MARATTO

article · International Journal of Numerical Methods for Heat &amp Fluid Flow

Nonplanar integer and fractional dust-acoustic solitary and cnoidal waves in lunar terminator plasma: a first analytical investigation

In plain language

This research provides an analytical investigation into nonplanar dust-acoustic solitary and cnoidal waves within the dusty plasma of the lunar terminator region. Using a three-component fluid plasma model that accounts for inertial negatively charged dust and Boltzmann electrons and ions, the system is reduced to nonplanar Korteweg-de Vries equations in both standard integer and time-fractional forms. The mathematical models examine cylindrical and spherical geometries alongside temporal memory effects. Results demonstrate that only rarefactive wave structures form under lunar terminator conditions. Geometric curvature introduces explicit time dependence, leading to reduced wave amplitudes and changing widths over time, with spherical geometries demonstrating stronger effects than cylindrical forms. Furthermore, higher dust concentration and elevated electron-to-ion temperature ratios decrease wave amplitude and width.

Key takeaways

  • Under physical conditions typical of the lunar terminator, the plasma supports exclusively rarefactive dust-acoustic structures.
  • Geometric curvature causes dust-acoustic solitary and cnoidal waves to decay in amplitude and alter in width over time, with spherical waves experiencing greater damping than cylindrical waves.
  • Increases in dust concentration and the electron-to-ion temperature ratio compress both the amplitude and the width of the wave structures.
  • The formulation establishes a semi-analytical framework combining an ansatz method and the Tantawy technique to resolve curvature-modified fractional evolution equations.

Why it matters

Dust dynamics in the lunar environment influence electrostatic activity and particulate transport near the Moon's surface. Understanding how plasma waves behave in curved space and over time helps scientists model the physical environment of the lunar terminator. This provides foundational theoretical benchmarks needed to interpret data from numerical space simulations and upcoming lunar exploration missions.

Commercialisation angle

This is early-stage theoretical and mathematical research without direct commercial applications. The analytical models may eventually assist aerospace agencies, mission planners, and scientific software developers in designing numerical simulations and interpreting in situ electrostatic measurements collected by lunar instruments. However, the abstract does not indicate any current commercialisation pathway or direct industry partnership.

AI-generated from the published abstract. Always read the original work before citing.

Abstract

Purpose This work aims to investigate, for the first time, the nonplanar (cylindrical and spherical geometries) integer and time-fractional dust-acoustic (DA) solitary and cnoidal waves (CWs) in the lunar terminator dusty plasma, focusing on the combined influence of geometric curvature and temporal memory. Design/methodology/approach A three-component fluid plasma model with inertial negatively charged dust and Boltzmann electrons and ions is considered under nonplanar geometries. The reductive perturbation technique reduces the fluid model to a nonplanar Korteweg-de Vries (KdV) equation, for which a time-dependent ansatz provides semi-analytical solitary and CW solutions. Replacing the first-order time derivative with the fractional Caputo derivative yields a nonplanar fractional KdV equation, which is solved using the Tantawy technique. Findings For parameters relevant to the lunar terminator, only rarefactive DA structures are supported. Curvature makes solitary and CWs explicitly time-dependent, with amplitudes decreasing and widths evolving during propagation, and spherical waves are more strongly affected than cylindrical ones. Higher dust concentration and electron-to-ion temperature ratio reduce the amplitude and width, while decreasing a further dampens the structures; the semi-analytical solutions remain accurate according to residual-error measures. Practical implications The nonplanar integer and fractional KdV models supply a compact framework for interpreting nonlinear electrostatic activity and dust transport in the lunar terminator region and can serve as benchmarks for numerical simulations and future in situ observations. Originality/value To the best of the authors’ knowledge, this study provides the first analytical treatment of cylindrical and spherical DA solitary and CWs within a time-fractional KdV formulation tailored to the lunar terminator plasma and demonstrates a combined ansatz-Tantawy approach for nonintegrable curvature-modified fractional evolution equations.

Research topics

  • Dust and Plasma Wave Phenomena
  • Ionosphere and magnetosphere dynamics
  • Astrophysics and Star Formation Studies

Read the original research

This page summarises published work. The authoritative version sits with the publisher.

DOI: 10.1108/hff-05-2026-0684

Is something wrong with this record? Report it or request removal.

Discussion

Discuss this research

Have you built on this work, tried to replicate it, or seen it applied in practice? Share what you know. Verified researchers and MARATTO™ domain experts can open a discussion, and any member can reply. Contributions are reviewed before they appear.

No discussion yet. Open the first thread.