Tall Tower - Part 1

On Tuesday we were able to make a trip to the Tall Tower Antarctic Precipitation  System site. Transportation around Antarctica falls into three categories: wheeled vehicles in McMurdo and on the groomed snow roads to the airfields, tracked vehicles for generally nearby locations on the ice shelf, and by air using helicopter or airplane. Helicopter is used primarily for locations within 50 miles of McMurdo Station and airplane is used for locations beyond that range. The Tall Tower site is about 100 miles to the southeast of McMurdo Station so we took the Twin Otter airplane to do the work on the APS site. The Twin Otter flight to Tall Tower is relatively short as it took about 45 minutes in the air. The Twin Otters are ski equipped so that they can do open field landings. It is really amazing how they can land most anywhere, other than regions where there are crevasses, or cracks in the snow/ice, and it takes very little for them to takeoff.

The APS site at Tall Tower was found to be in relatively good condition. There was one instrument that were buried and needed to be raised. We raised some other equipment as well as there was about 20" of accumulation at this site. The drifting around the site was also quite variable, which is why one of the instruments was buried. The expectation was that this would be one of two trips to Tall Tower with the primary goals for this trip was to evaluate the condition of the site and retrieve an instrument and datalogger to bring back to the lab. Beyond those tasks, we wanted to do any other work that was worth doing on this flight so that we didn't have too much work on the next visit. The big story of for this visit was that the weather was beautiful. When we landed, the temperature was 0F. That might sound cold but when the sun is out, there is no wind, and you are in your cold weather gear, it is very nice conditions to work. It warmed up to 9F by the time we left. The plan was to do two hours of work at the site. At around two hours I talked with the pilot and commented that we'd prefer to get as much work done as we could with the weather so nice. He agreed and we ended up spending four hours at the site. The amount of work for our next visit should be very reasonable to complete and probably doable even if the weather is a little rough. On our second visit to Tall Tower last year we were working in 20 knot winds and it was a challenge.

Beyond the visit to Tall Tower, we took one trip by truck to one of the local sites, Willie Field, and will be doing another later today. The rest of the time this week was spent in the lab in town reviewing the instruments, dataloggers, programs, and the work that needs to be done. Thus far, the weather continues to be moderate to fairly good for this field season.