Open Questions on Ion–Neutral Collisions and Coupling in the Lower Thermosphere–Ionosphere: Electrodynamics, Energetics and Dynamics

Theodoros E. Sarris; Stelios Tourgaidis; Dimitrios Baloukidis; Maxime Grandin; Astrid Maute; Robert F. Pfaff; Jeffrey Thayer; James Clemmons; Karl Laundal; Hanli Liu; Panagiotis Pirnaris; Noora Partamies; Fazlul I. Laskar; Jean Jacques Berthelier; Mykola Ivchenko; David Knudsen; Tomoko Matsuo; Minna M.E. Palmroth; William K.William K.Bill Peterson; Gareth Perry; Claudia Stolle; Sarah Vines; Michel Blanc; Mathieu Barthelemy; Hilde Nesse

doi:10.1007/s10712-026-09937-8

Open Questions on Ion–Neutral Collisions and Coupling in the Lower Thermosphere–Ionosphere: Electrodynamics, Energetics and Dynamics

Theodoros E. Sarris
, Stelios Tourgaidis
, Dimitrios Baloukidis
, Maxime Grandin
, Astrid Maute
, Robert F. Pfaff
, Jeffrey Thayer
, James Clemmons
, Karl Laundal
, Hanli Liu
, Panagiotis Pirnaris
, Noora Partamies
, Fazlul I. Laskar
, Jean Jacques Berthelier
, Mykola Ivchenko
, David Knudsen
, Tomoko Matsuo
, Minna M.E. Palmroth
, William K.William K.Bill Peterson
, Gareth Perry

Claudia Stolle, Sarah Vines, Michel Blanc, Mathieu Barthelemy, Hilde Nesse

Democritus University of Thrace
University of Colorado Boulder
Finnish Meteorological Institute
Leibniz-Institute of Atmospheric Physics
NASA Goddard Space Flight Center
University of New Hampshire
University of Bergen
Technical University of Denmark
National Center for Atmospheric Research
University Centre in Svalbard
CNRS
KTH Royal Institute of Technology
University of Calgary
University of Helsinki
New Jersey Institute of Technology
Southwest Research Institute
Université de Toulouse
Université Grenoble Alpes

Research output: Contribution to journal › Review article › peer-review

Abstract

The Lower Thermosphere–Ionosphere (LTI) is the interface region between the Earth’s atmosphere and space. It is modulated by the energy and momentum deposition from the magnetosphere above and by the impacting waves from the lower atmosphere. The LTI region is defined by the co-existence and interaction of neutral and ionized species within the region’s electric and magnetic fields. This interplay results in unique and complex interactions between neutrals and plasmas, that are not fully understood and quantified to this date. In this paper we present an overview of some of the most important open questions related to ion/neutral coupling and the resulting collisional electrodynamics, collisional energetics and collisional dynamics processes. We outline the key reasons for addressing these questions, and highlight methodologies that can lead to their closure in the upcoming years.

Original language	English
Journal	Surveys in Geophysics
DOIs	https://doi.org/10.1007/s10712-026-09937-8
State	Accepted/In press - 2026
Externally published	Yes

Keywords

Collisional interactions
Dynamics
Electrodynamics
Energetics
Ion/neutral coupling
LTI
Lower Thermosphere–Ionosphere

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10.1007/s10712-026-09937-8

Cite this

Sarris, T. E., Tourgaidis, S., Baloukidis, D., Grandin, M., Maute, A., Pfaff, R. F., Thayer, J., Clemmons, J., Laundal, K., Liu, H., Pirnaris, P., Partamies, N., Laskar, F. I., Berthelier, J. J., Ivchenko, M., Knudsen, D., Matsuo, T., Palmroth, M. M. E., Peterson, W. K. W. K. B., ... Nesse, H. (Accepted/In press). Open Questions on Ion–Neutral Collisions and Coupling in the Lower Thermosphere–Ionosphere: Electrodynamics, Energetics and Dynamics. Surveys in Geophysics. https://doi.org/10.1007/s10712-026-09937-8

@article{03c495b39c79429b9cdca26089b681f4,

title = "Open Questions on Ion–Neutral Collisions and Coupling in the Lower Thermosphere–Ionosphere: Electrodynamics, Energetics and Dynamics",

abstract = "The Lower Thermosphere–Ionosphere (LTI) is the interface region between the Earth{\textquoteright}s atmosphere and space. It is modulated by the energy and momentum deposition from the magnetosphere above and by the impacting waves from the lower atmosphere. The LTI region is defined by the co-existence and interaction of neutral and ionized species within the region{\textquoteright}s electric and magnetic fields. This interplay results in unique and complex interactions between neutrals and plasmas, that are not fully understood and quantified to this date. In this paper we present an overview of some of the most important open questions related to ion/neutral coupling and the resulting collisional electrodynamics, collisional energetics and collisional dynamics processes. We outline the key reasons for addressing these questions, and highlight methodologies that can lead to their closure in the upcoming years.",

