Another Season at Summit!

Well, after some days travel – we are finally back at Summit again for our third and final season in this project. Let me give a brief summary of the journey that has happened over the past few days.

On Friday, 5.15 – we all arrived at the Scotia Air National Guard (ANG) base as chipper as we could be for 5 in the morning. After a quick tour around the cargo to make sure all of it was accounted for, we watched our safety video on the LC130’s and began our waiting game. As has come to be expected by now, we were eventually notified that mechanical delays would be pushing back our departure from 8am to ~10am. Luckily, that was the only delay we experienced as the guard eventually shuttled us out to the airfield and allowed to board the plane.

As is usual, we made a pit stop halfway on our way to greenland at ‘Goose Bay’ Newfoundland to refuel. Partly because the fuel is cheaper there, but also because we needed it since there were over 20,000lbs of cargo palletized in the back of the plane. Most importantly, however, we all got an ice cream bar while waiting in goose bay as a treat to enjoy while we waited.

As we were getting seated back on the plane, we were quickly notified that we needed to deboard and head back into the waiting area. Apparently one of the guardsman miscalculated how much fuel to add to the plane by 4000lbs. Oops – that seems like quite a bit to be off by. Glad it was caught by one other member of the flight crew!

We arrived in Kanger ~7pm local time with dinner waiting for us. In our briefing from the folks in the ‘Kangerlussuaq International Science Support’ (KISS) building, the science hostel where we stay in Kanger, we were told the bevy of changes that had happened since last year. I was happy to learn that ‘The Polar Bear’ – the not-so-great combination Thai-Pizza place was closed down this year. Instead, the King Kong Bar was serving food instead. This was a nice change of tune to hear, although upon further inspection it seemed that the family that owned the Polar Bear had just moved his operation inside of the bar – with essentially the same menu 😦 One nice thing about our visit to kanger was that KISS was very empty, meaning that each of us had our own room!

Photo by Ben Hmiel

A look at our cargo being palletized for the flight to Summit

The following day was spent tracking and organizing our cargo, making sure that all of it arrived and was en route to summit. This year, our combined Scince & Drill cargo came in ~11,000 lbs. This doesn’t even include the camp gear, food and Fuel that we will need to operate for the 6 weeks that our team is up here (probably on the order of another 12-15,000lbs). We spent an hour and a half in the CPS warehouse, packing foam into 90 Ice core boxes that will be drilled at PLACE camp as part of the core we will be collecting. (More on the Science in another Blog Post)

Following Lunch, we had a meeting to discuss the science and logistics involved with the project. After that, we were set to just get our rest and prepare for an early flight to summit the following day. Infact, 8am the following day came rather early, as we all met in the kitchen dressed in our ‘Emergency Cold Weather Gear’ (ECW) and waited for the ANG to call us to get on the plane. 830 came by and we received word that there were Mechanical delays. By 10, the word was that weather was good at Summit but the winds were too high in kanger to be able to return – The plane will only stop at Summit to Unload/Pickup People & Cargo, flying back to Kanger as it can’t reliably startup in the cold.

By 1030, the weather didn’t seem like it was going to improve so we were given our room keys back and told that it was unlikely we would fly, so we were fine to go back to sleep if we wanted. Delays like this are just part of polar travel I’ve become used to over the past few years. Having an extra day to just rest and relax was very nice, as I’ve been fairly overwhelmed with Labwork & logistics that I haven’t had much a chance to just sit on my hands and do nothing. Felt kinda good – aside from the fact that the food in Kanger stunk (though I need to give credit to a friend Robert, owner of the Phonecians Lebanese restaurant in Albany who sent Phil & I up with tons of Pita, Hommus, Mujadara, Falafel and a bunch more). Only downside was that it didn’t last for every meal in Kanger.

Well, after a day’s rest, we reconvened in the morning to await the status of our flight again. ~30mins after the scheduled departure, we reluctantly heard that the story was the same as yesterday – poor conditions in Kanger and not-so-great conditions at Summit. We were told that in the event that we took off and couldn’t land at summit, the backup landing point would be Akureyri, Iceland. Now, I’m not one to turn down a free trip to Iceland – although I would much prefer if it didn’t come at the expense of my third and final field season for this project. In fact, almost everybody in the room sounded a bit pleased to hear that we may actually end up in Iceland – rather than Greenland.

