Download 1. Explain this statement. “A thunderstorm is the result of convection

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PA5 Short Answer Question # 1 out of 4
1. Explain this statement.
“A thunderstorm is the result of convection.”
When preparing to answer this question, you need to know the definition of a thunderstorm and how a
thunderstorm (thundercloud) forms or develops; you need to know the definition of “result of”; and the
definition of convection. You then need to be able to show how convection can cause a thunderstorm
(thundercloud).
You need to know this information, but you will probably not use all of this information in your answer.
2. What information should you consider?
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A thunderstorm is in its developing stage as the thundercloud is forming and getting bigger.
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For a cloud to form, warm air rises and takes water vapor with it. The warm air rising is called an
updraft. The air rises to a point and then spreads out and transfers its heat to the surrounding cooler
air. After it transfers its heat, the warm air cools. When the warm air cools, so does the water vapor in
the air. The water vapor cools enough that it changes state to a liquid or a solid. These water droplets
or ice crystals cling to pieces of dust, pollution, smoke, etc. When enough droplets or ice crystals
gather, we see it as a cloud.
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During thunderstorm (thundercloud) formation, the air is really unstable and full of moisture. Both the
rising warm air and the condensing water vapor give off their heat to cooler air. That “cooler air” now
becomes warmer and rises higher, taking other water vapor with it. At some point the air and water
vapor cool, forming more cloud. This process continues until the cloud is really tall and anvil shaped.
Eventually, all of the air becomes the same temperature and the cloud stops growing. Plus, eventually,
there is no more water vapor. All of the vapor has condensed and is in cloud form.
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When the cooled air sinks, it is called a downdraft. Downdrafts bring precipitation with them.
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When the cooled air reaches the ground, it spreads out and seeks a low pressure area caused by an
updraft. This horizontal movement of air from high to low pressure is called wind.
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The heat transfer method when the warm air itself rises, spreads out, and then gives off its heat is
called convection. The sinking movement of the air and the horizontal movement of the air is also part
of a convection cycle. Without convection, heat in the air wouldn’t be transferred and water vapor
wouldn’t be taken up into the atmosphere and condense. Clouds couldn’t form without convection.
And really big thunderclouds definitely couldn’t form without convection.
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PA5 Short Answer Question # 1 out of 4
3. How do you put all of the above into an understandable answer that flows?
A thunderstorm develops when a thundercloud develops. A thundercloud is a very tall, anvil shaped cloud. In order
for the cloud to form, water vapor needs to be lifted high up into the atmosphere by warm unstable air. This rising
of the warm air, and the subsequent transfer of heat is a process called convection. Convection is a method of heat
transfer where the matter gains heat from one location and then the matter itself moves to another location to
transfer that heat. When the warm air spreads out and cools, so does the water vapor in that air. The water vapor
changes state to a liquid or a solid, and clings to dust, smoke, etc. to form a cloud. When the heat is transferred,
the “cooler air” now becomes warm, rises, and takes “new” water vapor with it. This process continues to make the
cloud extend higher and higher into the troposphere. During the process of convection, cooler air sinks back down
towards earth’s surface. During a thunderstorm, this sinking cooler air brings down precipitation with it. When the
cooler air hits the surface, it moves out as wind to find a low pressure area. As the air travels across earth’s surface,
it gets warmed and eventually rises again. This completes the convection cycle. The convection cycle also continues
to fuel the thunderstorm with the warm, unstable, moist rising air.
4. How about a shorter answer?
A thunderstorm develops when a thundercloud develops. In order for a thundercloud to form, you need unstable air
filled with water vapor (moisture). The unstable air rises and brings the water vapor with it, high into the
atmosphere. As the air rises, it encounters cooler surrounding air. This causes the warm air to transfer its heat and
become cooler, which causes the water vapor to cool. When the water vapor cools, it condenses and forms clouds.
The process of rising warm air giving off its heat, cooling, and sinking back down to earth is called convection.
Convection is one of the four methods of heat transfer. Without convection, warm air wouldn’t rise and transfer its
heat to the surrounding cooler air. Without the warm air rising and transferring its heat, water vapor wouldn’t be
taken up into the atmosphere, cool, and condense. Without condensation, clouds couldn’t form. And without
clouds, there would be no thunderstorm. So a thunderstorm is the result of convection.