CT SIA anomaly above zero

After all those negative records that were reported not so long ago (how many were there? I've lost count), it is nice to be once again given the opportunity to make known a positive record: Global sea ice area as reported on the Cryosphere Today website has been above the zero baseline for two days now (data here).

Even though the CT SIA anomaly dips ever lower, the anomaly can still go positive around this time of the year.  This event follows the previous one a lot earlier than the one before that, which was a record 444 days and the first full calendar year of negative anomaly.

As usual the Antarctic sea ice anomaly is so positive that it compensates for the semi-permanent negative anomaly in the Arctic:

Even though almost all of the ice down under is thin first year ice that almost completely melts out every year, the circumstances are not conducive to melting. The NSIDC explains the why in their latest monthly report:

Turning to Antarctica, we note that January 2013 saw an unusual northward (towards the equator) excursion of sea ice in the Weddell Sea. The ice edge was found approximately 200 to 300 kilometers (124 to 186 miles) beyond its typical location. Overall, sea ice extent in the Antarctic was nearly two standard deviations above the mean for most of the month.

The cause of this is very unusual sea ice pattern appears to be persistent high pressure in the region west of the Weddell Sea, across the Antarctic Peninsula to the Bellingshausen Sea. This pressure pattern means that winds are tending to blow to the north on the east side of the Peninsula, both moving the ice northward and bringing in cold air from southern latitudes to reduce surface melting of the ice as it moves north.

I wonder when we will get a really long stretch of CT Global SIA negative anomaly? If summer trends in the Arctic keep up, it will have an increasing effect on winter trends, and I'm not sure for how much longer Antarctic sea ice can keep up. We'll see. As I always say, global SIA is an interesting statistic, as all statistics are, but it tells even less of the story than either of the two-dimensional graphs for the two poles tell. We await close encounters with the third dimension.

Comments

[idunno]

Er, it's above zero again.

In addition to the sea ice, the Northern and Southern polar vortices appear to be doing the opposite of each other.

The weakening of the Arctic polar vortex has been well discussed here. New research now suggests that the thinning of the Antarctic ozone layer is strengthening the Southern polar vortex. (Sorry, I've not go the link to hand.)

[crandles]

>"Er, it's above zero again."

Did you mean below zero again:

2013.0850 -0.0751762 15.8898354 15.9650116
2013.0876 0.0004979 15.9685755 15.9680777
2013.0905 0.0194798 15.9880314 15.9685516
2013.0931 -0.0718173 15.8858833 15.9577007

[idunno]

er, yes

[Neven]

It might go above it again, if the Antarctic stays like this and we have a late season mega-thin ice outbreak on either side of the Arctic Ocean. Like last year.

[Artful Dodger]

Talking about Antarctic sea ice without mentioning the Antarctic ice sheet is like complaining that your chicken is cold to your waiter, Jumbo.

[Artful Dodger]

The volume of the Antarctic ice sheet is 7,600 x the volume of Antarctic perennial sea ice.

Antarctica is loses 100s of cubic km of land ice each year. It is not gaining perennial sea ice.

Denial is an ice river in the WAIS.

[John Christensen]

@AD,

I find information on Antarctic conditions to be quite conflicting.

E.g. that the ozone hole is causing colder temperatures and offshore winds, strengthening the circumpolar high pressure, and causing increase in SIA. However, last summer the ozone content was the highest in a decade, so should not cause abnormally low atmospheric temperatures, and SIA nearly set a new positive anomaly record in August.
Yes others claim that temperatures are raising and that this is actually causing precipitation to increase and therefore the landbased ice sheet to increase in volume.

Therefore, what is your reference for overall loss of ice sheet in Antarctica?

[Andrew Dodds]

John:

This sort of study:

http://www.sciencemag.org/content/338/6111/1183

Between 1992 and 2011, the ice sheets of Greenland, East Antarctica, West Antarctica, and the Antarctic Peninsula changed in mass by –142 ± 49, +14 ± 43, –65 ± 26, and –20 ± 14 gigatonnes year.

Simple addition gives Antartica as -71 Gt / year (not sure that you can add the uncertainty)

And this is apparently accelerating.

http://www.skepticalscience.com/antarctica-gaining-ice.htm

The reason seems to be not so much surface temperatures but oceanic heat transport melting the ice from underneath and so making ice drain faster.

[Jim Williams]

What's happening on the WEST side of the Peninsula (where the fragile ice sheets are)?

The Weddell Sea is nice and all that, but not exactly significant. The flow rate of the PIG, on the other hand, really matters.

[me.yahoo.com/a/nSjChi4X3vr8X3DRw93GkY1.cerja.8nvWk-]

Andrew for combining the uncertainties the usual procedure is to take the square root of the sum of the squared uncertainties. HTH
Phil.

[Kevin McKinney]

Waiter, chicken, Antarctica... and I get the following verbal psychotrope:

Man: Waiter, my chicken's cold!