After another our of waiting, I had nearly fallen asleep on the couch and everyone else was getting a bit antsy, however we were surprised to learn that conditions had improved enough for the ANG to clear the flight and take us on up to summit. Wooo, we’re going to Iceland the room cheered and Jeered. So we grabbed our things and hopped on the plane.

Photo by Ben Hmiel

Seeing the guard members lacking confidence didn’t bode well for mine

The flight to Summit is generally a bit under two hours in a C130. I kept note on my watch what time it was, and noticed that as we approached the two hour mark we hadn’t started to make our descent yet. Eventually, I felt that the plane was doing circles in the sky. Everyone had a bit of nervous look and wondered what was going on. Eventually, the loadmaster came to us and said that the visibility at summit was too low to land, so they planned to circle the area at altitude for a bit and home things improved. Greaaaaaaaaat. I phased in and out of sleep due to the heat as I was wearing most of my cold weather gear, but at least an hour went by before we got the signal from the load master that we were descending. Awesome! Before I knew it, we were getting off the plane at the familiar sight of the big house and the bitter cold winds I’ve been all too familiar with.

Photo by Ben Hmiel

The majestic big house of Summit station is a great sight right from getting off the C130

Summit camp seemed much more buried in snow that I remember from prior seasons. Turns out the reason for this is that the crew that was supposed to come up here was delayed for two weeks in kanger, so they are behind on much of their operations. In addition, their D6 tractor is down pending repair parts that came up on the same flight as us. Hopefully they can catch up and get their tasking done at the same time as helping us get our cargo together and out to camp. Speaking of which, I’ve got plenty to do with respect to cagro and trainings (not to mention resting to acclimatize to the 10,500ft altitude) that I must end this entry here. Things are progressing well, hopefully they stay that way. At least the weather is cooperating for now!

Photo by Ben Hmiel

Having a team meeting for discussing what needs to get done in order to move out to our satellite camp

-Ben

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Work in Progress!

 

Our worksite late at night

We have been at our remote camp (“C-14 camp”) for slightly over a week now , and our season is progressing well. The weather has been kind to us, with many cold nights around -35˚C, but no high winds. The Summit crew have done a fantastic job of setting up the site for us, and the camp and worksite were ready for us to move in.

This is the last field season of our Greenland Summit project. The overall goal of the project is to understand how cosmic rays interact with ice and firn (the compacted snow layer at the top of an ice sheet) to produce carbon-14. This season we are also collecting an ice core for analyses of carbon monoxide concentration and stable isotopes, to improve our understanding of how the atmosphere before the Industrial Revolution compares to that of today.

With an experienced put-in team (Mike, Don, Dean, Phil, Ben, Jochen and myself) and overall good weather, set up proceeded quickly. Phil and I worked on the large ice melter system and associated instruments.

Inside the “Flux” insulated building which serves as our main lab

Inside the “Flux” insulated building which serves as our main lab

The large ice melter full of water and tucked in for the night!

The large ice melter full of water and tucked in for the night!

With help from Ben and Jochen on the first day, we were able to assemble the entire system and successfully pass the crucial vacuum leak test in just 3 days. We have now completed the first melt-extraction, where we took firn cores from between 30 and 40 m depth and melted them under vacuum to extract any trapped carbon-14 that the cosmic rays have produced. We have also started on a series of control experiments (“blank tests”) which will tell us how much carbon-14 is added to the samples from our apparatus.

A brand-new analytical system, “the sublimator” is making its first appearance in the field this season.

The new ice sublimation system, assembled at our camp

The new ice sublimation system, assembled at our camp

This system can sublimate ice to extract carbon dioxide for analyses of carbon-14 – something that the large melter is not capable of. Ben has worked very hard to build and test this system in the months leading up to our field campaign. Ben and Jochen have assembled the sublimator and have successfully completed an initial round of tests.

Ben and Jochen going over the plan of action for the sublimator

Ben and Jochen going over the plan of action for the sublimator

Our fearless and incredibly competent camp manager, Dean, has done a great job of running camp and keeping us well-fed for the hard work and cold weather.

