The recent apparent abatement in the warming trend seen in some datasets (i.e. HAD/CRU & GHCN) though not in all (i.e. GISS) has been used to claim that global warming has ended. This misuse of the issue is a shame because there is actually an interesting question here, aside from the agenda-driven obfuscation. However as someone who often has to use Google to find sources on climate change, sorting the wheat from the chaff is an everyday activity.
So what has been going on? Two papers published in 2011 provide a broadly coherent picture. Kaufman et al examined the issue of temperature changes from 1998 to 2008. They found that emissions of sulphates aerosols (China's coal consumption playing a dominant role) offset most of the forcing from rising greenhouse gas emissions with dominance of La Nina ENSO phase and reduced insolation due to the solar cycle explain the lack of warming over that period. In contrast Foster and Rahmstorf consider the longer period 1979 to 2010 and find that over that whole period ENSO and volcanic forcing (stratospheric aerosols from Plinean eruptions) contribute the most with a lesser contribution from reduced solar insolation. Once these factors are allowed for Foster & Rahmstorf find that the signature of global warming is clear and unabated over that period. However both Kaufman et al and Foster & Rahmstorf consider the annual average temperature, there is new research that shows and explains a regional seasonal signal of devatiation from the pattern of global warming.
Saturday, 31 December 2011
Sunday, 18 December 2011
Cold Winters: The Snow Advance Index.
Recently (well, back in November) Dr Judah Cohen published a new paper on the linkage between Siberian snow cover and Northern Hemisphere winters. The paper By Judah Cohen and Justin Jones is "A new index for more accurate winter predictions." There's a link to it at the end of this post. I've previously commented on the possibility of increased incidence of cold winters due to low solar activity and Arctic sea-ice. I've seen those as biassing for colder winters, with Cohen's previous work on Siberian Snowfall showing a trigger for specific cold winter events. However Cohen and Jones' new index makes me wonder what room there is for the other factors.
Monday, 12 December 2011
AGU: Hansen, Rohling & Caldeira.
Last week there was a press conference with Jim Hansen, Eelco Rohling, & Ken Caldeira at the AGU. I'm a bit late on it, just got round to catching up on RC's coverage of it. But this is well worth watching, including the press questions at the end. Rather than use the Blogger video window - which is too small for this - here's a link to the Youtube page. The accompanying powerpoint presentation is available here.
Er.
That's it.
Er.
That's it.
Tuesday, 6 December 2011
Frozen Planet: Fact Checking David Attenborough.
In my previous post I fact-checked a response to David Attenborough by Nigel Lawson. This is based upon an extensive piece in the 3 - 9 December issue of the Radio Times (RT). Now as promised I'll look at David Attenborough's claims, which are quoted below as blockquotes.
Sunday, 4 December 2011
Frozen Planet: Fact Checking Nigel Lawson.
In the 3 - 9 December issue of the Radio Times (RT) there is a substantial piece by Sir David Attenborough about the final episode of Frozen Planet - On Thin Ice. I've fact checked that too, but here I'll fact check Lord Nigel Lawson's response, printed on page 15 of that issue of RT. The blockquotes below are Lawson's factual statements from the RT article.
Saturday, 3 December 2011
Arctic Sea-Ice in the Little Ice Age.
A recent paper by Kinnard et al examines the history of sea-ice using proxy data and recent observations. It really puts what's been going on recently in context and is another brick in the wall of evidence showing that current events in the Arctic are so unusual that they demand explanation and cannot simply be dismissed as being down to natural factors when anthropogenic warming is an ongoing process. Skeptical Science have covered Kinnard et al, now Tamino has a good post with an observation I was going to comment on over there, but it could do with some expanding. And as I have a blog...
Thursday, 24 November 2011
Sunday, 20 November 2011
Into the Hot Zone.
On Friday the IPCC released the draft version of their new report: Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX) PDF. The report relased is merely the Summary for Policy Makers (SPM), the full scientific basis report will not be released until early 2012. Much of the text concerns vulnerability and exposure to the risks of climate change, although there is a shallow but useful summary of the observations and projections related to climate extremes. RealClimate have already done a post on the findings related to Tropical Storms. I'm not going to go over SREX in great detail but a few points from it relate to the recent Hansen paper discussed in my previous post.
