Atmospheric Electricity and Lightning: PTE Listening: Fill in the Blanks practice questions

Inside a developing thunderstorm, intense upward air currents cause lighter ice crystals to collide repeatedly with heavier particles of soft hail. These energetic collisions transfer electrical charge between the particles, leaving the smaller ice crystals with a positive charge while the heavier material becomes negative. Over time, strong winds carry the lighter crystals toward the upper reaches of the cloud, creating a distinct electrical across the storm system. When this buildup becomes sufficiently intense, the insulating capacity of the surrounding air begins to , allowing an initial channel of ionised air to downwards. This rapid progression ultimately triggers the dramatic flash of light and heat that we observe from the ground.

When a powerful cloud to ground lightning bolt strikes sandy soil, the immense thermal energy instantly melts the surrounding mineral grains. Because the temperature along the central channel can several thousand degrees, the silica within the quartz sand fuses almost , forming hollow glassy tubes known as fulgurites. These delicate structures faithfully preserve the subterranean path taken by the electrical current as it dispersed into the earth. By examining the chemical and internal shape of these recovered formations, researchers can valuable information about ancient weather patterns and the historical of local lightning strikes over thousands of years.

High above active thunderstorm systems, brief luminous flashes known as red sprites occur in the upper atmosphere. Unlike standard lightning that strikes downward toward the earth, these phenomena emerge tens of kilometres above cloud tops and upward into the mesosphere. They are triggered by powerful positive lightning strikes below, which suddenly alter the electrical field and cause the thin upper air to electrical breakdown. Because these events typically last for only a few milliseconds, specialised high speed cameras are to record their intricate filamentary structures. Studying these elusive flashes helps scientists better understand the global electrical circuit and chemical occurring high above our planet.