On Friday March 2nd the temperature at the Eureka weather station was about -24 degrees during the day. Up at PEARL it hovered around -14 degrees, only a bit colder than where most of the team came from in the weeks leading up to the campaign! Just under 7 hours of sunlight was expected today, and luckily for the team despite early morning clouds, the sun made an appearance for part of the afternoon.
Sébastien and Erik began the morning by performing more tests of the Bruker FTIR alignment. Photos were taken of the Haidinger fringes at optical path differences. From the photos they found the instrument appears to be well aligned but they decided they would perform further tests for alignment on the next cloudy day. As the clouds cleared in the early afternoon, Sébastien and Erik prepared the instrument for mid-infrared solar measurements. Although active tracking was achieved with the solar-tracker, clouds and the low elevation angle of the Sun did not allow for adequate signal for measurements.
Kristof found the source of the PEARL-GBS tracker connectivity issues. After replacing the faulty components, the PEARL-GBS was able to resume normal operation. The instrument is now ready for MAX-DOAS measurements that are due to start in a few days.
Paul and Tom checked SPS in the morning and found the tracker pointing away from where the software thought it was. They reset the instrument and tracker control software and the issue seemed to be taken care of.Wary of the possibility that this issue might recur, Paul prepared the backup computer to take over control of the tracker and SPS. Around one in the afternoon they made the switch over between the two computers and SPS seemed to function well. However, after about an hour the instrument stopped pointing in the right direction. Attempts to troubleshoot this were further complicated by SPS losing power, which could not be restored. Attempts to fix the issue have so far been unsuccessful and currently SPS is awaiting further testing inside the PEARL Ridge Lab.
Last night was cloudy, but for a few minutes, when the sky cleared the DIAL started working. The laser is stable and Ghazal and Alexey are looking forward to do measurements tonight.
The CRL continues to run for 24 hours a day. Additionally, Emily finished plotting the data from the campaign to date, and shared these plots with the rest of the campaign team.
This morning, with the help from the weather station staffs Xin collected 50 ml samples of sea water from the hole used by the meteorological technicians to measure sea ice thickness. Afterwards he continued with salinity analysis from the samples he’s collected in the previous few days. In the afternoon, with help from Peter, Xin collected snow samples at 4 different heights from each of 7 snow holes, all within about a 1 square meter area.
Finally, Friday evening marked the last night some of the campaign team, namely Tom, Emily, and Alexey, would be in Eureka. Leaving with them would be almost half of the weather station staff. To make the most of this company the evening was whittled away by the campaign team socializing with each other and the weather station staff.
Cheers,
Paul Jeffery
[On Behalf of the 2018 Canadian ACE/OSIRIS Arctic Validation Campaign Team]