Saturday, 12 November 2011
Hansen's Climate Dice.
I'm facing another battle with scepticism. Previously when I was a sceptic of Anthropogenic Global Warming (AGW) I just wasn't thinking critically. Now I think I'm thinking more critically, and the battle I face now is with the issue; Just how bad is AGW going to be?
Sunday, 6 November 2011
Catch-22- The Commitment Catch.
Catch-22, is a logical paradox arising from a situation in which an individual needs something that can only be acquired with an action that will lead him to that very situation he is already in; therefore, the acquisition of this thing becomes logically impossible.Wikipedia
To prompt worldwide concerted action to severely reduce CO2 emissions we need to have such clear evidence of a real and present danger that we are already committed to dangerous climate change. At the stage we have observations of massive climate disruption that is clearly outside of previous natural variability it will be increasingly hard for people to continue to turn a blind-eye to the problem, putting action off until evidence of a disaster is at hand will no longer be an option.
Thus it is a case of Catch-22: To prove the danger of climate change we need evidence, not only that climate change is underway and is likely to be disastrous, but conclusive evidence that climate change is a disaster. However to gain that evidence we would need to leave climate change to proceed to a point where we are experiencing the disaster. The problem with leaving climate change to proceed until we have clear and irrefutable evidence of a catastrophe is that by that stage it will be too late to avert further global warming and an intensification of the problem.
Sunday, 30 October 2011
Cold Winters: Arctic Sea Ice.
The importance of Arctic sea-ice in Northern Hemisphere atmospheric circulation is well established. The driving force of the circulation of the atmosphere is the pole to equator temperature gradient, flows being modified by geography and the spin of the Earth. However the impacts of the radical reduction in Arctic sea-ice that have been seen in the last decade are only now being fully appreciated, with ongoing research details are becoming more clear. Amongst these impacts there is the prospect for a contribution of reduced sea-ice to colder winters in the Northern Hemisphere.
Sunday, 23 October 2011
Cold Winters: Siberian Snowfall.
Though observed global temperature trends continue toCohen et al 2010.
warm with no observed reversals (according to NOAA,
globally it was the fifth warmest December–February (DJF)
period), public perceptions were clearly influenced increasing
skepticism towards global warming (e.g., New York Times
Feb 10, 2010; Wall Street Journal Feb 16, 2010). Therefore,
we would argue that attribution of the harsh winter weather is
critical to the debate of anthropogenic climate change.
The winter of 2009/10 was very unusual. It was dominated by a low index Arctic Oscillation (AO), the value for February being -4.27 (NOAA), the lowest since records began in 1950. The winter was dominated by this negative AO and the consequently weak polar vortex, which allowed cold Arctic air masses to spill out into mid latitude regions causing extensive disruption due to cold and snow, while inflowing air warmed the Arctic. Cohen et al 2010 provides an explanation of why this happened.
Saturday, 22 October 2011
BBC: Frozen Planet.
On Wednesday 26 October at 09:00pm the BBC will be showing David Attenborough's latest documentary. Entitled "Frozen Planet."
The seven part series, four years in the making, will examine life at the poles, needless to say it will cover the changes being wrought by climate change on the ecosystems at the poles. This is an aspect which whilst touched upon in posts by blogs like Arctic Sea Ice Blog, Arctic.io, Patrick Lockerby, and other amateur enthusiasts following the demise of the Arctic, doesn't seem to be represented in a dedicated biology oriented blog.
Radio Times magazine has a lengthy article about the series in which Attenborough is quoted. The final episode of the series is particularly about the changes that will be touched upon in earlier episodes. The final line is:
I'll continue to do what I can. I don't drive or take holidays abroad anymore, I get the bus to work. The heating doesn't go on unless it gets stupidly cold (i.e. not at all most winters). I've started a blog, so that the genuinely undecided can see a growing number of voices crying alarm at what's going on.
