41、如表填空，以北半球为例，说明四季的形成 Season Time Position of direct sunlight Height of the noon sun Length of day

Spring (equinox) March 21 around the equator (0 °) Noon solar altitude has the equator to the north and south decreasing day and night equal length.

Summer (summer solstice) around June 22 Tropic of Cancer (23°26′N) Tropic of Cancer decreases to the north and south, northern hemisphere days are longer and nights are shorter, and the Arctic Circle and the polar day north of it.

Autumn (Autumn Equinox) Around September 23 Equator (0°) The equator decreases to the north and south, and day and night are equally divided.

Winter (Winter Solstice) Around December 22nd Tropic of Capricorn (23°26′S) The Tropic of Capricorn decreases to the north and south, the day is shorter and the night is longer, and the Arctic Circle and north of it is polar night.