The Geomagnetic Indices Bulletin is a one page sheet containing the magnetic indices Kp, Ap, Cp, An, As, Am and the provisional aa indices. The bulletin is published monthly.

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.

Report on the status of world wide geomagnetic observatories

The Deep Space Climate ObserVatoRy (DSCOVR) satellite is a NOAA operated asset at the first Lagrange (L1) point. The primary space weather instrument is the PlasMag suite. PlasMag includes a fluxgate magnetometer (MAG) that measures the local magnetic field, and a Faraday Cup (FC) that measures the solar wind bulk properties (wind speed, density and temperature). The PlasMag solar wind data are essential inputs for the forecasts and nowcasts provided to SWPC customers. The PlasMag data are also available to scientists for sensor cal/val and for research purposes. DSCOVR was launched on Feb. 11, 2015, so all data present in the Archive from earlier dates are data used for ground testing, and do not represent the space environment. DSCOVR became operational on July 27, 2016. End Of Life (EOL) is anticipated to be December 2019. NCEI plans to receive data until EOL, and will continue to archive the data in accordance with Data Center policies.

The NOAA National Centers for Environmental Information (formerly National Geophysical Data Center) receives, on a monthly basis, Q indices from Sodankyla. These data are available from July 1957 to the present. Sodankyla indices are the most complete records of Q indices that NCEI has. The archive also contains Q indices from 15 other observatories. The Q index is a measure of geomagnetic activity assigned by high latitude (geomagnetic latitude > 58 degrees) geomagnetic observatories for each 15 minute interval. The index is designed to study auroral and ionospheric phenomena over a time scale smaller than that possible with KP. The Q scale is loosely logarithmic, with possible values from 0 to 11.

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

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.

Several regions are represented in this unique collection of earth surface measurements of magnetic field parameters and their related anomalies. The DNAG Magnetics "Super grid" of Magnetic Anomaly Map of North America was created from the four "Original" DNAG Magnetic data sets distributed by The Committee for the Magnetic Anomaly Map of North America, 1987. This development of a super grid involved an extensive task of matching original quadrant information and eliminating overlap. The resulting grid, with x and y step intervals of 2.0 kilometers yields a grid with dimensions (4451 x 4273) containing 19,019,123 values. This process can be thought of as "stitching the grids." The data in this grid are in a Spherical Transverse Mercator projection, the kilometer coordinates of which can be recovered from the indices of a grid point. The Ministry of Geology of the USSR published a mosaic series of 18 maps in 1974, at a scale of 1:2,500,000 showing the residual magnetic intensity over the land mass of the USSR. Much of the source material originated from data collected between 1949-1962, during which time the entire territory of the USSR was surveyed using aerial magnetic survey techniques. These surveys wereadjusted based on many methods including secular variation linked to magnetic observatories. Anomalies were computed with reference to a normal field map for 1964-65 constructed from equally accurate total field measurements along control network strips. Digitization was accomplished in 1982 by the U.S. Naval Oceanographic Office. The "BRIGGS cubic spline" method was used to compute grid values. A one-minute grid was created by properly matching the boundaries of the digitized sub-sections. The units of the original map aremilli-Oersteds and the units of the resulting digital grid are milli-Oersted/100. Corrections to the digital contour file were made by Conoco Inc.in 1993. New Grid files at 2.5 Km and 5.0 Km spacing were created and re-archived by NGDC. These data are available on CD-ROM. World Data Center-A (WDC-A) for Solid Earth Geophysics presently holds Grid data from many U.S. and other regions. These data were contributed by: USGS, MINN G.S. and other Worldwide organizations. Grid intervals vary but are as fine as 213.36m for the NGS Super Grid of the state of Minnesota. Other grids were recreated indigital form from previously published maps and charts. The bulk of these grid data files were contributed to NGDC after 1985. A detailed list of the specific regions is available upon request.

Storm Sudden Commencements (ssc) 1868 to present: STORM1 and STORM2 Lists: (Some text here is taken from the International Association of Geomagnetism and Aeronomy (IAGA) Bulletin 39) 1868-1967 data (STORM1.SSC) are from IAGA Bulletin 33. These data are based on 3 observatories. Only one of them was at low latitude; the other two, with an invariant magnetic latitude of 50 degrees, were strongly sensitive to the auroral effect. 1968-1975 data (STORM2.SSC) are from IAGA Bulletin 39. These data are much more reliable. The monthly reports from all observatories guarantee that very few events are omitted. With the examination of five low-latitude records, the changes of rhythm could be evaluated much better, and events were kept of rejected on a more rational basis. However, it is probable that, for statistical use, both lists will be relatively homogeneous. Indeed, Alibag was the low-latitude observatory of the 100-year list and belongs, in the 1968-1975 list, to the group form which the amplitudes are close to the average of five observatories. 1976-1982 data are from IAGA Bulletin 32 series. These data are reduced in the same manner as the 1968-1975 data. 1983-present data are from the monthly ISGI Bulletins (DeBilt, Netherlands - 1983-1987 data; Institut de Physique du Globe, Paris, France - 1988-present data.

Geomagnetic 10 second data provides high temporal resolution of geomagnetic variations