Tsallis distributions of magnetic field strength variations in the heliosphere: 5 to 90 AU

Burlaga, L. F.; F-Viñas, Adolfo; Wang, C.

doi:10.1029/2006ja012213

Cited by 65 publications

(76 citation statements)

References 52 publications

(69 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At the lower limit of κ, 3/2, where the distribution is furthest from thermal equilibrium, the power-law tail at high energies is hardest (Livadiotis & McComas 2010). κ-distributions have many interesting applications in and out of space physics (e.g., Burlaga et al 2007;Tsallis 2009;Schwadron et al 2010). …”

Section: Discussionmentioning

confidence: 99%

OBSERVATIONS OF ISOTROPIC INTERSTELLAR PICK-UP IONS AT 11 AND 17 AU FROMNEW HORIZONS

Randol

Elliott

Gosling

et al. 2012

ApJ

View full text Add to dashboard Cite

We report new observations by the Solar Wind Around Pluto (SWAP) instrument on the New Horizons spacecraft of an energy-per-charge (E/q) spectrum of interstellar pick-up ions (PUIs) from an unprecedented heliocentric distance of 17 AU. This E/q spectrum is fit well by an isotropic PUI distribution function combined with the detailed response of the SWAP instrument. In contrast to earlier work, we are also able to fit an isotropic PUI model to an E/q spectrum measured by SWAP at 11.3 AU by explicitly including two additional effects. These are (1) the E/q-dependent geometric factor of SWAP, which increases with decreasing E/q owing to effects associated with the post-acceleration of particles exiting the electrostatic analyzer portion of the instrument; and (2) a solar wind distribution, the model spectrum of which contributes significantly to the low-E/q part of the overall model owing, presumably, to secondary particles produced within the instrument.

show abstract

Section: Discussionmentioning

confidence: 99%

OBSERVATIONS OF ISOTROPIC INTERSTELLAR PICK-UP IONS AT 11 AND 17 AU FROMNEW HORIZONS

Randol

Elliott

Gosling

et al. 2012

ApJ

View full text Add to dashboard Cite

show abstract

“…The state of an open system is usually associated with a degree of uncertainty that can be quantified by the BoltzmannGibbs entropy, a very useful uncertainty measure in statistical mechanics. However, Boltzmann-Gibbs entropy cannot describe non-equilibrium physical systems with large variability and multifractal structure such as the solar wind (Burlaga et al, 2007;Balasis et al, 2008). One of the crucial properties of the Boltzmann-Gibbs entropy in the context of classical thermodynamics is extensivity, namely proportionality with the number of elements of the system.…”

Section: Computation Of Tsallis Entropy and Other Entropy Measuresmentioning

confidence: 99%

The comparative study of chaoticity and dynamical complexity of the low-latitude ionosphere, over Nigeria, during quiet and disturbed days

Ogunsua

Laoye

Fuwape

et al. 2014

Nonlin. Processes Geophys.

View full text Add to dashboard Cite

Abstract. The deterministic chaotic behavior and dynamical complexity of the space plasma dynamical system over Nigeria are analyzed in this study and characterized. The study was carried out using GPS (Global Positioning System) TEC (Total Electron Content) time series, measured in the year 2011 at three GPS receiver stations within Nigeria, which lies within the equatorial ionization anomaly region. The TEC time series for the five quietest and five most disturbed days of each month of the year were selected for the study. The nonlinear aspect of the TEC time series was obtained by detrending the data. The detrended TEC time series were subjected to various analyses for phase space reconstruction and to obtain the values of chaotic quantifiers like Lyapunov exponents, correlation dimension and also Tsallis entropy for the measurement of dynamical complexity. The observations made show positive Lyapunov exponents (LE) for both quiet and disturbed days, which indicates chaoticity, and for different days the chaoticity of the ionosphere exhibits no definite pattern for either quiet or disturbed days. However, values of LE were lower for the storm period compared with its nearest relative quiet periods for all the stations. The monthly averages of LE and entropy also show no definite pattern for the month of the year. The values of the correlation dimension computed range from 2.8 to 3.5, with the lowest values recorded at the storm period of October 2011. The surrogate data test shows a significance of difference greater than 2 for all the quantifiers. The entropy values remain relatively close, with slight changes in these values during storm periods. The values of Tsallis entropy show similar variation patterns to those of Lyapunov exponents, with a lot of agreement in their comparison, with all computed values of Lyapunov exponents correlating with values of Tsallis entropy within the range of 0.79 to 0.81. These results show that both quantifiers can be used together as indices in the study of the variation of the dynamical complexity of the ionosphere. The results also show a strong play between determinism and stochasticity. The behavior of the ionosphere during these storm and quiet periods for the seasons of the year are discussed based on the results obtained from the chaotic quantifiers.

