On the way to the PEARL Ridge Lab this morning, a roadside Arctic Hare caught the team's attention. We stopped the truck to take a couple of photos. Mike must have left the Eureka Weather Station in the CANDAC truck not long after we did; he caught up to us on his way to the lab. It was a rare "traffic jam" in Eureka!
Mike and the campaign team were greeted at the PEARL Ridge Lab by relatively balmy temperatures. We experienced a high of -28°C this afternoon. Winds were calm. Temperatures in Eureka, however, remained around -44°C.
In the PEARL Ridge Lab's IR lab, Dan took 65 MIR measurements with the Bruker. Sebastien took 24 measurements with PARIS. Clouds ended solar measurements early.
Thanks to help from Jim Drummond (PEARL PI) and Yan Tsehtik (CANDAC Data Manager), the new Bruker computer now has a static IP address. This enables us to connect to it from the Eureka Weather Station, Toronto, or anywhere with an internet connection. Working from Toronto, campaign veteran Joseph Mendonca successfully tested using Remote Desktop to control the new Bruker computer (hereafter simply called "the" Bruker computer). Of course, on-site personnel remain necessary to take measurements, as the detectors require someone to add liquid nitrogen daily, change the beamsplitter to rotate between MIR and NIR measurements (to begin soon), add the HBr cell for instrument diagnostic tests, perform maintenance, and do troubleshooting. But remote access to the computer gives us the flexibility to run measurements later into the day (e.g. shut down measurements after dinner from the Eureka Weather Station) and will enable Joseph to assist with Bruker operations remotely during the campaign.
Given that it was a relatively warm and wind-free day, Paul, Sebastien and Dan ventured out of the lab for an hour-long walk along the ridge after lunch. It was a beautiful view. Joseph checked the FTS solar tracker remotely while they were out. Take a look at today's photo album for a few highlights of the ridge walk (and another bunny photo).
SAOZ, UT-GBS, and PEARL-GBS are running smoothly. However, based on the PEARL-GBS tracker camera image, Xiaoyi believes the pick-off mirror might be not in the correct position. Paul and Xiaoyi will open the side panel of the shelf (beneath the PEARL-GBS tracker dome on the roof) tomorrow to adjust it. Xiaoyi and Paul added a third heater to aid the PEARL-GBS dome defrosting effort. They hope to arrive at the lab tomorrow to find a clear dome. Xiaoyi also updated the code that runs the tracker parking and TCP shut down functions. He also stopped UT-GBS measurements for 3 hours today to work on labview upgrades. These improvements will enable UT-GBS to use active tracking code. It should be ready soon.
Meanwhile, Paul and Mike worked on troubleshooting the liquid nitrogen generator, which is currently offline.
In Eureka, today's ACE ozonesonde flight occurred at 6:15 PM (local time) and reached an altitude of 32,136 m (6.0 hPa).
Tonight, Dan and Jonathan took advantage of the conveniently-timed full moon to attempt taking nighttime FTIR measurements. They used an experimental version of Jonathan's latest tracker code to track the moon. They ran the code first in passive mode (calculating the moon's position), which worked well. Active tracking tests didn't work initially, but yielded information Jonathan used to correct the code. With active tracking working reasonably well, Dan checked what settings were necessary to get enough signal for Bruker spectra. He was able to get enough signal to take a couple of measurements using moonlight! The settings used for this experiment were not ideal and the resolution was lower than when using the sun, but (somewhat noisy) spectra were obtained. Whether we will be able to retrieve anything meaningful from them is unclear.
Tonight's experiment was a preliminary first step. Weather conditions were not great ñ clouds reduced the signal from the moonlight. If meaningful lunar FTIR measurements are possible, it could open an interesting avenue of atmospheric investigation at PEARL. Given the long Polar Night at Eureka when solar measurements are impossible, Bruker measurements using the moon as a light source is an attractive idea ñ even though the much lower signal would pose significant constraints on what atmospheric gases could be retrieved. The moon will be available in Eureka for another two nights before it stays below the horizon for the rest of the campaign.
It's been another great day (and night) of experimentation at PEARL!