ISO 22009:2009

INTERNATIONAL ISO
STANDARD 22009
First edition
2009-12-01

Space systems — Space environment
(natural and artificial) — Model of the
earth's magnetospheric magnetic field
Systèmes spatiaux — Environnement spatial (naturel et artificiel) —
Modèle du champ magnétique de la magnétosphère de la terre




Reference number
ISO 22009:2009(E)
©
ISO 2009

---------------------- Page: 1 ----------------------
ISO 22009:2009(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.


COPYRIGHT PROTECTED DOCUMENT


©  ISO 2009
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland

ii © ISO 2009 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 22009:2009(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Terms and definitions .1
3 General concepts and assumptions.2
3.1 Magnetic field induction in the earth's magnetosphere.2
3.2 Magnetospheric magnetic field standardization: process based approach.3
4 Model requirements .3
4.1 General .3
4.2 Magnetospheric magnetic field sources.3
4.3 Parameterization.3
4.4 Magnetospheric dynamics .3
4.5 Model testing and comparison with measurements.3
5 List of criteria.3
Annex A (informative) Paraboloid model of the magnetospheric magnetic field: calculation of
induction of the magnetic field of the magnetospheric currents.5
Annex B (informative) Submodels .10
Annex C (informative) .13
Bibliography.15

© ISO 2009 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 22009:2009(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 22009 was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles, Subcommittee
SC 14, Space systems and operations.

iv © ISO 2009 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 22009:2009(E)
Introduction
This International Standard describes the main requirements to the earth's magnetospheric magnetic field
model. The model satisfying the set of requirements is described in Annex A as example calculations. 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,
that are affected by solar-terrestrial interactions stimulated by solar activity such as solar flares and related
phenomena, which induce terrestrial magnetic disturbances such as magnetic storms.

© ISO 2009 – All rights reserved v

---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 22009:2009(E)

Space systems — Space environment (natural and artificial) —
Model of the earth's magnetospheric magnetic field
1 Scope
This International Standard describes the main magnetospheric large-scale current systems and the magnetic
field in the earth's magnetosphere and provides the main requirements for a model of the magnetospheric
magnetic field. Ionospheric currents are not considered in this International Standard. Annex A of this
International Standard gives a worked example of the model and establishes the parameters of
magnetospheric large-scale current systems that change according to conditions in the space environment.
This International Standard can be used to develop new models of the magnetospheric magnetic field. Such
models are useful in investigating the physical processes in the earth's magnetosphere as well as in
calculations associated with developing, testing and estimating the results of exploitation of spacecrafts and
other equipment operating in the space environment.
The main goals of standardizing the concepts of the earth's magnetospheric magnetic field are to provide
⎯ an unambiguous presentation of the magnetic field in the earth's magnetosphere;
⎯ compatibility for the results of the interpretation and analysis of space experiments;
⎯ less labour-intensive calculations of the magnetic field of magnetospheric currents in space at geocentric
distances of 1,0 to 6,6 earth radii, R ;
E
⎯ the most reliable calculations of all elements of the geomagnetic field in the space environment.
The magnetic field model presented in Annex A of this International Standard can be used to predict the
radiation conditions in space, including the periods of intense magnetic disturbances (magnetic storms), when
developing systems of spacecraft magnetic orientation and when forecasting the influence of magnetic
disturbances on transcontinental piping and power transmission lines.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
internal magnetic field
〈main magnetic field〉 magnetic field produced by the sources inside the earth's core
NOTE It can be presented in the form of a series of spherical harmonic functions. The expansion coefficients
[International Geomagnetic Reference Field (IGRF) model] undergo very slight changes in time. The International
Association of Geomagnetism and Aeronomy (IAGA) is responsible for IGRF model development and modifications and
approves its coefficients every five years. Internal magnetic field is not addressed by this International Standard.
2.2
external magnetic field
〈magnetospheric magnetic field〉 magnetic field produced by magnetospheric sources of magnetic field
© ISO 2009 – All rights reserved 1

