On Monday March 5th, the temperature at the PEARL Ridge Lab oscillated quite a bit, starting near -26 degrees, decreasing to -29 degrees, then up to -24 degrees before once again falling, settling near -27 degrees. Down at the weather station the temperature was much less varied, hovering around -26 degrees all day. As a pleasant change from the last few days, the morning started off with mostly clear skies, which persisted through the majority of the day despite some low-lying cloud cover on the horizon. This allowed the campaign team to make use of the 8 hours of sunlight today.
Kristof took the first MAX-DOAS measurements of the year with the PEARL-GBS. The surface ozone levels have dropped to around 7 ppb today (from the usual 20-40 ppb), so he's hoping to see detectable levels of BrO in the MAX-DOAS measurements.
In the morning Paul checked on SPS and found that it had been working nominally overnight. However, when Paul checked on SPS just before noon, he found that the tracker for SPS had lost communication with the control computer at some point in the preceding hours, requiring a restart of the tracker and SPS software. Near 3 o’clock communication with the tracker again was found to have failed, and it seems that this was due to the communication port connection of the tracker on the roof having come loose. Paul fixed the connection and added further ties to keep it together, but the problem recurred around 4 o’clock. While he managed to get the tracker up and running again, Paul is looking into further ways to deal with this problem if it occurs again. For now he has left SPS and the tracker running overnight.
Last night was snowy and Ghazal was not able to do measurements. Tonight's weather looks more promising and Ghazal is looking forward to hopefully measuring some data.
Low-lying clouds prevented morning solar observations from the Bruker FTIR. During this time Erik and Sébastien placed the telescope of the alignment kit in the long arm of the interferometer to view the instrument’s apertures. In the afternoon they finally had their first opportunity to make solar measurements and 26 MIR spectra were recorded before the sun moved back behind the clouds.
This morning John and Xin visited the snow sampling sites that are about 5 km away from the station. They measured snow density at the inland site and collected snow samples for profile analysis from both the inland and sea ice sites. The morning was marked not only by sunshine, but also by quite strong winds and Xin was able to clearly observe drifting snow particles during this time. Additionally, a clear ozone depletion event was observed today, noted from the readout of the ozone analyzer in the 0PAL lab. In the afternoon Xin revisited the creek site behind 0PAL and collected snow samples there. Finally, he performed salinity analysis tests on the samples collected.
In the evening the team gathered to watch the ozonesonde launch at 6:15 (23:15 UTC), hoping to get a better view of its ascent than they had the previous day, when it was snowing. Afterwards they worked on individual projects and tasks, making it a rather quiet evening.
Cheers,
Paul Jeffery
[On Behalf of the 2018 Canadian ACE/OSIRIS Arctic Validation Campaign Team]