By Julian Spergel
At the time I’m writing this, we have completed three survey flights. It feels good to finally be collecting data. The night shift, myself included, has spent the past two days checking the collected data for signs of any instrument breakage or recording errors.
Although Peter Pan suggested ‘happy thoughts’ would get us airborne, in Antarctica we are still very much at the will of the weather. Yesterday evening’s flight was cancelled because of fog, and so this morning we wanted to get as much flying in as possible before the late afternoon fog rolled in. Although the morning shift had to wait a bit for the IcePod instruments and the plane to warm up before departing, they were able to complete two full survey lines before their afternoon return. It is early in the season and I haven’t been able to fly a mission yet myself, but I am eagerly waiting for my first opportunity.
Our daily schedule is not the easiest when we fly. This is especially true for those who need to make decisions about our daily activities. Every day, from 4 to 4:30 AM, Kirsty Tinto, our chief scientist, checks to see if that morning’s flight is going ahead. Next, she checks in with the team ending their night shift for updates on instrument functioning. At 5 am, she and the day’s flight engineer meet with the weather operations and flight operations team to go over the day’s flight plan considering the weather forecast. The team has to be flexible when building a daily mission that works with the daily weather constraints.
Meanwhile, the gravity instrument operators, affectionately called the “graviteers,” go down to the airfield with the aircraft load-masters to oversee the loading of the gravimeter into the plane. Collecting data on minuscule changes to gravity requires that we know exactly where in the plane the instruments sit to calculate accelerations. Although it is tempting to leave the sensitive instruments on the plane overnight, the gravimeters must be kept warm at all times for peak functionality, as a result the gravimeters must be loaded and surveyed at the beginning of every day and unloaded at the end of the day. The plane is readied for take-off with a systems check and the flight crew and our project’s flight engineers prepare for flying.
The non-flight members of our team arrive to Williams Airfield soon after from our base at McMurdo camp. Every shift has an archivist, someone who copies the data from the various digital storage units carried in flight and then carefully transports them back to the tent. The data is transferred to the central computer, as well as to two backup hard drives for redundancy. At the end of the shift, there are nine hard drives and two USB sticks filled with data. The archivist also selects three to four five-minute segments of data for quality control, which we call “QCing”. The other QCers and I look through the segments from every data set for breaks in the data, for anomalies, and for particularly good or interesting segments. Arguably, the most important data set to check is our positioning-navigation-timing system. None of our data is useful if we cannot precisely place where in the world we were when we collected the data. Some of our instruments must also know precisely the angle and velocity of the plane in order to yield useful data. Once that is checked, we look at the data readouts.
Timelapse video of a few hours of night shift “QCing” Credit: Julian Spergel
If there’s anything surprising within the Ross Ice Shelf, we QCers might be the first ones to know. While it is fun to wonder what we could find, what do we actually see? In the radar data, we can see the surface and bed of the ice shelf and often we can see areas of buried crevasses. In the shallow ice radar, we can often see where different ice masses from geographically disparate glacial sources merge as they flow towards the ocean. From LiDar (Light Detection and Ranging), we can see very highly detailed maps of the surface of the ice shelf, which can give us information about the flow of the ice and the changing surface climate conditions, i.e. wind and temperature. From gravity and magnetics readings, we can glean information about the size of the cavity under the ice shelf and the ocean bed beneath the water.
Though we’ve just begun our survey flying, we’re excited to see what our instruments will show us about the Ross Ice Shelf. Weather permitting, we will fly day and night this week pushing through being tired. Yes we are tired, and I know I am guilty of getting a little snippy, but we are down at the edge of the world for valuable scientific work. When I see the sun kiss the horizon, and watch the shadows lengthen for a moment and the snow become golden, I know that this experience will end up being incredible.
In non-science news, we saw the birth of a baby crabeater seal on Sunday. Everyone else on the team has named the newborn seal “Rosetta,” but in my mind, the seal’s name is “Boopy.”
For more information about Rosetta-Ice, check out our website and the archive of this blog. Have questions about Rosetta-Ice or about living and working in Antarctica? Feel free to email your question to juliansantarctica@gmail.com, and I will try to answer it in the next blog entry!
Julian Spergel is a graduate student at the Department of Earth and Environmental Science at Lamont-Doherty Earth Observatory and will be blogging from Antarctica. He works with Professor Jonathan Kingslake on analyzing spatial and temporal trends of supraglacial lakes on the Antarctic Ice Sheet using satellite imagery.
