12- hour plot of Boulder Magnetometer H- and D components

See Data List Notice below

Period (UTC) 1500-1800 1800-2100 2100-0000 0000-0300
Value
K-index
H-trace
D-trace
K NT
1 5.0
3.4 28.8
3.5 30.4
K NT
0 2.0
1.7 8.7
3.4 28.1
K NT
2 10.0
2.5 14.6
1.8 9.2
K NT
0.5 2.5
0.5 2.5
0.2 0.8

12-hour Boulder-NOAA Magnetometer Monitor
with 3-hourly K-Indices

Boulder Magnetometer Data Lists Discontinued

April 15, 2009 -- the USGS, an acknowledged center of expertise for geomagnetism, assumed full responsibility for the Boulder magnetometer and its data. SWPC will continue to be a user of that data, but will no longer be the point of distribution of raw magnetometer data. However, this web page will continue unchanged.

Carol Finn, USGS Geomagnetism Group Leader, (cafinn@usgs.gov) is the point of contact for interested parties. Please direct any comments or questions to her.

Final Boulder K-indices are available at Geomagnetic and Solar indices, A/K Indices lists, and the Geophysical Alert Message (WWV)

SWPC Space Weather Alerts for geomagnetic phenomena are based primarily on real-time data from the Boulder-NOAA magnetometer, which is used as a proxy for mid-latitude locations, and as a general indicator of the trend in USAF Planetary K-indices that are not available in real-time.

The geographic location of the Boulder-NOAA geomagnetic observatory is N40.1 W105.2. Magnetometer values are the average of 60 1-second samples. The H component is directed along magnetic north, which is currently about 10 degrees east of geographic north. The D component is pointing 90 degrees clockwise relative to H. This is currently about 10 degrees south of geographic east. For more information see Boulder-NOAA Magnetometer description and The K-index.

This page updates dynamically every minute.

NOAA / Space Weather Prediction Center