Submitted by Anonymous on Thu, 04/02/2009 - 11:31

Answer to question: The National Weather Service upper-air network releases about 75,000 radiosondes each year, but less than 20 percent are returned to the National Weather Service for reconditioning. Reconditioned radiosondes are used again, saving the NWS the cost of purchasing a new instrument

A network of upper-air observation site around the world release weather balloons twice a day at 00z and 12z. In Tucson, Arizona, the weather balloon is release at the National Weather Service (NWS) located at the University of Arizona campus.

By the time the balloon reaches 100,000 feet it has grown to the height of a two story building. When the balloon has expanded beyond its elastic limit and bursts, a small parachute slows the descent of the radiosonde, minimizing the danger to lives and property.

The radiosonde is harmless and safe to handle. You may detect an odor coming from the instrument, but this is from a sulfur compound used in the battery. If the radiosonde is not severely damaged, the NWS would be grateful if you return the instrument. Each radiosonde comes with a mail bag (postage is pre-paid) and mailing instructions. After placing the radiosonde in the mailbag, hand the package to your postal carrier.

I am not sure what she is looking for with the question about zones. She might be refering to time zones or the zone forecasts that are issued.

Jeff Davis

Betsy Wilkening

Thanks for the response.  I didn't realize that the return rate was so low on the radiosondes.