Traditional Culture Encyclopedia - Weather forecast - How to understand that the daily temperature difference in low latitudes is greater than that in high latitudes?

How to understand that the daily temperature difference in low latitudes is greater than that in high latitudes?

The daily temperature range is closely related to latitude, season, ground properties and weather conditions. As far as latitude is concerned, the average noon sun height in low latitudes is larger, so the daily variation of average solar radiation and temperature is also larger, while the opposite is true in high latitudes. As far as seasons are concerned, the height of the sun is high at noon in summer, so the daily variation of average solar radiation and temperature is large; Winter is the opposite. This seasonal variation is most significant in the mid-latitude region, because the daily variation of solar radiation intensity in the mid-latitude region is much greater in summer than in winter. The differences of ground properties include the differences of land and sea, topography and vegetation. Land and sea: the daily temperature difference of the ocean is smaller than that of the land, and the coastal area is smaller than that of the inland area. The daily temperature difference where the wind blows from the ocean is smaller than that where the wind blows from the land. Terrain: The daily temperature difference in valleys is greater than that in peaks, and that in depressions is greater than that in highlands. As far as the weather is concerned, the daily temperature difference on cloudy days is smaller than that on sunny days.

On the convex terrain, such as the top of the mountain, due to the small contact area with the mainland, it is less affected by the surface temperature rise during the day and the temperature drop at night, and because of the high wind speed, the turbulent exchange is strong. In addition, the cold air near the ground can sink along the slope at night, but it exchanges warmer air in the free atmosphere, and the annual amplitude and daily temperature difference are small. On the contrary, the concave ground is uneven, the turbulent exchange is weak, and it is surrounded by the surrounding slopes. During the day, under the strong sunlight, the ground temperature rises sharply. And peaks > cliffs > valleys. There is a similar phenomenon in the temperature during the year. In the low latitude plateau, the daily variation of temperature is large and the annual variation is small.

The difference of topography and landform also has obvious influence on temperature. On the convex terrain such as the top of the mountain, due to the small contact area with the land surface, it is less affected by the ground heating in the daytime and cooling at night, and because of the high wind speed and strong turbulent exchange, the cold air near the ground can sink along the slope at night to exchange warmer air in the free atmosphere, so the daily temperature difference and annual temperature difference are small; On the other hand, the depression has the opposite topography, poor airflow and weak turbulence exchange, and is surrounded by surrounding hillsides. Under the strong sunlight during the day, the ground temperature rises sharply, which affects the lower temperature, and the ground heat dissipates quickly at night. Due to the sinking of cold air, the valley bottom and basin bottom are particularly cold, so the daily temperature difference is very large.