Sea Ice North: The new field of ice-free Arctic Ocean science
Sea Ice North: The new field of ice-free Arctic Ocean science
I recently read a paper in Physics Today entitled The Thinning of Arctic Sea Ice by R. Kwok and N. Untersteiner. (Nice essay by Untersteiner) This paper was written for a general scientist audience, and provides a good summary of the state of the science. The primary focus of the article is on understanding the small change to the surface energy balance required to explain the increased rate of sea ice melt in the summer. Some time ago I wrote a few blogs on Arctic sea ice; they can be found here and this one is most relevant: Sea Ice Arctic.
When the IPCC Assessment Report was published in 2007 the Arctic sea ice was in visible decline. In the summer of 2007 there was a record decline that caught the attention of both climate scientists and the broader public. As suggested in Kwok and Untersteiner immediately following the release of the 2007 IPCC report papers started to appear about how the IPCC synthesis had underestimated the melting of both sea ice and ice sheets. Much of this underestimate could be summed up as simplistic representation of the dynamics of ice melting. For example, brine-laden sea ice floating in salty sea water turns over. Snow gets on the top. It melts, then there are puddles and ponds that can flow down into ice. Simplistically, and I am a simpleton, it’s like a pile of ice cubes sitting in a glass versus stirring those ice cubes, or blowing air over the ice, heat gets carried around and ice melts faster.
The presence of large areas of open ocean in the Arctic is new to us. It motivates new research; it motivates claims to newly accessible oil, gas, and minerals; it motivates new shipping routes; it suggests changes in the relationships of nations; it motivates the development of a military presence. (All things Arctic from the Arctic Council) The natural progression of scientific investigation starts to explore, describe, and organize what is to us modern-day humans: a new environment, new ecosystems, and new physical systems. For example, the Mackenzie River now delivers a massive pool of fresh water into the ocean. Fresh and salt – big differences to flow in the ocean because the density is different; big difference to the formation of ice because the freezing temperature is different; and big differences in the plants and animals in the water.
Compared with trying to attribute the contribution of global warming to a particular weather event, it is easier to link the recent, rapid decrease of sea ice to a warming planet. The freezing, melting and accumulation of ice require persistent heating or cooling. It takes a lot of heat for a sustained period to melt continental-size masses of ice. Historically, the sea ice that was formed in the winter did not melt in the summer and there was a buildup of ice over many years – it accumulated; it stored cold. Around the edges of this multi-year ice are areas where the sea froze and melted each year. The melting of multi-year ice, therefore, represents the accumulation of enough heat to counter years of cold. The movement, poleward, of the area where ice freezes and thaws each year is the accumulation of spring coming earlier. The requirement for energy to persist and accumulate to affect changes in sea ice reduces the uncertainty that is inherent in the attribution of how much global warming has impacted a particular event.
Understanding the detailed mechanisms that provided the heat to melt the ice remains a challenge. (This is the real point of in Kwok and Untersteiner) We know it takes about 1 watt per square meter of energy to melt that much ice that fast. This could be delivered by the Sun, transported by the air, by the ocean, by warm water from the rivers of Canada and Siberia, by snow – yes, snow is energy. Once the ice is gone in the summer, then the ocean can absorb heat from the Sun. If there is growth of phytoplankton or zooplankton, then they might enhance the absorption of energy – yes, life is energy. Ocean acidification might change. The natural question that arises – do these processes that are active in this new environment work to accelerate sea ice melting or might they contribute to freezing of water. What are the local feedbacks? (This is above – see below.)
Another study that is of interest is the paper in Geophysical Research Letters, Recovery mechanisms of Arctic summer sea ice, by S. Tietsche and colleagues. This is a model study. With a model the scientist owns the world and can prescribe what it looks like. In these numerical experiments, the Arctic is prescribed with no ice. Then whether or not the ice recovers is explored. In these studies the ice does recover. The ocean does indeed take up extra heat in the summer, but it gives it up quickly in the fall. This is followed by the formation of first year ice in the winter. The ice-albedo feedback that might let the ice melt runaway is limited. Tietsche et al. conclude that it is not likely that Arctic sea ice will reach a tipping point this century.
This does not mean that summer ice loss will decrease. This does not mean that there will not be huge changes in the Arctic. This only says that it still gets cold in the winter.
