What is summer stratification ? Explain.

Explanation

During summer in temperatę lake, the density of the surface water decreases because of increase in its temperature `(21-25^(@)C).` This .upper most warm layerThermocline of a lake is called epilimnion. Below the epilimnion Hypolimnion there is a zone in which the temperature decreases at the rate of `1^(@)C` per meter in depth, and it is called Summer stratification in a lake thermocline or metalimnion. The bottom layer is the hypolimnion, where water is relatively cool, stagnant and with low oxygen content (due to absence of photosynthetic activity).
During autumn (also called fall). The epilimnion cools down, and the surface water becomes heavy when the temperature is 4°C and sinks to the bottom of the lake overturns bring about .uniform temperature. in fakes during that period, this circulation dụring the autumn is known as fall. The upper oxygen rich water reaches the hypoliminion and the nutrient rich bottom water comes to the surface. Thus, there is uniform distribution of nutrients and oxygen in the lake,