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Title: Long-term Longitudinal Recurrences of the Open Magnetic Flux Density in the Heliosphere

Abstract

Open magnetic flux in the heliosphere is determined from the radial component of the magnetic field vector measured onboard interplanetary space probes. Previous Ulysses research has shown remarkable independence of the flux density from heliographic latitude, explained by super-radial expansion of plasma. Here we are investigating whether any longitudinal variation exists in the 50 year long OMNI magnetic data set. The heliographic longitude of origin of the plasma package was determined by applying a correction according to the solar wind travel time. Significant recurrent enhancements of the magnetic flux density were observed throughout solar cycle 23, lasting for several years. Similar, long-lasting recurring features were observed in the solar wind velocity, temperature and the deviation angle of the solar wind velocity vector from the radial direction. Each of the recurrent features has a recurrence period slightly differing from the Carrington rotation rate, although they show a common trend in time. Examining the coronal temperature data of ACE leads to the possible explanation that these long-term structures are caused by slow–fast solar wind interaction regions. A comparison with MESSENGER data measured at 0.5 au shows that these longitudinal magnetic modulations do not exist closer to the Sun, but are the resultmore » of propagation.« less

Authors:
;  [1]
  1. Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, H-1121 Budapest, Konkoly-Thege Miklós st 29-33 (Hungary)
Publication Date:
OSTI Identifier:
22661203
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 838; 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; COMPARATIVE EVALUATIONS; CORRECTIONS; EXPANSION; FLUX DENSITY; HELIOSPHERE; INTERACTIONS; INTERPLANETARY SPACE; MAGNETIC FIELDS; MAGNETIC FLUX; MODULATION; PLASMA; ROTATION; SOLAR CYCLE; SOLAR WIND; SUN; VARIATIONS; VELOCITY

Citation Formats

Dósa, M., and Erdős, G., E-mail: dosa.melinda@wigner.mta.hu. Long-term Longitudinal Recurrences of the Open Magnetic Flux Density in the Heliosphere. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA657B.
Dósa, M., & Erdős, G., E-mail: dosa.melinda@wigner.mta.hu. Long-term Longitudinal Recurrences of the Open Magnetic Flux Density in the Heliosphere. United States. doi:10.3847/1538-4357/AA657B.
Dósa, M., and Erdős, G., E-mail: dosa.melinda@wigner.mta.hu. Sat . "Long-term Longitudinal Recurrences of the Open Magnetic Flux Density in the Heliosphere". United States. doi:10.3847/1538-4357/AA657B.
@article{osti_22661203,
title = {Long-term Longitudinal Recurrences of the Open Magnetic Flux Density in the Heliosphere},
author = {Dósa, M. and Erdős, G., E-mail: dosa.melinda@wigner.mta.hu},
abstractNote = {Open magnetic flux in the heliosphere is determined from the radial component of the magnetic field vector measured onboard interplanetary space probes. Previous Ulysses research has shown remarkable independence of the flux density from heliographic latitude, explained by super-radial expansion of plasma. Here we are investigating whether any longitudinal variation exists in the 50 year long OMNI magnetic data set. The heliographic longitude of origin of the plasma package was determined by applying a correction according to the solar wind travel time. Significant recurrent enhancements of the magnetic flux density were observed throughout solar cycle 23, lasting for several years. Similar, long-lasting recurring features were observed in the solar wind velocity, temperature and the deviation angle of the solar wind velocity vector from the radial direction. Each of the recurrent features has a recurrence period slightly differing from the Carrington rotation rate, although they show a common trend in time. Examining the coronal temperature data of ACE leads to the possible explanation that these long-term structures are caused by slow–fast solar wind interaction regions. A comparison with MESSENGER data measured at 0.5 au shows that these longitudinal magnetic modulations do not exist closer to the Sun, but are the result of propagation.},
doi = {10.3847/1538-4357/AA657B},
journal = {Astrophysical Journal},
number = 2,
volume = 838,
place = {United States},
year = {Sat Apr 01 00:00:00 EDT 2017},
month = {Sat Apr 01 00:00:00 EDT 2017}
}