We can all only do what we can do. At least then if this process does turn out to be as bad as it may well be and future generations ask why we let it happen, we can say we acted, we did not stand silently or idly by. We can refer such questioners on to the deniers.
What will the deniers say?
The seven part series, four years in the making, will examine life at the poles, needless to say it will cover the changes being wrought by climate change on the ecosystems at the poles. This is an aspect which whilst touched upon in posts by blogs like Arctic Sea Ice Blog, Arctic.io, Patrick Lockerby, and other amateur enthusiasts following the demise of the Arctic, doesn't seem to be represented in a dedicated biology oriented blog.
Radio Times magazine has a lengthy article about the series in which Attenborough is quoted. The final episode of the series is particularly about the changes that will be touched upon in earlier episodes. The final line is:
Can we respond now to what is happening to the frozen planet?Radio Times asks Attenborough how urgent our response to climate change should be. He replies:
As urgent as it can get, this is a mouse trying to move a mountain.... It has to exert every sinew to try and shift this huge boulder. So it's no good saying 'Well, it would be quite nice if we shitfed the boulder' - you've got to use all your energies and say, 'Look, this is really important.When asked if he's convinced that global warming is man made Attenborough replies:
In one sense it is irrelevant, in that whatever the causes we cannot ignore what is happening. But I have no doubt that it is man made.This looks to be an epic and informative series at a vital time of vast climate change in the Arctic, but will it change anything. Will humanity keep the foot on the accelerator and drive right past this bleedin' obvious warning sign? Attenborough says he's pessimistic, I am too, but you won't find me arguing that case anywhere. Humanity can achieve great things when people have faith in their actions, I won't undermine the efforts to make humanity change path.
I'll continue to do what I can. I don't drive or take holidays abroad anymore, I get the bus to work. The heating doesn't go on unless it gets stupidly cold (i.e. not at all most winters). I've started a blog, so that the genuinely undecided can see a growing number of voices crying alarm at what's going on.
We can all only do what we can do. At least then if this process does turn out to be as bad as it may well be and future generations ask why we let it happen, we can say we acted, we did not stand silently or idly by. We can refer such questioners on to the deniers.
What will the deniers say?
Cold Winters: Low solar activity.
Research shows that there is very likely a role of solar forcing in the occurence of cold winters in Northwestern Europe. Mechanisms remain somewhat unclear, although as we seem likely to be entering a period of low solar activity, possibly similar to the Maunder Minimum that caused the Little Ice Age, there should be ample chances for observation to pin down the causal linkages involved.
Tuesday, 18 October 2011
Cold Winters: Opening comments.
On 20/9/11 a UK paper, The Daily Express, published a story stating that a long term weather forecaster predicted another unusually cold winter for the UK. This is part of a general mood in Britain with many people seeming to expect colder winters on the basis of the last two winters.
Shifting Sun-Earth-Moon Harmonies.... WTF!
There's an, ahem, interesting page and paper at What The F**K's Up With That? Never was a humorous acronym so apt.
I've skipped through the document and it seems to be a extreme case of Gerlich and Tscheuschner's leaving the disproof of the Greenhouse effect as an exercise for the reader. Von Neuman once said "With four parameters I can fit an elephant, and with five I can make him wiggle his trunk." From the graphs this appears at face value to be an extreme example of that. But frankly I can't be sure as it's hard to discern a structured argument.
Have WTFUWT been had by a practical joke?
...to ask the community to start thinking carefully about what can be learned from rotating multivariate lunisolar spatiotemporal phase relations shared by Earth Orientation Parameters (EOP) and terrestrial climate records, while seizing the same opportunity to highlight critical omissions in “classic” works on alleged solar-barycentric terrestrial influences (section II).The material reads like it was put together using SciGen. A site that allows you to compose gibberish of an equal order, like this.
I've skipped through the document and it seems to be a extreme case of Gerlich and Tscheuschner's leaving the disproof of the Greenhouse effect as an exercise for the reader. Von Neuman once said "With four parameters I can fit an elephant, and with five I can make him wiggle his trunk." From the graphs this appears at face value to be an extreme example of that. But frankly I can't be sure as it's hard to discern a structured argument.
