Closing out the season at Concordia

Posted on January 16, 2025 by rochestericelab

On December 9^th I (Sebastian) made it to Casey station Antarctica, and then later on December 16^th made it all the way to Concordia. During this time the rest of the team was hard at work closing the gap between 200m and 300m with the drill and melter. Despite being exited to finally get the chance to help the rest of the team reach 300m I was also experiencing the effects of a rapid ascent to over 10,000 ft. The French drill made it to 300m a few days after I arrived and subsequently moved about 2m over to start a second borehole. I was able to work at full capacity right when the team was finishing the 300m deep borehole with the US drill and prepping to start a second borehole. As we drill deeper, the time it takes for the drill to go down and come back up the hole increases, so we were only able to drill 10m each day close to the end of the first borehole. It therefore took two days of drilling to get enough ice for one melt. To alleviate the additional day of exposure to cosmic rays that our ice would be experiencing, we moved the drilled ice deeper into the snow cave we stored our ice cores in. During my acclimatization, I was still able to learn and help with the ice melting procedure for the last few US ice melts. Our CO concentration results were still being influenced by the mystery contamination; however, it was fairly consistent through the last 60m.

Sebastian Miller — Alex triumphantly holding up the last section of the 300m borehole

Tristan Guilot — Jay and Sebastian pushing the winch of the US drill to its new location for the second borehole a couple of meters away

Finishing both boreholes and positioning the drills for second boreholes was a big achievement for the team and just in time for Christmas! Since Concordia is so dry it receives about 20cm of snow every year. When compressed into the ice sheet, 20cm of snow is only about 20mm of ice. Such a small amount of ice each year makes Concordia a very good place to drill ancient ice cores. About 30km away from Concordia at a place called Little Dome C there is another team of European scientists and engineers that has been drilling for ice that is older than 1 million years. Also just before Christmas a team of Australians arrived at a location about 10km away to establish a drilling camp for ice older than 2 million years. We got to have both teams join us for a Christmas celebration that included a lot of good food and general joyous activities. A week later they joined us again for a similar New Years Eve blowout.

After the Christmas celebrations we resumed gas extractions for the first French borehole. The carbon monoxide concentrations in the ice from the first French borehole had been high and variable all season, which led us to believe there was contaminant being periodically introduced to the ice. The first French gas sample we analyzed from their second borehole measured a monstrous 352ppb, by far the highest carbon monoxide concentration we’ve seen. This caused another halt in operations. We decided that since the US measurements were less sensitive to contamination, we would instead do the melt-extractions for the second US core while we considered our options for what to do about the contamination in the French core.

We only drilled the second US borehole to 200 m, as the goal for this borehole was to test a different gas extraction technique. We didn’t need a full 8,000-year gas record to do this. For the new method we want to see if just as much ¹⁴CO from the ice dissolves out of the water as our original method. The original method requires agitating the melted water to get it’s dissolved gas into equilibrium with the air in the headspace of the melter, but the new method skips the agitation and may reduce contamination. Since these two methods are performed on the same depths of ice we can see if they produce the same results. The results showed fairly consistent CO values between the two boreholes, but we will have to wait and see what the influence is on the ¹⁴CO until further analysis is done once we get out of the field. Meanwhile, the French finished their second borehole and moved their drill to Little Dome C. The idea behind this is to get a cleaner sample for the 110-130m depths, because their other two melts from this depth were the two most highly contaminated samples of the season. Little Dome C is a newer camp and there isn’t as much heavy machinery operating that might contaminate samples with engine exhaust.

Sebastian riding in the back of a skidoo trailer with ice core boxes and a cutter head

Now that the US drill had finished all its work, it was time to start packing it up, but not before letting curiosity get the best of us. We decided to drop a 50cm piece of ice down the 300m hole and film it. It didn’t make any sound when it hit the bottom because of the porous firn ice dampening out the sound on its way back up. Alex made a TikTok out of this that has since garnered over 2 million views! Despite the distractions, pack up of the US drill went very smoothly and all the drill cargo is awaiting its departure by traverse.

While packing, the French finished the melts for their second borehole. The results were similar to their previous extractions—carbon monoxide was high and variable, implying a contamination source. In between theses melt-extractions and the highly anticipated Little Dome C melt-extraction, we did some more conditioning of the melter to hopefully remove any contaminants before the one chance we had at the Little Dome C melt-extraction. This included another melter blank and a firn blank. Finally, the Little Dome C melt-extraction was run and produced an anticlimactic 117 ppb concentration of CO. This is significantly better than the previous extractions at the same depth of 200ppb and 352ppb respectively, but still much higher than the expected 40 ppb of CO.

