Why is the temperature difference between day and night large in the valley?

The comparison of these temperature differences has a comparison object. For example, valleys and hilltops, plateaus and basins, plains and mountains. So, you can't just remember which is bigger. We should remember by comparing objects. Otherwise, it is easy to be confused. I think the reason for the large temperature difference between the plain and the mountainous area is that the sunshine time in the plain is longer than that in the mountainous area, so the temperature rises quickly and high. The near-surface atmosphere is rapidly heated. On the corresponding night, if there is no atmospheric reverse radiation and no circulation formed in the mountains to keep warm, the temperature will drop quickly.

Reason: The small area on the top of the mountain and the fast air circulation are obviously affected by the natural air regulation-the sun radiates the ground to heat up during the day, and the high-temperature air near the ground will be quickly taken away by the surrounding low-temperature air to cool down, but the opposite is true at night. A small valley and daily range form the top of the mountain.

A narrow depression between two mountains.

mountain ridge

The contour line, protruding downward is the ridge.

Ridge is a convex landform composed of two slopes with opposite slopes and different slopes. The line connecting the highest point of the ridge is the intersection of two slopes, which is called the ridge line.

seat

In the topographic map, two sets of contour lines representing the same height of hills are closely juxtaposed, with a saddle in the middle.

Saddle is a low and shallow place between two mountains on the ridge, but it is slightly higher than the ravine.

Because the ridge makes the precipitation flow to the ridge, it naturally separates their respective precipitation flows, which is the river watershed. For reference only.