On average, the Earth has 4 to 5 active rivers in the atmosphere at all times. Atmospheric rivers are responsible for 90% of the movement of moisture from the tropics towards the poles.
They form during the winter season, that is, during December, January, and February in the Northern Hemisphere, while they form during June, July, and August in the Southern Hemisphere. Sky rivers contribute to increasing water levels in watersheds, which enhances the biodiversity of the ecosystem, and contributes to replenishing groundwater reserves.