ATMOSPHERIC RIVERS (Syllabus: GS Paper 1 – Geography)

Context: A second, more powerful atmospheric river storm was headed for Southern California recently, threatening to unleash life-threatening floods and landslides.

Atmospheric Rivers

• About: Atmospheric rivers are extended bands in the atmosphere that efficiently transport moist air from the tropics to higher latitudes.
• Moisture Movement: Responsible for 90% of the tropical-to-polar moisture transport, atmospheric rivers stand as Earth's largest freshwater conveyors.
• Formation: These dynamic channels emerge when large-scale weather patterns align, creating concentrated filaments of intense moisture transport.
• Global Occurrence: Simultaneously, ten or more atmospheric rivers can occur across the globe, contributing to diverse weather patterns.
• Pineapple Express: It is, a prominent atmospheric river, channels moisture from the tropical Pacific to the US and Canadian West Coasts.
• Geographical Dimensions: Typically 250 to 375 miles wide and stretching over a thousand miles long, atmospheric rivers display considerable dimensions.
• Seasonal Prevalence: These phenomena are predominantly observed during the winter hemisphere when extratropical cyclones are at their peak.
• Water Vapor Equivalent: On average, an atmospheric river carries water vapor comparable to the flow at the mouth of the Mississippi River, North America's second-longest river.
• Landfall Effects: Passing over land, atmospheric rivers can induce hurricane-like conditions, including rapid rainfall, cyclone-force winds, and heightened wave activity.