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REVIEW 3 major objections 5 minor 36 references

One year of ASPEX-SWIS operation -- Characteristic features, observations and science potential

T0 review · 3 major / 5 minor · reviewed 2026-08-06 · deepseek-v4-flash

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Pith's one-line read Aditya-L1's SWIS solar wind speed measurements match Wind's to a correlation of 0.94 over 17 months.

desk verdict A genuinely useful first-year validation of a new L1 solar wind ion spectrometer, with solid velocity agreement against Wind, but the density and temperature moment products need substantial clarification and sensitivity testing. read the letter →

arxiv 2507.17523 v1 pith:V3P65L6K submitted 2025-07-23 astro-ph.SR physics.space-ph

Abhishek Kumar , Shivam Parashar , Prashant Kumar , Dibyendu Chakrabarty , Bhas Bapat , Aveek Sarkar , Manan S. Shah , Hiteshkumar L. Adalja
show 21 more authors
Arpit R. Patel Pranav R. Adhyaru M. Shanmugam Swaroop B. Banerjee K.P. Subramaniam Tinkal Ladiya Jacob Sebastian Bijoy Dalal Aakash Gupta M.B. Dadhania Santosh V. Vadawale Shiv Kumar Goyal Neeraj Kumar Tiwari Aaditya Sarda Sushil Kumar Nishant Singh Deepak Kumar Painkra Piyush Sharma Abhishek J. Verma P. Janardhan Anil Bhardwaj
This is my paper · ORCID
classification astro-ph.SRphysics.space-ph
keywords Aditya-L1ASPEX-SWISsolarwindin-situplasmameasurementsinstrumentcross-calibrationinterplanetarycoronalmassejectionMHDturbulencevelocitydistributionfunctionmoments
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper reports the first extended validation of the Solar Wind Ion Spectrometer (SWIS) aboard India's Aditya-L1 mission, comparing its derived proton density, bulk speed, and thermal speed with contemporaneous Wind and DSCOVR measurements over 17 months. Its central claim is that SWIS bulk velocity measurements agree strongly with Wind ($R^2=0.94$, slope $\sim 0.97$), while density and thermal speed show larger scatter that the authors attribute to known inter-instrument differences. The paper also shows that SWIS resolved the structure of an August 2024 interplanetary coronal mass ejection, captured $\alpha$-to-proton abundance enhancements, and measured a velocity-fluctuation power spectrum with an inertial-range slope near $-1.5$. If these results hold, SWIS is a scientifically usable solar wind monitor at L1 for both transient space weather events and long-term heliospheric studies.

What carries the argument

The central machinery is the dual Top-Hat Electrostatic Analyzer configuration (THA-1 in the ecliptic plane and THA-2 in the perpendicular plane), a curved-plate energy selector that turns 0.1–20 keV ion energy spectra into velocity-space moments. Assuming the proton distribution is approximately Maxwellian and isotropic in the spacecraft frame, the paper derives number density, bulk speed, and thermal speed from flux-weighted moments, with a parametric Gaussian fit used to cross-check the non-parametric estimates. The dual-plane design is what lets SWIS claim directional sensitivity without a spinning platform, and the moment derivation is what produces the bulk parameters validated against Wind and DSCOVR.

What would settle it

Compare SWIS moment-derived density and thermal speed with Wind-3DP-PLSP during intervals selected for strong proton beam or temperature anisotropy, and check whether the SWIS-minus-Wind residuals grow with the measured anisotropy; if the residuals do not track anisotropy, the Maxwellian-and-isotropic assumption is not the limiting factor, whereas if they do, the two-plane moment derivation is the cause.

Watch

Extended reading notes

Core claim

The paper's central discovery is that a two-plane, top-hat electrostatic analyzer on a 3-axis stabilized spacecraft—without full three-dimensional distribution coverage—can recover solar wind bulk velocity with accuracy comparable to established spinning-platform instruments. Concretely, over January 2024 to May 2025 the AL1-ASPEX-SWIS bulk speed matches Wind-SWE-FC with $R^2=0.94$ and slope $0.97$, and matches Wind-3DP-PLSP with slope $1.00$ and $R^2=0.94$, while the 11–12 August 2024 ICME shock, sheath, and magnetic cloud boundaries appear in SWIS data at the same times as in Wind and DSCOVR. The authors take this as confirmation that SWIS is suited to monitor both transient solar wind structures and long-term solar wind conditions from L1.