Four out of seven team members (Mike, Don, Phil, Dean) are now at our second sampling location, known as PLACE camp, 36 km away from C-14 camp. PLACE camp is the chosen location of our carbon monoxide ice core. Our ice drillers Mike and Don have by now assembled our drill (the BID, which stands for Blue Ice Drill), drilled 40 m of core at C-14 camp, disassembled the drill completely, moved it to PLACE camp, re-assembled it, and drilled over 40 more meters of core.

The Tucker departs C-14 camp for PLACE camp, loaded with ice core boxes, the Blue Ice Drill and camp supplies.

The Tucker departs C-14 camp for PLACE camp, loaded with ice core boxes, the Blue Ice Drill and camp supplies.

To conclude, work has been progressing well, the team is in high spirits and we look forward to the arrival of the rest of our team at Summit

Vas

Ready, Set, Sublimate

Hello folks, apologies for being slow to update during the season.  Now that I’m back home and basking in the summer heat, I wanted to take a minute to go over one of the critical objectives that we embarked upon this past season – the Field Sublimation device!

Photo by Ben Hmiel

The system as it was assembled in the field

First, allow me to explain the rationale behind the system.  The overall goal of the project at summit is to characterize the production and retention of cosmogenic in-situ 14C through the firn column.  To put that more simply, we’re trying to find out how much 14C is produced by nuclear reactions from cosmic rays in the upper part of the ice sheet, as well as how much actually comes to be trapped in the air bubbles as opposed to just diffusing out of the firn matrix.  We’ve already discussed the large-volume Ice melting system in another blog post, but one big limitation to highlight of that system is that it can only characterize the 14CO and 14CH4 content in the Ice – not 14CO2.  This is because melting of ice can lead to extra CO2 production from carbonate dust present in the ice (especially significant in Greenland – less so in Antarctica). So with only the Melter, we’re left with an incomplete picture of 14C production as 14CO2 is a major contribution of the overall 14C content.  By sublimating the, ice we skip the liquid phase during the extraction and prevent the aqueous carbonate equilibrium reactions from producing extra CO2.  We’re able to do this by keeping the Ice below the ‘Triple-Point’ on the water phase diagram, enabling the conversion directly from Ice -> vapor just by keeping the Ice cold and under vacuum.

Other laboratories have attempted to measure 14CO2 by dry extraction methods, however since the cosmogenic 14C is produced within the ice matrix itself (not just the air bubbles), results suggest that dry extraction methods fail to liberate all of the in-situ CO2 leading to inconsistent results.

Great, so we need to sublimate the Ice if we want to extract 14CO2.  Then why on earth would we bring our system to the field – isn’t it easier to build a complicated extraction system in a laboratory with stable temperatures and electricity not provided by generators?

Well, the reason for that is two-fold.  First, we want to sample the firn column to determine the amount of in-situ 14C that is retained through to bubble close off.  Firn samples are known to trap bubbles over time following drilling and shipment back home.  This would lead to atmospheric air being trapped (which is high in 14CO2) and mistakenly part of our sample.  Thus for the firn samples we plan to collect – the only option is to extract the 14CO2 in the field immediately after drilling.  Additionally, once an Ice sample is drilled, it is subjected to intense 14C production at the surface of the ice sheet at a high altitude, high-latitude location like Summit (and even more at higher altitude during the airplane shipment back home).  Thus, there would be significant post-coring production of 14CO2 that would need to be accounted for and subtracted out.  That being said – we still did collect some Ice samples in the field for the purpose of testing this effect.  I plan on running them in Rochester during the months to come in order to see how my field results compare; however to get the best data, we aimed to sublimate each sample with hours or a few days of being drilled.

OK, so with the justification and science explained, let’s get into what a typical sampling day for me would entail in the field.  Just after waking up, I would sleepily crawl out of my tent to head into Plan Q to check on the system from the overnight evacuation (while also hoping that my generator did not run out of fuel overnight).  After performing a few checks, I head to breakfast while setting up a test to test for any leaks of ambient air that could contaminate my sample. Technically there is always a leak of ambient air in any vacuum line, however it is a matter of whether or not the amount is significant in terms of the analytes being measured.  During the course of the sublimation, I need to make sure that the leak rate into the vessel and surrounding lines was less than ~1×10-5 sccm (standard cc’s/min) to avoid trapping any significant amount of extraneous CO2.  To think of it another way, that equates to a cube of air 6mm on each side (roughly the size of a corn kernel) entering the vessel every hour – that’s not very much air!

