Maintained by: Beijing Astronomical Observatory, Chinese Academy of Sciences.

Summary of Data Held: Chinese Solar-Geophysical Data from 1971 onward:
Daily relative sunspot numbers, sunspot areas and groups, daily magnetograms of active regions from Purple Mountain Observatory
Smoothed predicted monthly sunspot numbers H-alpha solar flares and patrol observations
Solar radio emission flux and outstanding occurrences, patrol observations and burst profiles
Cosmic ray meson and neutron intensity, from Center for Space Science and Applied Research
Sudden ionospheric disturbances (D-region) Geomagnetic activity indices K and Ak List of magnetic storms, from Beijing Geomagnetic Observatory
Special issues for data of selected events
Forecasts of solar flares, sudden ionospheric disturbances
Ancient records of sunspots and phenomena related to Solar-Terrestrial Physics
Earth rotation parameters from several stations from 1959; Earth rotation parameters from optical astrometry from 1989

User Services: Open to visitors during normal working hours. Advance notice is recommended.

Data products, publications: Coordinates of epoch pole and time signals. Chinese Solar-Geophysical Data; Earth rotation parameters (Annual Report,Monthly Bulletin, Weekly Bulletin , Earth rotation parameters from optical astrometry). Catalog of Ancient Solar Events.