The units of declination and inclination are degrees.
Declination is negative when west of true north.
Inclination is positive in the downwards direction. The units of horizontal intensity, the north component, the east component, vertical intensity and total intensity are nT. Vertical intensity is positive in the downwards direction. The hourly mean data are from the three UK observatories from 1st January 1990 up to yesterday's date. Values up to the end of 1992 have had baseline corrections applied and are the finalised absolute hourly mean values. Baseline corrections have not been applied to the 1993 data.