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Title: An Alternative Method for Identifying Interplanetary Magnetic Cloud Regions

Abstract

Spatio-temporal entropy (STE) analysis is used as an alternative mathematical tool to identify possible magnetic cloud (MC) candidates. We analyze Interplanetary Magnetic Field (IMF) data using a time interval of only 10 days. We select a convenient data interval of 2500 records moving forward by 200 record steps until the end of the time series. For every data segment, the STE is calculated at each step. During an MC event, the STE reaches values close to zero. This extremely low value of STE is due to MC structure features. However, not all of the magnetic components in MCs have STE values close to zero at the same time. For this reason, we create a standardization index (the so-called Interplanetary Entropy, IE, index). This index is a worthwhile effort to develop new tools to help diagnose ICME structures. The IE was calculated using a time window of one year (1999), and it has a success rate of 70% over other identifiers of MCs. The unsuccessful cases (30%) are caused by small and weak MCs. The results show that the IE methodology identified 9 of 13 MCs, and emitted nine false alarm cases. In 1999, a total of 788 windows of 2500more » values existed, meaning that the percentage of false alarms was 1.14%, which can be considered a good result. In addition, four time windows, each of 10 days, are studied, where the IE method was effective in finding MC candidates. As a novel result, two new MCs are identified in these time windows.« less

Authors:
; ;  [1];  [2];  [3];  [4]
  1. Laboratory of Physics and Astronomy, IP and D/Universidade do Vale do Paraíba—UNIVAP, São José dos Campos, SP (Brazil)
  2. Division of Space Geophysics, National Institute for Space Research, São José dos Campos, SP (Brazil)
  3. Department of Space Geophysics, Institute of Geophysics and Astronomy, Havana (Cuba)
  4. Associate Laboratory of Applied Computing and Mathematics, National Institute for Space Research, São José dos Campos, SP (Brazil)
Publication Date:
OSTI Identifier:
22661281
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 837; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; DIAGNOSIS; EMISSION; ENTROPY; INTERPLANETARY MAGNETIC FIELDS; MASS; SEASONAL THERMAL ENERGY STORAGE; SOLAR WIND; STANDARDIZATION; SUN

Citation Formats

Ojeda-Gonzalez, A., Prestes, A., Klausner, V., Mendes, O., Calzadilla, A., and Domingues, M. O., E-mail: ojeda.gonzalez.a@gmail.com. An Alternative Method for Identifying Interplanetary Magnetic Cloud Regions. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA6034.
Ojeda-Gonzalez, A., Prestes, A., Klausner, V., Mendes, O., Calzadilla, A., & Domingues, M. O., E-mail: ojeda.gonzalez.a@gmail.com. An Alternative Method for Identifying Interplanetary Magnetic Cloud Regions. United States. doi:10.3847/1538-4357/AA6034.
Ojeda-Gonzalez, A., Prestes, A., Klausner, V., Mendes, O., Calzadilla, A., and Domingues, M. O., E-mail: ojeda.gonzalez.a@gmail.com. Fri . "An Alternative Method for Identifying Interplanetary Magnetic Cloud Regions". United States. doi:10.3847/1538-4357/AA6034.
@article{osti_22661281,
title = {An Alternative Method for Identifying Interplanetary Magnetic Cloud Regions},
author = {Ojeda-Gonzalez, A. and Prestes, A. and Klausner, V. and Mendes, O. and Calzadilla, A. and Domingues, M. O., E-mail: ojeda.gonzalez.a@gmail.com},
abstractNote = {Spatio-temporal entropy (STE) analysis is used as an alternative mathematical tool to identify possible magnetic cloud (MC) candidates. We analyze Interplanetary Magnetic Field (IMF) data using a time interval of only 10 days. We select a convenient data interval of 2500 records moving forward by 200 record steps until the end of the time series. For every data segment, the STE is calculated at each step. During an MC event, the STE reaches values close to zero. This extremely low value of STE is due to MC structure features. However, not all of the magnetic components in MCs have STE values close to zero at the same time. For this reason, we create a standardization index (the so-called Interplanetary Entropy, IE, index). This index is a worthwhile effort to develop new tools to help diagnose ICME structures. The IE was calculated using a time window of one year (1999), and it has a success rate of 70% over other identifiers of MCs. The unsuccessful cases (30%) are caused by small and weak MCs. The results show that the IE methodology identified 9 of 13 MCs, and emitted nine false alarm cases. In 1999, a total of 788 windows of 2500 values existed, meaning that the percentage of false alarms was 1.14%, which can be considered a good result. In addition, four time windows, each of 10 days, are studied, where the IE method was effective in finding MC candidates. As a novel result, two new MCs are identified in these time windows.},
doi = {10.3847/1538-4357/AA6034},
journal = {Astrophysical Journal},
number = 2,
volume = 837,
place = {United States},
year = {Fri Mar 10 00:00:00 EST 2017},
month = {Fri Mar 10 00:00:00 EST 2017}
}