23 January, 1999

Saturday, January 23rd, South Pole Station

What a busy day we had! Hope yours was good as well.

The temperature was still - 22C. The wind had calmed down, though not as much as we wanted (15 knots), but we made an attempt to launch our plastic balloon anyway to review the winter balloon procedure before Bryan's leave. We had an early start with "on the day of flight preparations" for the 2Z-ozone model which I discussed earlier. Andy and Joel were trying to launch this large balloon on their own because they would have to do it all winter long. The plastic balloons need to be used in the winter because the latex balloon, which we use in the summer, would become brittle in temperatures of - 75 to - 85 degrees of Celsius. Starting at 7:30 am with all the preparations, we were ready to launch at 10:30am.

The filling of the balloon was an interesting procedure (see photos). The balloon had an extension attached that needed to be held carefully during launching. Since we still had about 15 knots of wind to deal with we were hoping all would go well and it did. As Joel let go of the balloon, Andy needed to run in the direction of the wind and then let go of the ozonesonde together with the balloon. These plastic balloons will be used until October - which means that they are also used during the ozone-hole-formation.

The flight was done at 12:30, just in time to pick up Dr. Dave Hofmann from the plane. The whole NOAA group had lunch together (those baked deserts are truly something). Bryan and I took care of last-minute issues regarding the transfer of data and future communication, and at 4:30p.m we brought him to the plane that will bring him to McMurdo with continuation to Christchurch. I caught up with emailing and answered questions students had and then joined the NOAA group (Joel, Andy, and Dave) for dinner (we had pizza - it must be Saturday). A social gathering followed and Dave spoke a lot about the earlier years in ozone research. The stories were interesting and helped me to answer yesterday's questions about when and how was the ozone hole discovered.

History of the ozone hole research:

I have discussed before that DOBSON suggested that ozone is important for our protection from UV light. because it absorbs the UV. He also found natural fluctuations in ozone level depending on the season, the time of the day, and the location in the world. JOE FARMAN from the United Kingdom (British Antarctic Survey) is credited with having discovered the ozone hole in 1985 by observing a decrease in total ozone in late September through October at Halley Bay, Antarctica. DAVE HOFMANN, my PI, parcticipated in the 1986 National Ozone Expedition (NOZE) to provide the airborne ozone data profiles, which told which ozone of which the region of the atmosphere was being destroyed. SUE SOLOMON from the NOAA Aeronomy Laboratory, also in Boulder, Colorado, was a member of NOZE as well and worked with a spectrometer on the ground which was capable observing trace gases in the stratosphere such as nitrogen dioxide and molecules which contained chlorine. She has proposed a theory to explain ozone depletion. Her theory involved the chemistry which takes place on tiny parcticles in the clouds which form in the winter Antarctic stratosphere - Polar Stratospheric Clouds. Based on their observations, the NOZE group concluded that the ozone hole was basically the result of chemistry involving chlorine which is mainly man-made.

This initial work was done in McMudo. Both, Hofmann and Solomon, collected their data during WINFLY which stands for 'Winter flights into Antarctica'. The Winfly season starts in late August when it is still dark in the Antarctic. Its main purpose is to fly people into the Antarctica to prepare the runways for aircraft operations during the summer season. When the sun rises in the Antarctica, the ozone hole is formed. Why is the ozone hole formed during the Antarctic spring and why does the hole appear - in all places in the world --- over the Antarctic? Is the Ozone hole a true gap in the atmosphere? What are the pollutants that contribute(d) to the depletion of the ozone. These are questions I received by many of you and I will answer them tomorrow.

By the way, the Smithsonian Institute in Washington D.C. honored Hofmann's and Solomon's work and efforts in a very special way. The institute created a wax-figure exhibition of Hofmann and Solomon and their field work in the Antarctic as part as the "Science in American Life" Exhibit. Make sure you go to see it when you are visiting Washington the next time!!

About 11pm - just before bedtime - I went skiing again. The exercise did me well and I slept through the night.

Joel is filling the plastic balloon inside the BIF

The plastic balloon inside the BIF. Loree, a weather analyst at South Pole, cleaning the entrance.

I am inspecting the balloon!

I am helping filling the balloon!!

Andy attaching the 'way-off weight' to the balloon.

Joel is letting go of the plastic balloon in 15 knots winds.