On Thursday, February 28th the temperatures at the Eureka Weather Station held steady at -35 degrees C, with a slight wind giving a windchill of -38 degrees C. Up at the PEARL Ridge Lab, temperatures were quite a bit warmer than at Eureka, at -26 degrees C, however 4 knot winds brought the windchill index down to -38 degrees C. The streak of sunny, clear weather has come to an end, and the area was enveloped in clouds and a consistent light dusting of ice crystals. Today we had a total of 6 hours and 4 minutes between sunrise and sunset (34 minutes longer than yesterday). The team hopes that the sun and clear skies will return soon, as the Pandora is awaiting its first measurements.
Sebastien and Tyler started the morning off with an HCl cell test for the Bruker 125HR in preparation for a realignment of the instrument (the cell tests give insight into the performance of the instrument and how well it is currently aligned). They then spent the remainder of the afternoon using a telescope, a laser and a system of mirrors to carefully align the entrance aperture, as well as the fixed mirror inside the Bruker to remove a shear misalignment issue.
Tomorrow they will finish the alignment process by adjusting the internal mirrors to bring the new exit aperture into focus with the new entrance aperture. They will then take a second set of cell tests to assess the performance of the instrument following the full alignment.
Due to the persistent cloud cover today, Kristof was unable to align the newly installed Pandora. Instead, he spent time finalizing the instrument setup. First he secured the cables on the inside of the hatch, then, with help from Pierre, they made sure the cables will stay in place on the roof as well. During the rest of the day, Kristof set up network access for the Pandora computer and the remote access power bar. Pending a sunny day, the Pandora is ready for measurements.
Xin spent his morning at the PEARL Ridge Lab analyzing last years’ snow sample data. Around noon, with the help of John he collected several snow samples at a sampling site near the Ridge Lab. For the first time, Xin was successful in collecting a small amount of falling snow from the sampling tray which he mounted on the roof of the Ridge Lab. Later in the afternoon, Xin and John visited the sampling sites west of the Weather Station and collected more snow samples. They then headed back to 0PAL, where Xin was able to collect enough snow to fill up a 50 ml sampling tube for chemical analysis from another sampling tray which he had set up there.
After ensuring the proper operation of the SPS instrument yesterday, Tom left his instrument running automatically overnight. In the morning, he confirmed that the tracker had functioned properly throughout the night with the SPS pointing toward the direction of the sun. A preliminary analysis of the data collected yesterday indicated that everything is functioning properly, and his instrument will continue to collect data in the days to come. Tom spent some time in the afternoon showing Ali how to analyze data from the SPS, and Ali spent the remainder of his day working on data taken by the DIAL earlier in the campaign before the laser power supply had failed.
Alexey and Ali have decided to shutdown the DIAL for the remainder of the campaign, and the current plan is to repair it over the summer to have it ready for operation in the fall of 2019.
In the absence of the DIAL, Alexey has spent most of his time on drone flights around the flux tower at SAFIRE where he hopes to measure vertical temperature profiles and the temperature inversion at the boundary layer.
After dinner, several of the campaign team members gathered outside the Eureka Weather Station to watch the launch of the first campaign ozonesonde, carried by a Raven balloon (often referred to as a ‘jellyfish’ due to its appearance). The balloon was launched at 6:15pm local time, and it reached an altitude of 33.36km (a pressure level of 5 hPa).
Cheers,
Tyler Wizenberg
[On Behalf of the 2019 Canadian Arctic ACE/OSIRIS
Validation Campaign team]
* Instrument Status *
Bruker FTIR: Offline (cell measurements)
EM/27 SUN FTIR: In transit to Eureka