Sierra+Legg-+Weather+Balloons

Weather balloons are used all over the world to receive and record data. At exactly the same time all around the world, we launch weather balloons to provide weather information used in our weather forecasts. The balloons are all released at the same time in every country, 18:00 and 6:00 hours GMT (Greenwich Mean Time). There are 70 sites in the United States where we cast weather balloons and over 700 worldwide. This system has been used since WWll. Meteorologists use the balloons to get profiles of temperature, relative humidity, pressure, and wind velocity of our upper atmosphere. This helps with weather predictions and announcements. The balloons are made out of rubber and are inflated with either helium or hydrogen gas to propel it into the air. Its ideal diameter reaches about 2 meters. An instrument package is attached to the balloon and stays with it as it rises aloft. This instrument is the one that takes all the data of temperature, pressure, and relative humidity and records it. This instrument package is attached to the balloon by a 15 meter chord. Relative humidity is tracked from a device that contains polymer that absorbs the atmospheres moisture and causes an electrical resistance of a carbon layer in the polymer. These electrical changes transmit to readings of humidity. We track the wind velocity by using a radar on the balloon that determines where it is, where it is going and how fast it is moving, thus recording the wind velocity. The instrument attached to the weather balloon sends all this information back to the home base on the ground and it goes out to the public.

~Sierra

Picture! http://www.newlaunches.com/archives/spaceloon_may_soon_be_the_answer_to_broadband_problems_in_africa.php