On Wednesday evening the team went out after dinner with two of the Eureka weather station meteorological technicians, Allison and Renée, to watch them launch the ozonesonde. Later in the evening Renée brought some of the team outside again to demonstrate how boiling water reacts to temperatures close to -50 when it is thrown. For those who've not had the chance to see it for yourself, the thrown water rapidly freezes forming a dense mist and larger ice pellets that fly out. It is quite an interesting sight. Unfortunately in trying to record this one camera ran out of memory and another froze due to the cold.
On Thursday morning the temperature started at -49 degrees, and through the course of the day it briefly warmed up to -47 degrees before returning to this starting temperature. The sky was clear with ice crystals throughout the day, and the sun was up for just under 9 and a half hours. The promising conditions for making solar measurements put the team into a good mood as they left the Eureka weather station in the morning. On the way up to the PEARL Ridge Lab the team stopped briefly to take pictures with the sign denoting 80 degrees North latitude.
At the Ridge Lab, Kristof spent the day analyzing data from the UT-GBS and PEARL-GBS to check the data quality. The PEARL-GBS data showed that high levels of bromine oxide were present near Eureka over the past three days. This likely explains the observed destruction of near-surface ozone in the same time period, and Kristof will be looking at all available data to understand the details of the bromine event.
Wednesday evening, Erik, Sébastien, and Pierre went back to the ridge lab after dinner to further test the alignment kit. The telescope was set up in the long arm of the interferometer in order to examine both the exit and entrance apertures of the Bruker instrument. Today, clear skies allowed Erik and Sébastien to take 97 MIR measurements with the Bruker.
At 0PAL on March 8th CRL made 24 hours of measurements with both lasers. Emily spent the day today working on water vapour code.
Ghazal had a smooth night of measurements last night. The measurements started at 22:00 and lasted till 4:30.
PARIS-IR's detector temperature was behaving oddly today, slowly heating up by 0.01-0.03 degrees per minute despite frequent top ups over the course of the day with liquid nitrogen. Despite this anomaly PARIS never strayed from acceptable detector temperature ranges, the detector values remained within a range comparable to the rest of the data recorded, and this anomalous warming eventually ceased in the afternoon. Over the course of the day Paul made 23 solar measurements. Tomorrow he will attempt to identify the issue that occurred today and continue making solar measurements.
Gurpreet tried to troubleshoot the suntracker today but was unsuccessful in doing so. For tomorrow he plans to bring the SPS onto the roof to record data in the zenith position for the remainder of the campaign.