keywords = "Collisional interactions, Dynamics, Electrodynamics, Energetics, Ion/neutral coupling, LTI, Lower Thermosphere–Ionosphere",

author = "Sarris, \{Theodoros E.\} and Stelios Tourgaidis and Dimitrios Baloukidis and Maxime Grandin and Astrid Maute and Pfaff, \{Robert F.\} and Jeffrey Thayer and James Clemmons and Karl Laundal and Hanli Liu and Panagiotis Pirnaris and Noora Partamies and Laskar, \{Fazlul I.\} and Berthelier, \{Jean Jacques\} and Mykola Ivchenko and David Knudsen and Tomoko Matsuo and Palmroth, \{Minna M.E.\} and Peterson, \{William K.William K.Bill\} and Gareth Perry and Claudia Stolle and Sarah Vines and Michel Blanc and Mathieu Barthelemy and Hilde Nesse",

note = "Publisher Copyright: {\textcopyright} The Author(s) 2026.",

year = "2026",

doi = "10.1007/s10712-026-09937-8",

language = "English",

journal = "Surveys in Geophysics",

issn = "0169-3298",

publisher = "Springer Netherlands",

}

Sarris, TE, Tourgaidis, S, Baloukidis, D, Grandin, M, Maute, A, Pfaff, RF, Thayer, J, Clemmons, J, Laundal, K, Liu, H, Pirnaris, P, Partamies, N, Laskar, FI, Berthelier, JJ, Ivchenko, M, Knudsen, D, Matsuo, T, Palmroth, MME, Peterson, WKWKB, Perry, G, Stolle, C, Vines, S, Blanc, M, Barthelemy, M & Nesse, H 2026, 'Open Questions on Ion–Neutral Collisions and Coupling in the Lower Thermosphere–Ionosphere: Electrodynamics, Energetics and Dynamics', Surveys in Geophysics. https://doi.org/10.1007/s10712-026-09937-8

TY - JOUR

T1 - Open Questions on Ion–Neutral Collisions and Coupling in the Lower Thermosphere–Ionosphere

T2 - Electrodynamics, Energetics and Dynamics

AU - Sarris, Theodoros E.

AU - Tourgaidis, Stelios

AU - Baloukidis, Dimitrios

AU - Grandin, Maxime

AU - Maute, Astrid

AU - Pfaff, Robert F.

AU - Thayer, Jeffrey

AU - Clemmons, James

AU - Laundal, Karl

AU - Liu, Hanli

AU - Pirnaris, Panagiotis

AU - Partamies, Noora

AU - Laskar, Fazlul I.

AU - Berthelier, Jean Jacques

AU - Ivchenko, Mykola

AU - Knudsen, David

AU - Matsuo, Tomoko

AU - Palmroth, Minna M.E.

AU - Peterson, William K.William K.Bill

AU - Perry, Gareth

AU - Stolle, Claudia

AU - Vines, Sarah

AU - Blanc, Michel

AU - Barthelemy, Mathieu

AU - Nesse, Hilde

PY - 2026

Y1 - 2026

N2 - The Lower Thermosphere–Ionosphere (LTI) is the interface region between the Earth’s atmosphere and space. It is modulated by the energy and momentum deposition from the magnetosphere above and by the impacting waves from the lower atmosphere. The LTI region is defined by the co-existence and interaction of neutral and ionized species within the region’s electric and magnetic fields. This interplay results in unique and complex interactions between neutrals and plasmas, that are not fully understood and quantified to this date. In this paper we present an overview of some of the most important open questions related to ion/neutral coupling and the resulting collisional electrodynamics, collisional energetics and collisional dynamics processes. We outline the key reasons for addressing these questions, and highlight methodologies that can lead to their closure in the upcoming years.

AB - The Lower Thermosphere–Ionosphere (LTI) is the interface region between the Earth’s atmosphere and space. It is modulated by the energy and momentum deposition from the magnetosphere above and by the impacting waves from the lower atmosphere. The LTI region is defined by the co-existence and interaction of neutral and ionized species within the region’s electric and magnetic fields. This interplay results in unique and complex interactions between neutrals and plasmas, that are not fully understood and quantified to this date. In this paper we present an overview of some of the most important open questions related to ion/neutral coupling and the resulting collisional electrodynamics, collisional energetics and collisional dynamics processes. We outline the key reasons for addressing these questions, and highlight methodologies that can lead to their closure in the upcoming years.

KW - Collisional interactions

KW - Dynamics

KW - Electrodynamics

KW - Energetics

KW - Ion/neutral coupling

KW - LTI

KW - Lower Thermosphere–Ionosphere

UR - https://www.scopus.com/pages/publications/105029855989

U2 - 10.1007/s10712-026-09937-8

DO - 10.1007/s10712-026-09937-8

M3 - Review article

AN - SCOPUS:105029855989

SN - 0169-3298

JO - Surveys in Geophysics

JF - Surveys in Geophysics

ER -

Open Questions on Ion–Neutral Collisions and Coupling in the Lower Thermosphere–Ionosphere: Electrodynamics, Energetics and Dynamics

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Keywords

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