Hourly Means
Information about the observatory hourly mean data
The hourly mean data are from the three UK observatories Eskdalemuir, Lerwick and Hartland. Eskdalemuir data are available from 1911, Lerwick from 1926, Hartland from 1957 and all three are available up to yesterday's date.
Values of declination (D), horizontal intensity (H) and vertical intensity (Z) are available. The units of declination are degrees. Declination is negative when west of true north. The units of horizontal intensity and vertical intensity are nT. Vertical intensity is positive in the downwards direction.
Values from Abinger (1926-1956) are available on request.Please note :
- Although the provisional data can sometimes be missing (denoted by *****) when they are first made available, these gaps are usually filled no later than one week after the end of the month and often earlier than this.
- The following jumps have been applied to the data to correct
for site changes. All the jump values are given as new values
minus old values and have the units of minutes of arc for declination
and nT for horizontal and vertical intensity.
Eskdalemuir
1990.0 - Dec. 0; Horiz. 11; Vert. 22
1994.0 - Dec. 0; Horiz. -8; Vert. -23
Lerwick
1934.0 - Dec. 0; Horiz. 0; Vert. 144
1990.0 - Dec. 0; Horiz. 5; Vert. -8
1996.0 - Dec. 0; Horiz. 0; Vert. 8
Hartland
1980.0 - Dec. 0; Horiz. 0; Vert. -6
1990.0 - Dec. 0; Horiz. -6; Vert. 23
BGS Observatory Data
Global Observatory and Survey Data
