June 16, 2010
We turned EARL on in the morning before our presentation and ran it from 1:11pm GMT until 3:30pm GMT. It was a mostly clear day, partly cloudy, with a lot of humidity outside (about 79% relative humidity). We did not know whether we would observe later, so we just closed the hatch and covered up the machine. By the time we came back, we would only be able to get another hour of data before leaving, so we decided not to start EARL back up again. The aerosol optical thickness for today was 2.599 for 500 nm. It would have been interesting to have a longer observation, considering this fact, because more aerosols might have shown up on the Depolarization Ratio graph.
Low clouds with depolarization signal
As you can see on the Range Corrected Backscatter graph, something was happening at about 500 meters at about 1:45pm GMT or so. A slight blip, noteworthy only in its contrast to the blur of nothingness, on the Depolarization Ratio graph at the same point suggests that something might have stirred in the atmosphere above the EARL. There were low clouds at this point in time, but we did not understand why the low clouds, full of spherically-shaped water droplets, would have a noteworthy depolarization signal. The Depolarization Ratio has to be fine-tuned to see it, though, almost half the value that the Depolarization Ratio graph is usually set to. We saw this on other days, as well.