Which solar term has the longest shadow in Taizhou Noon Building?

Solstice of winter. According to relevant data, the shadow length of the noon building in Taizhou is the longest during the winter solstice. Taizhou, referred to as "Tai", was called Hailing in ancient times. It is a prefecture-level city in Jiangsu Province. It is located in the middle of Jiangsu Province, bordering the Yangtze River in the south, Yancheng in the north, Nantong in the east and Yangzhou in the west. The city's inland river network is densely covered and criss-crossed. The northern region is low-lying, and the water network is centripetal, and it is concentrated from all around to the lower part. There are many lakes here.