September 18-19, 2008
Weather: Full sun in the morning, but high-level cirrostratus clouds present. Still see full shadows though. Cool and light breeze from west. Seas calm with only small wind waves present. Clouds clearing by 12:00 local. Wind increasing throughout the afternoon to 12 – 15 knots by 15:00 local; waves increasing as well. White caps present during afternoon and current can be felt. As DPOL is lowered to a depth of 40m, the current becomes very apparent at the line holding the instrument is push well east of where it should be suspended under the boom. Good chance instrument is not looking direct up. By 17:00 local wind nearly 18 knots. Data collected with DPOL all the way to sunset.
Instrumentation used: Sky camera system was run from 17:15 GMT – 17:30 GMT and 18:45 GMT – 21:45 GMT. Images were taken in cycles that took 1 image with each appropriate spectral filter and polarizer combination. A typical cycle took about 6 minutes to complete and cycles were started every 15 minutes. Cleaned camera and filter wheel o-rings last night, but camera still cutting out a lot. Tried lowering the voltage to the system from 13.0V to 12.7V; didn’t really help.
DPOL instrument was run from 16:30 GMT – 01:30 GMT (September 19, 2008) sampling downwelling light. DPOL data was collected at a depth of 1 meter from 16:30 GMT – 17:00 GMT, then at 4 meters depth from 17:15 GMT – 18:00 GMT, then at 7 meters from 18:15 GMT – 19:15 GMT, then at 10 meters from 19:30 GMT – 20:30 GMT, then at 15 meters from 20:45 GMT – 21:30 GMT, then at 25 meters from 21:45 GMT – 22:30 GMT, then at 32 meters from 22:45 GMT – 23:15 GMT, then at 40 meters from 23:30 – 00:00 GMT (September 19, 2008). The camera was then brought back up to a depth of 5 meters from 00:15 GMT – 01:00 GMT (September 19, 2008), then at 2 meters for the remainder of the sampling time. Images from this instrument were taken in cycles that consisted of 1 image with each spectral filter and then that sequence was looped 5 times. Cycles took about 12 minutes to complete and cycles were started every 15 minutes corresponding with the sky camera cycles.
Microtops sunphotometers were also taken every 15 minutes corresponding to the previous 2 instruments’ sampling schedule. The microtops were taken from 15:15 GMT – 15:30 GMT, 17:15 GMT – 23:30 GMT and at 00:45 GMT (September 19, 2008).
Sky File Summary (Excel file)
Image movie between 1515 and 1909, movies exclude "bad" catagory
http://www.youtube.com/watch?v=-2GvctTN37Q
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Full data images for above movie
http://www.youtube.com/watch?v=Z691z8ER3vo
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Full data images for above movie