ISO 22009:2023

Space environment (natural and artificial) - Model of the Earth's magnetospheric magnetic field

This document describes the main magnetospheric large-scale current systems and the magnetic field in the Earth's magnetosphere and provides the main requirements to the model of the magnetospheric magnetic field. Ionospheric currents are not considered in this document. The document also provides a working example of the model and establishes the parameters of magnetospheric large-scale current systems which are changing in accordance with conditions in the space environment. The document can be used to develop the new models of magnetospheric magnetic field. Such models are useful in investigating physical processes in the Earth's magnetosphere as well as in calculations, developing, testing and estimating the results of exploitation of spacecrafts and other equipment operating in the space environment.

Environnement spatial (naturel et artificiel) — Modèle du champ magnétique de la magnétosphère de la terre

General Information

• Status: Published
• Publication Date: 30-Jan-2023
• ICS: 49.140 - Space systems and operations
• Technical Committee: ISO/TC 20/SC 14 - Space systems and operations
• Drafting Committee: ISO/TC 20/SC 14/WG 4 - Space environment (natural and artificial)
• Current Stage: 6060 - International Standard published
• Start Date: 31-Jan-2023
• Due Date: 01-Sep-2022
• Completion Date: 31-Jan-2023

Relations

• Revises: ISO 22009:2009 - Space systems - Space environment (natural and artificial) - Model of the earth's magnetospheric magnetic field
• Effective Date: 01-Jan-2022

Overview

ISO 22009:2023 - Space environment (natural and artificial) - Model of the Earth's magnetospheric magnetic field - defines requirements and a process-based framework for modelling the large-scale magnetic field produced by currents in the Earth's magnetosphere. The standard describes the principal magnetospheric current systems (magnetopause currents, tail current, ring and partial ring currents, and field-aligned currents), provides a working example model (the paraboloid model in Annex A), and establishes parameterization, testing datasets (Annex C) and conformity criteria for candidate models. Ionospheric currents are excluded from this standard.

Key topics and technical requirements

• Scope and domain: Models are expected to represent the magnetospheric magnetic field vector in solar‑magnetospheric coordinates between 1.0 and 6.6 Earth radii (Re), including day–night asymmetry, magnetospheric compression by the solar wind and dipole tilt effects (geomagnetic dipole tilt angle −35° to +35°).
• Magnetospheric sources covered: magnetopause screening currents, magnetotail (tail current and associated closure), symmetric and partial ring currents, and region‑1 field‑aligned currents.
• Parameterization and dynamics: Each magnetospheric source must depend on parameters derived from empirical data (submodels in Annex B). Magnetospheric dynamics are represented as sequences of instantaneous states.
• Model validation and testing: Candidate models must document modelling approach (empirical or theoretical), specify data used to derive the model, define area of applicability, report RMS comparison errors against independent spacecraft and ground datasets, and publish results in internationally accessible refereed journals. Annex C provides datasets and coordinate-system guidance for testing.
• Working example: Annex A presents the paraboloid model, with key parameters (e.g., dipole tilt ψ, magnetopause stand‑off distance R, tail flux Φ, ring current intensity b, and region‑1 FAC total intensity I).

Practical applications and users

ISO 22009:2023 is useful for:

• Spacecraft system and mission designers (magnetic attitude control, magnetometer calibration, radiation environment assessment)
• Space weather researchers and model developers (standardized model development and comparison)
• Operators and engineers concerned with magnetic disturbances (effects on transcontinental pipelines, power transmission lines)
• Standards bodies and agencies seeking interoperable magnetospheric field descriptions

Practical uses include model-based forecasting of magnetic disturbances (magnetic storms), testing and validating onboard instruments, simulating spacecraft-environment interactions, and improving comparability across scientific studies.

Related standards and references

• Connection to the IGRF (International Geomagnetic Reference Field) for the internal (core) magnetic field is noted in the revision history.
• ISO 16695 is referenced for internal magnetic field description.
• Prepared by ISO/TC 20/SC 14 (Space systems and operations).

