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Measuring Atmospheric Trace Gases Near the Top of the World

By Ellen Eckert

For just over two decades, students and postdocs working with Professors Kimberly Strong and Kaley Walker have traveled to Eureka, Nunavut, in the Canadian High Arctic (80˚N) each spring to collect unique measurements of atmospheric trace gases.

This year’s campaign team included six early career scientists from U of T, namely graduate students Ramina Alwarda, Kristof Bognar, Beatriz Herrera Gutierrez, and Tyler Wizenberg, and postdoctoral fellows Ellen Eckert and Ali Jalali. Joined by U of T Senior Research Associate and PEARL Site Manager Dr. Pierre Fogal, Operator John Gallagher, Research Associate Dr. Alexey Tikhomirov from Dalhousie University, and Professor Emeritus Tom McElroy from York University, they had the extraordinary opportunity to work with a wide suite of instruments at the Polar Environment Atmospheric Research Laboratory (PEARL). The intensive phase of the campaign took place from 21 February to 12 March this year, and yielded many valuable measurements that are being used to validate satellite data products and to investigate a variety of atmospheric phenomena.  This year was particularly interesting, as we observed record low Arctic ozone; the team is currently analyzing these results to understand why conditions were so different this year.


Photo: The team stopping at the 80˚N sign on the way from Eureka to the Ridge Laboratory: in back row (from left): Pierre Fogal, Alexey Tikhomirov, Kristof Bognar, Tom McElroy, Ali Jalali, Tyler Wizenberg; in front row (from left): John Gallagher, Ellen Eckert, Ramina Alwarda, Beatriz Herrera Gutierrez (photo credit: Pierre Fogal).

But why go to this remote location and why do it at this time of the year? PEARL in a sweet spot for atmospheric research for several reasons: it is located in an area of the world that is crucial for understanding the global atmosphere and there are no other stations anywhere near, as the polar regions are severely under-sampled. Another reason is that satellites that have high inclination orbits, like the Canadian-led Atmospheric Chemistry Experiment, frequently pass over this area, which makes it a great location for validation studies. The spring campaigns coincide with when the transition from polar night to midnight sun occurs. This transition only takes about seven weeks at Eureka. Since some of the instruments operate at night and some need sunlight to operate, this time of year is ideal for comparisons between the different instruments to determine if there are biases between their measurements.

When the team arrived at Eureka this year, the Sun was only above the horizon for about two hours, while when they left, daylight hours had exceeded nine hours. The team lives at Environment and Climate Change Canada’s Eureka Weather Station, where they enjoy the hospitality of the permanent staff, the amazing food and recreational activities. To do their research,the team members head up to the PEARL Ridge Laboratory each day, where most of the instruments are located, to take measurements.  They also perform maintenance and repair tasks when necessary.  This work can be interrupted by poor weather such as storms, so the team must always be aware of the meteorological conditions.


Photo: Ramina Alwarda and Kristof Bognar troubleshooting the PEARL-GBS suntracker, located on the roof of the PEARL Ridge Lab (photo credit: Ellen Eckert).

Working in the high Arctic is challenging but very rewarding. Temperatures of -40°C and lower mean that seemingly simple tasks such as tightening screws and adjusting components need to be done quickly and carefully, with fingers well protected.

The cold takes its toll on the instruments as well, but the lab is well stocked with tools and spare parts so things can often be fixed on site. On rarer occasions, specific spare parts are shipped up north and instruments are sometimes taken south for major repairs. This year’s campaign was a great success, as the team was able to get all the instruments running and to keep them collecting data that will provide insight into Arctic atmospheric phenomena.

Visiting Eureka is a unique and fantastic experience,not only for the scientific research, but also for the mind-blowing scenery and the wildlife that sometimes crosses the team’s path. This year,we were lucky to encounter a couple of foxes close to the Ridge Laboratory, a musk ox that had made itself comfortable around the Eureka Weather Station, and even a pack of wolves that strolled through the station on the last day of the campaign.


Photo: Wildlife in Eureka (left to right): Arctic fox, musk ox, and wolf (photo credits (left to right): Ellen Eckert, Guillaume Gamache and Ramina Alwarda).

In addition, the students and postdocs got the chance to learn about amateur radio as Pierre and Alexey, who are both licensed amateur radio operators, participated in a contest this year and happily shared their knowledge with the rest of the team.


Photo: UofT team members joining Dr. Pierre Fogal in the radio room at PEARL photo credit: Ramina Alwarda

For more details on the campaign, please check out our website:

The spring 2020 measurements at PEARL were made during the Canadian Arctic ACE/OSIRIS Validation Campaign, supported by the Canadian Network for Detection of Atmospheric Change (CANDAC), the Canadian Space Agency, Environment and Climate Change Canada, NSERC, and the Northern Scientific Training Program.