Load-bearing premise

The load-bearing assumption is that the protons streaming past the spacecraft have speeds spread out evenly in every direction, although SWIS only samples two planes and ignores all particles slower than 280 km/s; if the flow is beamed or direction-dependent, the derived density and temperature are biased.

Editorial extensions

If this is right

  • SWIS bulk velocity data can be used as a reliable L1 solar wind speed input for space weather monitoring, with agreement to Wind at $R^2=0.94$.
  • Transient events like ICMEs can be identified in SWIS energy-time spectrograms and moment time series, including shock, sheath, and magnetic cloud phases.
  • Density and thermal speed from SWIS should be used with caution or after instrument-specific cross-calibration, since their agreement with reference instruments is weaker.
  • The observed difference between THA-1 and THA-2 fluxes indicates SWIS can be used to study solar wind ion anisotropy and alpha-particle directionality.
  • SWIS velocity fluctuations can support inertial-range turbulence studies, with power spectral slopes near the MHD prediction.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • If SWIS's density and thermal speed biases come mainly from the two-plane sampling assumption, then adding a response-model correction for the unsampled out-of-plane direction could bring density and temperature into closer agreement with Wind-3DP without changing the velocity result.
  • The ratio of THA-1 to THA-2 flux is itself a local measure of anisotropy, so it could be compared against moment-derived temperatures to flag intervals where the isotropy assumption fails.
  • The weak density and thermal speed agreement with DSCOVR suggests that spacecraft separation or Faraday-cup response, not SWIS alone, may dominate those discrepancies; a triple co-location study could separate those effects.
  • Over a longer baseline, SWIS's 5-second cadence could resolve kinetic-scale solar wind fluctuations at L1 with better temporal resolution than Wind-SWE-FC's 92-second cadence, making it a useful complement for turbulence studies.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

3 major / 5 minor

Summary. The paper reports on the first year of operations of the Aditya-L1 ASPEX-SWIS solar wind ion spectrometer. It describes the instrument and the derivation of proton density, bulk speed, and thermal speed from dual top-hat electrostatic analyzer data, assuming an isotropic Maxwellian distribution in the spacecraft frame. The authors validate SWIS against Wind and DSCOVR through an August 2024 ICME case study, a dual-plane anisotropy analysis, a turbulence power spectral density comparison, and a 17-month statistical comparison (January 2024 to May 2025). The central claim is that SWIS bulk velocity measurements agree strongly with Wind (R2 = 0.94), while density and thermal speed show larger scatter attributed to inter-instrument differences, and that SWIS is scientifically useful for both transient and long-term solar wind monitoring.

Significance. If the validation is robust, the paper establishes a new L1 solar wind monitor with high-cadence dual-plane measurements, which would be valuable for multi-point heliospheric studies and space weather monitoring. The strongest positive evidence is the bulk velocity agreement with Wind: R2 = 0.94 with slopes near unity for both Wind-SWE-FC and Wind-3DP-PLSP, a well-resolved ICME case study, and a turbulence spectral slope close to the MHD inertial-range expectation. The paper also provides public data access for the cruise-phase dataset and clear documentation of the instrument configuration. However, the density and thermal speed products, which are central to the long-term monitoring claim, are derived under an isotropic-spacecraft-frame assumption that is physically questionable for the supersonic solar wind, and the validation metrics for those parameters are poor (e.g., density R2 = -0.35 against Wind-3DP and thermal speed R2 = 0.07 against DSCOVR). The scientific significance is therefore conditional on reworking or carefully qualifying the moment derivation and the associated validation claims.

