The state of global polar sea ice area nearing the middle of July 2011 has gotten much worse than at the beginning of June: well below climatological conditions (1979-2009) continue to persist.

Sea ice in the Arctic continues to track significantly below average, with the 2nd to lowest readings for the month (depending on the day) in the modern era.  Weather conditions around Antarctica caused a temporary stall in sea ice freezing, causing extent conditions to tack toward below average conditions before recently recovering somewhat.  Global sea ice area therefore took a turn for the worse during June and early July, reaching for historical lows reached only a couple of times before now.  Within the last month, global sea ice area reversed the gains made in May toward eliminating the deficit from climatological conditions that characterized the first four months of 2011 and has instead declined rapidly to a 2 million sq. km. deficit by early July.

To help put this in context, only three previous times in recent history have seen conditions as bad as they are today: in 2007, 2008 and 2010.  The difference between these previous occurrences and current conditions is profound: they previously occurred around September, when Arctic ice reached its annual minima.  This, of course, is July.  There are over two months left before melting in the Arctic stops.  Will a new record low sea ice area be recorded this year?  Stay tuned.

Arctic Ice

Portions of the Arctic are experiencing warmer near-surface conditions in 2011 than at the same point in 2007, when the record low extent of sea ice was recorded.  Additionally, warmer water than in past years continues to be transported into the Arctic Ocean at rates that are quickening (more warm water flowing through the Ocean faster – not a good thing for long-term ice survivability).  Weather conditions (local pressure centers, resulting wind patterns, etc.) will have the final influence on what conditions in Sep. 2011 look like.  As this summer has progressed, the dipole anomaly has again been established.  Prior to the late 1990s, this atmospheric phenomenon didn’t occur.  It is postulated that it is setting up in response to climate change.  Updating my guess from last month, I think 2011 might challenge 2007 for setting the record low extent.  The extent is hovering at daily record low values and the dipole has set up again.  It will only take a couple of storm systems to prevent 2011 from setting the record low, however.  But I don’t think it will miss it by much.
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ice path by Grant MacDonald, on Flickr

Most of the projections in the science portion of the IPCC’s 2007 4th Assessment Report have been shown many times since its issuance to be too conservative.  Temperatures have risen faster; ice (sea- and land-based) has melted faster; ocean acidification and warming has happened faster, the number of extreme weather events has increased faster, etc.

I’ve written before about most of these.  I will take this space to write once again about polar ice melting faster than projected (according to observations) and the impact that will have on global coastlines.

According to the executive summary of a new assessment of Arctic climate, the international Arctic Monitoring and Assessment Program (AMAP) reports that Arctic temperatures in the past six years were higher than at any time since measurements began in 1880.  Moreover, feedback mechanisms have already started.

What this means is the arctic sea ice area and global sea level projections made by the IPCC just 4 years ago underestimate this year’s conditions, which means they also very likely underestimate future conditions too.  In an updated projection that has deep significance for billions of people worldwide (emphasis mine):

The melting of Arctic glaciers and ice caps, including Greenland’s massive ice sheet, are projected to help raise global sea levels by 35 to 63 inches (90-160 centimeters) by 2100, AMAP said, though it noted that the estimate was highly uncertain.

That’s up from a 2007 projection of 7 to 23 inches (19-59 centimeters) by the U.N. panel, which didn’t consider the dynamics of ice caps in the Arctic and Antarctica.

Is the difference between one-half to 2 feet and 3 feet to 5 feet significant?  Only those of us who are sane seem to think so.  This is but one effect of oil corporations continuing to post record profits quarter after quarter, year after year.  How much infrastructure exists near 5ft above sea level worldwide?  How much is that infrastructure worth?  How much cropland exists at those low altitudes?  How many miles of ruined cropland from rising seas only will occur before widespread food shortages occur?  How much is our lifestyles worth; how much do they really cost?

AMAP scientists will discuss their findings in Copenhagen, Denmark starting tomorrow.

My most recent `State of the Poles` post discussed shorter-term influences on sea ice conditions (monthly to seasonal effects).  I’ve stated in that series that a new regime now exists for the Arctic.  Findings like these support that assessment.

