The terminator line coincides with the meridian only in vernal equinox? What about Xia Dongerzhi?

At the vernal equinox (2 1 year in March) and the autumnal equinox (September 23rd), the direct point of the sun is on the equator, and the terminal line coincides with the meridian.

On the summer solstice (June 22nd), the direct point of the sun moves to the Tropic of Cancer, at which time the terminator line is tangent to the South Arctic Circle.

draw

On the winter solstice (65438+February 22nd), the direct point of the sun moved to the Tropic of Capricorn, and the ending line was also tangent to the South Arctic Circle. ?