子午環の赤緯観測から求めた緯度値の変化について

抄録

The latitudes derived from the observations of declinations of the Fundamental stars with the eight-inch Meridian Circle at the Tokyo Astronomical Observatory are compared with the latitudes derived from the observations of Tokyo's PZT. Before comparison, the latter is transformed to the values based on the ILS-system. Thus the difference between them in non-polar variation is found, amounting to 0." 078 sin (2mt+201.) in semi-annual term. It may be mainly due to the effect of the anomalous refraction caused by the semi-annual variation of the temperature in the reversing layer. In May and November, the migratory anticyclones overlay Japan, and the temperature in the reversing layer becomes higher than the normal one. In February and August the temperature becomes lower.