Have WTFUWT been had by a practical joke?
Monday, 10 October 2011
Irrelevant.
There's been a study recently that is being touted (e.g.) as showing that AGW denialists are more scientifically literate than those who accept AGW.
Matters arising from D'Aleo 3: The 1940s and the present.
The warming of the 1940s was not like the current warming. There are differences in observations and the model evidence supports the idea that while the 1940s was an outcome of natural variability, whereas the recent warming is externally forced.
Sunday, 9 October 2011
Matters Arising from D'Aleo 2: The AMO & PDO.
Regarding the Atlantic Multi-decadal Oscillation (AMO). D'Aleo claims it "Looks like an awfully good fit. There is very little, if any, global warming." I've already pointed the following out to him. The Center for Atmospheric Research suggests that the major part of recent ocean warming in the AMO is due to global warming, once the global warming signature is removed the AMO is rather a small effect. So that source suggests that if warmer ocean waters due to the AMO are substantially responsible for loss of Arctic sea-ice, then it is global warming that is causing most of the warming.
Friday, 7 October 2011
Matters arising from D'Aleo 1: Opening comments.
Recently Joseph D'Aleo has posted a reply to Tamino's posts Cold Cherries from Joe D'Aleo and More Cherry Ice from Joe D'Aleo. D'Aleo's response is here.
Friday, 30 September 2011
The Loss of the Ellesmere Ice Shelves
In April 2001 the Journal "Polar Record" published a paper by Vincent, Gibson and Jeffries entitled: "Ice-shelf collapse, climate change, and habitat loss in the Canadian high Arctic." hereafter referred to as Vincent et al.
They started their discussion by stating:
They started their discussion by stating:
Wednesday, 21 September 2011
Summer Daze.
I've recently posted about an apparent dip in temperature in the Central England Temperature series and it's apparent support of my notion that since 2007 our summers have been dominated by low pressure weather. In that post I said I couldn't do the required analysis because NCEP/NCAR didn't have the functions for me to do monthly studies. I was wrong, in the intervening time I've found the relevant page.
Sunday, 18 September 2011
What's up with D'Aleo?
Well known denialist Joseph D'Aleo has recently written a load of specious claptrap at the internet's great repository of specious claptrap; Watt's up With That. Tamino exposes D'Aleo's cherry picking (denialists so love their cherries). That noted, my disagreement is with the overall gist of D'Aleo's post. Which is essentially a boring re-run of a tired denialist meme that Arctic sea-ice loss is due to natural processes in the atmosphere and ocean.
Cooling of the Arctic Stratosphere since 2007
In comments on my earlier post "Arctic Dipole: A Positive Feedback" Kevin O'Neill raised an intriguing point regarding stratospheric cooling and tropospheric warming in the post 2007 period during the summer (June - August).He also pointing out that there was a mixed picture previously, see here. Kevin's graphic is here.
This has had me puzzling over it for the last few days, so yet again the posts I was going to do on the recent cold winters will be delayed. However I think I now have a reasonable explanation for the observations Kevin raised.
This has had me puzzling over it for the last few days, so yet again the posts I was going to do on the recent cold winters will be delayed. However I think I now have a reasonable explanation for the observations Kevin raised.
Thursday, 15 September 2011
Cool wet summer.
Here in the UK we've had another cool wet summer dominated by low pressure systems. UK temperature is notably very variable, this is due to our location and the interplay of weather systems. We're in the battleground between continental European, and maritime Atlantic air masses, at the end of the Jetstream's path across the Atlantic.
Unfortunately the NCEP/NCAR interface doesn't allow me to compare a string of years seasonally, and looking for any changes in the summer weather needs to be seasonally based (by definition). However there is a publicly available dataset that does allow me to look at temperatures, the world's longest instrumental temperature series, the Central England Temperature series (CET).
