Three orthogonal flux-gate magnetometer elements, (spinning twin fluxgate magnetometer prior to GOES-8) provide magnetic field measurements in three mutually perpendicular components: HP, HE and HN. HP is perpendicular to the satellite's orbital plane. HE lies parallel to the satellite-Earth center line and points earthward. HN is perpendicular to both HP and HE, and points westward for GOES-4 and earlier satellites, and eastward for later spacecraft. The Synchronous Meteorological Satellites (SMS-1 and SMS-2) and the Geostationary Operational Environmental Satellites (GOES-1, GOES-2, etc.) all carry on board the Space Environment Monitor (SEM) instrument subsystem. The SEM has provided magnetometer, energetic particle, and soft X-ray data continuously since July 1974. Geosynchronous satellites have an unobstructed view of the sun for all but the few dozen hours per year when the Earth eclipses the sun. You can identify these intervals as gaps in the X-ray data near satellite local midnight in March-April, and September-October. The volume of these data makes it impossible to issue a guarantee as to the quality of each and every data point. Users should be suspicious of 'spikes' in the data and attempt to correlate them with other sources before assuming that they represent the space environment. The time of these observations has not been corrected for the down-link and preprocessing delay which is within 1 - 5 seconds.

This file is comprised of the variation one minute values of the geomagnetic components X, Y and Z. These data were calculated by the Air Force Geophysics Laboratory magnetometer network during the years 1978-1983. The values are variation values and should not be used in looking at absolute values of the geomagnetic components.

Space Weather Analysis archives are model output of ionospheric, thermospheric and magnetospheric particle populations, energies and electrodynamics

The file is comprised of monthly DST indices. These indices are derived from a network of eight stations in the equatorial latitudes. Hourly DST indices provide an index of geomagnetic activity as a function of universal time. DST may reflect variations in the stratospheric tail current and field-aligned currents in the magnetosphere. The DST indices are available from 1957 to present.

The abbreviations used for observatory names are as follows: GEOMAGNETIC OBSERVATORIES Code Station Geomagnetic Latitude ABG Alibag AMS Martin de Vivie. These data present the principal magnetic storms for the month as reported by several observatories through cooperation with the International Association of Geomagnetism and Aeronomy (IAGA). These are the data formerly published in the Journal of Geophysical Research. They are now, however, grouped by the storm rather than by station. The geomagnetic latitude of the station is indicated. The beginning time is given to the hour and minute in UT. The tupe of sudden commencement, if any, together with its magnitude in each element D, H or Z is next in the format: sc = sudden commencement; sc* = small initial impulse followed by main impulse (in this case the amplitude is that of the main pulse only, neglecting the initial brief pulse); dots in these columns represent a stomr with gradual commencement; blanks indicate no data entries. Signs of amplitudes of D and Z are taken albegraically; D reckoned positive if toward the east and Z reckoned positive if vertically downward. In the next columns the day and the three-hour periods on that day when the K index reached its maximum are given followed by the K index value. In the next three columns the maximum ranges in D, H and Z during the storm are given. The ending time is given only to the nearest hour. This is the time of cessation of reasonably marked disturbance movements in the trace. More specifically, it is the time when the K index measure has diminished to 2 or less for a reasonable period. For each date the data are listed in north-to-south geomagnetic latitude order.

Wang-Sheeley-Arge (WSA)-Enlil is a large-scale, physics-based prediction model of the heliosphere, used by the Space Weather Forecast Office to provide 1-4 day advance warning of solar wind structures and Earth-directed coronal mass ejections (CMEs) that cause geomagnetic storms. Solar disturbances have long been known to disrupt communications, wreak havoc with geomagnetic systems, and to pose dangers for satellite operations.

The NOAA National Centers for Environmental Information (formerly National Geophysical Data Center) maintains an active database of worldwide geomagnetic observatory data to further the understanding of Earth magnetism and the Sun-Earth environment.Historically, magnetic observatories were established to monitor the secular change (variation), of the Earth's magnetic field, and this remains one of their most important functions. This generally involves absolute measurements sufficient in number to monitor instrumental drift and to produce annual means. Over 70 countries operate more than 200 observatories worldwide. The magnetic observatory data are crucial to the studies of secular change, investigations into the Earth's interior, navigation, communication, and to global modeling efforts. In addition to the continuously operating magnetic observatories, many countries make measurements at temporary magnetic stations (known as repeat stations), over a period of days every 5 - 10 years.The Earth's magnetic field is described by seven parameters. These are declination (D), inclination (I), horizontal intensity (H), vertical intensity (Z), total intensity (F) and the north (X) and east (Y) components of the horizontal intensity. By convention, declination is considered positive when measured east of north, inclination and vertical intensity positive down, X positive north, and Y positive east. The magnetic field observed on Earth is constantly changing.

The Space Environment Monitor (SEM) Magnetometer (MAG) instrument onboard the GOES satellite series measures the magnitude and direction of the Earth's ambient magnetic field in geosynchronous orbit. This data collection includes Reprocessed Level-1b and Level-2 SEM/MAG data from GOES 8-15. The data are enhanced to science quality from the original operational archive. Enhancements include the highest temporal cadence (2Hz), recomputed means, corrected calibration parameters, updated quality flagging, vector measurements in geophysically relevant coordinates, and full ephemeris information. The data were produced by NOAA’s National Centers for Environmental Information (NCEI) and archived by NOAA's Comprehensive Large Array-Data Stewardship System (CLASS).

The Magnetometer Instrument Engineering Telemetry Data file contains data used to support the generation of the Magnetometer Level 1b product, and monitor and evaluate the health and performance of the two magnetometers. This data is transmitted to the ground in raw digital counts, and subsequently converted into physical units by the ground system. Some of the data pertains to the temperature of components of the magnetometers. This includes temperatures for the electronics and sensors. Other telemetry includes reference voltages and temperature dependent scale factors and offsets relating raw observed counts to magnetic field units (nanoteslas) for the two magnetometers. The Magnetometer Calibration Data file contains raw observation counts and data acquisition status from the inboard and outbound magnetometers for a one second interval during a calibration maneuver. Nominally, this file contains ten observation samples acquired at one-tenth of a second intervals.

The geomagnetic aa index provides a long climatology of global geomagnetic activity using 2 antipodal observatories at Greenwich and Melbourne- IAGA Bulletin 37, 1975 p. 128