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Title: Determination of errors in derived magnetic field directions in geosynchronous orbit: results from a statistical approach

Journal Article · · Annales Geophysicae (Online)

This study aims to statistically estimate the errors in local magnetic field directions that are derived from electron directional distributions measured by Los Alamos National Laboratory geosynchronous (LANL GEO) satellites. First, by comparing derived and measured magnetic field directions along the GEO orbit to those calculated from three selected empirical global magnetic field models (including a static Olson and Pfitzer 1977 quiet magnetic field model, a simple dynamic Tsyganenko 1989 model, and a sophisticated dynamic Tsyganenko 2001 storm model), it is shown that the errors in both derived and modeled directions are at least comparable. Second, using a newly developed proxy method as well as comparing results from empirical models, we are able to provide for the first time circumstantial evidence showing that derived magnetic field directions should statistically match the real magnetic directions better, with averaged errors< ~2°, than those from the three empirical models with averaged errors >~5°. In addition, our results suggest that the errors in derived magnetic field directions do not depend much on magnetospheric activity, in contrast to the empirical field models. Finally, as applications of the above conclusions, we show examples of electron pitch angle distributions observed by LANL GEO and also take the derived magnetic field directions as the real ones so as to test the performance of empirical field models along the GEO orbits, with results suggesting dependence on solar cycles as well as satellite locations. This study demonstrates the validity and value of the method that infers local magnetic field directions from particle spin-resolved distributions.

Research Organization:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
USDOE
Grant/Contract Number:
AC52-06NA25396
OSTI ID:
1325839
Alternate ID(s):
OSTI ID: 1334136
Report Number(s):
LA-UR-15-27475
Journal Information:
Annales Geophysicae (Online), Journal Name: Annales Geophysicae (Online) Vol. 34 Journal Issue: 9; ISSN 1432-0576
Publisher:
Copernicus Publications, EGUCopyright Statement
Country of Publication:
Germany
Language:
English
Citation Metrics:
Cited by: 2 works
Citation information provided by
Web of Science

References (19)

The energy spectrometer for particles (ESP): Instrument description and orbital performance
  • Meier, M. M.; Belian, R. D.; Cayton, T. E.
  • Workshop on the Earth’s trapped particle environment, AIP Conference Proceedings https://doi.org/10.1063/1.51533
conference January 1996
REPAD: An empirical model of pitch angle distributions for energetic electrons in the Earth's outer radiation belt: pitch-angle model for outer-belt e- journal March 2014
Event-specific chorus wave and electron seed population models in DREAM3D using the Van Allen Probes: Tu et al.: Event-specific chorus and seed electrons journal March 2014
Relativistic electrons in the outer-zone: An 11 year cycle; Their relation to the solar wind
  • Belian, R. D.; Cayton, T. E.; Christensen, R. A.
  • Workshop on the Earth’s trapped particle environment, AIP Conference Proceedings https://doi.org/10.1063/1.51526
conference January 1996
Modeling the dynamics of the inner magnetosphere during strong geomagnetic storms journal January 2005
The energization of relativistic electrons in the outer Van Allen radiation belt journal July 2007
An observational test of the Tsyganenko (T89a) model of the magnetospheric field journal November 1996
High- Z energetic particles at geosynchronous orbit during the Great Solar Proton Event Series of October 1989 journal January 1992
Multisatellite determination of the relativistic electron phase space density at geosynchronous orbit: Methodology and results during geomagnetically quiet times journal January 2005
A statistical comparison of commonly used external magnetic field models: A COMPARISON OF MAGNETIC FIELD MODELS journal October 2008
“Pancake” electron distributions in the outer radiation belts journal June 1999
Deep dielectric charging effects due to high-energy electrons in earth's outer magnetosphere journal October 1987
Energetic electrons, 50 keV to 6 MeV, at geosynchronous orbit: Their responses to solar wind variations: ENERGETIC ELECTRONS AT GEOSYNCHRONOUS ORBIT journal April 2005
Acceleration and loss of relativistic electrons during geomagnetic storms: ACCELERATION AND LOSS OF RELATIVISTIC ELECTRONS journal May 2003
A magnetospheric magnetic field model with a warped tail current sheet journal January 1989
Storm-time distortion of the inner magnetosphere: How severe can it get?: DISTORTION OF THE INNER MAGNETOSPHERE journal May 2003
Multisatellite determination of the relativistic electron phase space density at geosynchronous orbit: An integrated investigation during geomagnetic storm times: STORM journal November 2007
Dynamic Radiation Environment Assimilation Model: DREAM: DYNAMIC RADIATION ENVIRONMENT ASSIMILATION MODEL journal March 2012
A quantitative assessment of empirical magnetic field models at geosynchronous orbit during magnetic storms: TEST MAGNETIC FIELD MODELS journal April 2008