Unfortunately, the team faced another rather cloudy day on Friday, February 28. The temperature at the weather station was similar to previous days, hovering just above -40°C. However, the wind had significantly picked up at the Ridge Lab. With winds of up to almost 10m/s the -35°C felt more like -52°C to -53°C (windchill). Since it was not safe to work on the roof, the team focused on indoor tasks. They headed back to Eureka shortly after 3 PM today and stopped at the 80°N sign on their way down for a group picture.
Since the day was cloudy, Beatriz and Tyler were unable to make solar measurements. They worked on the macro for the HCl test cell and changed the configuration to perform measurements with an optical path difference of 45 cm to save time. They performed an additional HCl test to make sure the macro was running properly. They also checked that the MIR auto-measurement macro was in agreement with the optical settings, e.g., the apertures, of the previous campaigns.
In the morning, Kristof and Ramina analyzed the dark current measurements taken overnight by the PEARL-GBS, and the results looked similar to previous years. To confirm that the CCD position remained stable after moving the instrument to the IR lab, they performed one last resolution test. With the PEARL-GBS lab tests completed, Kristof and Ramina replaced the optical fibre used for testing with the fibre that connects to the suntracker on the roof. Since strong winds prevented the pair from working on the roof, they were not able to get started on troubleshooting the tracker. Instead, they spent the afternoon organizing their notes and finalizing the results form the lab tests. They've also left the PEARL-GBS running, since while the tracker is stuck, it still points at the zenith sky. Kristof and Ramina will be able to use these first measurements to assess the quality of the spectra. The Pandora collected 2.5 hours of solar alignment measurements on Thursday, February 27. Kristof switched the instrument to the regular measurement schedule, since no alignment scans were possible today.
Last night, February 27 to February 28, Ali and Alexey started the DIAL around 7 PM from Ridge Lab. The wind had already picked up during the night and a lot of blowing snow got into the hatch and they had to clean the mirror every couple of hours. The signal was weak by the end of the measurement period. In the early afternoon of Friday, February 28, they cleaned the optics of the laser and also changed the laser gas mixture. Alexey instructed Ali during this procedure, cleaning one side himself and Ali repeating his steps the other side of laser optics.
The CRL measured for 23.5 h on February 27, with both the Green and UV lasers. During the evening's clear skies Emily, remotely from Newfoundland, began a start delay calibration for the polarotor, but clouds arrived after a half hour, and the rest of the calibration had to be postponed. Regular measurements continued after that.
Guillaume finished the cooler replacement of the E-AERI and will put the outside cover on tomorrow with Ellen's help. He seized the chance before flying out tomorrow to take a closer look at the icebergs in the fiord with Jane, Flora, Cole and Scott from the weather station.
The first ozonesonde of the campaign was launched today at 6:15 PM. It was carried by a "Raven" balloon which is larger than a regular weather balloon and rises to higher altitudes. Today's Raven reached a final alitude of 25832 m (15.8 hPa) collecting measurements of ozone, pressure and temperature on its way up. Senior aerological observer Jane gave the team a tour of the hydrogen shed and explained the functioning of the hydrogen generator. The team then watched the successful launch of the Raven balloon.
Even though we are looking forward to the service plane bringing CANDAC operator Andrew Hall and heavy equipment operator Jay Roberts in tomorrow, as well as fresh goods, we are sad see a lot of people leave on the same plane who added so much to our stay up here: Jane who always put a smile on everyone's face and gladly took the time to explain something or open the gift shop for us, Steve who prepared our delicious meals, Dave and Roger who kept the roads clear for us, John who made sure we got to and back from the Ridge Lab and had all the supplies we needed, Tom who not only got the SPS back and running but also always had a great story to share, and Guillaume who provided the E-AERI with a new cooler, shared his pictures with us and often joined us at the rec room for a game of pool or a chat.
Cheers,
Ellen Eckert
[on behalf of the 2020 Canadian Arctic ACE/OSIRIS Validation Campaign]