Sunday 28 July 2013

If HYCOM is correct.

Looking at CT Area anomalies and the US Navy's HYCOM model, link, I suspect that August may see record losses as did 2012. This means my prediction of early this month is already looking unlikely to be correct.

Friday 19 July 2013

What does CT Area show?

This post is a few days late due to work commitments, basically a comment on my last post, link, has raised the question; what does the Cryosphere Today Area (CT Area) index actually show?

Monday 15 July 2013

How Fragmented is the Pack?

There's a discussion going on over at the Sea Ice Forum, link, about whether the pack this year is more fragmented than previous years. I'm with Peter Ellis on this, looking at different satellite systems and at certain areas it's possible to reach either a 'for' or 'against', conclusion. Certain features such as the Laptev/North Pole low concentration anomaly are quite exciting, although it remains to be seen what role that feature will play in the coming season.

I'm not posting to launch into a long boring discussion of the pack floe by floe. I think there's a more objective way to cut to the heart of the issue. The data I use are IJIS Sea Ice Extent index, data, and CT Area, data.

Thursday 4 July 2013

June Status Part 3: PIOMAS Volume.

PIOMAS data is now out and shows a similar pattern of a retarded melt season as does the CT Area data. However the volume losses of June still place 2013 firmly in the post 2007 group. All data from PIOMAS, all volume units in 1000km^3.

Wednesday 3 July 2013

June Status Part 2b - Atmosphere and Ice.

In my previous post I produced a series of sea level pressure (SLP) plots from NCEP/NCAR reanalysis showing how anomalous the SLP field for 2013 is in the context of the other post 2007 years, link. As stated previously, looking at Cryosphere Today Area (CT Area) on 30 June one has to go back to 2009 for a single year above 30 June 2013, and back to 2004 to find successive preceding years of higher area for that date. Given the loss of volume in 2010*, and that this was followed by a new record in the CT Area data for 2011, 2012 then setting a new record by a substantial margin, the late start to the melt season in spring 2013 is highly anomalous. *Whilst this was an event first noticed in PIOMAS it was a real event in the real world, and not just an event within the PIOMAS model, link.

Tuesday 2 July 2013

June Status Part 2a: Atmosphere - SLP fields.

Rather than present these graphics in an animated gif (which can't be paused), or YouTube (which has poor resolution) I thought it best to put them all on one page. Here is a sequence of NCEP/NCAR sea level pressure (SLP) fields, the 2007 to 2012 average and the previous ten years including this year (2013). Source.

Monday 1 July 2013

June Status Part 1: CT Area.

OK, rant over, it's time to get back to sea-ice.

Now that Cryosphere Today's area data (CT Area) are in for yesterday, it's possible to summarise the status for June. The take-home message I read from the data is that a new record is now very unlikely based on past year's behaviour due to the late start to melt, despite other indicators of pack condition (for example the Laptev to N Pole region, link). Posts on the atmospheric status (key to understanding the late melt) and PIOMAS will follow when PIOMAS and NCEP/NCAR updates come in for the month of June.