What is strong convection?

Strong convection refers to the process that liquid or gas transfers energy through the relative flow of its parts, which is one of the basic forms of heat transfer.

Strong convection is short for forced convection. It refers to the process that liquid or gas transfers energy through the relative flow of its own parts, and the convective movement of fluid is caused by the uneven temperature of fluid caused by external heating or lifting. Forced convection in the atmosphere is mostly thermal convection. However, the uplift caused by the convergence of weather systems can often also cause dynamic forced convection when air flows through mountains.

Convection refers to the process that liquid or gas transfers energy through the relative flow of various substances, and it is one of the basic forms of heat transfer. Usually divided into natural convection and forced convection. Strong convection usually refers to a large amount of energy exchanged during convection, and is sometimes considered as the abbreviation of forced convection. There are many kinds of strong convective weather, the most important ones are thunderstorm, thunderstorm and gale, hail, squall line, tornado and short-term heavy precipitation.

Causes of severe convective weather

Strong convection is actually a weather phenomenon caused by strong vertical movement of air. The most typical is the strong convective weather in summer afternoon: during the day, the ground constantly absorbs short-wave radiation from the sun, and the temperature rises, releasing long-wave radiation to heat the atmosphere. When the air near the ground receives enough heat from the earth's surface, it will expand and reduce its density, and then the atmosphere will be in an unstable state.

It's like oil and water in a water tank. When the less dense oil is at the bottom of the water tank and the water is at the top, there will be a strong upward movement, and finally the oil will float to the water surface. In the same way, the hot air near the ground rises under the buoyancy, forming a rising hot and humid airflow.

When it rises to a certain height, the water vapor contained in the air will condense into water droplets due to the temperature drop. When water droplets fall, they are picked up by stronger updraft, and so on. Small water droplets begin to accumulate and integrate into large water droplets until the upper air cannot support their weight, and finally they fall into the rain. This is why thunderstorms in summer are not as rainy as spring rains in Mao Mao, and the water drops are bigger.