The temperature in Eureka was a cold -47 °C this morning, and rose to -41 °C in the afternoon.
Thanks to the temperature inversion, PEARL enjoyed somewhat warmer -30 °C. A thick layer of clouds
blocked the Sun for the entire day, preventing Bruker and PARIS measurements. Joseph helped Xiaoyi
by finishing and analyzing resolution tests for the UT-GBS. Debora ran her Linefit program using HBr
cell measurements taken earlier in the campaign to check the calibration of the instrument. She compared
them to previous years' results to check that the spectra taken by PARIS are in a good shape. Debora and
Volodya also attempted to revive a damaged network card, used for the internet connection used for data
backups, and created a temporary fix.
Early this afternoon, the team took a break to raise a new Canadian flag on the PEARL flagpole. The old
flag had become worn from the Arctic climate. It was the first time some of us had raised our national
symbol, and was a powerfully uplifting experience.
Xiaoyi has continued his work with the PEARL-GBS in the UV/Vis lab. Last night, it again stopped taking
dark current measurements prematurely. Fortunately, Xiaoyi appears to have now isolated the issue to the
instrument computer's communication with the sun tracker. This problem should be solved with relative ease
by adjusting the labview code. Having consulted with an ACE Campaign and GBS veteran, Cristen, Xiaoyi again
left the PEARL-GBS taking dark current measurements overnight with the sun tracker disabled. He feels confident
tomorrow will finally yield success!
Meanwhile, Pierre worked on the roof to prepare for the installation of the new sun tracker.
If the weather is good, he and Xiaoyi will install the sun tracker tomorrow.
Also in the UV/Vis lab today, Volodya tested Brewer 021. The SPS and MAESTRO continue normal operation collecting
zenith sky data, which will be used to retrieve over 20 different atmospheric species.
During the day, Emily ran several calibration runs for the CRL lidar system at 0PAL, two with white light and two
with bright skylight. She also installed the sheet polarizer in the depolarization channel. In the evening, Chris
and Emily worked together to coordinate optimizing the photo-multiplier tube focus and the rotation angle of the
polarizer to maximize the depolarization channel signal. We now receive sufficient photons for this channel to be
useful for measurements. With this modification complete, Chris ran the lidar for 10 hours overnight, taking data
in all receiver channels.
The first ACE ozonesonde flight successfully occurred today. The balloon was launched at 18:05 and reached an
altitude of 33,500 m and 5.1 millibar.
The Polar Vortex continues to be centered over the Arctic Ocean. The edge stretches from northern Russia to the
northernmost edge of Ellesmere Island.
Also in the news today, the end of full-time year-round operations at PEARL as of April 30th was formally announced.
The closure notice can be found here.
The French version can be found here.