Waiter: What the hell do you expect? This is Antarctica!

We now return to our scheduled program...

[me.yahoo.com/a/nSjChi4X3vr8X3DRw93GkY1.cerja.8nvWk-]

Should divide by number of points of course, I.e. RMS. Sorry

Phil.

[Downpuppy]

Why divide by the number of terms if you're measuring the sum, not the mean? In any event, I think the real question is whether to assume the uncertainty among regions is independent, which seems unlikely.

Pay wall at AAAS is rather annoying.

[Donald]

Look at Station Nord -- http://ocean.dmi.dk/arctic/nord.uk.php Image 07-02-2013 0735

Really cracked up.

[crandles]

31 Jan PIOMAS volume 16.843 which is down by 0.751 on 2012 and 0.722 on 2011.

Down 0.751 on last year has caught up 0.307 on the -1.058 deficit at 31 Dec 12. If that rate of catch up continues, the volume at maximum this year might not be a record low. I doubt that will happen but still the catch up is noticeable.

[Djprice537]

"The reason seems to be not so much surface temperatures but oceanic heat transport melting the ice from underneath and so making ice drain faster."

Could this actually be contributing to growing sea ice in the antarctic? If the ice is draining faster and melting from underneath more, this would cause a freshening and chilling effect on the sea water around the antarctic.

[Djprice537]

I have been following the discussions here for about a year. I have also been traveling to the links to get some of the background information and data to try to understand these discussions.

I have some observations and questions. As new SIA mimumums are reached both for the entire cryosphere and individual seas and CAB, we then frequently see "record breaking recoveries" during the following freeze season. Looking at global warming denier sites (WUWT et. al.) they seem to always use this rapid rebound of SIA during the freeze season as evidence of the recovery of Arctic Ice as a whole. Obviously this is not the case. The rapid rebound is nothing more than an observation that water freezes when it gets cold.

Looking at Cryosphere Today, are there any measures that track the min-max range for SIA of the crysophere and the individual seas over time (year to year comparisons)?

What I've noticed is this. The min-max range increases for each area as new annual minimums are reached but the rebound during refreeze returns to a historically stable maximum, usually 100% coverage. The CAB, Canadian Archipelage and Laptev Sea are good examples of this. There are others.

At some point, the annual minimums stabilize (approach zero area usually) and as the maximums continue to reach there historical levels the slope of range trend (year to year)flattens.

When maximums begin to fall due to refreeze being impacted, the range now begins to fall. Would such a measure be worth tracking and how might this range metric be interpreted?

I know this is presumptuous but if the metric could reveal something and it does not exist I would like to propose a new cryosphere measure, BICOT.

Biannual Interpretive Cover Oscillation Tilt

or alternatively....

"Baby, It's Cold Out There" (Hopefully this shuts up WUWT.)

This measure would be the range between min-max (biannual)in SIA (cover) as it oscillates. The tilt is to signify the slope of this range measure as we compare yearly trends. When the annual trend "tilt or slope" is increasing this measures the impact of AGW during the melt season. When this slope tilts to a decreasing trend this is measuring the impact of AGW during the freeze. WYDT(What do you think)?

[Neven]

Djprice57's last comment was released from the spam filter.

[Neven]

Gareth Renowden from the Hot Topic blog nailed it even better. Like I just commented on his blog post:

When the re-freeze starts, and the Arctic basin is covered in ice once more (early December), Anthony Watts will report on the record rate of ice formation, calling it a “stunning recovery“.

You’re timing isn’t perfect, but you nailed it, Gareth. Congratulations.

From the best science blog in the universe:

“From the Nature abhors a vacuum department comes this note from RealScience showing that Arctic sea ice has made a stunning rebound since the record low recorded in the late summer of 2012.”

"Stunning". Gareth knows this psychopathologic subject well. :-D

[Neven]

This comment over at Gareth's made me chuckle:

Yep, some areas in QLD and NSW just experienced the greatest retreat from flood levels ever, too! Come to think of it, much of charred Tasmania and the Victorian high-country will shortly be experiencing a record burst of new shoot emergence and epicormic budding!...

[Steve Bloom]

Re that last comment of Neven's, folks who don't reside in semi-arid climates should be aware that an alternating pattern of droughts and pluvials is the absolute worst thing for fire since the fuel keeps getting replaced. A smaller version of the effect can be seen in the annual cycle in Mediterranean climate zones (dry hot summers alternating with wet cool winters). Such climate zones, BTW, exist outside of the Mediterranean region, most prominently California (where I live) but also parts of Australia, Chile and South Africa.

[idunno]

The global anomaly is back above zero:

http://arctic.atmos.uiuc.edu/cryosphere/timeseries.global.anom.1979-2008

[John Christensen]

Thanks Andrew Dodds, had not seen that article.