Tuesday, July 17, 2012


I have been offline for eight months, with personal stuff happening. But I am back now.

The main thing to discuss is that we have had a fair bit of rain this year. :)

However, inflow has again not come close to matching historical averages.

In 2011, we received  577.7 mm of rainfall, with inflow of around 55,000 megalitres.

Thus far in 2012, we have received 495 mm, with inflow of around 45,000 megalitres. With an El Nino forecast for late spring/early summer, it is likely that we will get less than average rainfall. However, we should still get more than average for the year, given that we are only 120 mm or so short.

I will also discuss the state of the Arctic sea ice. At present, satellites are recording the lowest ice area on record, with ice extent in the bottom three (2007 and 2011 are the lowest and second lowest). Area and extent are two different but related ways of measuring the amount of sea ice. For a clear discussion on the difference, see here: http://nsidc.org/arcticseaicenews/faq/

With regard to volume, PIOMAS (http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/) currently estimate that sea ice volume is the lowest for this date in the historical record, around 1,000 cubic kilometres below the previous record set last year. For context, last year's minimum was around 4,000 cubic kilometres. My own model predicts that this year's minimum will be 3,200 cubic kilometres. (This is up from the prediction made last year, because the PIOMAS model is now version 2). At present, the situation is tracking below that, but not too much below.

Weather over the next three months will determine if we set records. But the sea surface temperatures in the Arctic are three, four, five and more degrees above average in many areas, and significant melt is to be expected.

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