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State of Polar Sea Ice – January 2013: Arctic Below and Antarctic Above Normal

8:25 am in Uncategorized by WeatherDem

Global polar sea ice area in early January 2013 remains below climatological normal conditions (1979-2009), but has improved in the past month.  Antarctic sea ice loss is occurring at a climatological normal rate.  Arctic sea ice gain is slightly more rapid than normal, but we should expect this given the record low extent that occurred in September 2012.  Polar sea ice recovered from an extensive deficit of -2.5 million sq. km. area late last year to a -500,000 sq. km. anomaly within the last week.

In March-April 2012, global sea ice area was above normal, but sea ice area anomaly quickly turned negative and then spent an unprecedented length of time near the -2 million sq. km. deficit in the modern era in 2012.  Generally poor environmental conditions (warm surface temperatures and certain wind patterns) established and maintained this condition, predominantly across the Arctic last year.  For the third time in modern history, the minimum global sea ice area fell below 17.5 million sq. km. and for the fourth time in modern history, the anomalous global sea ice area fell below -2 million sq. km.  This is a significant development given that Antarctic sea ice area has been slightly above average during the past few years.  This means that the global anomaly is almost entirely due to worsening Arctic ice conditions.

The rapid ice melt and record-setting area and extent values that occurred in 2012 are the top weather/climate story for 2012, in my opinion.  I think we have clearly seen a switch to new conditions in the Arctic.  Whether these events will occur in similar magnitude or are merely transitory as the Arctic continues to move to a new stable state that the climate will not achieve for years or decades remains to be seen.  The problem is we don’t know all of the ramifications of moving toward or achieving that new state.  Additionally, I don’t think we want to know.

Arctic Ice

According to the NSIDC, weather conditions once again caused less freezing to occur on the Atlantic side of the Arctic Ocean and more freezing on the Pacific side.  Similar conditions occurred during the past six years.  Sea ice creation during December measured 2.33 million sq. km.  Despite this rather rapid growth, December′s extent remained far below average for the month.  Instead of measuring near 13.36 million sq. km., December 2012′s extent was only 12.2 million sq. km., a 1.16 million sq. km. difference!  The Barents and Kara Seas remained ice-free, which is a very unusual condition for them in December.  Recent ice growth in the Seas has slightly alleviated this state, but this is happening very late in the season.  The Bering Sea, which saw ice extent growth due to anomalous northerly winds in 2011-2012, saw similar conditions in December 2012.  This has caused anomalously high ice extent in the Bering Sea.  Temperatures over the Barents and Kara Seas were 5-9°F above average while temperatures over Alaska were 4-13°F below average.  The reason for this is another negative phase of the Arctic Oscillation, which allows cold Arctic air to move southward.  This allows warm sub-arctic air to move north.

In terms of longer, climatological trends, Arctic sea ice extent in December has decreased by 3.5% per decade.  This rate is closest to zero in the spring months and furthest from zero in late summer/early fall months.  Note that this rate also uses 1979-2000 as the climatological normal.  There is no reason to expect this rate to change significantly (more or less negative) any time soon, but increasingly negative rates are likely in the foreseeable future.  Additional low ice seasons will continue.  Some years will see less decline than other years (like this past year) – but the multi-decadal trend is clear: negative.  The specific value for any given month during any given year is, of course, influenced by local and temporary weather conditions.  But it has become clearer every year that humans have established a new climatological normal in the Arctic with respect to sea ice.  This new normal will continue to have far-reaching implications on the weather in the mid-latitudes, where most people live.

Arctic Pictures and Graphs

The following graphic is a satellite representation of Arctic ice as of September 17, 2012 (yes, it’s been that long since I’ve written a Polar post):

Photobucket

Figure 1UIUC Polar Research Group‘s Northern Hemispheric ice concentration from 20120917.

Here is the similar image from January 9, 2013:
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State of the Poles – Mid-September 2012: Record Low Arctic Ice Extent; Antarctic Ice Above Climatological Normal

7:29 am in Uncategorized by WeatherDem

Judging by recent search terms used to get to this blog and the relative recent peak in traffic, readers have been searching for this post.  I wanted to wait a little longer into the month so that I could capture the expected Arctic minimum, which officially occurred on the 16th of September.  The NSIDC announced this date, after which I started gathering the plots that are found below.  This post will be longer than it usually is because this year’s minimum shattered the record minimum set in 2007, which shattered the previous record set in 2005.  Most of the post is made up of figures, so I encourage readers to at least view them to get a good picture of today’s conditions.  I’m purposefully framing things this way to relay the truly stunning situation the Arctic is in today.  2012 is additional proof the Arctic cryosphere is searching for a new stable point, but hasn’t found it yet.  That does not bode well for the rest of the globe.  With that, let’s begin.

