earth science

Whirlwind

Whirlwind is a earth science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Whirlwind rather than just read about it. In short: A whirlwind is a phenomenon in which a vortex of wind (a vertically oriented rotating column of air) forms due to instabilities and turbulence created by heating and flow (current) gradients. Whirlwinds can vary in size and last from a few minutes to a few hours.

Key takeaways

Whirlwind belongs to earth science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Whirlwind to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Whirlwind from memory before moving on to harder problems.

Reference excerpt

A whirlwind is a phenomenon in which a vortex of wind (a vertically oriented rotating column of air) forms due to instabilities and turbulence created by heating and flow (current) gradients. Whirlwinds can vary in size and last from a few minutes to a few hours.

Types Whirlwinds are subdivided into two types, the great (or major) whirlwinds, and the lesser (or minor) whirlwinds. The first category includes tornadoes, waterspouts, and landspouts. The range of atmospheric vortices constitute a continuum and are difficult to categorize definitively. Some lesser whirlwinds may sometimes form in a similar manner to greater whirlwinds with related increase in intensity. These intermediate types include the gustnado and the fire whirl. Other lesser whirlwinds include dust devils, as well as steam devils, snow devils, debris devils, leaf eddy or hay devils, water devils, and shear eddies such as the mountainado and eddy whirlwinds.

Formation Major whirlwind

A major whirlwind (such as a tornado) is formed from supercell thunderstorms (the most powerful type of thunderstorm) or other powerful storms. When the storms start to spin, they react with other high altitude winds, causing a funnel to spin. A cloud forms over the funnel, making it visible. Minor whirlwind A minor whirlwind is created when local winds start to spin on the ground. This causes a funnel to form. The funnel moves over the ground, pushed by the winds that first formed it. The funnel picks up materials such as dust or snow as it moves over the ground, thus becoming visible.

Duration Major whirlwinds last longer because they are formed from very powerful winds, and it is hard, though not impossible, to interrupt them. Minor whirlwinds are not as long-lived; the winds that form them do not last long, and when a minor whirlwind encounters an obstruction (a building, a house, a tree, etc.), its rotation is interrupted, as is the windflow into it, causing it to dissipate.

Associated weather Supercell thunderstorms, other powerful storms, and strong winds are seen with major whirlwinds. Wind storms are commonly seen with minor whirlwinds. Also, small, semi-powerful “wind blasts” may be seen before some minor whirlwinds, which can come from a wind storm. These wind blasts can start to rotate and form minor whirlwinds. Winds from other small storms (such as rain storms and local thunderstorms) can cause minor whirlwinds to form. Like major whirlwinds, these minor whirlwinds can also be dangerous at times.

Similar phenomena Eddies and vortices may form in any fluid. In water, a whirlpool is a similar phenomenon.

Illustrations

Worked examples

Example 1 — a first encounter with Whirlwind

Start with the simplest possible case. Write down what Whirlwind claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In earth science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Whirlwind before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Whirlwind ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Whirlwind

In research: Whirlwind appears in earth science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Whirlwind in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Whirlwind is common in secondary-school and first-year university syllabi. It links to neighbouring topics Meteorological phenomena, Severe weather and convection, Vortices, so understanding it makes those chapters shorter.
In everyday life: Look for Whirlwind outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Whirlwind in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Whirlwind means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Whirlwind out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Whirlwind in simple terms?

Why does Whirlwind matter?

Because it connects several earth science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Whirlwind?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Whirlwind.