Unfortunately the NCEP/NCAR interface doesn't allow me to compare a string of years seasonally, and looking for any changes in the summer weather needs to be seasonally based (by definition). However there is a publicly available dataset that does allow me to look at temperatures, the world's longest instrumental temperature series, the Central England Temperature series (CET).
Wednesday, 14 September 2011
Australia's Big Dry and AGW.
The Big Dry in South East Australia is a classic case of the complexity with which AGW affects climate. I've chosen to write about it because the linkage is more subtle even than just an AGW interaction with a mode of variability in the atmosphere. Yet the AGW role is as clear as it has proven devastating for South East Australia.
Sunday, 11 September 2011
9/11
On September 11 2001 I was working as a technician involved in the commissioning of a new private branch phone system and callcentre switching system for a large firm here in the UK. Having installed successfully, I was one of the technicians remaining on site to be quickly available to deal with any teething problems.
At around 1400 the callcentre system appeared to go down. Incoming calls dropped to barely nil, callcentre agents were sitting in their seats doing nothing. We technicians weren’t; both software and hardware side swung into action to sort the problem out. We couldn’t find a problem. British Telecom confirmed that there were barely any calls to put through.
Then the news started to come in, staff in the callcentre, and colleagues of mine receiving emails and text messages relaying what was happening over in New York. What we were hearing seemed unreal, work lost it's importance.
As I sat in my hotel room that evening I wept tears of sorrow and anger as I watched the horror on TV news. Despite thousands of miles of ocean 9/11 was a tragedy I felt part of. It still affects me emotionally, it always will.
Saturday, 10 September 2011
Has 2007 been beaten?
According to University of Bremen a new record low has already been set. NSIDC and IARC-JAXA still show 2011 lagging 2007, this confirms the pattern this year - Bremen have shown consistenly less of a gap between 2011 and 2007. Cryosphere Today's sea ice area also shows a new record, but in this post I'll concentrate mainly on extent so as not to compare apples and oranges. Sea ice extent considers any area with over 15% sea-ice as ice covered, sea-ice area adds up the concentrations in individual areas.
Monday, 5 September 2011
ROFLMAO
Via the ever-excellent (and somehow missing from my blog-roll - doh!), ArcticIO - daft questions asked by tourists from a polar expedition guide.
My favourite has to be: "Does the midnight sun set above the horizon?"
I'd suggest visiting the ArcticIO page first if only for the photo at the top of the post. But there's more at the original source: Dioclese's blog.
My favourite has to be: "Does the midnight sun set above the horizon?"
I'd suggest visiting the ArcticIO page first if only for the photo at the top of the post. But there's more at the original source: Dioclese's blog.
Sunday, 4 September 2011
Arctic Dipole: A Positive Feedback.
In a previously discussed paper, Zhang et al open their closing discussion with the following line:
"The atmospheric circulation change identified here
could be a mixed response to rising greenhouse-gas-emissions
forcing or unexpected natural climate variability, or both."
Friday, 2 September 2011
An Honourable Decision.
Wolfgang Wagner was editor of the Journal 'Remote Sensing' when the journal published a paper by Roy Spencer and William Braswell entitled "On the Misdiagnosis of Surface Temperature Feedbacks from Variations in Earth’s Radiant Energy Balance." link.
Spencer and Braswell was glowingly received at Watts Up With That (aka WTF), which is to be expected as WTF is heavy on the applause of anything that bolsters their increasingly bizarre stance, but light on the analysis. It was similarly received on Faux News and other wingnut media. Meanwhile more reputable commentators actually read the paper and pointed out the obvious flaws.
Spencer and Braswell was glowingly received at Watts Up With That (aka WTF), which is to be expected as WTF is heavy on the applause of anything that bolsters their increasingly bizarre stance, but light on the analysis. It was similarly received on Faux News and other wingnut media. Meanwhile more reputable commentators actually read the paper and pointed out the obvious flaws.
Monday, 29 August 2011
Playing Around with PIOMAS.
The daily PIOMAS volume anomaly series shows the difference for each day's volume from the volume for an average period. In this post I've used the 20 year period 1979 to 1998 to calculate the daily average.