With all the science done, it was time to pack up the lab space for the season. Over 3 full days of work, we carefully put our sensitive scientific equipment back in its boxes and made sure to properly label and sort out the cargo into its various piles. Some cargo needs to be kept warm, and some cargo can be frozen on the traverse back to the coast. The most important cargo like our samples are going to be put on the plane with us to fly back to the coast. We have officially declared victory on the packing with everything in boxes and ready to be picked up to go home. To celebrate the end of the season, the French among us got the idea to host a crepe party. We made over 100 crepes and invited the whole station. As I write this now, the traverse of heavy tractors that will pull our cargo back to the coast is expected to arrive within the hour.

-Sebastian

Progress and Problems

Posted on December 8, 2024 by rochestericelab

We have continued to make good progress with ice core drilling and extraction of ancient air from the ice. The US ice core drill has reached 200 m, and we have now successfully extracted all the air from these cores, so the sampling for the U Rochester side of the project is about 50% complete. The oldest air we have collected so far is about 3500 years old!

As we get deeper in the ice sheet, the ice is under more pressure and the ice cores become more brittle. For the most recent U Rochester sample (180 – 201 m depth range), there were several ice cores that had sections that were broken up into small ice pieces.

Estelle looking sad next to the ice melter full of broken cores

Thankfully, we extract air from the ice shortly after it is drilled (within 24 hours), so we can get pristine ancient air even out of fractured ice, although we do get less of it. We use our Picarro instrument to measure greenhouse gas concentrations on the extracted air and compare to what previous ice core measurements have shown for Antarctic air of the same age. Our methane measurements are confirming that we are getting pristine ancient air, without contamination from modern air. We can also measure the amount of air we get per meter of ice, and the most recent sample had about 7% less air than the samples that came before it – this is due to the loss of some air bubbles from the many fractures in the ice cores. Jay has been working on modifying the ice core drill in the hope of improving the quality of the cores.

We have recently switched to working on air extraction from the French ice cores. On this side, the drilling has already reached about 230 m, and the cores have been stored in a snow cave. This side of the project is trying to measure the Oxygen-17 isotope in carbon monoxide (∆C¹⁷O), because it can provide information about how fast oxidants in the atmosphere remove greenhouse gases and pollutants. For this side of the project, it is very important to keep the amount of carbon monoxide contamination from sample handling (extra carbon monoxide that is not from the ancient air) low. When we extracted the air from the first batch of French ice cores (100 – 120 m depth), we saw a very high carbon monoxide concentration (200 parts per billion; in the ice cores we expect about 35 – 40 parts per billion) – by far the highest value we have seen all season.

Seeing this, we paused the work to investigate where the contamination was coming from. We tested our air transfer lines, pumps, canisters, as well as the ice melter itself (all clean). We even tested the air inside ice core boxes and plastic bags where the cores are stored, as well as the air in the ice core storage cave (all clean also).

Air inside ice core box air being measured (top) and sampling canister being filled with air from ice core storage cave (bottom)

So this is a mystery that has yet to be solved. The best hypothesis we have is that there is some sort of contaminant that was introduced to the surface of the ice cores that produces carbon monoxide when the ice cores melt. We are now trying to take more precautions with ice core processing, wearing masks to prevent any organics from our breath from getting on the surface of the cores, as well as removing a thin layer of ice from the surface with clean scrapers to see if this eliminates the problem.

Estelle scraping a section of ice core

As we are getting close to the half-point of the season, Vas is scheduled to leave in about a week, and Sebastian is scheduled to arrive to replace him. Sebastian has made it part of the way but has been stuck in Tasmania for almost two weeks now as his flight to Antarctica keeps getting delayed. Fingers crossed that he arrives soon!

– Vas

Ice core drilling and melting are off to a good start!

Posted on December 5, 2024 by rochestericelab

We had a slow start the first few days at Concordia to get used to the altitude (equivalent to about 12,500 ft) and the cold and very dry air. We were checking in with the station medical staff every day for the first five days to ensure all our vital signs were good and no one was developing a serious case of altitude sickness.