show abstract

“…In the distant solar wind and heliosheath, the distribution of increments of B (dB=B(t + τ) − B(t)) is generally a qGaussian distribution function (Burlaga et al 2006(Burlaga et al , 2007b which has the form [1 + (q − 1)β 2 ] −α where α=(1/q − 1) (Tsallis 1988(Tsallis , 2009). This is also true of the V2, 2012 observations of the daily and hourly increments of B, as shown in Figure 10.…”

Section: Distributions Of B and Increments Of Bmentioning

confidence: 99%

“…A one-dimensional MHD model with pickup ions was used by Burlaga et al (2007b) to follow the radial evolution of the supersonic solar wind flows out to 90 au. The passage of the supersonic solar wind to the subsonic heliosheath by means of a TS was modeled by Borovikov et al (2011).…”

Section: Structure and Formation Of The Interaction Regionmentioning

confidence: 99%

Heliosheath Magnetic Field and Plasma Observed by Voyager 2 During 2012 in the Rising Phase of Solar Cycle 24

Burlaga

Ness

Richardson

et al. 2016

ApJ

Self Cite

View full text Add to dashboard Cite

We discuss magnetic field and plasma observations of the heliosheath made by Voyager 2 (V2) during 2012, when V2 was observing the effects of increasing solar activity following the solar minimum in 2009. The average magnetic field strength B was 0.14 nT and B reached 0.29 nT on day 249. V2 was in a unipolar region in which the magnetic polarity was directed away from the Sun along the Parker spiral 88% of the time, indicating that V2 was poleward of the heliospheric current sheet throughout most of 2012. The magnetic flux at V2 during 2012 was constant. A merged interaction region (MIR) was observed, and the flow speed increased as the MIR moved past V2. The MIR caused a decrease in the >70 MeV nuc −1 cosmic-ray intensity. The increments of B can be described by a q-Gaussian distribution with q=1.2±0.1 for daily averages and q=1.82±0.03 for hour averages. Eight isolated current sheets ("PBLs") and four closely spaced pairs of current sheets were observed. The average change of B across the current sheets was a factor of ≈2, and B increased or decreased with equal probability. Magnetic holes and magnetic humps were also observed. The characteristic size of the PBLs was ≈6 R L , where R L is the Larmor radius of protons, and the characteristic sizes of the magnetic holes and humps were ≈38 R L and ≈11 R L , respectively.

show abstract

Tsallis distributions of magnetic field strength variations in the heliosphere: 5 to 90 AU

Cited by 65 publications

References 52 publications

OBSERVATIONS OF ISOTROPIC INTERSTELLAR PICK-UP IONS AT 11 AND 17 AU FROMNEW HORIZONS

OBSERVATIONS OF ISOTROPIC INTERSTELLAR PICK-UP IONS AT 11 AND 17 AU FROMNEW HORIZONS

The comparative study of chaoticity and dynamical complexity of the low-latitude ionosphere, over Nigeria, during quiet and disturbed days

Heliosheath Magnetic Field and Plasma Observed by Voyager 2 During 2012 in the Rising Phase of Solar Cycle 24

Contact Info

Product

Resources

About