Everyday here on the ship we receive a “sitrep”, which I am assuming means situation report. Now that our oceanographic deity has taken leadership Steve’s sitrep not only informs us of the weather, and current deployments but also provides scientific context for the work being conducted on the ship. I have cheated ever so slightly and cut and paste part of today’s sitrep in to this post because it’s very informative and I couldn’t put it better myself, in fact I would probably put it much worse. Here’s a little more on the moorings:
“Each of the moorings has an instrument that runs up and down the deepest 500 m of the mooring wire, measuring temperature, salinity and current velocity as it profiles up and down once each day. The two-year record from the profilers will allow us to see how the properties and transport of the dense “Antarctic Bottom Water “change with time. The sinking of Antarctic Bottom Water around the margin of Antarctica is an important part of the global network of ocean currents that influences climate patterns. The unanticipated calving of the Mertz Glacier Tongue in February 2010 should make these records particularly interesting because they will provide continuous measurements both before and after the calving of the glacier tongue.The dense water formed in the Mertz region flows west along the Antarctic coast and crosses the mooring array we are recovering now” S. Rintoul.
As I mentioned previously, the calving of the Mertz glacier tongue occurred due to B9B colliding with the feature on its way to block us from getting into Commonwealth Bay. There have been a number of phenomena occurring in the region that are thought to be due to this calving event, including enhanced biological productivity in the region. The Southern Ocean is severely ‘anemic’ and the release of iron from glacial melt (in the form of dust deposited within the glacier) is one potential candidate for the large blooming events that were seen last year. The fact that the large blooms are seen again this year has a couple of people scratching there heads but I have no doubt they will figure it out. I had someone explain to me once that being a researcher was like being handed a bag full of puzzle pieces. You only get one piece at a time, and in the beginning one can make a number of interpretations. The white pieces could mean snow…or a cloud…or a tablecloth. As you get more and more pieces you realise what you once thought was Antarctic ice floes is in fact bulldogs playing poker around a table. I should let someone know that the enhanced CO2 drawdown in the region is due to gambling canines…….