6 August, 1998

Thursday, August 6th, 1998

Ozonesonde -Launching

It was going to be a great day for field work: blue skies, temperature forecast 95 F, no forecast for rain. The launching was going to take place at the station at Marshall Fields, North of Boulder and I was looking forward to learn about the launching. During the previous days, we completed some testing and preparations of ozonesondes to use for the flight.

What is actually an ozonesonde?

In order to obtain vertical profiles of ozone and temperature measurements (compared to total ozone data measured with the "Dobson"), the instruments have to vertically rise into the air through the troposphere ( 0 - to about 15km) and stratosphere ( > 15km for Boulder, higher in the tropics and lower in the Antarctic). What better and simpler way can be used that rising a balloon with instruments attached?

There are several important parts to an ozone measurement unit. The ozonesonde contains of an electrochemical cell with an anode and cathode filled with two different reactive solutions (saturated and 2% KI) where the ozone is pumped through with a small piston pump. All of these parts are placed in styrofoam box. Attached to the side is a radiosonde. This device transmits ozone data as well as temperature, pressure and relative humidity back to the ground station where the scientist watches the computer record the data and adjusts the direction of the radio antenna. The data is observed until the balloon pops, usually around 35 km. If all works well, a parachute opens up and the burst balloon with the instruments floats to the earth surface. Consider yourself lucky if you find this strange white/orange box. It has been many kilometers higher than you will ever be able to fly (unless you are an astronaut) and you will receive a reward if you mail it back to Dr. Bryan Johnson, Boulder, Colorado. The address and reward notice is always attached. When returned, we can usually reuse the instrument for a future flight.

Thank you out there ahead of time for your support!

My finger is pointing at the electrochemical cells of an ozonesonde. Above the cell is the piston pump which pumps air through the cells. Before launching,this ozonesonde is placed inside the orange/white box. To the right of the box is the radiosonde attached. The blue rode pointing down is the antenna which sends the measurements during the flight to the computer in the lab.