Linda Young, age 12, of Newport News, Va., for her question:
WHAT IS NATURAL JET STREAM?
The amazing jet streams whiz along near the very top of the turbulent troposphere, which is the weathery layer of the atmosphere. Actually, they are wide wind tunnels that weave eastward like wavy ribbons around the globe. Some follow more or less regular paths across North America, at heights of 20,000 to 40,000 feet above the surface. The winds in the center of jet stream tunnels reach 150 m.p.h. or more.