Rotation of the Solar Magnetic Field During the Ascending Phase of Solar Cycle 25

We present a comprehensive analysis of solar photospheric rotation during the ascending phase of solar cycle 25 using Carrington synoptic magnetic maps (December 2019–July 2025) and cross-correlation techniques. By constructing rotational profiles and deriving the coefficients A (equatorial rotation rate) and B (latitudinal differential rotation), we investigate their temporal evolution and polarity dependence. Our key findings are as follows: (1) The rotational profile during solar cycle 25 exhibits classic differential rotation, peaking at the equator and decreasing with latitude, along with a transition to quasi-rigid rotation above 55○. (2) A hemispherically antisymmetric polarity dependence emerges at low-mid latitudes (0○–60○), where positive-polarity fields rotate faster in the northern hemisphere, while negative-polarity fields dominate in the southern hemisphere. (3) Temporal analysis during solar cycle 25 reveals a significant negative correlation between A and B. Notably, negative-polarity fields exhibit stronger A–B anticorrelations and larger parameter variations, dominating the total magnetic field evolution.