The state of global polar sea ice area in mid-September 2012 remains significantly below climatological normal conditions (1979-2009).  Arctic sea ice loss is solely responsible for this condition.  In fact, if Antarctic sea ice were closer to its normal value, the global area would be much lower than it is today.  Arctic sea ice melted quickly in August and the first half of September because it was thinner than usual and winds helped push ice out of the Arctic where it could melt at lower latitudes; Antarctic sea ice has refrozen at a faster than normal rate during the austral winter.  Polar sea ice recovered from an extensive deficit of -2 million sq. km. area late last year to a +750,000 sq. km. anomaly in March 2012 before falling back to a -2.2 million sq. km. deficit earlier this month.

After starting the year at a deficit from normal conditions, sea ice area spent an unprecedented length of time near the -2 million sq. km. deficit in the modern era in 2011 (i.e., almost the entire calendar year).  Generally poor environmental conditions (warm surface temperatures and certain wind patterns) established and maintained this condition, predominantly across the Arctic last year.  The last time global sea ice area remained near 19 million sq. km. during May was in 2007, when the Arctic extent hit its modern day record minimum.  The maximum in the boreal spring the past two years was ~19.5 million sq. km.

Conditions were prime for another modern-day record sea ice extent minimum to occur in September.  Specific weather conditions helped to determine how 2012′s extent minimum ranks compared to the last 33 years, but it was the overall poor condition of Arctic sea ice that contributed to this year’s record low values.

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State of the Poles – July 2012: Arctic Ice Extent Near Record Low Again; Antarctic Ice Near Climatological Normal

11:18 am in Uncategorized by WeatherDem

The state of global polar sea ice area in early July 2012 has once again fallen significantly below climatological normal conditions (1979-2009).  Arctic sea ice loss is solely responsible for this change in condition since last month.  Arctic sea ice melted quickly in June because it was thinner than usual and winds helped push ice out of the Arctic where it could melt at lower latitudes; Antarctic sea ice has refrozen at a near normal rate during the late austral autumn and early austral winter.  Polar sea ice recovered from an extensive deficit of -2 million sq. km. area late last year to a +750,000 sq. km. anomaly in March 2012 before falling back to a -1.8 million sq. km. deficit.

After starting the year at a deficit from normal conditions last year, sea ice area spent an unprecedented length of time near the -2 million sq. km. deficit in the modern era in 2011.  Generally poor environmental conditions (warm surface temperatures and certain wind patterns) established and maintained this condition, predominantly across the Arctic last year.  The last time global sea ice area remained near 19 million sq. km. through May was in 2007, when the Arctic extent hit its modern day record minimum.  The maximum in the boreal spring the past two years was ~19.5 million sq. km.

Conditions are prime for another modern-day record sea ice extent minimum to occur in September.  Specific weather conditions over the next two months will determine how 2012′s extent minimum ranks compared to the last 33 years.

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State of the Poles – June 2012: Arctic Ice Extent Below Normal; Antarctic Ice Near Climatological Normal

8:22 am in Uncategorized by WeatherDem

The state of global polar sea ice area in early June 2012 has once again fallen below climatologically normal conditions (1979-2009).  Arctic sea ice loss is primarily responsible for this change in condition since just last month.  Arctic sea ice melted quickly in May because it was thinner than usual; Antarctic sea ice has refrozen at a near normal rate during the late austral autumn.  Polar sea ice recovered from an extensive deficit of -2 million sq. km. area three months ago to a +750,000 sq. km. anomaly one to two months ago before falling back to a -1 million sq. km. deficit.  After starting the year at a deficit last year, sea ice area spent an unprecedented length of time near the -2 million sq. km. deficit in the modern era in 2011.  Generally poor environmental conditions established and maintained this condition, predominantly across the Arctic last year.  The last time global sea ice area remained near 19 million sq. km. through May was in 2007, when the Arctic extent hit its modern day record minimum.

Arctic Ice

According to the NSIDC, weather conditions during the latter part of the previous winter and spring were less conducive for Arctic sea ice freezing on the Atlantic side of the Arctic while conditions were more conducive than usual for freezing on the Pacific side.  Sea ice melt during May was more than normal: 1.62 million sq. km. instead of 1.38 million sq. km.  As such, May′s extent was below average for the month in the satellite record.  Arctic sea ice extent on in May averaged 13.13 million sq. km.  Barents and Kara Sea ice remained very much below normal, more so than in recent years.  The Bering Sea, which saw ice extent growth due to anomalous northerly winds in previous months, instead witnessed above normal conditions.  Overall, near surface temperatures were warmer than average across the Arctic Ocean.

