A.
It will have no significant effect on the jet stream.
B.
It is reducing the temperature difference between polar and tropical air masses.
C.
It is causing the jet stream to move faster.
D.
It is increasing the temperature contrast between the poles and the equator.
正确答案:B
译文
The jet stream is a fast-moving ribbon of air high in the atmosphere that affects global weather. Flowing west to east at speeds of up to 200 miles per hour, it forms due to the temperature contrast between cold polar air and warm tropical air, which creates pressure differences that generate strong winds. In the northern hemisphere, when the jet stream dips southward, it brings cold air and storms to lower latitudes.
The jet stream also influences cyclones and anticyclones, affecting precipitation and wind patterns. The jet stream's dynamics are influenced by factors like the Earth's rotation and uneven heating of its surface. Seasonal changes play a role; it’s stronger in winter due to the greater temperature contrast between the poles and the equator. Understanding the jet stream's behavior helps meteorologists predict weather and plan for climate events.
Recent research shows that climate change is impacting the jet stream. The warming Arctic reduces the temperature difference between polar and tropical air masses, which may weaken the jet stream. A weaker jet stream can lead to slower-moving weather systems, resulting in [#highlight5]prolonged[/highlight5] periods of extreme weather, such as heatwaves or heavy rainfall.