St. Patrick's day's rich breakfast came along with lovely decorations, which made up for this morning's overcast skies. After a rather smooth ride, the team arrived at the Ridge Lab shortly after 9 am. Around 10:30 am the skies cleared up, improving measurement conditions significantly, but unfortunately, only until the early afternoon. Nevertheless, Erik, Sébastien, Kristof and Ellen went out for a short walk on the ridge opposite PEARL, since it was neither windy nor cold - in Eureka terms - at just around -29℃. The team returned to the weather station shortly before 5 pm, perfectly in time for yet another delicious dinner.
Between the morning haze and the afternoon clouds, there was enough clear sky to take 45 NIR measurements in the IR lab. This afternoon, Pierre finished patching the last minor leaks of the chiller with an Epoxy solution. Erik and Sébastien will test it tomorrow.
The clouds prevented Kristof from working on the NetCam alignment again. Instead he re-did some of the lab tests for UT-GBS and removed the shutters from both instruments. The latter was done as a safety measure, since the shutters tend to break frequently.
When Ellen arrived at the Ridge Lab, she started to transfer yesterday's data from PARIS-IR to the laptop immediately, while setting up the globar and HBr gas cell for measurements. However, she opted for solar measurements instead once the file transfer was completed, due to the improved atmospheric conditions. When it became overcast again, she switched over to the HBr gas cell measurements. She took 12 solar and 11 HBr measurements with PARIS-IR today.
The entirety of 16 March UTC contained beautiful lidar weather at Eureka, and Emily made a complete day of CRL measurements. There were two tiny clouds at 5000 and 5500 m at the start of the day. Clouds below 2000 m came and went until 11:00 UTC. Skies were free of clouds for the following 10 hours, with a couple of small ones popping up at 4000 to 5000 km after 22:00 UTC. None of the clouds today managed to entirely extinguish the laser beam, so she should be able to make a low resolution data product for higher altitudes than are usually possible for CRL, and see whether anything faint shows itself under those conditions.
Emily and Ghazal started the seasonal shut down process for the system today, because nights are getting too short. The DIAL laser and Raman cell were pumped out of their working gas mixtures and were backfilled with Helium, and the telescope was covered for summer. They are expecting to complete their tasks by tomorrow afternoon.