On Tuesday March 12th, the temperature at the Eureka Weather Station was -21 degrees C, with winds of 17.8 knots (33 km/h) giving a windchill index of -34 degrees C. Up at the PEARL Ridge Lab, temperatures were approximately -24 degrees C, with winds of 26.2 knots (48.6 km/h), bringing the windchill temperature down to -41 degrees C. The weather today was characterized by strong winds and blowing snow, with very low visibility. Today the team had a total of 10 hours and 30 minutes of sunlight.
In the IR lab, Tyler spent the day finishing off the final series of cell tests for the Bruker 125HR to check the effect of the alignment process. Since the N2O cell test from March 10th displayed some unusual noise in the signal, he decided to do another N2O cell test and background measurement to discern whether it was a systematic issue or a one-off occurrence. Upon an initial inspection of the new spectrum, it appeared as though the noise was back to normal values, and this was later confirmed by Sebastien who ran Linefit on the N2O spectrum. The Linefit results displayed a significant improvement in the modulation efficiency and phase error when compared to the cell tests from before the alignment process. Tyler finished his last day at PEARL by starting a reference spectrum for the HBr cell test, and Pierre will finish the actual HBr cell test tomorrow. Overall, the intensive phase of the campaign was very successful for the Bruker 125HR as well as the EM27/SUN, and Peter and Pierre will continue to collect solar measurements with the FTIR spectrometers during the extended phase.
Kristof spent the day tidying the UV-vis lab space, and taking inventory of all the spare parts, tools, testing equipment and packing supplies. The Pandora and the PEARL-GBS will continue to measure for the rest of the year, and the UT-GBS repairs will commence once the replacement power supply arrives in Eureka.
This morning, Xin made his final snow salinity measurement on a few snow samples at 0PAL. Peter and Xin then visited the two sampling sites to the west of the Weather Station where Peter collected a set of surface samples for the second time. Due to the blowing snow and strong winds up at the Ridge Lab, sampling there was not possible. In the afternoon, Xin and Peter went through the instructions for surface snow sampling which Xin wrote as a brief guide for the continuation of the snow sampling project after his departure.
Today was windy and access to the roof was restricted. Ali followed the routine procedure to assess the quality of the SPS signal. He checked the retrieved ozone spectrum and found that it looked normal. Today was last day of the intensive phase of the campaign, and Ali collected the rest of the SPS data and sent it to Tom for further analysis. The SPS will continue to measure until the end of the campaign.
Since the DIAL has been operated since 1993 by various research groups, the dataset is a bit scattered, so Ali spent much of the afternoon trying to track down the DIAL data from the 1993-2001 time period. He will continue to track down the historical DIAL data over the next days, as this would extend the time series significantly.
The CRL has had a successful week. There were 24h/day measurements from March 7th through March 12th, with the exception of one 12-hour period on March 11th when CRL had to be closed to allow precipitation to evaporate from the roof window. The cloudy weather for the past couple of days has been fantastic for the CRL because cloud studies are one of this lidar's primary scientific goals. Emily will continue to operate the CRL from down south after the intensive phase team departs Eureka.
After dinner, Peter took the team out in the mat-track truck on the sea-ice to visit a large iceberg which had frozen in place in the middle of the fjord. However, due to the high winds and blowing snow, visibility was extremely low and it required a bit of searching before they found the iceberg. At the end of the day, the team gathered in the rec room to watch some TV, play some pool and enjoy their last night at the Eureka Weather Station.
Cheers,
Tyler Wizenberg
[On Behalf of the 2019 Canadian Arctic ACE/OSIRIS
Validation Campaign team]
* Instrument Status *
Bruker FTIR: Offline (for cell measurements)
EM/27 SUN FTIR: Nominal operations