There are two main areas where people are staying at Concordia: the main station and the summer camp.

Main station buildings of Concordia

Our lab (orange and white tunnel tent) as well as Summer Camp (blocky orange structure in background)

The main station has the dining hall (with truly outstanding food!), a couple of lounges, a small gym, offices and small 2-person sleeping rooms. The summer camp (where most of our team is staying) is a 10 min walk from the main station and has shared sleeping rooms as well as a lounge area. This is definitely more comfortable than sleeping in a tent (our room is warm and has good shades to block out 24-hour daylight), but sleeping here can still be challenging, in part because of the thin and very dry air.

Bunk bed at Summer Camp

This is my 18^th polar field campaign, and I have never been to a polar location with such amazingly stable weather. Every day so far has been clear skies. Sunny weather at Concordia doesn’t mean comfortable though. We’ve had temperatures drop as low as -50˚C (-58˚F) in the first few days, and one day with a wind chill of down to – 64˚C (-83˚F)! Now that we’re into December, during the middle of the day temperatures are starting to rise above -30˚C (-22˚F). If you’re working outside in the wind, every inch of your skin needs to be covered to prevent frostbite!

Vas on a tyoical early-season day at Concordia

We located all of our cargo that has arrived here over the course of the past year, and first set to work assembling our equipment. We have two ice core drills this year: a French drill that produces ice cores 98 mm in diameter, and a US Ice Drilling Program drill that produces slightly larger 104 mm ice cores.Both drills are working now, and have been making good progress, approaching 200 m depth.

Jay operating the 4-inch drill and Alex processing an ice core

The other key piece of equipment we have is a very large ice melter / air extractor system.

Ice melter

A full load of ice cores!

We use the ice melter system to extract ancient air from the ice cores and pump it into canisters for transport home to our labs.

Sample canisters ready for ancient air

At the start of field campaigns it is often the case that some pieces of equipment don’t work properly, or don’t work at all because of manufacturing defects, rough handling during shipping, etc. This season is no exception, and we had some problems with the ice core drills, with the ice melter as well as with the instruments that are used to analyze the air on site after we extract it from the ice.

Jay cutting off a seized bolt on the ice melter flange

Unstable methane and carbon monoxide measurements on our Picarro instrument

I am happy to report that most things are working now, and we are making very good progress with the drilling, melting and air extraction as well as measurements. Stay tuned for more updates!

– Vas

Dome C Field Season Has Begun!

Posted on November 17, 2024 by rochestericelab

After years of planning and preparations, our Dome C project is finally underway! This project is collaborative between US and French scientists, and is being supported by both the US National Science Foundation and the French Polar Institute. The scientific goals of the project for our lab are to:

Make measurements of carbon-14 of carbon monoxide (¹⁴CO) in ice cores to learn more about how intensity of cosmic rays changes over time. Cosmic rays produce certain types of atoms on Earth that help us understand Earth’s past climate and carbon cycle, but we don’t have a very good idea of how the intensity (flux) of cosmic rays has changed over time. Measurements of ¹⁴CO in ice cores can help with this.
Make measurements of carbon-14 of methane (¹⁴CH₄) in ice cores to learn more about where methane in the atmosphere was coming from during the last 7,000 years. Methane is an important greenhouse gas, but we don’t have a good understanding of how much fossil methane is leaking naturally from the ground versus emitted by mining coal and drilling for oil and gas. Measurements of ¹⁴CH₄ in ice cores can help with this.

If you are curious to learn more about how ¹⁴CO and ¹⁴CH₄ work, please see our Research page and our Publications.

This project is taking place at Concordia Station, Antarctica – one of the coldest locations in Antarctica (-55˚C / -67˚F average temperature!). Image: Google Earth

The first step is for us to get there. Before we fly to Antarctica, we need to get to Christchurch, New Zealand. See one of our recent Tik Toks for a map of what that might look like. Except that this time every single member of our research team had flight delays and cancellations, with some of the team making it to Christchurch just a few hours before the scheduled flight to Antarctica.

The 7 hour flight to Antarctica is on a C-130 cargo airplane

Vas in Christchurch before takeoff for Antarctica

Vas and Jay (Ice Drilling Program engineer / driller) during the flight

The plane landed late in the evening on a sea ice runway at the Italian Mario Zucchelli station.

Vas after getting off the plane

There’s 24-hour daylight, so still time to explore a bit around the station!

