Top row: ratio of the degree of polarization in the optical to NIR as a function of distance of stars in common between the IPS-GI and GPIPS observations in each region. Bottom row: systematic difference between the NIR and optical polarization angles as a function of the distance in each region. The horizontal blue dashed line is the mean value of the distribution shown in the right-side panels. The solid dark-orange lines represent the mean and standard deviation per distance bin. The weighted circular mean and standard deviation were used in the case of the angular difference.