major comments (3)
  1. [Section 2.2] The moment formulas n = Σ f_i Δv_i, v = (1/n) Σ f_i v_i Δv_i, and σ² = (1/n) Σ f_i (v_i − v)² Δv_i treat the measured fluxes as a one-dimensional speed distribution, but a proper phase-space moment requires a Jacobian factor (e.g., 4πv² in the isotropic case) and a transformation from the spacecraft frame to the plasma frame. The stated assumption that the proton distribution is 'approximately Maxwellian and isotropic in the spacecraft frame' is inconsistent with the solar wind being a supersonic beam in that frame (V ≈ 400 km/s, thermal speed ≈ 20 km/s). This is not merely a cosmetic issue: the derived density and thermal speed are systematically biased, and this bias is a direct, untested explanation for the poor validation metrics in Table 2, such as density R2 = -0.35 against Wind-3DP and thermal speed R2 = 0.07 against DSCOVR. The paper needs to either derive the moments correctly for a beam-like distribution, quantify the bias introduced by the current 1D isotropic treatment, or restrict the validated products to bulk velocity only.
  2. [Section 2.2, low-speed cutoff] The exclusion of data bins with v < 280 km/s removes a substantial portion of the slow solar wind and is applied without any sensitivity analysis. Because the cutoff is applied before the moment calculations, it systematically truncates the low-speed wing of the distribution and biases the density and thermal speed estimates, especially in slow-wind intervals. Given that the density and thermal speed comparisons already show weak or negative R2 values in Table 2, the paper should quantify how sensitive the reported statistical results are to the choice of cutoff, or justify the cutoff with a demonstrated physical or instrumental reason rather than as an unexamined preprocessing step.
  3. [Sections 3.6 and 4, Table 2] The abstract and conclusion claim 'expected variability in thermal speed and density due to inter-instrument differences' and 'strong agreement' in bulk velocity, but Table 2 shows that the DSCOVR comparisons are weak even for velocity: bulk velocity slope 0.82 with R2 = 0.44, thermal speed R2 = 0.07, and proton density R2 = 0.09. The paper does not provide error bars on the slopes or R2 values, nor any statistical test that the observed scatter is consistent with the claimed 'expected' inter-instrument differences. The central validation claim should be narrowed to the Wind velocity comparison, or the DSCOVR discrepancies need a quantitative treatment (e.g., regression uncertainties, cross-calibration factors, or a demonstration that the discrepancies are consistent with known instrument geometry and sampling differences).
minor comments (5)
  1. [Abstract] The sentence beginning 'In this study, we assess the performance of SWIS...' appears twice in the abstract and should be removed once.
  2. [Section 2.2] The sentence describing the total uncertainty starts with 'These sources are combined in quadrature to compute the total uncertainty in the differential flux' but then stops without giving the explicit formula or the resulting uncertainty propagation to n, v, and vt; please complete the derivation or provide a reference.
  3. [Figure 10 and Section 3.5] The spectral slope value of approximately -1.501 for AL1-ASPEX-SWIS is reported without an uncertainty or a description of the fitting procedure; since the text emphasizes agreement with Wind, the Wind slope and its uncertainty should also be given.
  4. [Section 3.2] The text refers to 'a simple exercise (not shown here)' involving a frequency-domain filter; either include this analysis in a supplemental figure or remove the reference to it, because the reader cannot evaluate the claimed improvement in correlation.
  5. [Data Availability] The ISSDC link is given as 'https://pradan1.issdc.gov.in/al1/'; please confirm that this is the correct public URL and that the dataset identifier is stable.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: validation is anchored to independent Wind/DSCOVR benchmarks; self-citations are contextual instrument references.

full rationale

The derivation chain in this paper is a validation exercise: SWIS L2 moments are computed from measured flux (Sec. 2.2) and then compared, via scatter plots and Table 2 regressions, with bulk parameters from Wind (SWE-FC, 3DP) and DSCOVR (PlasMag-FC). The targets of comparison are external datasets, so the central claim (bulk-velocity correlation R2=0.94; ICME timing agreement; PSD inertial-range slope -1.501) does not reduce by construction to any fitted input or to a self-citation. The moment formulas n=Σf_iΔv_i, v=(1/n)Σf_iv_iΔv_i, σ²=(1/n)Σf_i(v_i-v)²Δv_i are indeed 1D speed-space reductions that assume isotropy in the spacecraft frame; this is a physical-modelling assumption that could bias density and thermal speed, and Table 2's low/negative R2 values (e.g., density R2=-0.35 vs Wind-3DP, thermal speed R2=0.07 vs DSCOVR) are consistent with such bias. However, that is a correctness/validity limitation, not a circularity: the paper does not define Wind's or DSCOVR's density or temperature in terms of SWIS measurements, nor does it fit a parameter to a subset and then 'predict' the same quantity. Self-citations [1]-[4] and [33] are instrument-description, calibration, prior-comparison, and data-release papers by the same team; they support instrument configuration and ground calibration as external artifacts, and none of them is the sole load-bearing justification for the validation outcome. The attribution of density/thermal-speed scatter to 'inter-instrument calibration differences' is not quantified, but that is an evidentiary weakness, not a circular step. No self-definitional equation, uniqueness import, or ansatz-smuggled-by-citation was found.

