Study on Difference of Automatic Observation with Different Underlying Surfaces

Based on the observed temperature data of several typical underlying surfaces, namely, slabstone, the surface of the water, soil, cobblestone, grass land, cement, asphalt and the bare air temperature in Huaxi station of Banan, Chongqing, the characteristics and regularity of the temperature on the surfaces above were analyzed.Resultsare shown as follows. (1) The temperature of all the underlying surfaces and the bare air have significant seasonal and monthly changes, which is the highest in summer (especially in July), followed by spring and autumn, and the lowest in winter. And the difference of temperature is the most obvious in summer and the least in winter. (2) The diurnal variation trend of temperature is basically consistent with the air temperature, and the temperature of cement and asphalt which are the most highest have the largest diurnal variation. The temperature of cement is the highest, and the grass land is the lowest at night. (3) The diurnal variation range of water, which has larger heat capacity than cement and asphalt is smaller whether in sunny or rainy. That is, with the same solar radiation condition, the change of water temperature is less than the others. The difference between the observed items is relatively obvious at night, and the temperature of cement at night is always in a lower position.