What is summer stratification?
Summer stratification involves the formation of 2 different layers of water based on temperature and density: warm on top i.e. epilimnion and cold on below i.e. hypolimnion, both layers are separated by thermocline or metalimnion which is region of rapid change of temperature.
What conditions are required for thermal stratification?
Thermal stratification occurs when two types of steam with different temperatures come into contact. Their temperature difference causes the colder and heavier water to settle at the bottom of the pipe while allowing the warmer and lighter water to float over the colder water.
Does temperature affect stratification?
Stratification becomes increasingly stable with heating from the sun. The larger the difference in temperature (and density) between the epilimnion and the hypolimnion, the more stable the thermal stratification.
Why do lakes stratify in summer?
As the sun continues to warm the lake surface through late spring and early summer, the temperature differences increase between the surface and deeper waters. While wind influences the surface waters of all lakes, its ability to mix the entire water volume in summer- stratified lakes is greatly reduced.
How is thermal stratification prevented?
Destratification is a type of artificial circulation that completely mixes a stratified lake’s waters from top to bottom and thereby eliminates or prevents summer stratification (the division of a lake into water layers of different temperatures).
Why do lakes have three temperatures?
From late spring through early fall, some lakes in temperate climates experience thermal stratification, a phenomenon wherein lakes separate into three distinct thermal layers (Figure 1). The warming of the surface of the water by the sun causes water density variations and initiates thermal stratification.
Why is thermal stratification important?
It occurs when the surface layer of water, warmed by the sun, becomes less dense than the water underneath it. The significance of thermal stratification to anglers is that the lower layer of water, deprived of surface contact, slowly loses its dissolved oxygen and become less able to support aquatic life.
When does thermal stratification occur in a lake?
Thermal stratification is fairly pronounced during the summer seasons in most lakes of the temperate (cold) regions but is rare in lakes of tropical (hot) and subtropical regions where it occurs only in very deep lakes.
Which is more stable thermal or thermal stratification?
Stratification becomes increasingly stable with heating from the sun. The larger the difference in temperature (and density) between the epilimnion and the hypolimnion, the more stable the thermal stratification.
What are the effects of thermal stratification on a pipe?
Stresses of the cross-section of the pipe. Another observation during thermal stratification is the local variation of temperature in the fluid interface known as thermal striping. Thermal striping causes high cycle thermal fatigue and cracks on the internal surface of the pipe.
How does thermal stratification affect a reactor system?
The third cause of damage is known as thermal cycling. This can occur when the reactor system undergoes an operational transient event, or when turbulence in the main pipe interacts with the thermally stratified layer in a branch pipe. It causes a boundary between the two regions to fluctuate.