ISO TR 23989-2020 PDF

Full title and description

Space environment (natural and artificial) — Operational estimation of the solar wind energy input into the Earth's magnetosphere by means of the ground-based magnetic polar cap (PC) index. This ISO Technical Report provides guidance and an operational method for estimating the solar wind energy input into the magnetosphere using ground-based measurements of polar cap magnetic activity (the PC index) to support on-line monitoring and nowcasting of magnetospheric disturbances.

Abstract

The report describes a practical approach for qualitatively and operationally estimating solar wind energy input to the Earth’s magnetosphere by using the 1-minute polar cap (PC) index derived from near-pole geomagnetic observatories. It explains the empirical relationship between the interplanetary electric field and polar cap magnetic activity, gives the method for deriving PCN and PCS (Northern and Southern polar cap indices), and discusses how these estimates can be used for on-line monitoring, nowcasting of magnetic storms and substorms, and assessment of impacts on satellites, aviation, power systems and other technologies sensitive to space weather.

General information

• Status: Published
• Publication date: January 2020
• Publisher: International Organization for Standardization (ISO)
• ICS / categories: 49.140 (Space systems and operations)
• Edition / version: Edition 1 (2020-01)
• Number of pages: 11

Scope

The Technical Report gives recommendations and a unified technique for operational estimation of the solar wind energy input into the magnetosphere using ground-based polar cap magnetic activity indices. It is intended for on-line monitoring and nowcasting of the magnetospheric state and high-latitude ionospheric conditions; it does not prescribe hardware procurement but focuses on data processing, index derivation (PCN/PCS), regression relationships to interplanetary parameters, and practical limitations and accuracy considerations for operational use.

Key topics and requirements

• Definition and purpose of the 1-minute polar cap (PC) index (PCN and PCS) for characterizing polar-cap magnetic activity.
• Unified method for derivation of PC indices from near-pole magnetometer data, including determination of quiet daily curve (QDC) and calculation of the DP2 disturbance vector.
• Establishing regression coefficients and vector orientation (α, β, φ) linking the interplanetary electric field and the polar cap magnetic disturbance vector.
• Guidance on using PC indices to estimate solar wind energy input (coupling functions) and to nowcast magnetospheric disturbances (storms and substorms).
• Operational recommendations: required data cadence (1-minute PC index), typical source stations (northern and southern near-pole observatories), data quality considerations and limitations.
• Discussion of expected accuracy, limitations of empirical relationships, and practical caveats when using PC-based estimates for operational decision-making.

Typical use and users

This report is primarily used by space weather centres, national and international space agencies, satellite operators and mission control teams, research institutions studying magnetospheric dynamics, power grid and critical infrastructure operators concerned with geomagnetically induced currents, and aviation/airline meteorology services requiring high-latitude space weather nowcasts.

Related standards

The report sits within the body of ISO documents on space environment and operations. Related standards and technical reports include ISO standards and TRs on space weather information and environment models (examples: standards addressing the Earth’s atmosphere and ionosphere models, magnetospheric magnetic field models, and other space-environment guidance developed by ISO/TC 20/SC 14). Users should consult the broader ISO/TC 20/SC 14 catalogue for complementary standards on atmospheric models, ionosphere models, radiation and space weather information for operations.

Keywords

polar cap index; PC index; PCN; PCS; solar wind energy input; magnetosphere; space weather; geomagnetic storms; nowcasting; ground-based magnetometer; interplanetary electric field; DP2 disturbance; quiet daily curve.

FAQ

Q: What is this standard?

A: It is an ISO Technical Report (ISO/TR 23989:2020) that documents an operational method for estimating the solar wind energy input into Earth’s magnetosphere using the ground-based polar cap (PC) magnetic activity index.

Q: What does it cover?

A: It covers the derivation and operational use of the 1-minute PC index (PCN and PCS), the empirical relationship between the interplanetary electric field and polar-cap magnetic disturbances, guidance for on-line monitoring and nowcasting of magnetospheric disturbances, and practical considerations and limitations for operational implementation.

Q: Who typically uses it?

A: Space weather centres, satellite operators, mission planners, researchers in magnetospheric physics, infrastructure operators (e.g., power grid planners), and aviation services that need high-latitude space weather information.

Q: Is it current or superseded?

A: ISO/TR 23989 was published in January 2020 as Edition 1. Users should check the ISO catalogue or their national standards body for any later amendments or successor documents, but the published TR remains the formal reference for this methodology unless explicitly superseded.

Q: Is it part of a series?

A: It is part of the ISO body of standards and technical reports on space environment (ICS 49.140) developed by ISO/TC 20/SC 14 and complements other ISO documents addressing space weather information, atmospheric and ionospheric models, and magnetospheric modelling.

Q: What are the key keywords?

A: Polar cap index, PC index, PCN, PCS, solar wind energy input, magnetosphere, space weather, geomagnetic disturbance, ground-based magnetometer, nowcasting.