The team woke up to sunny skies in the morning and as results they were eager to arrive at the Ridge Lab and start measurements. Although thin clouds and haze were present in the morning, solar measurements were started anyways. Soon after conditions began to clear further resulting in cloud-free blue skies in by noon. The blue skies persisted through the remainder of the day allowing for a great day of measurements. After making sure that nothing was left behind, the team made it back to the weather station at around 4:45 pm. In the evening the team seized the opportunity to enjoy the Arctic one last time.
Erik and Sébastien started the day with near infra-red measurements but thin clouds and haze moved in quickly after 7 measurements. Thus they decided to swap the beamsplitters and took 25 mid infra-red measurements for the rest of the morning. After noon the sky was clear and Erik and Sébastien put the CaF2 beamsplitter back in the instrument and 102 more near infra-red measurements were taken. While the spectrometer was taking solar measurements they tested the chiller which functioned all afternoon without leaking. At the end of the day Erik and Sébastien drained the chiller and stored it in the IR Lab.
The PEARL-GBS tracker stopped working, due to the same issue from last weekend. Initially, Kristof attributed the issue to the azimuth motor, but replacing it with a spare one didn't solve the problem. Kristof and Pierre spent most of the day on the roof trying to solve the issue but in the end they had to put the old azimuth motor back in place and the problem remained unsolved. Since this was Kristof's last day at the ridge lab, the PEARL-GBS will remain in zenith sky - MAX-DOAS mode.
Today, it took Ellen 3 tries to boot PARIS-IR but afterwards the instrument ran without further problems. Ellen started by transferring yesterday's data to the laptop. Since the conditions were ideal, she started solar measurements right afterwards which ran from 10:30 am to close to 4:30 pm. Ellen checked PARIS-IR was running smoothly every 30 minutes because of the boot up problems in the morning but found that the instrument was doing fine. She completed 42 measurements today and started the file transfer before going down to the weather station, shutting the instruments down remotely.
The CRL was closed for several hours in the morning of 17 March UTC to do a computer backup. Other than that, Emily was measuring clouds, both snowing and not. As today was the last day in the lab at Eureka, Emily spent time organizing the lab, taking care of maintenance items which hadn't yet been completed (changing air filters, etc), and generally making sure that the lidar was in good shape to continue running once there is no longer a lidar operator on-site. Chris Perro (Dalhousie) will be operating the lidar remotely for several days while Emily is in transit.
Today, the DIAL was successfully shutdown for the season. Pierre, Emily, Ghazal and Peter drained the water from the Lidar's chiller. The whole system is ready to be operated again in the coming fall.
No ozonesondes were launched today.
At the end of successful campaign, we would like to thank the station program manager, André, for making our stay at Eureka weather station a pleasant one. The validation team was very grateful for meals prepared by Dean and Shawna who went out of their way to fulfil everybody's needs and keep the dessert fridge well stocked with delicious goodies during our entire stay to always keep our spirits up.
We would also like to thank Ron and Dave, who kept the roads clear for us, so we were able to return to PEARL as soon as possible after bad weather.
Thanks to Leanne, Kristin and James we were always up to date on current weather conditions and ozonesonde progress. We appreciate that they never got tired of explaining the unique Arctic weather phenomena to us.
We would also like to thank the Canadian Space Agency, Environment Canada, NSERC, the Northern Scientific Training Program, and CANDAC for continuing to financially and logistically support the Canadian Arctic ACE/OSIRIS Validation Campaigns. The opportunities that come with being in Eureka for polar sunrise are unmatched. The phenomenal data we collect in addition to the irreplaceable learning experience for us all is only possible because of the support you have provided.
Finally, thanks to everybody reading the daily updates and the positive feedback on them.