Power spectral signatures of interplanetary corotating and transient flows

Goldstein, M. L.; Burlaga, L. F.; Matthaeus, W. H.

doi:10.1029/ja089ia06p03747

Cited by 61 publications

(22 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A 1/f spectrum was also found in observations of the magnetic field strength at low frequencies in the solar wind at 1 AU (Matthaeus et al 1983;Goldstein et al 1984). Matthaeus et al (1983) attribute the 1/f spectrum observed at low frequencies in spectrum of magnetic field strength fluctuations at 1 AU as a signature of the early evolution of turbulence in the solar wind.…”

Section: Spectrum Of Sd(t)mentioning

confidence: 60%

MAGNETIC FIELD STRENGTH FLUCTUATIONS IN THE HELIOSHEATH:VOYAGER 1OBSERVATIONS DURING 2009

Burlaga

Ness

2011

ApJ

Self Cite

View full text Add to dashboard Cite

We analyze the "microscale fluctuations" of the magnetic field strength B on a scale of several hours observed by Voyager1 (V1) in the heliosheath during 2009. The microscale fluctuations of B range from coherent to stochastic structures. The amplitude of microscale fluctuations of B during 1 day is measured by the standard deviation (SD) of 48 s averages of B. The distribution of the daily values of SD is lognormal. SD(t) from day of year (DOY) 1 to 331, 2009, is very intermittent. SD(t) has a 1/f or "pink noise" spectrum on scales from 1 to 100 days, and it has a broad multifractal spectrum f(α) with 0.57 α 1.39. The time series of increments SD(t + τ ) − SD(t) has a pink noise spectrum with α = 0.88 ± 0.14 on scales from 1 to 100 days. The increments have a Tsallis (q-Gaussian) distribution on scales from 1 to 165 days, with an average q = 1.75 ± 0.12. The skewness S and kurtosis K have Gaussian and lognormal distributions, respectively. The largest spikes in K(t) and S(t) are often associated with a change in B across a data gap and with identifiable physical structures. The "turbulence" observed by V1 during 2009 was weakly compressible on average but still very intermittent, highly variable, and highly compressible at times. The turbulence observed just behind the termination shock by Voyager 2 was twice as strong. These observations place strong constraints on any model of "turbulence" in the heliosheath.

show abstract

Section: Spectrum Of Sd(t)mentioning

confidence: 60%

MAGNETIC FIELD STRENGTH FLUCTUATIONS IN THE HELIOSHEATH:VOYAGER 1OBSERVATIONS DURING 2009

Burlaga

Ness

2011

ApJ

Self Cite

View full text Add to dashboard Cite

show abstract

“…On the other hand, Voyager 1 and 2 observations in the interval July to December, 1982 show that essentially the same long--term (s 6 months) changes in cosmic ray intensity can be produced by distinctly different magnetic field configurations, suggesting that there are some general features of flow systems that are important, as discussed by Burlaga et al (1984a) and Burlaga and Goldstein (1984). Goldstein et al (1984) have identified some differences in the magnetic field spectra of The spectra were computed from one hour average data using the Blaclanan-Tukey method with 20 degrees of freedom, without detrending or filtering the data. Details of this approach are given in Matthaeus and Goldstein (1982).…”

