Tropic of Cancer (0.468″) of latitude, or 15 metres, per year (it was at exactly 23° 27′N in 1917 and will be at 23° 26'N in 2045). See axial tilt and circles of latitude for further information. North of the tropic are the subtropics and the North Temperate Zone. The equivalent line of latitude south of the Equator is called the Tropic of Capricorn, and the region between the two, centered on the Equator, is the tropics. There are approximately 13 hours, 35 minutes of daylight during the summer solstice. During the winter solstice, there are 10 hours, 41 minutes of daylight. Starting
Monsoon of South Asia orbit, its rotation, and its axial tilt cause these belts to shift gradually north and south, following the Sun's seasonal shifts. The "dynamic theory" explains the monsoon on the basis of the annual shifts in the position of global belts of pressure and winds. According to this theory, the monsoon is a result of the shift of the Inter Tropical Convergence Zone (ITCZ) under the influence of the vertical sun. Though the mean position of the ITCZ is taken as the equator, it shifts north and south with the migration of the vertical sun toward the Tropics of Cancer and