Definition of jet stream

The term "jet stream" was coined in the mid-20th century by meteorologists to describe a narrow, high-speed wind current in the upper atmosphere. The name "jet stream" is derived from the way these winds appear on weather radar imagery, which resemble streams of water (jets) shooting through the sky. In reality, jet streams are powerful air currents that originate in areas near the earth's poles and then shift equatorward as they gain momentum. They form as a result of the temperature difference between cold, dense air near the poles and warm, less dense air near the equator. These winds can travel at speeds of up to 400 kilometers per hour (250 miles per hour), making them the fastest winds on earth. Jet streams are a critical component of Earth's weather patterns, as they strongly influence the movement and distribution of air masses and storm systems around the globe. They can also have a significant impact on aviation, as they pose a major challenge for long-haul flights, particularly over the Atlantic and Pacific Oceans. Understanding the nature and behavior of jet streams is therefore essential for weather forecasting, climate research, and commercial air travel.