The state of the Arctic sea ice in late December 2009 remains the 2nd worst of any recorded December. The areal extent of sea ice continues to be well below the climatological average, and as it has for most of 2009, significantly below the negative 2nd standard deviation of the 1979-2000 area. The areal extent of Arctic sea ice continues to be anomalously low, as it has for well over a year now. The Hudson Bay has finally iced over. The late freeze this year was due to anomalously warm waters in the Bay in 2009. The Barents Sea remains relatively ice-free for this time of year. Remember, the Arctic Ocean hasn’t seen sun in a couple of months now.
The state of the Antarctic sea ice in late December 2009 is less disturbing. After reaching a high value of ~19 million sq. km. back in late September, the 2009 melt season exceeded that of the 2008 season. That trend shifted slightly as December drew to a close – the areal extent has increased from the 1979-2000 average to the positive 2nd standard deviation. The exact value of areal extent in 2009 remains below the value measured in 2008 by a small amount. The trend found in December is likely due to this year’s storms: both tracks and intensities vary year to year.
Globally, the extent of sea ice in 2009 continued the trend seen throughout the Aught’s: anomalously low extent, as seen in this graph. There were only a handful of times when global ice extent was significantly above the climatological average these past 10 years and none had the magnitude of the record low extents seen in 2007 and 2008. When viewed in the long term, it is clear to see that the state of the poles has shifted in the past 10 years. The majority of that state change has been in the Arctic.
The state of the Arctic ice in December 2009 is the 2nd worst of any December in recorded history. As has been the case for months now, the areal extent of Arctic sea ice continues to be nowhere near the climatological average. As I’ve stated before, that’s indicative that a new phase of the Arctic (and Antarctic) has been reached. Arctic ice through the month of November mimicked the behavior seen in 2007, the year the extent reached the record low. Slower ice growth was seen in the first half of the month; faster growth was seen in the second half of the month. Not everything is abnormal. Ice growth has been observed in the expected locations for the most part. There is always variability of where the ice grows and when it grows there from year to year. What hasn’t changed too much since 2007 is the lack of long-term (2-year or older) ice, which resists melting in the summer. A key point many climate change deniers miss is that the ice will appear winter after winter for many years to come. The lack of ice in the summer is the issue: increased solar radiation absorption by dark ocean water (instead of being reflected by white ice) adds to global ocean heat content instead of preventing it. Warmer oceans mean higher sea levels and shifting weather patterns – one aspect of climate change.
Here is my State of the Arctic post for November and for September. Here is a satellite representation of Arctic sea ice conditions from yesterday:
For comparison purposes, here is the similar picture from August:
Here is the time series graph with the +/- 2 standard deviations through yesterday:
The NSIDC hasn’t issued their early-month report on the Arctic yet. When they do, I’ll provide a link to it and share anything I find interesting from it. Absent that report, I want to share something else I keep me eye on. The University of Illinois’ Polar Research Group maintains a number of maps and plots for both poles of the cryosphere. Additionally, they track the state of sea ice globally through time. As of today, the maximum global extent of sea ice already occurred a couple of months ago and measured ~21 million sq. km. According to the time series, this is near a record low maximum for the year. The only other times this value was reached was in 2001 and 2007 (the record extends back to 1979). The climatological maximum is over 22 million sq. km. The difference might seem small – 1 million sq. km. – but it’s not. Egypt has 1 million sq. km. of land area. So this year, an area of ice the size of Egypt didn’t form. Of more concern is the low anomalies seen the past three years globally: between 2 and 3 million sq. km. or 2-3 Egypt’s worth of ice. That’s what I’m talking about when I say a new phase of the poles has been reached.
This larger view is probably something I’ll put more focus on in the future, hence the updated title from my ongoing series on this subject. Examining the Antarctic is and will be just as important as examining the Arctic.
The state of the Arctic ice in November 2009 is the worst of any November in recorded history. Arctic areal sea ice extent didn’t break the 2007 record for the absolute minimum, but it has never been this low in November. Further, the extent continues to be nowhere near the climatological average, just like it hasn’t been for most of this year. As I’ve stated before, that’s indicative that a new phase of the Arctic has been reached. For three years in a row, sea ice extent has bottomed out at well below two standard deviations from the average extent. For three years in a row, all-time ice-extent lows have been reached at some point in the season.
