Barrow Magnetic Observatory
Jack Townshend
U.S. Geological Survey, College Observatory, Fairbanks, Alaska 99775-5160
The Barrow Magnetic Observatory is the northernmost of the agencys 13 continuously recording, digital magnetic observatories. As such it serves as a singularly important site in a global network of observing stations whose combined data define the planetary magnetic field and track its secular change. Ground stations such as at the Barrow Observatory are controls for field modeling by harmonic analysis, essential reference stations for airborne and satellite surveys, and absolute calibration locations for field survey instrumentation. Data from Barrow are forwarded electronically to the United States Geological Survey (USGS) office in Golden, Colorado. Data are distributed by the USGS National Geomagnetic Information Center in Golden and by the international INTERMAGNET organization. Final processed data from Barrow and the other 12 USGS observatories are sent to the NOAA World Data Center A for archiving.
The primary instrumentation in operation at Barrow includes an EDA FM-100BR triaxial fluxgate magnetometer, EDA PPM-105 proton free-precession magnetometer, an Observatory Magnetometer Interface System (OMIS), and several pier-mounted instruments for absolute control observations. Data output consists of 1.0-minute values of three vector components of the Earths magnetic field, as well as total field.
In August 1993 the USGS and NOAA negotiated a Memorandum of Agreement to have CMDL personnel at Barrow service the USGS Barrow equipment, make instrument observations, and provide some logistic support. The weekly absolute measurements and equipment service made by NOAA personnel are essential for maintaining high standards for the observatory operation and data quality.
Principal investigators for the Barrow Observatory are located in the USGS office at Fairbanks, Alaska, and at Golden Colorado. The Barrow-Magnetic Observatory receives its authorization to operate from the USGS Central Region Geologic Hazards Team in Golden, Colorado.