world monthly means database project


This project aims at building a publicly available monthly means database. Monthly means were calculated as far back in time as possible from hourly means retrieved from the WDC in Edinburgh (previously in Copenhagen). They were systematically checked for internal consistency and by comparing them with annual means from the WDC Edinburgh and with the CM4 geomagnetic model. Anomalous data are not present in the database, awaiting resolution of the inconsistencies by the relevant observatories.

Monthly means are archived using a new, specific file format.

The first step of the project involves only INTERMAGNET magnetic observatories.

Any publication or website making use of data from this database should acknowledge the institution(s) in charge of the corresponding observatory(s). It should also acknowledge INTERMAGNET for facilitating the collection and dissemination of observatory data worldwide.


Chulliat, A. and K. Telali, World Monthly Means DataBase Project,, Publ. Inst. Geophys. Pol.
Acad. Sc., C-99 (398), 2007.

Web access to the database

Data download also possible via FTP
server: ftp.bcmt.fr, user name: bcmt_public, password: bcmt

Contacts: telali@ipgp.fr , chulliat@ipgp.fr