Keywords: ISO 22009:2023, Earth's magnetospheric magnetic field model, magnetopause, ring current, tail current, field-aligned currents, paraboloid model, space weather, spacecraft design, magnetospheric dynamics.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 22009
Second edition
2023-01
Space environment (natural and
artificial) — Model of the Earth's
magnetospheric magnetic field
Environnement spatial (naturel et artificiel) — Modèle du champ
magnétique de la magnétosphère de la terre
Reference number
ISO 22009:2023(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO 22009:2023(E)
Contents  Page
Foreword .iv
Introduction .v
1 Scope . 1
2  Normative references . 1
3  Terms and definitions . 1
4  General concepts and assumptions .2
4.1 Magnetic field induction in the Earth's magnetosphere . 2
4.2 Magnetospheric magnetic field standardization: process-based approach . 2
5  Model requirements .3
5.1 General . 3
5.2 The magnetospheric magnetic field sources . 3
5.3 Parameterization. 3
5.4 Magnetospheric dynamics . 3
5.5 Model testing and comparison with measurements . 3
6  List of criteria .3
Annex A (normative) Paraboloid model of the magnetospheric magnetic field: calculation
of induction of the magnetic field of the magnetospheric currents .5
Annex B (informative) Submodels.11
Annex C (informative) Coordinate systems and dataset for model testing .14
Bibliography .16
iii
ISO 22009:2023(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles,
Subcommittee SC 14, Space systems and operations.
This second edition cancels and replaces the first edition (ISO 22009:2009), which has been technically
revised.
The main changes are as follows:
— upgraded list of the relevant models;
— added connection with the IGRF geomagnetic model;
— added field-aligned currents;
— added data availability information;
— added information about magnetospheric current systems modelling.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
ISO 22009:2023(E)
Introduction
This document describes the main requirements to the Earth's magnetospheric magnetic field model.
A model satisfying the set of requirements is described in Annexes A and B as a working example. The
model can be used in scientific and engineering applications and is intended to calculate the magnetic
induction field generated from a variety of current systems located on the boundaries and within the
boundaries of the Earth's magnetosphere under a wide range of environmental conditions, quiet and
disturbed, affected by solar-terrestrial interactions simulated by solar activity such as solar flares and
related phenomena which induce terrestrial magnetic disturbances such as magnetic storms.
The main goals of standardisation of the Earth's magnetospheric magnetic field are:
— providing the unambiguous presentation of the magnetic field in the Earth's magnetosphere;
— providing compatibility of results of interpretation and analysis of space experiments;
— providing less labour-consuming character of calculations of the magnetic field of magnetospheric
currents in the space at geocentric distances of 1,0 to 6,6 Earth's radii (R );
E
— providing the most reliable calculations of all elements of the geomagnetic field in the space
environment.
The magnetic field model presented in the Annex A (general description) and Annex B (submodels)
can be used to forecast radiation situation in the space, including the periods of intense magnetic
disturbances (magnetic storms) when developing systems of spacecraft magnetic orientation, when
forecasting the influence of magnetic disturbances on transcontinental piping and power transmission
lines.
v
INTERNATIONAL STANDARD ISO 22009:2023(E)
Space environment (natural and artificial) — Model of the
Earth's magnetospheric magnetic field
1 Scope
This document describes the main magnetospheric large-scale current systems and the magnetic field
in the Earth's magnetosphere and provides the main requirements to the model of the magnetospheric
magnetic field. Ionospheric currents are not considered in this document. The document also provides
a working example of the model and establishes the parameters of magnetospheric large-scale current
systems which are changing in accordance with conditions in the space environment. The document
can be used to develop the new models of magnetospheric magnetic field. Such models are useful in
investigating physical processes in the Earth's magnetosphere as well as in calculations, developing,
testing and estimating the results of exploitation of spacecrafts and other equipment operating in the
space environment.
2  Normative references
There are no normative references in this document.
3  Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
magnetospheric magnetic field
external magnetic field
external magnetospheric magnetic field
magnetic field produced by magnetospheric magnetic field sources (3.4)
3.2
geomagnetic dipole tilt angle
angle of inclination of the geomagnetic dipole to the plane orthogonal to the Earth-Sun line
3.3
internal magnetic field
magnetic field produced by the sources inside the Earth's core
Note 1 to entry: It can be presented in the form of a series of spherical harmonic functions.
Note 2 to entry: The expansion coefficients (IGRF model) undergo very slight changes in time.
Note 3 to entry: The International Association of Geomagnetism and Aeronomy (IAGA) is responsible for IGRF
model development and modifications and approves its coefficients every 5 years.
Note 4 to entry: The internal magnetic field is described in ISO 16695.
3.4
magnetospheric magnetic field sources
sources of magnetic fields including the following:
ISO 22009:2023(E)
— currents flowing over the magnetopause and screening the geomagnetic dipole magnetic field;
— currents flowing inside the Earth's magnetosphere:
— tail current, produced by currents across the geomagnetic tail and closure currents on the
magnetopause;
— ring current, including symmetrical ring current, circling around the Earth and carried by
trapped particles and partial ring current, produced by currents flowing outside the region of
symmetrical ring current, mostly in the pre-midnight sector of equatorial plane, closured by
field-aligned and ionospheric currents;
— field-aligned currents, produced by currents flowing along the auroral magnetic field lines,
closured by currents on the magnetopause and in the ionosphere;
— currents flowing over the magnetopause and screening the ring current and partial ring current
magnetic fields
Note 1 to entry: In different magnetospheric models, either predefined current systems or current systems
dependent on parameters calculated from satellite data are used.
Note 2 to entry: Electric currents flowing entirely in the ionosphere (ionospheric currents) contribute to the
magnetic field variation at altitudes below 1 000 km. In the region above 1,5 Re effect of ionospheric current is
insignificant. Magnetic field of ionospheric currents is not the subject of this document.
3.5
magnetopause stand-off distance
geocentric distance to the subsolar point on the magnetopause
3.6
solar-magnetospheric coordinates
Cartesian geocentric coordinates, where X-axis is directed to the Sun, Z-axis lies in the one plane with
OX axis and geomagnetic dipole axis and Y-axis supplements the X and Z axes to the right-hand system
4  General concepts and assumptions
4.1  Magnetic field induction in the Earth's magnetosphere