Here is my State of the Arctic post for Sep and for Aug. I didn’t post anything in late October because I had a feeling a record low extent would be set shortly, which it did. The big change since my last post is the presence of weather conditions that have kept ice from refreezing at the rate it normally does this time of year. Two years ago, adverse weather conditions developed during the summer. This year, they’re around in the fall. The effect is the same: relatively little ice compared to climatological norms. Here is a satellite representation of Arctic sea ice conditions from yesterday:
Compared to the minimum reached earlier this year, there has been a recovery in ice in the Canadian archipelago, along the northeast coast of Greenland and from the Arctic Sea toward Siberia.
For comparison purposes, here is the similar picture from August:
Here is the time series graph through yesterday:
Notice the rapid refreezing that occurred in 2007, but which didn’t happen so far this fall. No, this fall, a high-pressure system sat over the Beaufort Sea, while unusually low pressure dominated the Barents Sea, according to the NSIDC. This brought 6C (11F!) warmer than normal air temperatures up from Siberia, preventing robust ice growth in that area.
Sea ice extent averaged over October 2009 was 7.50 million sq. km., 1.79 million sq. km. below the 1979 to 2000 mean for October, and only 730,000 sq. km. above the record low for the month, which occurred in October 2007. I expect the average extent for November to be very close to 2007′s, perhaps a little higher, perhaps a little lower, but in poor shape compared to climatological conditions.
The NSIDC released a report at the beginning of November with an additional time series representation of conditions. It shows the last two years’ worth of time series data, plus 2005′s time series, with +/- 2 standard deviations from the climatological average on the same graph:
This graph was made before 2009′s time series line crossed over 2007′s (as in the graph above), but the point remains: ice extent conditions in the Arctic have entered a new state, a state much lower than the 1979-2000 average. The volume of ice has decreased year after year recently, leaving one- or two-year old ice the predominant type in the Arctic. This ice is less capable of withstanding the warmer temperatures that October’s weather patterns produced. New ice is less able to grow around the younger ice. While refreezing will occur every winter, the times when ice does or does not refreeze is more dependent on favorable weather regimes. Additionally, since the Arctic waters absorbed large amounts of solar radiation again this year, the water is warmer than it used to be this time of year. It has to release a lot of heat to the atmosphere before freezing can occur. Thus, the past few falls have seen ice growth in fits and starts, remaining well out of the 2 standard deviations of extent, which is becoming increasingly statistically significant.
The U.S. Senate is slowly drawing closer to considering climate and energy legislation. The 2009 Copenhagen climate summit starts in less than a month. So there are important policy decision points staring us in the face. What will we do about them? The Arctic has demonstrated quite clearly that it has shifted to a new state. The consequences of a warming planet are showing up all over, in places and in ways that were unforeseen even a few years ago. The rate of warming and of other climate change indicators are occurring much faster than recent predictions indicated, exposing our lack of understanding of the complex systems in play. Do we really want to keep trying to kick the can down the road and letting some other group to deal with things? Or do we recognize that it damage to ecosystems and societies is already occurring and now is the time to act to prevent catastrophic situations?
The state of the Arctic in August 2009 is among the worst in recorded history. Arctic areal sea ice extent won’t break the 2007 record, but it’s nowhere near the climatological average – and that’s indicative that a new phase of the Arctic has been reached. For three years in a row, sea ice extent has bottomed out at well below two standard deviations from the average extent. The biggest difference between this year and 2007 is the shift of local weather patterns. This year, a high pressure system has kept moving ice toward cooler water near the Siberian coast rather than away from the Siberian coast. I’ll share some graphical images, then discuss them and the larger picture below.
Here is my last post showing conditions in July and June. Conditions have steadily worsened throughout this summer, as the pictures below demonstrate. As of yesterday, here is a satellite representation of Arctic sea ice conditions:
The state of the Arctic in July 2009 is bad and getting worse. In a continuation of the trend established during May 2009, Arctic areal sea ice extent continues to be characterized as being nearly as sparse as it was in what ended up being the modern-day record low of the 2007 season. The areal extent has been below 2008′s extent on a day-to-day comparison for all of July so far. In late July/early August 2008, the weather situation in the Arctic was such that very rapid melt caused a precipitous decline in areal extent. A similar, almost-as-rapid decline has taken place this July. As I will show below, the difference between my last post one month ago and this post is dramatic.
