Why is the corona hotter?

Why is the corona hotter?

Nanojets are thought to be initiated by a process called ‘magnetic reconnection’, where twisted magnetic fields explosively realign. One such reconnection can set off another, resulting in an avalanche of nanojets in the Sun’s corona, which is then thought to generate enough energy to heat the corona.

What triggers lightning?

Lightning is an electrical discharge caused by imbalances between storm clouds and the ground, or within the clouds themselves. Most lightning occurs within the clouds. This heat causes surrounding air to rapidly expand and vibrate, which creates the pealing thunder we hear a short time after seeing a lightning flash.

Do we know how lightning works?

In general, lightning occurs when the positive and negative electric charges in a cloud separate in different parts of the cloud. The charges are separated as the heavier graupel particles fall, while the lighter ice crystals are carried upward by updrafts in the turbulent thundercloud.

How can you tell where a lightning strike is?

Radio signals are detected by multiple stations (at least 3) are used to determine the location of the stroke by a time-of-arrival technique. Location accuracy is best when lightning occurs within a network of stations. Flashes outside of the network have larger location errors and may not even be detected.

What is a streamer in lightning?

During the development of the stepped leader, the positive charge on the ground increases. The result of the negative charge moving toward the ground, is that the channel of air directly above the taller objects becomes positively charged. This is usually referred to as an upward streamer.

What is a lightning 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 positive lightning?

Positive lightning originates at the top of a thunderstorm, where cloud tops are positively charged, and can strike many miles outside the parent thunderstorm.