Measuring Ions in Antarctica

Together with our partner Aerodyne Research, we are constantly supporting the operation of our mass spectrometers in remote and demanding settings.   In late 2014, 3 research groups deployed their instruments to Antarctica as parts of different studies.   To our knowledge, this was the first time our technology has run on that continent.

As part of the 2ODIAC campaign,  Prof. Peter DeCarlo and his research group from Drexel University set-up a mass spectrometer in a fish hut on the ice of Antarctica to measure the compositions of aerosols that may be associated with ozone depletion events.   We caught up with Prof. DeCarlo after his return to discuss why and how he took his research equipment to this remote destination.

What are the major themes of your group’s research?

My group is part of DARRL (Drexel Air Resources Research Laboratory).  We are interested in measuring the composition of trace gases and aerosol particles in the atmosphere, with applications to ambient air quality, formation and fate of atmospheric aerosols, and emissions from anthropogenic activities including natural gas development. We use an array of advanced analytical instrumentation including mass spectrometry.

What questions took you to Antarctica?

Photo compliments of P. DeCarlo, all rights reserved.
Photo compliments of P. DeCarlo, all rights reserved.

Our collaborator, Dr. Lars Kalnajs, has been making measurements in Antarctica for over a decade. On a recent measurement campaign he noticed a relationship between aerosol particle concentration and ozone depletion events. While the relationship was clear, there was no chemical information on the aerosol particles from these preliminary measurements. Linking the chemical composition of these particles to ozone depletion events was one motivating factor for the study, which  was funded by the National Science Foundation (Award #: 1341628  and 1341492).

Are there more convenient locations where you might have been able to make these same measurements?

There aren’t really other places that this type of measurement could be made. Antarctica is extremely remote and there are atmospheric phenomenon (e.g. the ozone hole) which make it unique. Further, we had 24 hours of sunlight per day for most of our study (this year). Additionally, the facilities maintained by the US Antarctic program make the logistics of these measurements easier than similar measurements would have been elsewhere. From a logistical standpoint, fieldwork in Antarctica is easier than some other places I have measured.

What mass spectrometer did you take? And what was it used to measure?

Aerodyne Aerosol Mass Spectrometer set-up at the field site. Outside air is sampled through an inlet in the wall. (P. DeCarlo, all rights reserved)
Aerodyne Aerosol Mass Spectrometer at the field site. (P. DeCarlo, all rights reserved)

We deployed an Aerodyne SP-AMS (Soot Particle Aerosol Mass Spectrometer) equipped with a TOFWERK HTOF.  This instrument can measure the quantity, size and chemical composition of aerosol particles in ambient air, with the sensitivity necessary for the pristine environment of Antarctica. Continuous measurements were made for weeks, so as to observe changes in aerosols across time.  These measurements are compared to data from other instruments that were run in parallel in order to determine (or rule out) correlations between aerosols and other factors.

Can you describe the field site?  

The fish hut where the mass spectrometer ran was located on the ice, 30 km from McMurdo Station.  (P. DeCarlo, all rights reserved)
The fish hut was located on the ice, 30 km from McMurdo Station.  (P. DeCarlo, all rights reserved)

The field site was a spot on the annual sea ice (meaning it melts and re-freezes every year) about 30 km from McMurdo Station. The instruments were housed in a “fish hut” equipped with a particle inlet and a gas measurement inlet. Power was generated by diesel generators housed in a separate fish hut ~150 meters away and in a direction that was seldom if ever upwind of out measurements. We had a direct communication link to McMurdo which provided access to the internet. This allowed us to monitor our instruments remotely, and maintain our Facebook page.

Researchers traveled the 30 km to the fish hut by snowmobile or in a Piston Bully. (P. DeCarlo, all rights reserved)
PistenBully for travel to the site. (P. DeCarlo, all rights reserved)

We typically traveled to the site with snowmobiles, but if the weather was bad, or we needed to bring equipment, we used a PistenBully. The instruments were all placed in the fish hut prior to the fish hut being dragged behind a bulldozer to the field site. The fish hut was on big skis, and the sea ice is pretty flat, so the ride was smoother than it would have been in a different vehicle.

What did you consider when determining whether your mass spectrometer would be able to run at the site?  Without FedEx, what was your “plan B” for any supplies you might need?

Scientists traveling to Antarctica. (P. DeCarlo, all rights reserved)
The long trip to Antarctica. (P. DeCarlo, all rights reserved)

One of our biggest concerns was low temperatures, which turned out to not be an issue. The power was adequate, and we had a large battery backup system in place to keep essential instruments running in the event of a generator problem. We did have a few issues early on with our power, and the backup system worked quite well.  We reviewed our packing list many times, and liberally added items to the boxes while packing. We didn’t have much of a “plan B”, although we did find out that a friend of ours was also coming down to McMurdo a few weeks after we got there, so if we needed something that wasn’t too big, we could have requested he hand carry it.

Did your work schedule allow any time for play/exploration?

A member of the 2ODIAC team performs at the McMurdo base (P DeCarlo, all rights reserved)
A member of the 2ODIAC team performs at the McMurdo base (P DeCarlo, all rights reserved)

There was some downtime for team members to enjoy the area. There are some historic supply huts in the area which were used to store food and supplies for early Antarctic explorers. In addition to the historic sites there are also a few trails around the area that can be explored, and for those wishing to remain on base, there were 3 bars as well.

How easy was it to communicate with the real world?

Surprisingly easy! We had satellite phones, VHF radios, beepers, but what was actually one of the most useful forms of communication was iMessage. All of the team members had iPhones, so with wifi at the field site, it was actually one of the simplest and most direct forms of communication. Several of our Facebook posts were made from a fish hut in the middle of the sea ice 30 km from anything resembling civilization. On base there were also telephones that we could make calls to the US, and all you needed was a calling card. For those in the 303 or 720 area codes, the calls were free.

The obvious question: Were you cold?!

P. DeCarlo, all rights reserved.
P. DeCarlo, all rights reserved.

Yes and no. The first couple of weeks we were there the weather was pretty awful. A lot of incoming flights were cancelled due to lack of visibility from blowing snow. Windchill got down into the -40 C/F range and people weren’t allowed to leave the base. After those initial couple of weeks, the weather improved significantly, and by the time I left, the temperatures were 20 F with sunny skies.

What next? 

We are in the process of analyzing the data and are already finding some exciting trends and observations. We still have a lot of work to do, but we’re excited about the ~5 weeks of data we currently have, and are looking forward to the next trip down in September of 2015. This year will be a little different since we will be arriving in the total darkness. Stay tuned for part 2!

 

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