Long-term synoptic observations of the Sun at the National Astronomical Observatory of Japan

The National Astronomical Observatory of Japan started regular synoptic solar observations about 100 years ago. At the beginning, Ca K spectroheliograms and white-light photographs were taken, and various other types of observations have been added. These historical data have been digitized and are now open at our web site (http://solarwww.mtk.nao.ac.jp/en/solarobs.html). Currently we are operating high-resolution imaging observations in the Hα line, the green continuum, and the G-band. Besides various kinds of imaging observations, magnetic field measurements have been carried out for about 30 years. We recently started to conduct full-Sun spectropolarimetry observations in the lines of He 10830 Å/Si 10827 Å and Fe 15648 Å. These near infrared observations show the magnetic field evolutions in both the photosphere and the chromosphere. In this paper, we present our data, which are expected to contribute to studying the long-term change of the solar activity.