15 December, 2000

We have a nice day for a flight! The morning dawned gray, but calm. In fact, the wind was slightly from the direction of the Dome which is very unusual for the Pole. The wind usually comes from the 0 degree to 90 degree sector. With such a low wind we were able to deploy the Blimp more directly above SPARCLE Trailer Park.

If this image actually came through you can see the logarithmic histogram of the daily mean wind directions from January 1957 through September 2000. The ARO building is located at about the 45 degree location and the station is located at about the 240 degree location. You can see from the diagram why the winds for today were so unusual. They are actually blowing the steam and exhaust from the Dome power plant toward the Clean Air Sector and ARO.

The Blimp and the FPH Instrument are ready to go up for their second deployment. It is really nice to see that the hoist line is not going to tangle with the probe extension arm. We worry about the possibility of the line clipping the sensors especially on windy days. Today we are safe.

During the flight the weather changed significantly. We had a rapid clearing and a sudden influx of Diamond Ice crystals. Von said that it was very unusual because it was coming from the edge of the cloud as they were breaking up. Von also mentioned that it was thicker than usual. The image really doesn't do the event justice. Imagine thousands of glittering reflections, it was dazzling!

Another real treat with today's launch was that we could actually follow the accent of the 9:30 AM radiosonde that was launched by the weather service. The sonde is taken aloft by a white round helium balloon that you can barely see to the right and slightly lower than our Orange Blimp. It is interesting that these NWS "National Weather Service" radiosondes are disposalable. They simply fly up till the balloon pops and the instrument falls back to earth. Rarely the sondes are recovered. Only one of the daily sondes launched here at Pole last year was ever found.

I really like this image! During the recovery we would winch in the Blimp for one minute and then let it stabilize for four minutes. When we started up the winch again it would stretch the line for a second as it started to pull causing the "frost" on the line to snap off. This frost actually is causing us some problems with our flights. The added weight of the frost is making it harder for the Blimp to go as high as we would like. We made an altitude of about 400 meters, better than yesterday but still not the kilometer and a half that we want.