World Library  


Add to Book Shelf
Flag as Inappropriate
Email this Book

Empirically Modelled Pc3 Activity Based on Solar Wind Parameters : Volume 28, Issue 9 (22/09/2010)

By Heilig, B.

Click here to view

Book Id: WPLBN0003983539
Format Type: PDF Article :
File Size: Pages 20
Reproduction Date: 2015

Title: Empirically Modelled Pc3 Activity Based on Solar Wind Parameters : Volume 28, Issue 9 (22/09/2010)  
Author: Heilig, B.
Volume: Vol. 28, Issue 9
Language: English
Subject: Science, Annales, Geophysicae
Collections: Periodicals: Journal and Magazine Collection (Contemporary), Copernicus GmbH
Historic
Publication Date:
2010
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications

Citation

APA MLA Chicago

Verő, J., Reda, J., Pajunpää, K., Sutcliffe, P., Raita, T., Lotz, S., & Heilig, B. (2010). Empirically Modelled Pc3 Activity Based on Solar Wind Parameters : Volume 28, Issue 9 (22/09/2010). Retrieved from http://worldebookfair.org/


Description
Description: Tihany Geophysical Observatory, Eötvös Loránd Geophysical Institute, Hungary. It is known that under certain solar wind (SW)/interplanetary magnetic field (IMF) conditions (e.g. high SW speed, low cone angle) the occurrence of ground-level Pc3–4 pulsations is more likely. In this paper we demonstrate that in the event of anomalously low SW particle density, Pc3 activity is extremely low regardless of otherwise favourable SW speed and cone angle. We re-investigate the SW control of Pc3 pulsation activity through a statistical analysis and two empirical models with emphasis on the influence of SW density on Pc3 activity. We utilise SW and IMF measurements from the OMNI project and ground-based magnetometer measurements from the MM100 array to relate SW and IMF measurements to the occurrence of Pc3 activity. Multiple linear regression and artificial neural network models are used in iterative processes in order to identify sets of SW-based input parameters, which optimally reproduce a set of Pc3 activity data. The inclusion of SW density in the parameter set significantly improves the models. Not only the density itself, but other density related parameters, such as the dynamic pressure of the SW, or the standoff distance of the magnetopause work equally well in the model. The disappearance of Pc3s during low-density events can have at least four reasons according to the existing upstream wave theory: 1. Pausing the ion-cyclotron resonance that generates the upstream ultra low frequency waves in the absence of protons, 2. Weakening of the bow shock that implies less efficient reflection, 3. The SW becomes sub-Alfvénic and hence it is not able to sweep back the waves propagating upstream with the Alfvén-speed, and 4. The increase of the standoff distance of the magnetopause (and of the bow shock). Although the models cannot account for the lack of Pc3s during intervals when the SW density is extremely low, the resulting sets of optimal model inputs support the generation of mid latitude Pc3 activity predominantly through upstream waves.