Section: Magnetic Field Spectra and Turbulencementioning

confidence: 84%

Cosmic ray modulation and turbulent interaction regions near 11 AU

Burlaga¹,

McDonald²,

Goldstein³

et al. 1985

J. Geophys. Res.

Self Cite

200

111

View full text Add to dashboard Cite

When Voyager 2 was near 11 AU, the counting rate of nuclei N 75 MeV/nucleon decreased during the interval from July, 1982 to November, 1982, and it increased thereafter until August, 1983. The counting rate fluctuated within this I'minicycle" with short term decreases lasting 1 to 4 days and recoveries lasting several days. A decrease in cosmic ray flux was generally associated with the passage of an "interaction region" in which the magnetic field strength B was higher than that predicted by the spiral field model, Bp . Several large enhancements in B/B p were associated with "merged interaction regions" which probably resulted from the interaction of two or more distinct flows. During the passage of interaction regions the cosmic ray intensity decreased at a rate proportional to (B/Bp -1), and during the passage of rarefaction regions (where B/B p < 1) the cosmic ray intensity increased at a constant rate. The general form of the cosmic ray intensity profile during this s 13 month I'minicycle" can be described by integrating these relations using the observed B(t), and it can be understood in terms of the sizes and separations of interaction regions. Latitudinal variations of the interaction regions and of the short-term cosmic ray variations were identified by comparing Voyager 2 observations with Voyager 1 observations made at higher latitudes O V to 200 ). The interaction regions were turbulent, with an f -5/3 spectrum from at least 3 x 10 -4 Hz to f 0 to 2) x 10 -6 Hz. A break in the spectrum at f corresponds to the characteristic width of the interaction regions, and it represents a "stirring scale" for the solar wind. The interaction regions, including merged interaction regions, may be viewed as "turbulent boundary layers" which grow in size with increasing distance from the sun.They act as barriers which impede the net flow of cosmic rays toward the sun.2

show abstract

“…It would be worthwhile to examine the previous heliosheath data for such a spectrum. An f −1 spectrum of B was observed in the solar wind near the Sun (Matthaeus et al 1982, and Goldstein et al 1984, but not in the distant supersonic solar wind. An f −1 spectrum associated with the microscale fluctuations of dSD1was observed in the heliosheath by V1 during 2009 (Burlaga & Ness 2012a, 2012b).…”

Section: Large-scale Fluctuations Of the Magnetic Field Intensitymentioning

confidence: 94%

MAGNETIC FIELD STRENGTH FLUCTUATIONS AND THEq-TRIPLET IN THE HELIOSHEATH:VOYAGER 2OBSERVATIONS FROM 91.0 TO 94.2 AU AT LATITUDE 30° S

Burlaga

Ness

2013

ApJ

Self Cite

View full text Add to dashboard Cite

Voyager 2 (V2) was in the heliosheath during 2010, at (91.0-94.2) AU from the Sun and at the latitudes (28.• 8-29.• 3 S) AU, observing solar wind that left the Sun during 2009, when solar activity was very low. There was no feature in B(t) associated with the changes in the plasma parameters observed near 2010.4. The CR-B relation was satisfied. The fluctuations of daily averages of B showed (1) a Gaussian distribution of B, (2) a q-Gaussian of the daily increments of B with q = 1.6, (3) a power-law correlation of B on scales from 1 to 16 days, (4) multifractal structure of B on scales from 1 to 8 days, and (5) a 1/f spectrum of B on scales from 1 to 100 days. The amplitude of the compressive microscale fluctuations of B during several hours on each day is described by the standard deviation (SD) of the 48 s averages of B during the day. Items 2, 3, and 4 determine a "q-triplet" in the heliosheath. Large-scale fluctuations of SD show (1) a lognormal distribution of SD; (2) an average value of SD = 0.19, 20% of the average B; (3) a q-Gaussian distribution of the increments of SD with q = 1.4; (4) a power-law correlation on scales from 1 to 16 days; and (5) a 1/f spectrum on scales from 1 to 100 days. The heliosheath was in a quasi-stationary, metastable equilibrium state with well-defined structure over a wide range of scales near V2 during 2010.

show abstract

Power spectral signatures of interplanetary corotating and transient flows

Cited by 61 publications

References 38 publications

MAGNETIC FIELD STRENGTH FLUCTUATIONS IN THE HELIOSHEATH:VOYAGER 1OBSERVATIONS DURING 2009

MAGNETIC FIELD STRENGTH FLUCTUATIONS IN THE HELIOSHEATH:VOYAGER 1OBSERVATIONS DURING 2009

Cosmic ray modulation and turbulent interaction regions near 11 AU

MAGNETIC FIELD STRENGTH FLUCTUATIONS AND THEq-TRIPLET IN THE HELIOSHEATH:VOYAGER 2OBSERVATIONS FROM 91.0 TO 94.2 AU AT LATITUDE 30° S

Contact Info

Product

Resources

About