Ask A Scientist Weather Archive

name         Lauren D.
status       student
age          13

Question -   Does wind travel at same speeds at different heights?
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Lauren,

No, wind speed can be very different at different heights. There are probably several Newton 
scientists who will respond to your question in more detail. However, consider this example 
you're certain to have already witnessed: You are standing in an open area on what appears to 
be a windless day and you look up and see the tops leaves in a nearby tree being moved by a 
breeze. There must be a wind current up there because the leaves are moving, Still, you feel no 
wind at all where you are standing.

For further information on this matter, go to the Newton archives and type in the term, "jet 
stream."

Regards,
ProfHoff 635
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Lauren -

At the altitudes that we usually inhabit or fly, as altitude increases wind speed tends to 
increase and (over the US) it tends to become more westerly. At any given moment this may not 
be true, but over time averaging speed and direction, this would hold true.

Larry Krengel
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Lauren,

The wind speed at the different heights can vary tremendously, from no wind speed to wind speeds 
of hundreds of miles per hour.

In general, wind speeds are lowest near the ground and increase with height, up to several 
hundred feet above the ground.   However, there are also special heights at which higher wind 
speeds are common -  these higher wind speed areas are called jet streams.

A low level jet stream can form at the top of the temperature inversion at night, at about 100 
to 300 feet, but is typically not more than about 50 miles per hour.

The upper level jet stream occurs at the top of the Troposphere, the lowest layer of the 
atmosphere, can occur at heights of anywhere from 20,000 to 45,000 feet, can be located just 
about anywhere in the United States depending on the weather situation, and can reach speeds of 
200 miles per hour in rare cases. The typical wind speed in the upper level jet is 100 to 150 
miles
per hour.

David R. Cook
Atmospheric Research Section
Environmental Research Division
Argonne National Laboratory
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Not at all!! Wind speed and altitude are related, but the relationship is complex and changing. 
You can see that by watching clouds move in the sky. NASA and NOAA monitor wind speed vs. 
altitude in many places around the globe on an almost continuous basis. They do this with both 
high altitude balloons, satellites, as well as ground based locations. You may find this web 
site interesting:
http://www.ed.arizona.edu/ward/Pathfinder/Temp/temp.html

Vince Calder
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Dear Lauren-

That is a good question, about wind speeds at different altitudes.  The answer is that no, the 
wind is not the same at altitudes above the ground.  And the differences in wind speeds and 
direction have a great deal to do with the changes in our weather.

One of the main uses of weather balloons is to measure the wind speed and direction above the 
ground in the area of the point of release. Winds can be very light near the earth's surface, 
yet be blowing at 150 mph in the "jet stream" directly above.  The jet stream is a fast-moving 
"river" of air, generally at levels of 25,000 to 40,000 feet above ground. The jet stream is not 
continuous, and changes location with the seasons.

Here is a link to a short but very understandable explanation of the jet stream and winds above 
the earth.

                http://www.usatoday.com/weather/wwind0.htm

Wendell Bechtold
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