Photo by Ben Hmiel

Here is the vessel empty without insulation and ethanol in the moat. Beneath the plate lies another chamber where the Ice is loaded

Once the system passed all the morning tests, I was ready to load my sample for the day into our large glass sublimation vessel above.  The design of this system allows for an Ice sample to be loaded onto a chilled pedestal from below.  There is then an array of IR lamps that irradiate the sample while it is under vacuum.  Then above the Ice sample, we designed a built-in ‘moat’ of Ethanol chilled with a probe chiller.  The moat serves to re-condense the bulk of the water vapor right away, allowing the gases and 14C to travel through the rest of the vacuum line and minimizing the amount of water vapor co-transferred.  This glass vessel is rather cumbersome and difficult to work around, but amazingly it worked well for the season and only suffered one breakage (luckily we had a spare made).  Thanks to Allen Scientific Glass for making this rather complicated device for us.

Photo by Ben Hmiel

Here is the system in operation with ethanol in the moat cooling the inner chamber.

Loading the Ice into the vessel is a delicate process that takes two people to perform.  By the time I was well rehearsed in the procedure, I was able to minimize the time that the vessel was open (and subjected to ambient CO2) down to ~5 minutes.  Once the Ice was in the vessel and the flange assembled, we begin by evacuating the ambient air out of the vessel.  This is a key part of the procedure that takes ~45 minutes allowing for a few flushes of CO2-free air to make absolutely sure that any ambient CO2 (including that which I breathe into the poorly ventilated building) is not collected during the extraction.  We also begin to sublimate a small amount of Ice off of the surface to ‘pre-clean’ it from any CO2 that may have adsorbed onto it.  CO2 is known to be a very “sticky” gas, meaning it readily adsorbs onto surfaces – making it a pain-in-the-neck for all scientists trying to measure it!

Photo by Xavier Fain

View from below with the lamps irradiating the ice block in the lower chamber

Following the evacuation it’s time to sublimate the Ice!  I set the lamps to ~25% power and monitor them over the course of the day.  The amount of time it takes to sublimate a sample depends on the CO2 concentration, sample mass and geometry.  In general for fully closed Ice, I can sublimate a 1.5Kg sample for ~7 hrs to extract ~20μg of CO2 that will be sent to ANSTO for graphitization and measurement by AMS.  The lamp voltage is adjusted from a pair of Rheostats mounted on the device.  Generator power is fairly inconsistent and unstable, so I would have to monitor and adjust the power based on my readings of the pressure inside of the vessel.  Too little lamp power and I’m not sublimating enough Ice, too much and the vapor pressure increases to an extent that I may end up pushing the system above the triple point and melting it slightly – neither are desirable scenarios.

The rest of the system is rather simple in comparison to the vessel.  Downstream of the vessel sits a pair of glass traps that are chilled to -90 in an Ethanol bath to condense any excess water vapor that is not trapped by the moat in the main vessel.  It is imperative to remove as much water as possible beyond this point, since water vapor behaves similarly to CO2 in our vacuum system and it is possible to mistakenly identify water as CO2 during a pressure reading in the manometer.

Photo by Ben Hmiel

Molecular sieve trap held under liquid nitrogen

Following the water trap is a small loop trap held under liquid nitrogen to trap the CO2 during the extraction.  At liquid nitrogen temperature (-196C), CO2 will freeze under vacuum while allowing the bulk Air (mostly N2 and O2, some noble gases as well) to pass through unaffected.  Other trace species (Eg. N2O) will also freeze at this temperature, however their concentration is generally too small to be significant.  Following the CO2 loop trap is one final glass trap, this time containing ~3g of molecular sieves that are also held under liquid nitrogen during the extraction process.  When cold, the molecular sieves will adsorb the majority of gases they are exposed to, save those with small molecular diameters (Eg. Ne, He).   This allows us to trap the remaining air that is released from the Ice during the extraction process.  This is needed in order for us to measure the concentration of CO2 we collect.  Additionally, the mole Sieves serve as a ‘pump’ – creating an area of low pressure that drives diffusion of the gases out of the sublimation vessel downstream towards the CO2 trap.      While it is not that strong of a ‘pump’ – over the ~7 hour extraction time it is certainly sufficient to get the majority of gases out of the vessel.