For the hard-core curious, the key findings of the report are reprinted below the fold (h/t ClimateProgress)

Here are the “key findings” of this must-read warning to humanity:

1. The past six years (2005–2010 have been the warmest period ever recorded in the Arctic Higher surface air temperature are driving changes in the cryosphere.
2. There is evidence that two components of the Arctic cryosphere – snow and sea ice  are interacting with the climate system to accelerate warming.
3. The extent and duration of snow cover and sea ice have decreased across the Arctic. Temperatures in the permafrost have risen by up to 2 °C. The southern limit of permafrost has moved northward in Russia and Canada.
4. The largest and most permanent bodies of ice in the Arctic – multiyear sea ice, mountain glaciers, ice caps and the Greenland Ice Sheet – have all been declining faster since 2000 than they did in the previous decade.(continued)
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photo: climatesafety via Flickr

The state of global polar sea ice area at the beginning of December 2010 remains well below climatological conditions (1979-2008).  Sea ice in the Arctic continues to track far below average while Antarctic sea ice stayed slightly above average.  Overall, the rate at which Arctic sea ice is refreezing and Antarctic ice is melting is not out of the ordinary.  The locations where freezing and melting is occurring is news this month.  Global sea ice is rapidly decreasing, as is normal for this time of year due to Antarctic environmental conditions.

Arctic Ice

The rate of freezing of Arctic sea ice slowed in November from October.  Ice growth was actually slower than the climatological normal rate.  It was so slow that Arctic sea ice extent averaged over November 2010 was the second-lowest November ice extent recorded – a mere 50,000 square kilometers above the previous record low of 9.84 million square kilometers set in 2006.  The presence of relatively warm pockets of water in the region, combined with local weather patterns, helped keep the extent this low.

A time series graph of ice extent anomalies maintained by the University of Illinois at Urbana-Champaign’s Polar Research Group shows that ice extent moved past the -1 million sq. km. anomaly line for a short time during November.  It is currently hovering near -1.1 million sq. km.  The duration of this low anomaly has only been recorded once before, in the record low 2007 year.  While still negative, the anomalies in 2008 and 2009 were not as severe as this year’s.  The change in November ice extent has been measured at -4.7% per decade by the NSIDC.  It should be noted that for the first 16 years of that record, the extent didn’t have a significant positive or negative trend.  It is only since the early 1990s that a noticeable trend has developed.

More important to polar climate processes than areal extent, however, is the volume of ice.  Arctic ice volume has been decreasing for decades, but has worsened considerably in the past 5 years.  After reaching a record low earlier this year, volume has recently risen back above -9000 cubic kilometers.  Older ice tends to be thicker ice.  Unfortunately, the age of ice in the Arctic has shifted significantly in recent years.  Back in the 1980s and early 1990s, between 50% and 60% of the September Arctic ice was older than 2 years.  That situation shifted in the 1990s and early 2000s when >2 year-old ice decreased to ~40% of all ice in the Arctic.  2008 was a devastating year for old Arctic ice, declining to 30% of all Arctic ice.  Reflecting the new regime, old ice in 2009 declined to 20% of all ages and declined even further in 2010 to 10%.  . . . Read the rest of this entry →

By way of introduction, I have written as WeatherDem at a couple of blogs: SquareState (Colorado’s progressive community blog) since 2005 and my own since 2007.  My primary issue is global warming.  While not a climatologist, I am an atmospheric scientist and understand the very real potential threat that global warming poses to global human societies and ecosystems.  Simply put, if we choose delay over action any longer on this issue, this planet will be a very different place in a very short time frame.  I first wrote about Arctic sea ice in March 2008.  I started this monthly series in approximately the same form in March 2009.  I added Antarctic sea ice to my posts about a year ago, in December 2009.  This is the latest incarnation of that series.

The state of global polar sea ice at the beginning of November 2010 is once again poor compared to climatological conditions (1979-2008). The Arctic sea ice extent remains well below average for this time of year. The Antarctic sea ice extent is above average, but not nearly so much as the Arctic sea ice is below average, which is why the global sea ice extent continues to track below average also. Global sea ice area has made a nice recovery since the mid-year low of ~17.5 million sq.km., as the time series at the above link shows. Some portions of the Arctic Sea weren’t as warm as they were after the 2007 or 2008 melt seasons, which has allowed Arctic Sea ice to refreeze in those areas quite rapidly. One of the plots below will demonstrate nicely which areas were cooler and which were warmer. The prime melt season for Antarctic sea ice is about to begin. The global sea ice area will start to plummet again towards its yearly minimum as the southern sea ice melts before bottoming out in a few months’ time.

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