GLOBAL SEA ICE AREA LARGEST IN HISTORY DEC 31,2013

Single day records are equally pointless. Especially with such relatively brief data histories.

But the thread title goes beyond pointless, to deception.

 

Yes, some do. I don't give any credibility to those loonies either. Mimicking their tactics won't get you anywhere.

 

AG@20 Incoming radiation certainly matters for albedo as the latter lacks meaning at night when infrared emissivity is what matters. Both of these high-latitude areas get lots of (low-angle) sunlight for half the year. Other half, zip. So as far as that goes, it would make more sense to compare ice areas only during the 'lit' season.

Which is now, in the south. So that comparison could be made since 1979 and (according to my assessment of the NSIDC spaghetti plot) there isn't much trend. One could do the same for the arctic since 1979 (strong trend) and that's about as far as we can go now.

The thing about albedo is that water and ice are basically at opposite ends of the spectrum. Nothing we change on land (forests, cities, etc.) has such a large impact on albedo.

To the extent that CO2 transfer to ocean water is physical, light would not matter. Open water area would. If phytoplankton are involved, completely different because they do nothing in the dark.

Now, clouds certainly matter for planetary albedo, but AFAIK satellite-era trends in cloud cover are small or not statistically significant. We have talked about that in other threads.

 

I finally took the latest datafile from mojo's linked page, and found the maximum and minimum anomalies for each day of the year.

The dataset starts Jan 2, 1979, and now covers just over 35 years. If the ice coverage was a function of random daily weather, with no climatic trends, and no autocorrelation, then each year should have an average of (365/35) or about 10 record daily highs, and ten record daily lows, per year.

Dec 31, 2013, was indeed a record daily high. But it was an isolated daily high record, the first -- and last -- since Apr 12, 2008. All but three daily record highs from Oct 20 to Dec 30 were set in 1988. The Jan 1 record was set in 1989, Jan 2-4 record set in 1995, and Jan 5 - Mar 5 record highs were set in 1979 (excluding Leap Day, which didn't happen that year). This year (through Jan 19, 2014) has not set any record highs, and is rapidly shrinking away from the high record envelope.

2013 did not set any record daily lows. But 2012 set more than 50 daily lows.

Due to the way the dates are listed, as decimal years, and numerous anomalies relating to how leap year dates are recorded, some of the dates and records I listed may be off (misinterpreted) by a day or two. That should not change the overall picture.

 

There is a new article in Nature (the journal) that provides much useful information about the dynamics of southern sea ice.

 

Continuing on the theme of my previous post, here is a graph derived from the datafile that Mojo linked:


The red line, record daily lows, is plotted as a negative number. The black line is the average of the daily anomaly figures for the whole year, and is plotted to a different scale (marked on the right).

The record daily high of December 31, 2013, the title of this thread and the first such high in more than five years, barely even shows as a blip of the blue line. The raw data seems to betray either a three day cold snap that delayed seasonal melting, or an instrument error that was cleared after three days.

As mentioned earlier, if the daily ice figures were random numbers with no climate trend and no day to day correlation, then there should typically be 10 record daily highs per year, and a similar number of lows. Records ought to be evenly distributed across the recorded time span.

But as clearly seen, the highs and lows are not evenly spread out, but are concentrated near the sides. On the 35 year time span, half the highs occurred in just the first 3.3 years. More than 86% of the highs occurred in the first 10 years.

Half the lows occurred in the last 6.7 years, and 96% of the lows occurred in the last 8 full years (excluding the few days tabulated from 2014).

The black line shows that the series ends with 2013 having slightly more ice year-round than average. But any moving average of multiple years still reveals a downward trend. Because this instrument record is relatively short, I won't try to read anything more into it.

This data comes from file linked both by me (post #7) and mojo (post #10). Date range when retrieved was Jan 2, 1979, to Jan 19, 2014.

 

For me the most interesting message in the #27 graph is that the annual anomalies can differ by so much year to year. The northern component is the source of the general downward trend, and the southern ocean is highly variable. Would be nice to understand that south thing.

Do S hemis land temperatures follow the sea ice extent, oppose it, or neither?