Assumptions & free parameters 2 free parameters · 3 assumptions · 0 invented entities

No invented entities. The paper introduces no new particles, forces, or conserved quantities. It relies on the assumption that the measured flux represents an isotropic proton distribution, and that the two orthogonal analyzers are sufficiently calibrated to infer anisotropy.

free parameters (2)
  • Low-speed cutoff v_min = 280 km/s (bins below excluded)
    Chosen by hand to reduce background/low-energy noise; affects derived density, bulk speed, and thermal speed moments, particularly in slow solar wind.
  • Inertial-range fit interval = 10^-4 to 10^-2 Hz
    Power-law slope in Section 3.5 is fit over this hand-selected frequency range; no uncertainty or sensitivity analysis is given.
assumptions (3)
  • domain assumption Solar wind proton velocity distribution is approximately Maxwellian and isotropic in the spacecraft frame.
    Invoked in Section 2.2 to derive bulk parameters from 1D slices of flux; biases are possible for beam or anisotropic wind, which may explain the weak density and thermal-speed agreement with references.
  • domain assumption Wind and DSCOVR measurements are contemporaneous and approximately co-located references at L1 for intercomparison.
    Sections 3.2 and 3.6 use Wind and DSCOVR as benchmarks; spatial separation is acknowledged but not quantitatively corrected.
  • standard math Flux-to-phase-space-density transformation is valid for moment computation.
    Section 2.2 computes moments from velocity-space flux; this assumes a known response function R(E,theta) and isotropic distributions.

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Cite this review

Pith. "Pith review of One year of ASPEX-SWIS operation -- Characteristic features, observations and science potential." pith.science (2026). https://pith.science/paper/V3P65L6K

@misc{pith2026250717523,
  author       = {Pith},
  title        = {Pith review of: One year of ASPEX-SWIS operation -- Characteristic features, observations and science potential},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/V3P65L6K}},
  note         = {Machine review of arXiv:2507.17523}
}
read the original abstract

The Aditya-L1 mission, India's first dedicated solar observatory positioned at the first Lagrange point (L1) of the Sun-Earth system, carries the Solar Wind Ion Spectrometer (SWIS) as part of the ASPEX payload suite. Even before settling into its Halo orbit, SWIS has been providing nearly continuous in-situ measurements of solar wind ion spectra. Moments of the velocity distribution functions (VDFs) have been calculated to derive key solar wind parameters such as density, bulk speed, and temperature. In this study, we assess the performance of SWIS (hereafter referred to as AL1-ASPEX-SWIS) by comparing its measurements with contemporaneous data from the Wind and DSCOVR missions. In this study, we assess the performance of SWIS (hereafter referred to as AL1-ASPEX-SWIS) by comparing its measurements with contemporaneous data from the Wind and DSCOVR missions. A detailed case study of the interplanetary coronal mass ejection (ICME) event on August 7, 2024, is presented, where sharp changes in bulk speed, thermal speed, and number density were found to be well-aligned with independent observations-confirming the instrument's ability to capture dynamic solar wind features. Spectral analysis of kinetic fluctuations revealed a well-defined inertial range with a spectral slope consistent with magnetohydrodynamic (MHD) turbulence. Furthermore, a 17-month statistical comparison (from January 2024 to May 2025) shows a strong correlation in bulk velocity (R2 = 0.94 with Wind), with expected variations in thermal speed and density arising from differences between instruments. These findings demonstrate the scientific value of AL1-ASPEX-SWIS for monitoring both transient solar events and long-term solar wind conditions.

Figures

Figures reproduced from arXiv: 2507.17523 by the authors.

