Relationship between water temperature and air temperature in pond reservoir

Temperature is one of the main factors that constitute climate, and it is also a reflection of climate characteristics. Temperature includes air temperature and water temperature, both of which exist. Air temperature is the temperature in the air, and it is a quantity indicating the air temperature; Water temperature refers to the temperature in natural water body, indicating the temperature in water body. The temperature and water temperature are directly determined by the sun's radiation and the sun's angle, and are also affected by conditions such as airflow, cloud thickness, terrain height and wind power.

The same sunshine, different altitudes, different geographical locations and different depths, even the same climate, will lead to temperature differences. Under certain geographical conditions, temperature restricts the water temperature, that is, with the increase of temperature, the water temperature will also increase, and with the decrease of temperature, the water temperature will also decrease, but the speed of water temperature decline obviously lags behind the air temperature.

We encounter cold air in summer, the weather suddenly turns cold, and the water temperature is still hot, which is the reason. In physics, this is called specific heat phenomenon. In addition to the difference between water temperature and air temperature, there are also differences in temperature. The daily weather forecast always has an upper limit and a lower limit, that is, the temperature difference of one day.

From the fishing point of view, the smaller the temperature difference in a day, the better. Because fish don't tend to warm up only when the temperature changes little. On the same day, at the same temperature, the water temperature will vary with the depth. In fishing, you can't catch fish in shallow water, but that's why you have to catch fish in deep water.

In the absence of climate change, there is little difference between air temperature and water temperature. In the temperate zone of the middle and lower reaches of the Yangtze River, the lowest water temperature and air temperature are 5438+ 10 in June, generally 2℃-4℃; The highest is July-August, generally 26℃-32℃; From May to June +065438+ 10, there is little difference between the surface water temperature and the bottom water temperature. When the sun shines directly in hot summer, the temperature in shallow water is higher than that in deep water. In severe cold and winter, on the contrary, the bottom temperature of deep water is slightly higher than the surface temperature.

How do fishermen know what the water temperature is? The meteorological department in the world never reports the water temperature, only the temperature. Anglers can carry thermometers with them to the fishing waters for testing. Without a thermometer, we need to know and master some knowledge about the temperature and water temperature. Generally speaking, knowing the temperature means knowing the water temperature. The two are interrelated and influence each other.

As the temperature rises, so does the water temperature. As the temperature drops, so does the water temperature. If the temperature is 20℃ at 6 o'clock in the morning, the surface water temperature is about 15℃- 18℃. At 2 pm, the temperature is 24℃, and the surface water temperature is about 65438 08℃-22℃. At 6 pm, when the temperature is 65438 06℃, the surface water temperature is about 65438 08℃-20℃; When the temperature drops to 8℃ at midnight, the surface water temperature is about 12℃- 18℃. In a word, the rise and fall of water temperature lags behind the change of temperature slightly; And there is only a short second time every day, and the temperature is the same as the surface water temperature.

So what are surface water and surface water temperature? According to fisheries and aquaculture, surface water refers to the water layer 50 cm deep from the surface to the water. Surface water temperature refers to the average temperature of surface water. Because water transfers cold and heat more slowly than air, there is a temperature difference between the water meter and the bottom. The deeper the water, the greater the temperature difference.