Sprites

Definition

Sprites are brief, luminous electrical discharges that occur high above thunderstorm clouds, typically in the mesosphere, and are a form of upper atmospheric discharge. They are often associated with strong lightning activity below and can manifest in various shapes, such as carrot-like structures or jellyfish-like formations. Sprites are fascinating because they connect ground-level storm activity to phenomena occurring far above the clouds.

5 Must Know Facts For Your Next Test

1. Sprites typically occur at altitudes ranging from 50 to 90 kilometers above the Earth's surface and can last for about 10 milliseconds.
2. They were first documented in the late 1980s through high-speed cameras and are still being studied to understand their formation and impacts.
3. Sprites often occur in clusters and can be triggered by a specific type of lightning known as positive cloud-to-ground lightning.
4. The study of sprites can provide insights into atmospheric electricity, ionospheric physics, and global electric circuit processes.
5. Sprites are not visible to the naked eye from the ground but can be captured by specialized cameras or observed from aircraft flying at high altitudes.

Review Questions

• How do sprites form and what specific conditions are necessary for their occurrence?
  • Sprites form during strong thunderstorms when there is significant positive lightning activity. These conditions create an electric field strong enough to ionize the air high above the thunderstorm, leading to a luminous discharge. Typically, positive cloud-to-ground lightning strikes trigger these upper atmospheric events, resulting in the characteristic shapes seen in sprites.
• Compare and contrast sprites with other types of upper atmospheric discharges like elves and blue jets.
  • While sprites, elves, and blue jets are all upper atmospheric discharges associated with thunderstorms, they differ in appearance, altitude, and formation. Sprites appear as elongated structures often resembling carrots or jellyfish and occur at altitudes between 50 to 90 kilometers. Elves manifest as glowing rings just above thunderstorms and happen at lower altitudes, while blue jets shoot directly upwards from storm tops and are characterized by their cone shape. Each type represents different aspects of electrical discharge phenomena linked to severe weather.
• Evaluate the significance of studying sprites in relation to understanding atmospheric physics and global electrical circuits.
  • Studying sprites is significant as it enhances our understanding of atmospheric physics by linking storm activities on the ground to phenomena occurring high in the atmosphere. This research sheds light on complex interactions between thunderstorms and the ionosphere, contributing to our knowledge of global electric circuits. Understanding these connections helps scientists model atmospheric behavior better and assess potential impacts on climate and weather systems.

Related terms

Elves:

Elves are another type of upper atmospheric discharge that appear as expanding rings of light above thunderstorms, formed by the interaction of lightning strikes with the ionosphere.

Blue jets: Blue jets are a type of transient luminous event that shoot upward from the tops of thunderstorms into the stratosphere, characterized by their blue color and cone-shaped appearance.

Lightning: Lightning is a powerful electrical discharge occurring during thunderstorms that can lead to various phenomena, including sprites, as it creates conditions favorable for upper atmospheric discharges.