Figure 1
Figure 1. This dual-plane configuration enables angular coverage across two perpendicular [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 1
Figure 1. Configuration of payloads aboard Aditya-L1. The Solar Wind Ion Spectrometer [PITH_FULL_IMAGE:figures/full_fig_p004_1.png] view at source ↗
Figure 2
Figure 2. Cutaway view of the Top Hat Analyzer (THA) sensor used in SWIS, showing the [PITH_FULL_IMAGE:figures/full_fig_p005_2.png] view at source ↗
Figures from the paper (9 more)
Figure 3
Figure 3. Figure 3: Time series of key solar wind parameters measured by AL1-ASPEX-SWIS during [PITH_FULL_IMAGE:figures/full_fig_p008_3.png]
Figure 4
Figure 4. Figure 4: In situ measurements of solar wind parameters observed by AL1-ASPEX-SWIS [PITH_FULL_IMAGE:figures/full_fig_p009_4.png]
Figure 5
Figure 5. Figure 5: Comparison of proton bulk parameters from AL1-ASPEX-SWIS and Wind-SWE [PITH_FULL_IMAGE:figures/full_fig_p010_5.png]
Figure 6
Figure 6. Figure 6: Comparison of solar wind proton parameters from AL1-ASPEX-SWIS and Wind [PITH_FULL_IMAGE:figures/full_fig_p011_6.png]
Figure 7
Figure 7. Figure 7: Comparison of proton bulk properties measured by AL1-ASPEX-SWIS and [PITH_FULL_IMAGE:figures/full_fig_p012_7.png]
Figure 8
Figure 8. Figure 8: Energy–time spectrograms of differential particle flux measured by [PITH_FULL_IMAGE:figures/full_fig_p014_8.png]
Figure 9
Figure 9. Figure 9: Temporal evolution of the alpha-to-proton density ratio ( [PITH_FULL_IMAGE:figures/full_fig_p015_9.png]
Figure 10
Figure 10. Figure 10: Power spectral densities (PSDs) of solar wind velocity fluctuations from [PITH_FULL_IMAGE:figures/full_fig_p017_10.png]
Figure 11
Figure 11. Figure 11: Comparison of v (left), nd (center), and vt (right) between Wind–SWE–FC and AL1–ASPEX–SWIS from January 2024 to May 2025. The y-axis shows Wind–SWE–FC values; the x-axis shows AL1–ASPEX–SWIS values. Linear regression fits and R2 values are overlaid. Point density is i…

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Works this paper leans on

36 extracted references · 15 canonical work pages

  1. [1]

    21919, 2025

    Dibyendu Chakrabarty, Bijoy Dalal, Santosh Vadawale, and others, Energetic ( < 2 MeV) Ion Environment of the Magnetosphere as measured by ASPEX-STEPS on board Aditya-L1 during its earth-bound phase , Preprint at https://arxiv.org/abs/2506. 21919, 2025

    work page 2025

  2. [2]

    Shah, and others, Aditya Solar Wind Particle Experiment (ASPEX) on Board Aditya—L1: The Solar Wind Ion Spectrometer (SWIS), Solar Physics, vol

    Prashant Kumar, Bhas Bapat, Manan S. Shah, and others, Aditya Solar Wind Particle Experiment (ASPEX) on Board Aditya—L1: The Solar Wind Ion Spectrometer (SWIS), Solar Physics, vol. 300, no. 4, p. 37, 2025. doi:10.1007/s11207-025-02443-x

    doi:10.1007/s11207-025-02443-x 2025

  3. [3]

    Patel, and others,Aditya Solar Wind Particle Experiment on Board Aditya–L1: The Supra-Thermal and Energetic Particle Spectrometer, Solar Physics, vol

    Shiv Kumar Goyal, Neeraj Kumar Tiwari, Arpit R. Patel, and others,Aditya Solar Wind Particle Experiment on Board Aditya–L1: The Supra-Thermal and Energetic Particle Spectrometer, Solar Physics, vol. 300, p. 35, 2025. doi:10.1007/s11207-025-02441-z

    doi:10.1007/s11207-025-02441-z 2025

  4. [4]

    Jacob Sebastian, Abhishek Kumar, Dibyendu Chakrabarty, and others, Comparison of Solar Wind flux and bulk parameters obtained from Aditya L1-ASPEX with Wind- 3DP-PESA-L and ACE-EPAM-LEMS120 , GSICS Quarterly, vol. 18, no. 4, 2025. doi:10.25923/gmzc-9a28

    work page doi:10.25923/gmzc-9a28 2025

  5. [5]

    Loto’aniu, K

    P. Loto’aniu, K. Romich, W. Rowland, and others, Validation of the DSCOVR Space- craft Mission Space Weather Solar Wind Products , Space Weather, vol. 20, 2022. doi:10.1029/2022SW003085

    doi:10.1029/2022sw003085 2022

  6. [6]

    Wilson, A

    L. Wilson, A. Brosius, N. Gopalswamy, and others, A Quarter Century of Wind Space- craft Discoveries, Reviews of Geophysics, vol. 59, 2021. doi:10.1029/2020RG000714

    work page doi:10.1029/2020rg000714 2021

  7. [7]

