What is the definition of temperature curve?

Explanation of daily temperature range and annual range curve with latitude.

Hebei Langfang Development Zone New Century Middle School Xu Jianguo

Temperature difference is also called temperature range. Refers to the difference between the highest temperature and the lowest temperature in a day or a year. The difference between the highest temperature and the lowest temperature in a day is called diurnal range or diurnal range; The difference between the highest temperature and the lowest temperature in a year is called annual amplitude or amplitude. Temperature difference is one of the important signs to distinguish climate types in different regions. For example, areas with poor daily range and large annual range belong to continental climate; On the contrary, it belongs to a maritime climate. The temperature in high latitudes in annual range is higher than that in low latitudes. The diurnal temperature range is higher at low latitudes than at high latitudes, which is of course a big law (the diurnal temperature range and annual range change with latitude as shown below: ① annual range at continental latitude; (2) annual range at ocean latitude; ③ Daily range of continental latitude; ④ Diurnal range of ocean latitude. ), a simple explanation is as follows.

Variation curve of daily temperature range and annual range with latitude

Annual variation of (1) temperature

The annual change of temperature is the same as the daily change. In a year, the monthly average temperature has a maximum and a minimum. As far as the northern hemisphere is concerned, the monthly average maximum temperature in the inland areas of middle and high latitudes appears in July, and the monthly average minimum temperature appears in 65438+ 10. The temperature in the ocean is the highest in August and the lowest in February. The difference between the highest and lowest monthly average temperature in a year is called the temperature annual range.

There are several factors that affect the temperature and annual variation range.

(a) latitude temperature annual range increases with the increase of latitude. This is because the annual variation of solar radiation energy increases with the increase of latitude. The annual temperature in low latitudes is very low, and the annual temperature in high latitudes can reach 40 ~ 50℃.

(2) Due to the different thermal characteristics of land and ocean, the difference of heat income between China mainland in winter and summer is larger than that of ocean, so the annual temperature of mainland is much higher than that of ocean. In general, the temperature difference of temperate oceans last year was 1 1℃, and it could reach 20 ~ 60℃ in Chinese mainland. In the picture, ① is annual range at continental latitude, ② is annual range at ocean latitude.

(c) Away from the ocean, the temperature of the ocean rises and falls slowly due to the thermal characteristics of water. The closer to the ocean, the greater the influence of the ocean, the smaller the temperature annual range, and the farther away from the ocean, the smaller the influence of the ocean and the greater the temperature annual range.

In addition, the influence of topography and weather on the temperature annual range is the same as that on the daily temperature range.

(2) Daily variation of temperature

The continuous change of temperature with time in a day is called the daily change of temperature. In a day, the temperature has a maximum and a minimum, and the difference between them is the daily temperature difference. Usually, the highest temperature appears between 14 ~ 15, and the lowest temperature appears around sunrise. Due to the influence of season and weather, the occurrence time may be ahead of schedule or behind schedule. For example, the highest temperature in summer occurs in14 ~15; Winter is 13 to 14. Because the sunrise time is different at different latitudes, the occurrence time of the lowest temperature will also be different with different latitudes. The daily range of temperature is smaller than the daily range of surface soil temperature. The farther away from the ground, the smaller the daily range of temperature, and the later the highest and lowest temperatures appear. In agricultural production, sometimes a large daily temperature difference is needed, which is beneficial to the high yield of crops. Because a large diurnal range means that the temperature is higher during the day and lower at night, so that the photosynthesis of leaves is strong during the day and more carbohydrates are produced, while at night, the respiratory consumption is less and the accumulation is more, and the crop yield is high and the quality is good.

The factors that affect the daily temperature range are as follows.

(a) The diurnal range of latitude temperature decreases with the increase of latitude. This is because the change of sun height in a day decreases with the increase of latitude. The daily temperature difference in the tropical area of the mainland is about 65438 02℃; The daily range of temperate zone is 8.0 ~ 9.0℃; The daily temperature difference of polar circle is 3.0 ~ 4.0℃. So ③ in the figure is the daily range of continental latitude.

(2) Generally, the daily temperature difference in summer is greater than that in winter, but in the middle and high latitudes, the maximum daily temperature difference in a year appears in spring. Because in summer, although the height angle of the sun is large, the sunshine time is long and the temperature is high during the day, the daily temperature difference in summer is not as large as that in spring because of the short day, short cooling time and high temperature at night in the middle and high latitudes.

(c) The daily temperature difference in low-lying areas (such as basins and valleys) is greater than that in convex areas (such as hills). The terrain is low and concave, the contact area between air and the ground is large, and the ventilation is poor. At night, it is often the place where cold air sinks and meets, so the daily temperature difference is large. On the other hand, because of high wind speed, strong turbulence, fast heat exchange and small daily temperature difference, the flat land is in between.

(4) Properties of the underlying surface Due to the differences in thermal characteristics and solar radiation absorption capacity of the underlying surface, the daily temperature difference is also different. The daily temperature difference on land is greater than that on the sea, and the farther away from the sea, the greater the daily temperature difference. The daily temperature difference of sandy soil, dark soil and dry loose soil is greater than that of clay, light soil and wet compact soil respectively. So ④ in the figure is the daily variation range of ocean latitude.

(e) The daily temperature difference in sunny days is greater than that in cloudy days (rainy days), because the solar radiation is strong in sunny days, the ground temperature is strong, and the effective ground radiation is strong at night. The daily temperature difference in windy days is small.