Photo by Ben Hmiel

Manometers for measuring CO2 and air content

The only part of the line left to explain are a series of manometers for measuring the pressure of the bulk Air collected on the sieves as well as the pure CO2 that is distilled from the liquid nitrogen trap.  Once all the measurements are made, the CO2 is manipulated into one side of the line where I flameseal it into a sealed glass ampoule.  This part is a bit nerve-wracking, however with plenty of practice it becomes fairly routine.  I’m proud to say that I have never botched a flameseal on a real sample (either here or on the 14CH4 extraction line back home) – though that says nothing about how many failed while I was practicing.  The glass vials will eventually be shipped halfway around the world to Australia to be measured for 14C on the AMS (Accelerator Mass Spectrometer).

I hope that gives everyone an informative view of what I did up in Greenland this past season.  Once we get some results from this system I’ll be sure to share it on the blog!

-Ben

My experience in Greenland

Hello there! I’m the lowly undergrad who was strong-armed into writing about my experience travelling with the group to Greenland this summer.  It was my first time doing anything like this and really felt like I had stepped into a different world.   The conditions were unlike anything I have ever experienced.  The combination of the altitude, 24-hour daylight and the cold meant that I basically didn’t sleep for the first few days on the ice.  Even though I was taking altitude medication, I was sick for the first two days up there. Once I got used to the conditions (and found out where the meds were kept), I actually got some sleep and quickly felt better.

I was paired with Don the Driller and put on the nighttime drilling shift.  After a few days of training, Don and I began drilling the cores needed for our samples.  We would usually work for a few hours at 6pm (pretty cold) and then a few more hours starting at 3am (VERY cold).

Photo by Matt Pacicco

This was how I had to dress to work the much colder “night” shift.  While Don and I were outside drilling in the cold the rest of the team was either resting comfortably in their beds or watching ice melt in a heated building.  After spending hours drilling outside during the coldest part of the day we would go in to warm up, primarily to complain to our fellow teammates about the cold.

Photo by Matt Pacicco

Most of the cores that we drilled weren’t at the depth that we needed, so they were essentially useless.  These cores got tossed to the sides of the drill and ended up in large piles like the one shown above.  Snow would slowly drift over and hide them causing the drillers (well mostly just me) to constantly trip over them.

Photo by Matt Pacicco

Here’s a look at the science side of our camp at the start of a 3am shift.  The two largest buildings (both heated) housed our team’s melter system and sublimation system.  The drill rig (pictured below) is off in no-man’s-land to the left of this picture.

Photo by Matt Pacicco

In this picture the main part of the drill is down the hole.  There were two people working the drill during each shift.  One person would man the control and actually do the drilling part while the other would assist with taking the drill apart when it surfaced to get the core out. As you can see we are clearly working outside in the cold and not inside one of the nice heated buildings shown in the previous picture.  We drilled a total of 5 holes to depths ranging from 55 meters to 135 meters.  The drill we were using would drill anywhere from 4 to 6 meters in an hour, so drilling those holes took a couple weeks.  By the time the samples were drilled, melted and collected, it was time to pack up the camp and head home.

The experience was amazing for me.  I was born in New York City and lived my whole life in the city and its suburbs, so going to such a remote place was an incredible opportunity to try something completely different.  I remember talking to my grandmother a few days before I was going to leave, and she was asking me if “city boys survive up there.” Well guess what grandma; I did survive.  And I really enjoyed the experience.  I was fortunate to be surrounded by a great group of people who (even though they gave me a hard time) were always there to help.  I want to really thank the Petrenko group for giving me this opportunity and thank the rest of the team (Alden, Dean, Don, Jayred, Jochen, Ross and Xavier) for making the expedition so much fun to be a part of.

Matt