    Tripathi, D

    D. Tripathi, D. Chakrabarty, A. Nandi, and others, The Aditya-L1 mission of ISRO , Proc. IAU, vol. 18, pp. 17–27, 2022. doi:10.1017/S1743921323001230

    doi:10.1017/s1743921323001230 2022

  8. [8]

    K. W. Ogilvie, D. J. Chornay, R. J. Fritzenreiter, and others, SWE, a comprehensive plasma instrument for the WIND spacecraft , Space Science Reviews, vol. 71, no. 1, pp. 55–77, 1995. doi:10.1007/BF00751326

    doi:10.1007/bf00751326 1995

Show all 36 references
  1. [9]

    R. P. Lin, K. A. Anderson, S. Ashford, and others, A three-dimensional plasma and energetic particle investigation for the WIND spacecraft , Space Science Reviews, vol. 71, pp. 125–153, 1995. doi:10.1007/BF00751328

    1995 doi

  2. [10]

    Daly, Analysis Methods for Multi-Spacecraft Data , ISSI Scientific Reports Series, vol

    G¨ otz Paschmann and Patrick W. Daly, Analysis Methods for Multi-Spacecraft Data , ISSI Scientific Reports Series, vol. 1, ESA/ISSI, 1998

    1998

  3. [11]

    Feldman, E

    U. Feldman, E. Landi, N. A. Schwadron, On the sources of fast and slow solar wind , JGR: Space Physics, vol. 110, no. A7, 2005. doi:10.1029/2004JA010918

    2005 doi

  4. [12]

    Alterman and J

    B. Alterman and J. Kasper, Helium Variation across Two Solar Cycles Reveals a Speed- dependent Phase Lag , ApJ, vol. 879, p. L6, 2019. doi:10.3847/2041-8213/ab2391

    2019 doi

  5. [13]

    Chakrabarty, N

    Yogesh, D. Chakrabarty, N. Srivastava, New insights on the behaviour of solar wind protons and alphas in the Stream Interaction Region in solar cycle 23 and 24 , MNRAS Letters, 2023. doi:10.1093/mnrasl/slad112 20

    2023 doi

  6. [14]

    Kilpua, H

    E. Kilpua, H. E. J. Koskinen, T. I. Pulkkinen, Coronal mass ejections and their sheath regions in interplanetary space , Living Rev. Solar Phys., vol. 14, no. 1, p. 5, 2017. doi:10.1007/s41116-017-0009-6

    2017 doi

  7. [15]

    D. F. Webb and T. A. Howard, Coronal Mass Ejections: Observations , Living Rev. Solar Phys., vol. 9, no. 1, p. 3, 2012. doi:10.12942/lrsp-2012-3

    2012 doi

  8. [16]

    J. D. Richardson, Shocks and sheaths in the heliosphere , JASTP, vol. 73, no. 11, pp. 1385–1389, 2011. doi:10.1016/j.jastp.2010.06.005

    2011 doi

  9. [17]

    J. D. Richardson, Y. Liu, C. Wang, and others, ICMEs at very large distances , Adv. Space Res., vol. 38, no. 3, pp. 528–534, 2006. doi:10.1016/j.asr.2005.06.049

    2006 doi

  10. [18]

    J. J. Podesta, D. A. Roberts, M. L. Goldstein, Power spectrum of small-scale tur- bulent velocity fluctuations in the solar wind , JGR: Space Physics, vol. 111, 2006. doi:10.1029/2006JA011834

    2006 doi

  11. [19]

    Smith, Comparison of plasma parameter values obtained from the WIND SWE and 3DP instruments , NOAA Technical Memorandum ERL SEC 91, 1998

    Z. Smith, Comparison of plasma parameter values obtained from the WIND SWE and 3DP instruments , NOAA Technical Memorandum ERL SEC 91, 1998

    1998

  12. [20]

    Kasper, Michael L

    Justin C. Kasper, Michael L. Stevens, Alan J. Lazarus, and others, Solar Wind Helium Abundance as a Function of Speed and Heliographic Latitude , ApJ, vol. 660, no. 1, p. 901, 2007. doi:10.1086/510842

    2007 doi

  13. [21]

