# Is lightning caused by the cloud acting as a capacitor?

• ChromeBit
In summary, thunderstorms are caused by a buildup of negative charge on hail, while positive charge remains near the top of the cloud. When the attraction between these two charges becomes too strong, they discharge in a flash of lightning, causing the loud clap of thunder. This process can be compared to a capacitor, where the potential difference between the two charges results in a discharge. However, this explanation is not complete and may be subject to revision in the future. There is also the presence of capacitance between the two charges, which can be calculated using the formula V = Q / C. This leads to the question of whether capacitance "causes" lightning, which is open to interpretation. Additionally, there are other types of lightning, such
ChromeBit
So I was looking up what causes thunderstorms online and found this:
"As hail moves within the cloud it picks up a negative charge by rubbing against smaller positively charged ice crystals. A negative charge forms at the base of the cloud where the hail collects, while the lighter ice crystals remain near the top of the cloud and create a positive charge.

The negative charge is attracted to the Earth's surface and other clouds and objects and when the attraction becomes too strong, the positive and negative charges come together, or discharge, to balance the difference in a flash of lightning (sometimes known as a lightning strike or lightning bolt). The rapid expansion and heating of air caused by lightning produces the accompanying loud clap of thunder."

The line that really interested me was this: "and when the attraction becomes too strong, the positive and negative charges come together". This sounds to me like a capacitor.

Am I correct in thinking this or am I mistaken?

Well, you have separated charges with a bad conductor (air) in between, that is similar to a capacitor.

(i think) you have thought a correct analogy between lighting and capacitance . What i think is that when lighting strikes them the maximum capacitance of air is crossed and the charge is finally transferred from clouds to the land .

ChromeBit said:
Am I correct in thinking this or am I mistaken?
You have described the currently accepted paradigm correctly. Unfortunately it does not explain everything that is observed and so will be subject to revision at some time in the future.

When the potential difference between two parcels or pools of opposite charge exceeds the breakdown voltage of the air, an ionised path called lightning forms that discharges the local charge difference.

There is capacitance between the two parcels of air and there is a charge difference. The voltage is therefore V = Q / C, derived from the definition of capacitance C = Q / V.

To answer the question you posed in the title, whether capacitance "causes" lightning is a matter of semantics.
Without the capacitance, there would still be a discharge, but it would have to be a continuous current. It would not be lightning-like.

spacewrinkle

## 1. How does a cloud act as a capacitor?

A capacitor is a device that stores electrical energy. In the case of a cloud, the upper portion of the cloud is positively charged and the lower portion is negatively charged. This separation of charges acts as a capacitor, storing electrical energy until it is discharged as lightning.

## 2. Can any type of cloud act as a capacitor?

Yes, any type of cloud can act as a capacitor as long as there is a separation of charges within the cloud. However, thunderstorm clouds are the most common type of cloud associated with lightning due to their strong updrafts and high concentration of water droplets and ice crystals.

## 3. Is lightning always caused by a cloud acting as a capacitor?

No, lightning can also be caused by the buildup of static electricity between the ground and the cloud, or between two separate clouds. However, the majority of lightning strikes are a result of the cloud acting as a capacitor.

## 4. How does the discharge of a cloud's electrical energy result in lightning?

When the electrical energy stored in the cloud's capacitor is discharged, it creates a flow of electrons between the positively and negatively charged portions of the cloud. This flow of electrons creates a visible lightning bolt as it travels through the air.

## 5. Can lightning occur without a cloud present?

Technically, yes. Lightning can also occur within a volcanic ash cloud or in a dust storm. However, these occurrences are much less common than lightning from a thunderstorm cloud acting as a capacitor.

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