What is a stepped leader?

Stepped leaders develop within thunderstorm clouds when charge differences between the main region of negative charge in the middle of the thunderstorm and the small region of positive charge near the base of the storm become large (Figure 1).

What is the definition of stepped leader?

[′stept ′lēd·ər] (geophysics) The initial streamer of a lightning discharge; an intermittently advancing column of high ion density which established the channel for subsequent return streamers and dart leaders.

What is a stepped leader and an upward leader?

Stepped leaders tend to branch out as they seek a connection with the positive charge on the ground. When a branch of the stepped leader reaches within about 50 meters of the ground or some object on the ground, it connects with an upward-developing positive charge, often referred to as an upward streamer.

What is a stepped leader and in what direction does it go?

In thunderstorm: Initial stroke. …to thousands of amperes, the stepped leader propagates toward the ground at an average velocity of 1.5 × 10⁵ metres per second, or about one two-thousandth the speed of light. It is called a stepped leader because of its downward-moving “stepped” pulses of luminosity.

What are stepped leaders made of?

Following a charge transfer event in the lower part of the cloud, the released electrons proceed to the ground. Uman "The vehicle by which these electrons move from the cloud to the ground is called a stepped leader... it moves to the ground in rapid, luminous steps that are about fifty yards long.

stepped leader and dart leader

How fast is the leader in a lightning strike?

The entire process is very rapid; the leader stroke reaches the ground in about 30 milliseconds, and the return stroke reaches the centre of the cloud in about 100 microseconds.

Is it possible to thunder without lightning?

No, it is not possible to have thunder without lightning. Thunder starts as a shockwave from the explosively expanding lightning channel when a large current causes rapid heating. However, it is possible that you might see lightning and not hear the thunder because it was too far away.

What are lightning streamers?

Simply put, during a storm a charge builds in the cloud, eventually generating a step leader which descends from the cloud. In reaction, streamers are launched from ground-based objects. The two connect and a strike is formed.

What is a stepped leader an upward streamer and a return stroke?

The connection between the stepped leader and the upward discharge creates a "short circuit" between the charge in the cloud and the charge in the ground. A powerful current travels back up the channel from the ground toward the cloud. This is the 1st return stroke.

What is upward lightning?

The most important finding about upward lightning, is that it primarily occurs when there is a nearby positive cloud-to-ground flash. The electric field change caused by the preceding flash causes an upward positive leader to initiate from a tall object such as a building, tower or wind turbine.

What is a dart leader?

(Also called continuous leader.) The leader which, after the first stroke, typically initiates each succeeding stroke of a multiple-stroke flash lightning. (The first stroke is initiated by a stepped leader.) The dart leader derives its name from its appearance on photographs taken with streak cameras.

What does Ball lightning look like?

The bizarre phenomenon, also known as globe lightning, usually appears during thunderstorms as a floating sphere that can range in color from blue to orange to yellow, disappearing within a few seconds. It's sometimes accompanied by a hissing sound and an acrid odor.

What is a positive streamer?

A positive streamer is a potential ionizing wave,opagates against the direction of electron drift. In ap filled with gas at near-atmospheric pressure peamers are visible as a bright filaments propawards the cathode [7].

What is lightning and lightning conductor?

Definition of lightning conductor

British. : a metal rod that is placed on a building and connected with the ground below to protect the building from being damaged by lightning.

Are stepped leaders formed by ionized air?

Once the ionization process begins and plasma forms, a path is not created instantaneously. In fact, there are usually many separate paths of ionized air stemming from the cloud. These paths are typically referred to as stepped leaders.

What is meant by pilot streamer?

A relatively slow-moving, nonluminous lightning streamer, the existence of which has been postulated but not verified, to provide a physical explanation for the observed intermittent mode of advance of a stepped leader as it initiates a cloud-to-ground lightning discharge.

What is a step ladder lightning?

Stepped leaders develop within thunderstorm clouds when charge differences between the main region of negative charge in the middle of the thunderstorm and the small region of positive charge near the base of the storm become large (Figure 1).

What is fork lightning?

Cloud-to-Ground (CG) Lightning

In CG lightning, a channel of negative charge, called a stepped leader, will zigzag downward in a 'forked' pattern - hence it is sometimes called forked lightning. This stepped leader is invisible to the human eye, and travels to the ground in a millisecond.

Does every lightning bolt hit the ground?

No, lightning does not always strike the ground. In reality, there are three main kinds of lightning in nature, which are distinguishable on the basis of where they occur. The lightning on the ground is seen in the case of cloud to ground lightning.

What is a corona streamer?

Like the related corona discharges and brush discharges, a streamer discharge represents a region around a high voltage conductor where the air has suffered electrical breakdown and become conductive (ionized), so electric charge is leaking off the electrode into the air.

What is a return stroke?

The return stroke is the very bright visible flash that we see as lightning, caused by the rapid discharge of electricity. Once the step leader makes contact with a streamer, the negative charge that has accumulated along the leader channel flows rapidly to ground.

What is Spider lightning?

Spider lightning refers to long, horizontally traveling flashes often seen on the underside of stratiform clouds. Spider lightning is often linked to +CG flashes.

Is lightning hotter than the sun?

In fact, lightning can heat the air it passes through to 50,000 degrees Fahrenheit (5 times hotter than the surface of the sun). When lightning strikes a tree, the heat vaporizes any water in its path possibly causing the tree to explode or a strip of bark to be blown off.

Does lightning make a sound?

Thunder is the sound caused by a nearby flash of lightning and can be heard for a distance of only about 10 miles from the lightning strike.

Why do trees get hit by lightning?

WHY LIGHTNING STRIKES TREES. Because lightning tends to hit tall objects, trees are likely targets. They're especially prone to lightning strikes because electricity seeks the path of least resistance, and the sap and moisture inside a tree make it a better conductor than the surrounding air.