It is useful to keep in mind that there is a lack of multi-year ice in the Arctic, as I’ve detailed before. Why is this important? One- and two-year old ice is thinner than multi-year ice and is thus more susceptible to fully melting during the Arctic summer, especially in the face of less-than-optimal weather conditions for a week or two. One factor working against record low areal extent is the decreasing amount of solar radiation impacting the Arctic. The sun is sinking lower and lower in the Arctic sky every day and will continue to do so through the end of the calendar year. Lower solar incidence and cloudy conditions could prevent another record low areal extent from being set.
After a rather lengthy hiatus for a well deserved vacation, I’m settling back into things. That includes keeping an eye on the Arctic ice sheet for my monthly post. The state of the Arctic in June 2009 could be better. In a continuation of the trend established during May 2009, Arctic areal sea ice extent continues to be characterized as being nearly as sparse as it was in what ended up being the modern-day record low of the 2007 season. Helping this unfortunate trend along is the lack of multi-year ice, as I’ve detailed before. One- and two-year old ice is thinner than multi-year ice and is thus more susceptible to fully melting during the Arctic summer.
So to update my last post, here is an ice extent picture (as detected by satellite) and an ice extent graph (note that the picture includes data only through the 20th of June, the most up-to-date on the University of Illinois’ website today):
As can be seen from the time-series graph, ice extent continued to decrease at a very rapid pace from late May through mid-June. Conditions briefly matched those from 2007 before moderating ever so slightly. The areal extent of ice has nearly matched 2007′s for the better part of 3 weeks or so. Late June 2007 produced negative weather conditions for ice, as can be seen by the very rapid drop in extent of a couple of million square kilometers. Will late June 2009 conditions be as severe? Time will tell. The fact that conditions are already so far below climatological norms is unsettling.
The satellite composite shows a large amount of ice that is moving toward 20% or less concentration. The amount of area with next to 100% coverage is steadily decreasing.
In what’s becoming a monthly write-up of Arctic sea ice conditions, here is May 2009′s State of the Arctic.
April was kind to Arctic sea ice – very little areal extent was lost during April, as I covered in my last post on the subject, contrary to recent or climatological standards. Monthly variation doesn’t have to follow climatology, of course, as May’s sea ice conditions continued to demonstrate. Also contrary to recent or climatological standards, Arctic sea ice areal extent decreased at a faster rate. Conditions are now closer to the record-low year of 2007, at this point in the year, than they are to climatology, a reversal of April conditions. However, conditions in April were closer to climatology than conditions now are to the 2007 season. One important factor in May’s areal extent decrease is the low ice volume. Due to multiple years in a row of declining sea ice in the midst of warming ocean temperatures, there is less ice this season that can withstand another melt season than in previous years. Indeed, this phenomenon is expected to create summer-time ice-free conditions in the near future.
To update my last post, here are the corresponding graphs showing the state of the arctic ice sheet as of yesterday, starting with a graphical look at ice extent:
The questions I asked at the end of my last post still apply: now that La Nina conditions have transitioned to a neutral state, how will atmospheric and oceanic currents affect the remaining ice extent? What happens when the next El Nino begins and matures? What kind of weather patterns will exist over the Arctic this summer and fall? These all have direct implications on the final ice extent value for 2009. Case in point: the rapid drop-off in extent seen in the 2007 season during June. Will we see something similar this year? Are we already starting to?
The Arctic ice sheet areal extent has slowly decreased in the month since my last post. It has done so at a rate that is less than the climatological norm as well as less than the melt seen during March and April the past couple of seasons. This should be good news for the areal extent of ice later this season, barring anomalous weather conditions this summer and fall. I want to point out that areal extent does not equal volume extent. The Arctic ice sheet’s volume is lower this year than in past years due to the extensive summer melts that have occurred in consecutive years. As the NSIDC notes, thin ice is more susceptible to summer melting than is thick ice, which makes perfect sense. So to update my last post, here are the corresponding graphs showing the state of the arctic ice sheet as of yesterday:
The extent of the ice sheet graphically looks like this:
The recent La Nina that hung around for the better part of two years has recently ended. As we move toward neutral El Nino conditions this year, what kind of storm systems will the Arctic experience? How long will one-year ice last under even climatological conditions? Will weather conditions this summer and fall only be “normal” or will they be as warm or warmer than recent summers and falls? I’ll keep an eye on developments.