Mario Zucchelli station

A wind-eroded rock on a hillside above the station

We had a few hours of sleep, and then it’s time for our next flight, to Concordia station. This one is 4 hours on a Basler airplane. See one of our TikToks for some footage from the flight!

Getting ready for the Basler flight

Arrived at Concordia tired but happy. Much colder here at -40˚F / – 40 ˚C!

Vas in front of Concordia station

All Systems Go and Mid-season Changeover

Posted on December 19, 2018 by rochestericelab

There is much progress to report, and lots of exciting science happening at Law Dome. First, all of our systems have now been set up and tested. Sharon and Jose have excavated a beautiful 2m-deep trench, which is now the home of the 4-inch drill, the bandsaw and the freezer.

Tanner and Grant drilling in the trench. Photo: Vas

Tanner and Grant promptly set up the 4” drill, which is what will be used to recover the deep (up to ≈240m) preindustrial ice and the air it contains. Andrew set up the ANSTO bandsaw, which produces fantastic straight cuts on our ice cores.

Andrew testing the ANSTO bandsaw with some 4” core. Photo: Vas

The bandsaw will be used for taking a sliver from one of the 4” cores. This continuous sliver of ice will be analyzed for isotopes of H2O and allow us to determine the ages of the ice layers as well as a more accurate history of snow accumulation rate at the site.

The large ice melter (which we’re using to extract lots of old air from the ice, for measurements of carbon – 14 of carbon monoxide) has been performing extremely well, much better than in all of our tests back home in the lab. We have now completed 5 melt-extractions of air from the large BID cores. These samples will help us to understand how much of the carbon – 14 in our samples is due to production by cosmic rays directly in the ice.

We also did a first test of the large melter system with 4” ice cores, to confirm that the drilling and handling process for these smaller cores is equally clean (it is) and works well (it does).

Vas and Peter with 4” cores stored in a side cave. Photo: David E

Vas pulling the clean sled with 4” cores toward the melter. Photo: David E

Loading ice chips into melter bottom (needed for melting to start quickly). Photo: David E

4” core getting its final cleaning prior to the melt. Photo: David E

The large ice melter full of 4” cores. Photo: Vas

It is hard to believe, but the field season is already over for some of us. Vas, David Etheridge, Richard and Andrew left Law Dome 2 days ago for Casey Station, arriving almost exactly at the same time as Ed and David Thornton, who came via a Basler flight from McMurdo station.

The Challenger tractor at a rest stop on our way back to Casey. Photo: Vas

The team is down to 5 up on the Dome (Sharon, Jose, Tanner, Grant and Peter) – they are currently short-staffed, but are doing their best to keep some of the work going. Fingers crossed that the weather holds and Ed and David Thornton are able to get up to the field site quickly!

-Vas

First week at Law Dome

Posted on December 9, 2018 by rochestericelab

It has been one week on Law Dome for the entire team, and what an incredibly productive week it has been.

We arrived in two teams, with an advance group of 5 people heading up the dome November 20th with much of the camp and science cargo. As they battled snow and wind to get all the equipment to our new camp, “DE08-OH,” the rest of us were trapped 130 km away at Casey Station due to bad weather. The three-day blizzard at Casey peaked with winds of 70 knots and a maximum gust of 94 knots!

After a long, snowy, bumpy ride up the ice dome in two tracked Hagglunds, we were all finally united.

The science team on their 10-hour long traverse from Casey to DE08-OH.

Camp living structures shortly after arriving.

Once at camp, everyone was eager to move temperature-sensitive cargo into tents (heroically erected in gale-force wind and blowing snow by the advance team). Making a long story of unpacking boxes short, we went from a 3-day blizzard to having most of our equipment set up in structures 3 days later.

Excitedly unloading science cargo after finally getting to camp.

Ice coring with the US 3” Eclipse drill has progressed to 60 m depth, with firn-air sampling from the surface to capture how the layers of snow trap air as they are compressed into ice.

The Eclipse and firn-air tent.

David Etheridge and Lenneke Jong excited to see the first ice core of the season!

The “ice melter” is safely at home in its melter shelter (or “melta shelta,” depending on your accent). This protective wooden box was put up in 2 days by AAD carpenter Brett, handily assisted by our traverse drivers Juan and Shane from Casey Station.

