Saturday, 14 December 2013

Early freeze season volume gain.

I've accidentally deleted this post while deleting a post in progress about the recent Tang paper, having decided to relegate that to a mid monthly miscellanea post. So this is a quick re-write of the post that was deleted.

The early freeze season volume (PIOMAS) gain is from the date of minimum to the 30 November. For 2013 early season volume gain has been strong, which surprises me.

The relationship between CT Area and NSIDC Extent at minimum and the early freeze season volume gain is shown below.

The post 2007 years show a movement upwards as well as to the left, indicating that with the thinning post 2007 has come an increase in volume gain in the early part of the freeze season. This is to be expected due to the thickness growth feedback.

The relationship between early freeze season volume gain, and total volume gain in the freeze season suggests that larger early freeze season volume gain is likely to lead to a larger total volume gain over that freeze season. This suggests we should expect a significant pulse of increased volume to go into the sea ice system as a result of 2013, this will probably place the volume maximum between 2009 and 2010.

I've also been working on improving my PIOMAS volume calculations, the following graph is of errors between volume calculated from the gridded PIOMAS data and the PIOMAS monthly series. HTNxHTE is the rough method suggested by Dr Zhang in the comments of some of his code. HTNSxHTEW aka Wipneus, is the improved method of calculating devised by Wipneus. Zhang method, is the method Dr Zhang uses to calculate grid box areas.

I am awaiting confirmation from Dr Zhang about a couple of matters and will blog further when the grid box area method is sorted out.

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