In terms of longer, climatological trends, Arctic sea ice extent in April has decreased by -2.3% per decade.  This rate is lowest in the spring months than the late summer months.  Note that this rate also uses 1979-2000 as the climatological normal.  There is no reason to expect this rate to change significantly (more or less negative) any time soon.  Additional low ice seasons will continue.  Some years will see less decline than other years (like this past year) – but the multi-decadal trend is clear: negative.  The specific value for any given month during any given year is, of course, influenced by local and temporary weather conditions.  But it has become clearer every year that humans are establishing a new normal in the Arctic with respect to sea ice.  This new normal will continue to have far-reaching implications on the weather in the mid-latitudes, where most people live.

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State of the Poles – Aug 2011: Arctic Ice Near Record Low; Antarctic Ice Back To Average

2:30 pm in Uncategorized by WeatherDem

"Arctic Ice"

"Arctic Ice" by U.S. Geological Survey

The state of global polar sea ice area in early August 2011 continues to fare poorly: well below climatological conditions (1979-2009) persist, as they have for every month so far this year.

Sea ice in the Arctic continues to track significantly below average, between the second worst and worst readings during July (depending on the day) in the modern era.  Weather conditions around Antarctica returned to normal during July, recovering from a temporary stall in freezing that occurred during June.  Global sea ice area therefore tracked well below normal during July, reaching for historical lows reached only three times before now.  During July, global sea ice area hovered near the negative 2 million sq. km. anomaly mark.  To date, this is the longest stretch of time that such a negative anomaly has stayed near 2 million sq. km.

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.   Will a new record low global sea ice area be recorded this year?  Stay tuned.  There is only one more month of melting to go in the Northern Hemisphere, while the Southern Hemisphere’s freezing rate will slow down.

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State of the Poles – July 2011: Arctic Ice At Record Low; Antarctic Below Average

12:22 pm in Climate Change, Environment by WeatherDem

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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State of Polar Sea Ice: Arctic Near Record Low; Antarctic Normal

11:56 am in Uncategorized by WeatherDem

The state of global polar sea ice area at the beginning of June 2011 remains poor: well below climatological conditions (1979-2009) continue to persist.

Sea ice in the Arctic continues to track significantly below average, with the 3rd lowest readings for the month in the modern era.  Antarctic sea ice recovered somewhat more quickly to normal conditions than was the case the month before.  Global sea ice area has therefore remained near historical lows for an extended period of time this year.  Within the last month, global sea ice area has finally improved from the 1 million sq. km. deficit from climatological conditions that characterized the first four months of 2011.  To help put this in context, only 2006 and 2007 saw similar conditions.  In 2007, the Arctic (and global) sea ice area fell to its lowest extent in modern history.

Arctic Ice

Portions of the Arctic are warmer places in 2011 than at the same point in 2007.  Warmer water than in past years continues to be transported into the Arctic Ocean at rates that are quickening (more warm water faster – not a good thing for ice survivability).  Weather conditions (local pressure centers, resulting wind patterns, etc.) will have the final influence on what conditions in Sep. 2011 look like.  Updating my guess from last month, I don’t think 2011 will challenge the record low extent of 2007.  I think it is likely that Arctic ice extent will end up in the lowest 3 extents on record.

According to the National Snow and Ice Data Center, Arctic sea ice extent in May was the 3rd lowest on record.  Averaged over May 2011, Arctic sea ice extent was only 12.79 million sq. km.  Arctic ice in May almost matched the rate of decrease recorded in May 2010, which was the fastest in the past decade.

The change in May ice extent has been measured at -2.4% per decade by the NSIDC.  What that means is as of the end of May 1978, the Arctic had 14 million sq. km. of sea ice while May 2011′s extent was, as stated above, only 12.79 million sq. km.  After posting record low extent values in 2004 and 2006, the past Mays saw a rebound in extent values.  The past three Aprils looked more like the extents of the 1990s.  Alas, 2011 looks a lot more like 2004 than 2010.

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State of the Poles: Anomalously Warm Regions Affect Global Polar Sea Ice Conditions

9:48 am in Climate Change, Environment by WeatherDem

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 →

State of the Poles: Global Polar Sea Ice Poor Again as November Begins

8:22 am in Environment by WeatherDem

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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