On Monday, March 4th the temperature at the Eureka Weather Station was -22 degrees C, with winds of 14 knots (26 km/h), bringing the windchill temperature down to -35 degrees C. Temperatures at the PEARL Ridge Lab dropped to -26 degrees C in the morning but slowly climbed to -22 degrees C through the day, with a windchill index of approximately -33 degrees C. The winds reached a maximum of 38.9 knots (72 km/h) around 1pm, preventing the team from working on the roof of the Ridge Lab, but they gradually died down in the afternoon. Monday started out very cloudy, but the clouds parted in the late afternoon just in time for the team to catch a glimpse of a beautiful sunset. Today there was a total of 7 hours and 35 minutes between sunrise and sunset.
Due to the cloudy conditions earlier in the day, solar measurements with the Bruker 125HR were not possible and Tyler decided to use the day to run an HBr cell test, in addition to a background measurement. While the cell test was running, he spent some time updating the standard operating procedure (SOP) document for the Bruker 125HR, as well as making a few minor changes to the macros used to run the instrument. He also worked with Pierre to set up remote access on the laptop for the EM27/SUN so that the instrument can be run remotely from Toronto.
Kristof spent the day monitoring the two GBS’s and the Pandora. He analyzed some data from the PEARL-GBS to assess quality of the data after the lab tests, and found that the results are similar to previous years. When the sun came out in the afternoon, the Pandora alignment looked different from yesterday's. It is likely that the tracker base moved slightly in the strong winds earlier today, so Kristof restarted the alignment procedure.
Xin spent his morning at 0PAL, where he collected one tube of blowing snow from the tray outside and then collected four tubes surface snow from a nearby site. He continued his work on analyzing the salinity of his samples before lunchtime. In the afternoon, with help of Peter, Xin collected samples from his sampling sites to the west of the Weather Station before heading up to the Ridge Lab to continue sampling there. He found that there was some frost growing on his sample tray on the roof of the Ridge Lab, likely due to the extreme wind speeds in the morning. After watching the ozonesonde launch at 6:15pm, Xin walked over to 0PAL to finish up his salinity analysis on a few of his snow samples.
Ali spent the morning working on his optimal estimation method (OEM) codes to retrieve temperature profiles from the Rayleigh high-range channel data in the upper stratosphere and lower mesosphere from the DIAL. In order to extrapolate temperature profiles in the lower atmosphere, he tried to use the vibrational Raman channel of DIAL, but because of aerosol effects, he noticed an offset in the retrieved temperature and decided to disregard this portion of the data. Instead, he used the Rayleigh medium-range channel of the DIAL to estimate the temperature profiles between 15 and 24 km above sea level, and compared this to radiosonde temperature data. He found that the retrievals from the Rayleigh medium-range channel matched the radiosonde temperature profiles very closely. Next, he aims to merge the data from the two Rayleigh channels to obtain a more complete vertical temperature profile of the atmosphere.
Cheers,
Tyler Wizenberg
[On Behalf of the 2019 Canadian Arctic ACE/OSIRIS
Validation Campaign team]
* Instrument Status *
Bruker FTIR: Nominal operations
EM/27 SUN FTIR: Offline (awaiting sunny conditions)