What do you get when you cross Friday the 13th with Valentines Day? Apparently a lot of drama in the Arctic as we found out this past Friday and Saturday. Friday started like any normal day: we prepared an ICE-MITT box to take out in the field, Box #4. It was working fine in the Theatre (garage); so we packed it on the sled; rode out to Site 2 and… the box didn’t turn on. It pulled what Ellyn calls “a Porky Pig” (“Th-th-th-th-th-th-that’s all folks!”) and refused to start in the cold; -28˚F is evidently a problem for electronics.
Because we had figured this out AFTER we had unpacked all of our equipment, we left Box #4, the generator and the corer out on the ice and went back to pick up a second ICE-MITT box (#6). Other than this little bump in the road – uh, ice – everything else went great! We took one ICE-MITT core at Site 2, moved up the coast a mile or so to Site 3 and got an ICE-MITT core there, plus an isothermal core to go in the core tube. This was all pretty success, and we got home in time for a late lunch.
After lunch, Ross tried to diagnose the problem with Box #4 … but it was again running fine indoors! He narrowed it down to the (highly scientific) conclusion that Box #4 is just the worst and has been cursed from the beginning (apparently that box and Ross have a troubled past). Or we can chalk it up to Friday the 13th. All very scientific reasoning of course.
The next day was Valentines Day! Rachel woke up the house yelling “Cupid’s here!” And Ross and I sleepily tumbled out of our rooms to find all of the Valentine’s Day lovin’ displayed on the kitchen table—aw, thanks Cupid!
Chocolate for days! We wasted very little time in exploring the many flavors of Russell Stover, though, and headed back to the Theatre where our ICE-MITT boxes and supplies are all kept. (Gentle Reader: You know those people who bite a corner off each chocolate to see what kind it is? A certain undergraduate team member – her name withheld for privacy – is one of those people!)
This is where the real drama started (curse you, Cupid!). We arrived at the Theatre to find that Box #6, the replacement for Box #4 on Friday, was not running at all. Ross tried to quickly diagnose to problem but, realizing that this box was going to take a long time to fix, we removed the cores we had taken the day before and relocated them to open slots in other working boxes.
We were afraid this would be tricky, as sometimes the core ends freeze to the aluminum end plates in the ICE-MITTS, but fortunately we had minimal trouble with these ones. Having solved the largest problem at hand, maintaining the ice cores at their right temperatures, we left the broken box in the Theatre and headed out for the field day that we had planned.
This was the day that we were installing the wire harp. The wire harp is a device developed, and loaned to us, by Dr. Dirk Notz of the Max Planck Institute for Meteorology in Hamburg, Germany, that permits in situ measurements of salinity and solid fraction as a function of depth in growing sea ice.
It has 32 pairs of parallel platinum wires and measures electrical impedance between these. Impedance is the opposition that a circuit presents to an alternating current. Voltage is applied to the wire harp from a 12V car battery.
The impedance between the pairs of wires is a function of how much solid ice there is. Brine is much more conducting. Thus, we are essentially using the wire harp to measure solid (ice) fractions, or brine channel fraction, as the sea ice freezes.
Mike and Nelson helped us cut a 2.5 x 2.5 ft square out of sea ice that was over a meter thick. Ice does not exactly cut like butter! Even with augers, chainsaws, ice saws, and pry bars, opening a 2.5 foot square hole in meter thick ice was a several hour undertaking. All in all though it was rather fun, a bit like destroying a sandcastle with your feet or demolishing a wall with a sledgehammer.
Finally, Rachel suspended the wire harp in the pool we had created and set the 12V marine battery on one side and the box containing the electronics on the other… the whole contraption is held down with ice screws and rope. Hopefully it won’t look too appealing to polar bears. In case it does, we hope the mini ice-henge we erected around it will distract them!
Now we wait. The ice will freeze about 10 cm the first day and then more slowly each day after that. We want ice to completely freeze over the wire harp, while it collect impedance data. We expect it to take 1-2 weeks for the ice to grow past the bottom of the wire harp, 27 cm down. Rachel said, “This thing is going to be a bear to get out! Hopefully not literally.”