    Borrini, J

    G. Borrini, J. D. Richardson, K. W. Ogilvie, and others, Helium abundance enhancements in the solar wind , JGR, vol. 87, no. A9, pp. 7370–7378, 1982. doi:10.1029/JA087iA09p07370

    1982 doi

  14. [22]

    T. H. Zurbuchen, I. G. Richardson, In-Situ Solar Wind and Magnetic Field Sig- natures of Interplanetary CMEs , Space Science Reviews, vol. 123, pp. 31–43, 2006. doi:10.1007/s11214-006-9010-4

    2006 doi

  15. [23]

    Chakrabarty, N

    Yogesh, D. Chakrabarty, N. Srivastava, Distinctive changes in solar wind helium abundance in solar cycle 24 , MNRAS Letters, vol. 503, no. 1, pp. L17–L22, 2021. doi:10.1093/mnrasl/slab016

    2021 doi

  16. [24]

    Chakrabarty, N

    Yogesh, D. Chakrabarty, N. Srivastava, Helium enrichment in ICMEs: new insights , MNRAS Letters, vol. 513, no. 1, pp. L106–L111, 2022. doi:10.1093/mnrasl/slac044

    2022 doi

  17. [25]

    E. N. Parker, Dynamics of the Interplanetary Gas and Magnetic Fields , ApJ, vol. 128, pp. 664–676, 1958. doi:10.1086/146579

    1958 doi

  18. [26]

    S. R. Cranmer, Coronal Holes and the High-Speed Solar Wind , Living Rev. Solar Phys., vol. 6, no. 3, 2009. doi:10.12942/lrsp-2009-3

    2009 doi

  19. [27]

    J. T. Gosling, CMEs and Magnetic Reconnection in the Solar Wind , JGR, vol. 98, pp. 18937–18949, 1993. doi:10.1029/93JA01405

    1993 doi

  20. [28]

    W. H. Matthaeus, M. Velli, Turbulence Effects in the Heliosphere and on the Solar Wind, Space Science Reviews, vol. 160, pp. 145–168, 2005. doi:10.1007/s11214-005-3824-3 21

    2005 doi

  21. [29]

    Grevesse, A

    N. Grevesse, A. J. Sauval, Standard Solar Composition, Space Science Reviews, vol. 85, pp. 161–174, 1998. doi:10.1023/A:1005161325181

    1998 doi

  22. [30]

    J. J. Podesta, D. A. Roberts, M. L. Goldstein, Spectral Exponents of Kinetic and Mag- netic Energy Spectra, ApJ, vol. 664, no. 1, p. 543, 2007. doi:10.1086/519211

    2007 doi

  23. [31]

    Asplund, N

    M. Asplund, N. Grevesse, A. J. Sauval, and others, The Chemical Composition of the Sun, ARA&A, vol. 47, pp. 481–522, 2009. doi:10.1146/annurev.astro.46.060407.145222

    2009

  24. [32]

    J. M. Laming, A Unified Picture of FIP and Inverse-FIP Effects , ApJ, vol. 614, no. 2, p. 1063, 2004. doi:10.1086/423780

    2004 doi

  25. [33]

    doi:10.5281/zenodo.15861770

    Abhishek Kumar, Prashant Kumar, Dibyendu Chakrabarty, and others, AL1-ASPEX-SWIS [06–12 November 2023], L2 Data , Zenodo, July 2025. doi:10.5281/zenodo.15861770

    2023 doi

  26. [34]

    Ogilvie, Richard J

    Keith W. Ogilvie, Richard J. Fitzenreiter, Alan J. Lazarus, Justin C. Kasper, Michael Stevens, Wind SWE 92-sec Definitive Solar Wind Proton Data , NASA HPDE, 2021. https://hpde.io/NASA/NumericalData/Wind/SWE/Definitive/PT92S

    2021

  27. [35]

    Lin, Stuart D

    Robert P. Lin, Stuart D. Bale, Lynn B. Wilson III, Peter Schroeder, Wind 3DP 24- sec Ion OmniDirectional Fluxes and Moments , NASA HPDE, 2021. https://hpde.io/ NASA/NumericalData/Wind/3DP/PLSP/PT24S

    2021

  28. [36]

    doi:10.7289/V51Z42F7 22

    NOAA SWPC, Deep Space Climate Observatory (DSCOVR) , NOAA Dataset, 2016. doi:10.7289/V51Z42F7 22

    2016 doi

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Reviewed August 6, 2026 · model on record in the stance chip above.