Vector of magnetic field induction B in the Earth's magnetosphere is calculated by Formula (1).
M
 
BB=+B (1)
M 12
where

is the vector of induction of the internal magnetic field, in nT;
B

is the vector of induction of the magnetospheric magnetic field, in nT.
B

The magnetic field of the magnetospheric currents (magnetospheric magnetic field), B , is calculated
in terms of the quantitative model of the magnetosphere.
4.2  Magnetospheric magnetic field standardization: process-based approach
The magnetospheric magnetic field standard does not specify a single magnetospheric model,
theoretical or empirical. In order to encourage continual improvements in magnetospheric modelling,
this document is process-based for determining the magnetospheric magnetic field. Magnetospheric
magnetic field model, after its development, may satisfy the requirements in Clause 4 and the list of
criteria presented in Clause 5. The working example of the model is presented in the Annex A and
ISO 22009:2023(E)
shall be reconsidered every 5 years on the basis of competitions of the candidate models. The current
working example is presented in Annex A.
5  Model requirements
5.1 General
— The model of the magnetic field of magnetospheric currents (referred to below as "model") presents
the vector of induction of magnetospheric currents in solar-magnetospheric coordinates.
— The model describes a regular part of the magnetic field in the region from 1,0 R to 6,6 R .
E E
— The model reflects compression of the Earth's magnetosphere in the dayside due to interaction
with the solar wind, day-night asymmetry (the field on the nightside is weakened), day and season
variations.
— The model takes into account the geomagnetic dipole tilt angle, varying in the range from −°35 to
+°35 .
5.2  The magnetospheric magnetic field sources
The standardised magnetospheric magnetic field is produced by currents described in 3.3. Ionospheric
currents' effect is not considered in this document.
5.3  Parameterization
Each magnetospheric source of magnetic field depends on parameters which are calculated from
empirical data.
5.4  Magnetospheric dynamics
The magnetospheric dynamics is determined to be a sequence of its instant states.
5.5  Model testing and comparison with measurements
The model testing is carrying out with the help of databases which include the spacecraft-based and on-
ground measurements. The dataset used for the model testing is presented in the Annex C.
6  List of criteria
The conformity criteria for this document consist of the activities common for any candidate
magnetospheric magnetic field model. These criteria specify the conformity process which includes the
model documenting, publishing and testing.
— The candidate model shall include the statement of the modelling approach used (empirical or
theoretical model). The empirical models are required to include a clear specification of the input
data used to derive the model and where these data were measured. Theoretical models are required
to include a description of the physical principles and approaches that are used as the basis of the
model.
— The statement about the candidate model area of application and domain applicability should be
included.
— The statement about the rms errors during the model calculations comparison with observational
data obtained from measurements should be included. For empirical models, the comparisons
should also be made with data, different from those from which the model was built.
ISO 22009:2023(E)
— The description and implementation of the magnetospheric magnetic field model should be
published in internationally-accessible refereed journals.
ISO 22009:2023(E)
Annex A
(normative)
Paraboloid model of the magnetospheric magnetic field:
calculation of induction of the magnetic field of the
magnetospheric currents
A.1 General
The magnetospheric magnetic field calculated by paraboloid model is the solution of the magnetostatic
problem inside the paraboloid of revolution.
A.2 Paraboloid model of the magnetic field of magnetospheric currents
A.2.1 General
Vector of induction of the magnetic field of magnetospheric currents is calculated by Formula (A.1).
  
BB= ()ψψ,,RB+ ()RR,,Φ +Bb()ψψ,,+BR(),bB+ ()I (A.1)
21sd tr12 ∞ tsrf1 r aac 0
where

is the magnetic field of currents on the magnetopause screening the dipole field;
B
sd

is the magnetic field of the magnetospheric tail;
B
t

is the magnetic field of the ring current;
B
r

is the magnetic field of currents on the magnetopause, screening the ring current field;
B
sr

is the magnetic field of region 1 field-aligned currents.
B
fac
    
The components of the magnetic field of magnetospheric currents, B , B , B , B , B are calculated
sd t r sr fac
separately in terms of the paraboloid model of the magnetosphere in the form of series in the Bessel
functions or Legendre polyn
...