To melt a given volume of ice requires a certain amount of energy, this is the enthalpy of fusion, 334kj/kg. So the volume anomaly can be transformed into an energy anomaly, in this post I call this the implied energy anomaly: it's the energy anomaly implied by the volume anomaly.
To melt a given volume of ice requires a certain amount of energy, this is the enthalpy of fusion, 334kj/kg. So the volume anomaly can be transformed into an energy anomaly, in this post I call this the implied energy anomaly: it's the energy anomaly implied by the volume anomaly.
Sunday, 21 August 2011
Arctic Dipole: Sea-Ice Loss.
In what I consider a very important paper, Wang et al 2009 ask: "Is the Dipole Anomaly a major driver to record lows in Arctic summer sea ice extent?"
They start by noting that since 2002 the Arctic Oscillation (AO) has become neutral to negative, yet there has been rapid sea-ice retreat over that period. Since the 1970s there has been a correlation between the AO and sea ice loss through the Fram Strait, with the positive AO of the 1990s leading to a significant increase in sea ice loss. So it seems that the AO has not played a role in the ice loss since 2002. As previously discussed, Zhang found that in the period 2002 to 2007 the Arctic Dipole (AD) has become the dominant mode of variability in the Arctic, taking over from the AO.
They start by noting that since 2002 the Arctic Oscillation (AO) has become neutral to negative, yet there has been rapid sea-ice retreat over that period. Since the 1970s there has been a correlation between the AO and sea ice loss through the Fram Strait, with the positive AO of the 1990s leading to a significant increase in sea ice loss. So it seems that the AO has not played a role in the ice loss since 2002. As previously discussed, Zhang found that in the period 2002 to 2007 the Arctic Dipole (AD) has become the dominant mode of variability in the Arctic, taking over from the AO.
Monday, 15 August 2011
Home straight.
It's now coming up to a month until this year's minimum. I normally don't provide a running commentary of ice conditions as that's done more comprehensively elsewhere than my time will allow. Furthermore in my opinion earlier in the season short term events have less of an impact on the final minimum figure. However as we near the end of this season the game is still afoot.
Thursday, 11 August 2011
Arctic Dipole: A dominant role.
Zhang et al (2008) identify a recently emerging Dipole Anomaly in the Arctic, they call this the Arctic Rapid Change Pattern, or ARP, throughout this post I will however use the commonly accepted term; Arctic Dipole (AD). They use a running window EOF technique to examine small time periods over which the AD has changed. This means that instead of Wu et al's approach of applying the EOF to a long period, Zhang et al apply the EOF to short (5 year) runs over the period 1886 to 2006, this allows them to analyse the spatial changes with time. They don't refer to the previously discussed Wu et al paper.
Tuesday, 9 August 2011
28 Weeks Days Hours Later.
Here in the UK the vermin are rioting. I guess I can't let this go without blogging, it is pretty amazing.
Monday, 8 August 2011
Arctic Dipole: In the 20th Century.
The classic mode of variability in the Arctic atmosphere is the Arctic Oscillation. This is annular (circular) in form so moves air around the Arctic Basin. The AO is identified using a technique called Empirical Orthogonal Functions (EOFs), which is a technique used to identify patterns in data. Recently a pattern called the Arctic Dipole has been found, this has a key role in the recent atmospheric changes in the Arctic.
Monday, 1 August 2011
Sea-ice drift speeds in the Arctic.
Hakkinen et al, 2008, use observations of sea-ice drift to examine possible trends in Arctic sea ice drift. Their aim is to examine whether sea-ice drift reveals anything about possible increase in storms in the Arctic, previous research has suggested that mid-lattitude storm systems are more frequently moving into the Arctic. As the authors note because sea-ice movement responds within hours to changes in wind this is a reasonable approach to the problem.
The mechanisms of sea-ice loss: A clarification.
I'm cramming a load of papers about the Arctic Atmosphere, changes in Arctic atmospheric circulation will be my theme for the next few posts. In the process of re-reading papers and reading new ones it's occurred to me that I haven't been as prescise as I should have been in some of my previous statements.
