I learned how to put together a radio sonde today. Didn't leave any time for pictures so I set up the camera for a time-lapse of the sunset. The sky showed great promise for a spectacular sunset at the beginning of this 25-minute section, but it mainly just got dark! The movie does show the effect of the trade winds blowing the lower clouds to the west, but the flow in the upper atmosphere is to the east.

Not only does the movie show that, but my first radiosonde did too! That is a fourth of what radiosondes are all about: winds. The other three quarters are temperature, humidity and pressure. A radiosonde is a package that gets packed inside cardboard and styrofoam and the radiosonde is carried aloft by a helium balloon. The radiosonde has instruments to measure temperature, humidity and pressure. A ground "tracking station" keeps track of where the radiosonde is, and from that information wind speed and direction are calculated.

Each of the sondes that went up today started on the ground at about +22 degrees Celsius and eventually passed through air that was colder than minus 70! By that time these sondes were more than 30 km away. Eventually the balloon burst to end the flights, but I find it impressive that a balloon can remain flexible throughout that temperature range and than a small, battery-powered instrument can collect data and radio it back from 30 km away through that range of temperatures.

The journal has to be short for the next couple days because training occupies a lot of time and I am also trying to finish a proposal that I am writing. So I am off to proposal writing. Many more details about training and sondes and upper air to come....

Alan Nelson