---------------------- Page: 6 ----------------------
ISO 22009:2009(E)
2.3
magnetospheric sources of magnetic field
sources of magnetic fields including the following:
⎯ currents flowing over the magnetopause and screening the geomagnetic dipole magnetic field;
⎯ currents flowing inside the earth's magnetosphere, including
⎯ tail currents, produced by currents across the geomagnetic tail and closure currents on the
magnetopause,
⎯ ring currents, including symmetrical ring current, circling around the earth and carried by trapped
particles and partial ring current, produced by azimuthal currents at low latitudes flowing mostly in the
pre-midnight sector, and closed by field-aligned and ionospheric currents,
⎯ field-aligned currents, produced by currents flowing along the high-latitude magnetic field lines,
closed 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 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 R , the effect of the ionospheric current is insignificant.
E
NOTE 2 Magnetic field of ionospheric currents is not addressed by this International Standard.
2.4
geomagnetic dipole tilt angle
angle of inclination of the geomagnetic dipole to the plane orthogonal to the earth-sun line
2.5
solar-magnetospheric (GSM) coordinates
Cartesian geocentric coordinates, where the X-axis is directed to the sun, the Z-axis, which is orthogonal to
the X-axis, lies on the plane with the X-axis and the geomagnetic dipole axis, and the Y-axis supplements the
X-and Z-axes to the right-hand system
2.6
magnetopause stand-off distance
geocentric distance to the subsolar point on the magnetopause
3 General concepts and assumptions
3.1 Magnetic field induction in the earth's magnetosphere
G
The vector, B , expressed in nanoteslas, of the magnetic field induction in the earth's magnetosphere is
M
calculated from Equation (1):
GG G
B =+BB (1)
M1 2
where
G
B is the vector of induction of the internal magnetic field;
1
G
B is the vector of induction of the external magnetospheric magnetic field.
2
G
The magnetic field of the magnetospheric currents (external magnetic field), B , is calculated in terms of the
2
quantitative model of the magnetosphere.
2 © ISO 2009 – All rights reserved

---------------------- Page: 7 ----------------------
ISO 22009:2009(E)
3.2 Magnetospheric magnetic field standardization: process-based approach
This International Standard for magnetospheric magnetic fields does not specify a single magnetospheric
model, theoretical or empirical. In order to encourage continual improvements in magnetospheric modelling,
this International Standard is a process-based standard for determining the magnetospheric magnetic field.
The magnetospheric magnetic field model, after its development, can satisfy the requirements in Clause 4 and
the list of criteria presented in Clause 5. The worked example of the model is presented in Annex A and it is
necessary that it be reconsidered every five years relative to the candidate models. The current worked
example is presented in the Annex A.
4 Model requirements
4.1 General
The model of the magnetic field of magnetospheric currents (subsequently referred to as the “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 the compression of the earth's magnetosphere in the dayside due to interaction with the
solar wind, day-night asymmetry (i.e. the field on the nightside is weakened), daily and seasonal variations.
The model takes into account the geomagnetic dipole tilt angle, varying in the range from −35° to +35°.
4.2 Magnetospheric magnetic field sources
The standardized magnetospheric magnetic field is produced by the currents described in 2.3. The effect of
the ionospheric currents is not addressed by this International Standard.
4.3 Parameterization
Each magnetospheric source of magnetic field depends on parameters that are calculated from empirical data.
4.4 Magnetospheric dynamics
The magnetospheric dynamics is determined from a sequence of its instantaneous states.
4.5 Model testing and comparison with measurements
The model testing is carried out with the help of databases that include spacecraft-based and on-ground
measurements. The dataset used for the model testing is presented in Annex C.
5 List of criteria
The compliance criteria for this International Standard consist of the activities common for any candidate
magnetospheric magnetic field model. These criteria specify the compliance process that includes the
documentation, publication and testing of the model and include the following.
⎯ The candidate model shall include a statement of the modeling approach used (empirical or theoretical
model). The empirical models shall include a clear specification of the input data used to derive the model
and where these data were measured. Theoretical models shall include a description of the physical
principles and approaches that are used as the basis of the model.
© ISO 2009 – All rights reserved 3

---------------------- Page: 8 ----------------------
ISO 22009:2009(E)
⎯ A statement concerning the candidate model area of application and domain of applicability should be
included.
⎯ A statement about the root-mean-square (rms) errors during the model calculations relative to the
deviations from the observational data obtained from measurements should be included. For empirical
models, comparisons should also be made with data, different from those on which the model is based.
⎯ A description and implementation of the magnetospheric magnetic field model should be published in
internationally accessible, refereed journals.

4 © ISO 2009 – All rights reserved

---------------------- Page: 9 ----------------------
ISO 22009:2009(E)
Annex A
(informative)

Paraboloid model of the magnetospheric magnetic field: calculation of
induction of the magnetic field of the magnetospheric currents
A.1 Paraboloid model of the magnetic field of magnetospheric currents
A.1.1 General
The magnetospheric magnetic field calculated by paraboloid model is a solution of the magnetostatic problem
inside the paraboloid of revolution.
The vector of induction of the magnetic field of magnetospheric currents is calculated from Equation (A.1):
GG G G G G
BB=+ψψ,,R B RR,,Φ+Bψ,b+Bψ,R,b+B I (A.1)
() ( ) () () ()
2sd 1 t 12 ∞ r t sr 1r fac 0
where
G
B i
...