In an earlier post I've claimed that thermodynamics best explain the loss of Arctic sea-ice, I still think that this is the case. however think some clarification may be appropriate as I don't discount atmospheric and oceanic factors and may have given the impression that I do.
In an earlier post I've claimed that thermodynamics best explain the loss of Arctic sea-ice, I still think that this is the case. however think some clarification may be appropriate as I don't discount atmospheric and oceanic factors and may have given the impression that I do.
Sunday, 31 July 2011
An Observer's Prediction.
Over at Neven's Sea-Ice Blog there's an interesting post by Russell McKane predicting September sea-ice extent using a site and technique I've never seen before. It's as well to read that post before proceeding here.
Monday, 25 July 2011
Arctic sea-ice free this decade?
As I outlined in my post In Flux, a key finding concerning the Arctic has made me wonder about whether we are indeed on a fast-track to a seasonally sea-ice free Arctic this decade. However on reflection that is in part an emotional reaction to an observation that unsettles me. I had been going to wait until September to post on this subject, so I could see what happens this year: I still see 2011 as having the makings of a spectacular season. But in the light of Maslanik's latest paper, and of the points raised by two commenters on the 'In Flux'page, I thought it might be as well to state in detail why, on balance, I don't think we are on a fast-track, and why I think key observations are being misinterpreted.
Update - I have since changed my view on this as outlined in this post.
Update - I have since changed my view on this as outlined in this post.
Saturday, 23 July 2011
Maslanik, Arctic sea ice change in Spring 2011.
Neven has recently posted a good summary article about what I consider a very important recent paper from Dr James Maslanik and co-authors. If you've not read it, or the original paper, I suggest you read his post before my comments.
Maslanik et al find an increasing trend in multi-year (MY) sea ice through the 1980s and a loss through the early 1990s, these are associated with different phases of the Arctic Oscillation (AO). During the period of gain from 1996 to 2001 the sea level pressure showed a weak positive Arctic Dipole Anomaly (AD) (high pressure over Canada, low over Siberia), then the losses of 2002 to 2011 were associated with a negative index AD. This could be taken to imply that the main process at play in the loss of Arctic sea ice is due to changes in wind patterns, a common denialist meme. However that is not the case, as I will explain.
Maslanik et al find an increasing trend in multi-year (MY) sea ice through the 1980s and a loss through the early 1990s, these are associated with different phases of the Arctic Oscillation (AO). During the period of gain from 1996 to 2001 the sea level pressure showed a weak positive Arctic Dipole Anomaly (AD) (high pressure over Canada, low over Siberia), then the losses of 2002 to 2011 were associated with a negative index AD. This could be taken to imply that the main process at play in the loss of Arctic sea ice is due to changes in wind patterns, a common denialist meme. However that is not the case, as I will explain.
Sunday, 17 July 2011
In flux.
I've been a sceptic of the idea that the Arctic will have a virtually sea-ice free minimum this decade, I've said elsewhere that I think it will happen next decade at the earliest. Now I find myself questioning my position.
The loss of multi-year sea ice Part 2.
In the previous post I looked at what had been happening to the extent of Multi Year (MY) sea-ice and the nature of it's presence in the Arctic sea-ice. There is more research however that pertains to changes in it's thickness, and the thickness of the Arctic sea ice in general.
Down came the rain.
Pretty good weather last week, then come Friday, leaving work...
It's rained Saturday and Sunday as well.
Arse!
Hat tip to the Late Great John Peel for this one.
It's rained Saturday and Sunday as well.
Arse!
Hat tip to the Late Great John Peel for this one.
Saturday, 16 July 2011
Thursday, 14 July 2011
The loss of multi-year sea ice, Part 1.
There are two types of sea-ice in the Arctic, first-year (FY) and multi-year (MY). It's been known for some time that MY sea ice is in decline.
Here is an NSIDC graphic of the series of James Maslanik.
Here is an NSIDC graphic of the series of James Maslanik.
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