When the earth rotates to its position, the sun shines directly in the northern hemisphere. In which 24 solar terms is China?

(1) As can be seen from the schematic diagram of the earth's revolution, when the earth revolves to ②, the sun is facing the Tropic of Cancer, which is the summer solstice in the northern hemisphere, and the date is around June 22nd.

(2) It can be seen from the schematic diagram of the earth's revolution that when the earth revolves to ④, the latitude of direct sunlight is tropic of Capricorn, which is the winter solstice in the northern hemisphere, and the date is about 65438+February 22nd. At this time, there will be polar night in the Arctic Circle, and the length of day and night in the northern hemisphere is as follows: the shortest day and the longest night; After that, the direct point of the sun will move northward, and the days in the southern hemisphere will become shorter and shorter.

(3) Reading Figure 2, we can see that the sun is on the tropic of Capricorn at this time, which is the winter solstice in the northern hemisphere. On this day, the earth is in the orbital position ④ shown in figure 1.

(4) According to the latitude of Quanzhou (24 55' n), Quanzhou is located in the north of the Tropic of Cancer (23.5 N), and the sun is always located in the south of Quanzhou, so it can be judged that the shadows of trees are facing north under the midday sunlight; In a year, when the shadow of trees is the longest at noon, that is, when the sun's altitude angle is the smallest, the sun shines directly on the tropic of Capricorn, and the length of day and night in Quanzhou is short.

Therefore, the answer is: (1) summer solstice; Tropic of Cancer; (2) 65438+February 22nd; Extreme night; The days are short and the nights are long; Shorter and shorter; (3)④; (4) the north; The days are short and the nights are long.