particles penetrate to altitudes of 100 km and less. Joule heating on the other hand leads to enhanced temperatures in the ionosphere resulting in enhanced ion loss from either ion upflow or from enhanced recombination. This tends to occur at altitude above about 250 km. At mid-latitudes the variability during substorms may be more related to the propagation of atmospheric gravity waves stimulated by the heating at cusp latitudes or auroral latitudes on the nightisde. These waves propagate to mid and low latitudes resulting in variation in the ionospheric plasma density on time scales of hours. Mid-latitude variations due to storms are extremely complex due to transport of plasma due to winds. In this presentation we shall concentrate on observations of the ionosphere made by the Super Dual Auroral Radar Network (SuperDARN) which extends from the poles to about 40 degrees of latitude in both hemispheres. These radars provide information on the electric fields responsible for Joule heating, ionospheric plasma distributions, in particular enhanced absorption and changes in the F region peak density, and gravity waves. With the continued extension to mid latitudes particularly in the American sector, these radars now provide critical information on the ionospheric variability on the short term.
Page 1 and 2:
SCOSTEP 2010 (STP12) Berlin, 12 - 1
Page 3 and 4:
STP12 Abstracts Berlin, 12 - 16 Jul
Page 5 and 6:
Page 7 and 8:
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Page 39 and 40:
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
Page 69 and 70:
Page 71 and 72:
Page 73 and 74:
Page 75 and 76:
Page 77 and 78:
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
Page 85 and 86:
Page 87 and 88: STP12 Abstracts Berlin, 12 - 16 Jul
Page 137: STP12 Abstracts Berlin, 12 - 16 Jul
Page 189 and 190:
Page 191 and 192:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
Page 203 and 204:
Page 205 and 206:
Page 207 and 208:
Page 209 and 210:
Page 211 and 212:
Page 213 and 214:
Page 215 and 216:
Page 217 and 218:
Page 219 and 220:
Page 221 and 222:
Page 223 and 224:
Page 225 and 226:
Page 227 and 228:
Page 229 and 230:
Page 231 and 232:
Page 233 and 234:
Page 235 and 236:
Page 237 and 238:
Page 239 and 240:
Page 241 and 242:
Page 243 and 244:
Page 245 and 246:
Page 247 and 248:
Page 249 and 250:
Page 251 and 252:
Page 253 and 254:
Page 255 and 256:
Page 257 and 258:
Page 259 and 260:
Page 261 and 262:
Page 263 and 264:
Page 265 and 266:
Page 267 and 268:
show all

scostep 2010 (stp12) - Leibniz-Institut für Atmosphärenphysik an der ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?