The science tent and melter shelter, with the large-volume ice extraction “ice melter” inside.

We have fully set up this system and as of December 6th have successfully undertaken our first tests with large ice cores (24 cm diameter, 1 meter long) drilled using the US Blue Ice Drill. The BID is at home in what we call “driller heaven,” a heavenly white tent that should make the operation weatherproof.

A peek inside the Blue Ice Drill tent, where large ice cores are drilled.

The latest project is excavating a trench to house one more drill, the US 4-inch system. The trench is marked out and the snowblowers are getting to work.

The 4-inch drill trench in the process of being marked out. The Blue Ice Drill tent is in the background.

We hope everyone back home is having a great winter. If you’re dealing with snowy weather, we can relate down here on the wet side of Law Dome!

Ready and waiting…

Posted on November 23, 2018 by rochestericelab

410 words (2-3 minutes)

It’s (for the most part) been a busy two weeks at Casey Station! We now have about half of the team up at Law Dome, moving heavy sleds of equipment from a depot near the dome summit to our now camp–dubbed “DE08-OH.”

The traverse route up Law Dome. The advance team is currently shuttling equipment between a depot at D-28 and our new camp, DE08-OH. Map data are from the Reference Elevation Map of Antarctica, plotted with QGIS and Quantarctica.

DE08 was an ice core site used by our team member David Etheridge and others to reconstruct past atmospheric CO2 and CH4 (methane) concentrations. This site remains one of the best linkages between modern measurements of atmospheric greenhouse gases, and the ice core record. We are going there again to take advantage of its high snowfall (a fact the advance team may be regretting as they wade through snow…) to shield our samples from too much in-situ Carbon-14 produced by cosmic ray bombardment .

The rest of the team remains at Casey Station, in part to keep the camp population manageable before several tents are erected. We also have more sensitive science equipment back here with us which cannot freeze, so we need warm structures at the site before heading up.

Over the last week or so, we completed our survival training, which was a great combination of hiking out in the sun and snow, watching Adelie penguins, and sleeping out with only the survival gear that we are required to carry whenever we leave station. It’s a minimal setup, including only a “bivy” bag, sleeping bag, and mat to sleep in. But with emergency cold weather clothing, this was still quite comfortable.

A cold, beautiful night at survival camp.

Adelie penguins wallowing in the snow on Shirley Island.

Part of the Shirley Island Adelie penguin colony, including what looks to be a new species: the rock-lier penguin (get it?).

For now, those of us still on station remain ready to drive up Law Dome as soon as possible–hopefully in the next two days. The support from Casey Station has so far been amazing. We are rested, eating too much, and are eager to get to work setting up camp and science equipment at DE08-OH on Law Dome!

Oh, and Happy Thanksgiving! Again, we’re eating plenty of food here…

-Peter

For another perspective on the project, check out this recent article from Nature News! You can also follow Peter’s posts on Twitter, under the hashtag #LawDome1819.

Settling in and sending the first traverse up the dome

Posted on November 13, 2018 by rochestericelab

(200 words, 1 minute read)

We have now been at Casey Station for nearly three full days, and have realized that our advance team from the Australian Antarctic Division—Sharon and Jose—have been very busy! They had already prepped two gargantuan sleds, full of camp and science cargo, for traversing up Law Dome (see below).

^ Sharon and Jose with their tractor train to haul up Law Dome.

Yesterday, Monday, November 12, Sharon, Jose and field trainer Anthea headed up the dome with this first load of cargo, which represents a significant portion of the cargo that we need to build our camp more than 100km from station. They are returning from the trip in a few hours.

Any time you arrive at a small Antarctic research station, a significant portion of the first few days goes into getting to know base operations and becoming a safe and helpful part of the community. Casey is a station of about 80 people right now, and in such a small community everyone really needs to pitch in to get all the work done and take care of one another. So far, our experience here has been very warm and friendly, with absolutely spectacular support of our science project! See some photos of the station, below.

^Scenes from Casey, including the station signpost, the main “Red Shed” building, and the field store.

Expedition to Law Dome, Antarctica is underway

Posted on November 8, 2018 by rochestericelab

(330 words, 1-2 minute read)

After a bit of a blogging hiatus, we’re back in action and on our way to Antarctica! This is Peter writing, at the moment from Hobart, Tasmania. Vas and I are currently waiting for a weather window to fly south to Casey Station, Antarctica with the Australian Antarctic Program!

