We past the mid-way point in the campaign's Intensive Phase this weekend. There are 10 days left at PEARL. Temperatures have been stable over the last 11 days. This weekend temperatures in Eureka were -43°C. Temperatures outside the PEARL Ridge Lab were around -33°C. Today was sunny and clear.
In the PEARL Ridge Lab's IR lab on Saturday, Dan took 72 MIR measurements with the Bruker. Sebastien took 16 measurements with PARIS. On Sunday, Dan took 50 MIR measurements with the Bruker and Sebastien took 9 measurements with PARIS. Starting today, there is sunlight past 4:30 pm, making solar measurements possible after the team's usual departure time. Dan will now shut down Bruker measurements remotely from the Eureka Weather Station when weather conditions allow for it. This weekend, Dan also wrote a new OPUS (software that runs the Bruker) macro and set up a new executable program that together automatically transfer Bruker measurement files to the CANDAC cube at the end of the day and email a log file to the Bruker team.
Jonathan loaded a pre-release version of his latest code on the PEARL FTS tracker computer. Among other improvements, this includes a "beta" version of a feature Dan is thrilled about: automatic iris adjustment. Currently, we monitor the suntracker regularly and adjust the iris of the tracker camera to ensure the right amount of light reaches it. We must avoid saturating the camera with too much light, while also maintaining sufficient light for tracking to work. The amount of light reaching the camera can change significantly throughout the day, and can change quickly if the sun passes behind clouds. The auto-iris code is not ready for challenging cloudy circumstances quite yet, but is a very useful addition to the tracker code's functionality. Dan and Sebastien monitored the ability for the auto-iris code to adapt to changing light conditions over the weekend and were impressed at how well it has performed so far.
On Saturday night, Dan attempted lunar Bruker measurements. Unfortunately, there were again clouds along the horizon. The moon will be below the horizon for the remainder of the campaign. Nonetheless, Dan and Jonathan were very pleased to have the opportunity to successfully test lunar tracking and Bruker measurements a few nights ago. When Polar Night arrives, this research thread will pick up again, and hopefully lead to interesting science.
Over in the UV-Vis side of things, SAOZ, UT-GBS, and PEARL-GBS operated nominally this weekend. Xiaoyi and Paul covered the PEARL-GBS dome with blankets on Saturday afternoon. This finally vanquished the frost patch! Xiaoyi is happy. Over the weekend, Xiaoyi performed DOAS spectral analysis for PEARL-GBS and UT-GBS measurements. The retrieved ozone and NO2 vertical column densities indicate the instruments are working well.
Paul and Dan helped Xiaoyi work on the PEARL-GBS tracker, whose active tracking is not yet working. Paul opened the side panel of the tracker shelf (below the dome on the roof), and Xiaoyi took pictures. Dan helped them to control the tracker to find a proper correction for azimuth angle. The second camera pick-off mirror is not aligned properly. Xiaoyi is coordinating a plan to correct the optics with the tracker support team (Jonathan, Orfeo, and Pierre).
On Saturday and Sunday, Paul cleared frost from the SPS window in the morning. He tried to run a new macro from Zahra that will not be affected by tracker communication issues; however, they still need to work out some bugs in the code. The tracker needed to be restarted at end of the day on Saturday.
Paul and Mike worked hard over the weekend to troubleshoot the malfunctioning liquid nitrogen generator. They consulted with the Eureka Weather Station mechanic, Dave, who came up to the PEARL Ridge Lab and got the main air compressor working on Saturday. They discovered a couple of leaks in the system. They removed one leak, but the other persists. The generator is currently operating at a reduced rate. It produced º of a tank of LN2 by Sunday. Hopefully by Tuesday morning we will be close to a full dewar.
Saturday's ozonesonde flight was launched at 6:15 PM (local time) and reached an altitude of 31,666 m (6.2 hPa).
Sunday's ozonesonde flight was launched at 6:15 PM (local time) and reached an altitude of 32,295 m (5.6 hPa).
On the way back from the Ridge Lab on Saturday, the team spotted a couple of Arctic Hare and an Arctic Fox. The fox ran away too quickly for good photos, but Paul and Dan were able to get nice photos of the Arctic Hares.
On Sunday, Dan and Sebastien accidentally woke up an hour early Sunday morning. Eureka doesn't observe Daylight Savings Time, but it can be difficult to avoid automatic smartphone time changes. It turned out well. They went out looking for wildlife with Paul before brunch, and had an awesome encounter with an Arctic Fox! Take a look at the daily photo album for highlights.