Thursday, February 28, 2013

Ozonesondes with Met Tech Jane

Ozonesondes. These fly on a weather balloon and collect ozone measurements periodically as they rise. The data is sent back to earth by an antenna. Usually, these are buddies with a radiosonde, which measures pressure, temperature, relative humidity, etc. They are taped together, put on the same balloon, and all the data gets sent back to the computer together in real time.
The weather station launches one per week through most of the year. During the ACE Validation campaign, they're launched just about every day. This morning, Jane The Meteorological Technician was kind enough to let me look over her shoulder as she prepared the ozonesonde for launch.

She plugged it into a machine that can feed ozone or clean air into the sonde. This is to check whether the sonde is sensitive to ozone, and to changes in ozone. She turns the ozone flow on, lets it reach a certain level, then turns it off and sees how much ozone the sonde is measuring as the ozone levels decrease.

Next, she checks the flow rate. There's a little tube that hangs outside of the ozonesonde box in order to suck air in from the atmosphere. There's another tube for the air the sonde spits out the other end. That's the end she hooks up to the burette (the glass tube on the wall). She puts a tiny bit of soapy water down the burette to get it wet. And then, for the next 5 minutes, she earns her living by blowing bubbles. She uses the red bulb at the bottom to squeeze a little of the soapy water into a bubble. Then the air pressure from the outlet of the sonde pushes the bubble up the tube.

She times how long it takes the bubble to get to the top (29 seconds, if you're wondering), and this gives a measure of the sonde's flow rate. This bubble method works better than I would have thought! If you squeeze just one bubble, it's pretty easy to see where it is.

Once the sonde is all checked out, it's time to screw on the interface board. Ah, hardware. This job allows me to make myself useful for 4.3 seconds. This will let the ozonesonde talk to the radiosonde.

Then it's time to pack it all in the styrofoam box! It will get a radiosonde attached to the outside of the box just before its time to launch it after supper tonight.

No comments:

Post a Comment