We are headed to a location called Law Dome, which is a dome of ice on the coast of East Antarctica essentially dead south of Perth, Australia. This site is ideal for the past atmospheric reconstruction we are hoping to do, using carbon-14 of carbon monoxide (14-CO) to learn how atmospheric oxidation has changed through the modern industrial period, from about the year 1880 to present. Here’s a video from the Australian Antarctic Division with a bit of an overview from our Australian project leader, David Etheridge.

It’s been a busy few days for us, flying half-way across the planet, trying not to be jet-lagged, completing cold-weather clothing outfitting, and undertaking many training courses.

Traveling with us are Tanner Kuhl and Grant Boeckmann, ice-core drillers with Ice Drilling Design and Operation. Our training has been thorough and varied… even including chainsaw training with a Tasmanian logger so that we can safely use these tools to build a snow-trench to house one of our ice-core drills!

Currently we are waiting for weather to improve in Antarctica, so we can fly to the Wilkins blue-ice runway and get to Casey. You can see current conditions on their station webcam.

Delays are a part of life in Antarctica, so although we are not surprised we are still eager to get to work preparing our cargo for an overland traverse up to the “DE08” site on the east side of Law Dome.

Stay tuned here for updates from Casey Station and the deep field (as we can get information out). Some of us will be working at Law Dome through January 2019 and won’t be home from Antarctica until mid-to-late February!

Where there’s smoke, there’s CO.

Posted on September 11, 2017 by rochestericelab

(540 words, ~2-3 minute read)

Over the last few weeks, I (Peter) have been in the lab testing our new ice melting system for extracting ancient air from Antarctic ice in order to study carbon-14 of carbon monoxide (14CO). 14CO can tell us about how the atmosphere oxidizes trace gases and particles out of the atmosphere, something we know little about before modern observations.

We are primarily running these tests to quantify the CO contribution of individual parts of the sampling process. For instance, moving an air sample through transfer pumps adds on the order of 10 ppb CO, while the sample itself begins with less than 100 ppb CO. We want to quantify this “blank” so we can correct our final sample measurements.

To sample the test gases, we use a Picarro cavity-ringdown spectrometer which, briefly, uses laser-light absorption to measure gas concentrations down to parts per billion (see more information from Picarro).

While not running tests, this instrument has been measuring ambient concentrations of trace gases in our laboratory. You can see it in the pictures below, along with the shiny new stainless-steel 14CO melter system.

Over this past Labor Day weekend, I noticed something very interesting in the Picarro data: the concentration of CO in room air was steadily rising from just over 100 parts per billion (ppb, same as 0.1 parts per million on the plot) on September 1st, and nearly doubling to over 200 ppb by September 6th!

CO_AirQuality_LaborDayWeekendto By September 7th the concentration had dropped back down to near where it was before the weekend.

What caused this!?

It took me until September 5th to realize the likely culprit: smoke from forest fires burning across the western US and Canada traveling across the continent on the jet stream.

I am originally from Washington State and had been hearing from friends and family about the many active fires and thick smoke and even ash falling in metropolitan areas!

The image below was taken on September 4th, from the NASA Visible Infrared Imaging Radiometer Suite and featured in a NASA Earth Observatory article last week. You can see a pall of smoke crossing the entire United States, reaching to New York and beyond.

IDL TIFF file

Upstate New York air quality data, gathered from AirNow, show a clear rise in the air quality index—indicating moderate/poor air quality—at the same time as the lab background air rising.

CO_AirQuality_LaborDayWeekend

Carbon monoxide is produced in fires due to incomplete combustion (not all the way to producing CO2), so where there are large forest fires or other biomass burning events one can expect elevated CO concentrations—which are dangerous for human health if concentrations reach into parts per million. For more information, NASA Earth Observatory in 2015 wrote a great in-depth article about large fires and CO in Indonesia.

Luckily, this rise in background CO didn’t affect the tests I was running—our systems are quite leak-tight by design—but this demonstrates the long-reaching effects of events occurring on the other side of North America!

We live in a very inter-connected world in many ways, and this goes to show how we can detect impacts of events like forest fires even 1,500 miles from where they occur!

-Peter

*The lab air data in the plots (magenta +) is taken from approximately representative 10-20 minute periods, plotting all measurements to show variability (about one measurement is taken every 2.5 seconds).