Summary
Empirically modelled Pc3 activity based on solar wind parameters

Excerpt
Anderson, B. J., Erlandson, R. E., and Zanetti, L. J.: A model of the Earth's distant bow shock, J. Geophys. Res., 97, 3089–3101, 1992.; Bishop, C. M.: Neural {N}etworks for {P}attern {R}ecognition, Oxford University Press, 1995.; Bol'shakova, O. V. and Troitskaya, V.: Relation of the IMF direction to the system of stable oscillations, Dokl. Akad. Nauk+ (Proceedings of the Russian Academy of Sciences), 180, 343–346, 1968.; Chen, L. and Hasegawa, A.: A theory of long-period magnetic pulsations, 1. Steady state excitation of field line resonance, J. Geophys. Res., 79, 1024–1032, 1974.; Chi, P., Russell, C., Bloom, R., and Singer, H.: Solar wind control of ultralow-frequency wave activity at L=3, J. Geophys. Res., 103, 29467–29477, 1998.; Chugunova, O. M., Pilipenko, V. A., Engebretson, M., and Rodger, A.: Statistical Relations between the Probability of Occurrence of Pc3-4 Pulsations at High Latitudes in the Antarctic Regions and the Solar Wind and IMF Parameters, Geomagn and Aeronomy+, 47, 205–215, 2007.; Fausett, L.: Fundamentals of {N}eural {N}etworks: architectures, algoritms and applications, Prentice Hall, 1994.; Gary, S. P.: Electromagnetic ion beam instability and energy loss of fast alpha particles, Nucl. Fusion, 18, 327, 1978.; Greenstadt, E. W. and Olson, J. V.: Pc 3,4 Activity and Interplanetary Field Orientation, J. Geophys. Res., 81, 5911–5920, 1976.; Haykin, S.: Neural N}etworks: {A {C}omprehensive {F}oundation, Pearson {E}ducation, 2nd edn., 1999.; Heilig, B., Csontos, A., Pankratz, L., Pajunpää, K., Kultima, J., Raita, T., Reda, J., and Váczyová, M.: Upstream wave related Pc3 pulsations observed by the MM100 meridional magnetometer array, Publications of the Institute of Geophysics of the Polish Academy of Sciences, C-99, 339–346, 2007a.; Saito, T.: Geomagnetic pulsations, Space Sci. Rev., 10, 319–412, 1969.; Saito, T., Yumoto, K., and Koyama, Y.: Magnetic pulsation Pi2 as a sensitive indicator of magnetospheric substorm, Planet. Space Sci., 24, 1025–1029, 1976.; Heilig, B., Lühr, H., and Rother, M.: Comprehensive study of ULF upstream waves observed in the topside ionosphere by CHAMP and on the ground, Ann. Geophys., 25, 737–754, doi:10.5194/angeo-25-737-2007, 2007b.; Hundhausen, A., Bame, S., Asbridge, J., and Sydoriak, S.: Solar Wind Proton Properties: Vela 3 Observations from July 1965 to June 1967, J. Geophys. Res., 75, 4643–4657, 1970.; Juusola, L., Amm, O., Kauristie, K., and Viljanen, A.: A model for estimating the relation between the Hall to Pedersen conductance ratio and ground magnetic data derived from CHAMP satellite statistics, Ann. Geophys., 25, 721–736, doi:10.5194/angeo-25-721-2007, 2007.; Kepko, L., Spence, H. E., and Singer, H. J.: ULF waves in the solar wind as direct drivers of magnetospheric pulsations, Geophys. Res. Lett., 29, 1197, doi:10.1029/2001GL014405, 2002.; Kim, Y., Street, W. N., Russell, G. J., and Menczer, F.: Customer Targeting: A Neural Network Approach Guided by Genetic Algorithms, Manage. Sci., 51, 264–276, doi:10.1287/mnsc.1040.0296, 2005.; Kivelson, M. G. and Russell, C. T.: Introduction to space physics, Cambridge University Press, London, 1995.; Kivelson, M. G. and Southwood, D. J.: Resonant ULF waves: A new interpretation, Geophys. Res. Lett., 12, 49–52, 1985.; Kovner, M. S., Lebedev, V. V., Plyasova-Bakunina, T. A., and Troitskaya, V. A.: On the generation of low frequency waves in the solar wind in front of the bow shock, Planet. Space Sci., 24, 261–267, 1976.; Kucharek, H., Möbius, E., Scholer, M., Mouikis, C., Kistler, L. M., Horbury, T., Balogh, A., Rème, H., and Bosqued, J. M.: On the origin of field-aligned beams at the quasi-perpendicular b

 

Click To View

Additional Books


  • Comparisons Between Canadian Prairie Mf ... (by )
  • New Low-frequency Electromagnetic Modes ... (by )
  • Simulation of Aerosol Optical Properties... (by )
  • Multi-resolution Analysis of Global Tota... (by )
  • Variations in Schumann Resonances and Th... (by )
  • Gnevyshev Peaks in Solar Radio Emissions... (by )
  • Mf Radar Observations of the Diurnal Tid... (by )
  • Polar Cap Patches Observed During the Ma... (by )
  • Coronal Magnetic Fields Inferred from Ir... (by )
  • Visan Mhd: a Toolbox in Matlab for Mhd C... (by )
  • Modeling of the Jovian Magnetosphere : V... (by )
Scroll Left
Scroll Right

 



Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Fair are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.