The nice part about science is the ability to retest things as new data and better methods become available. In the case of climate change, new data and updated models are producing increasingly higher warming predictions for the end of this century. MIT joined other entities in retesting their predictions with their Integrated Global System Model . The IGSM is used to make probabilistic projections of climate change from 1861 to 2100. Back in 2003, at the time of their original predictions, end of the century median surface temperatures were 2.4°C higher than the climatological average of the preceding century. Armed with additional data and significant updates to the model, their latest prediction is an astounding 5.1°C (median value) in the 2091 to 2100 time period. That’s more than double the value found just a handful of years ago. I can guarantee, and I’m sure they would agree, that their data isn’t completely sufficient; nor is their model accounting for critical feedback processes, many of which we’re only now becoming aware of.
Their new study also includes new predictions of CO2 concentrations over the next 80 years. Their new 5th percentile projection is higher than their 2003 median (50th percentile) at just under 700ppm (current values are 387ppm and increasing). Their new 50th percentile projection is almost as high as their 2003 95th percentile projection: 866ppm vs. 900ppm. Finally, their new 95th percentile projection registers at a nearly unfathomable 1100ppm. Concentrations of CO2 leading up to 1100ppm would certainly open the door to out-of-control climate feedback processes, the kind which nobody would want to deal with.
Warming in their simulations range from 3.1°C to 7.3°C by 2100. They make sure to note that not one of their 400 simulations resulted in globally averaged temperature increases of less than 2°C. Not one. That’s a very significant result. Why the big change? The authors explain:
Rather than interacting additively, these different affects appear to interact multiplicatively, with feedbacks among the contributing factors, leading to the surprisingly large increase in the chance of much higher temperatures.
That multiplicative description is characteristic of non-linear systems, such as the climate system. It’s quite frankly something that many climate change deniers/delayers don’t understand or gloss over. Additive changes of GHG emissions result in multiplicative surface temperature changes down the road. We don’t have to inject too much CO2 or other gases to generate large temperature increases. Which little additive change in emissions will result in more feedback processes kicking in? We don’t know. As such, I don’t think it’s worth it to continue emitting GHGs until we see the feedback has kicked in – it will be too late to slow things down at that point.
Another important result: polar amplification is present in their simulations. By that, I mean that just as has already been observed in the past 30 years, polar temperatures are expected to increase more than temperatures across the mid-latitudes and tropics. There are some differences between the Northern and Southern Hemispheres. Their median percentile projection calls for a 10°C rise at the north pole by 2091-2100 compared to 1981-2000, a 7°C rise at 45°N and a 6°C rise at the Equator. At 45°S, the median temperature change is predicted to be slightly more than 4°C; the south pole temperature change is predicted to be about 7°C.
Does anybody think the Arctic ice sheet can exist year round with 10°C warmer annual temperatures? I certainly don’t. This report identifies a 5% probability of Arctic Ocean ice disappearing in the summer by 2100. I don’t think it will take until 2025 before that happens. Again, the poles are observed and sampled very infrequently in time and space. We simply don’t have solid ideas of how polar climate dynamics behave – not in stable conditions and certainly not in unstable conditions.
The Arctic ice sheet likely already reached its yearly maximum extent about a month ago. Instead of starting to steadily decrease in the week since my last post on it, a weather system set up over Alaska and the Pacific to its west that was able to induce more ice formation than what was lost over the remainder of the ice sheet. This is a positive development as it could allow the ice extent minimum this September to be a bit higher than it otherwise would have been. Conversely, it would only take a couple analogous systems this summer to melt the ice away as more people are fearing will happen every summer. Time will tell. So to update my last post, here are the corresponding graphs showing the state of the arctic ice sheet as of yesterday:
The extent of the ice sheet graphically looks like this:
I’ll take this opportunity to remind myself and others that a moderate La Nina hung on through the end of 2008. At this time, a more neutral phase is being established. As it does so, I expect the current set of strom tracks to shift course. Again, what that means the remainder of the year will have to wait. Even with generally cooler conditions and mostly favorable storm tracks, the ice extent still couldn’t match the climatological norm this winter. I don’t expect this summer’s extent to either.