Models: One of the things I like about the Kwok and Untersteiner paper is their brief discussion of models. They point out that none of the models available for the 2007 IPCC assessment were able to predict the rate of sea ice decrease. Looking forward, they state that the model projections for 2060 range from no sea ice in September to more sea ice than is observed today. The Tietsche et al. paper is a focused model experiment – not a climate projection. It is also a model result that, perhaps, helps to understand the differences in the 2060 projections. That is, how is the recovery of sea ice in the autumn represented in the projection models?
A couple of other points: First, the amount of energy needed to cause the observed melting in sea ice is 1 watt per square meter. If you calculate the amount of energy in the different factors at play in melting of sea ice, then the numbers are 10s of watts per square meter. As suggested above, there are many reservoirs of energy – the Sun, rivers, etc. So when we look at the different ways 1 watt per square meter can be delivered to the sea ice, then there are several paths. The existing models tell us that with the increased heat due to greenhouse gases, energy gets delivered to the Arctic and sea ice melts. The existing models say that there might be several different paths; it is likely, that several of them operate at different times. The second point: Of course the Tietsche et al. paper will enter as an isolated contribution to the political argument, Arctic “death spiral” – as will those of accelerated melt, New warning on ice melt.
r
Figure 1: Simplistic summary of Arctic sea ice
Useful links
Recent sea ice trends
Sea ice data
Rood’s Blogs on Ice
Reader Comments
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 — Blog Index
Happened before and will happen again despite all
our good intentions.
It could be a good thing as well!
A Brain for All Seasons
Human Evolution and Abrupt Climate Change
by William H. Calvin
One of the most shocking scientific realizations of all time has slowly been dawning on us: the earth's climate does great flip-flops every few thousand years, and with breathtaking speed. Many times in the lives of our ancestors, the climate abruptly cooled, just within several years. Worse, there was much less rainfall in many places, together with high winds and severe dust storms. Many forests, already doing poorly from the cool summers, dried up in the ensuing decade. Animal populations crashed—and likely early human populations as well. Lightning strikes surely ignited giant forest fires, denuding large areas even in the tropics, on a far greater scale than seen during an El Nio because of the unusual winds. Sometimes this was only the first step of a descent into a madhouse century of flickering climate.
Our ancestors lived through hundreds of such episodes—but each became a population bottleneck, one that eliminated most of their relatives. We are the improbable descendants of those who survived—and later thrived.
Brings up all sorts of issues
Here is the retraction you spoke of:
Retraction via Canada Free Press
On January 10, 2011, Canada Free Press began publishing on this website an article by Dr. Tim Ball entitled “Corruption of Climate Change Has Created 30 Lost Years” which contained untrue and disparaging statements about Dr. Andrew Weaver, who is a professor in the School of Earth and Ocean Sciences at the University of Victoria, British Columbia.
Contrary to what was stated in Dr. Ball’s article, Dr. Weaver: (1)never announced he will not participate in the next IPCC; (2) never said that the IPCC chairman should resign; (3) never called for the IPCC’s approach to science to be overhauled; and (4) did not begin withdrawing from the IPCC in January 2010.
As a result of a nomination process that began in January, 2010, Dr. Weaver became a Lead Author for Chapter 12: “Long-term Climate Change: Projections, Commitments and Irreversibility” of the working Group I contribution to the Fifth Assessment Report of the IPCC.”
That work began in May, 2010. Dr. Ball’s article failed to mention these facts although they are publicly-available.
Dr. Tim Ball also wrongly suggested that Dr. Weaver tried to interfere with his presentation at the University of Victoria by having his students deter people from attending and heckling him during the talk.
CFP accepts without reservation there is no basis for such allegations.
CFP also wishes to dissociate itself from any suggestion that Dr. Weaver “knows very little about climate science.” We entirely accept that he has a well-deserved international reputation as a climate scientist and that Dr. Ball’s attack on his credentials is unjustified.
CFP sincerely apologizes to Dr. Weaver and expresses regret for the embarrassment and distress caused by the unfounded allegations in the article by Dr. Ball.
REPORT
What I posted already had that portion retracted. So, your post was unnecessary and stated nothing relevant to my post. Do you deny the accuracy of what stated in the edited article? I didn't think so.
Yes, I do "deny the accuracy of what stated in the edited article"; political nonsense, even when edited, is still nonsense, especially when it's written by oft-debunked Big Energy shills who have a long and storied history of fudging their credentials. Hey, I don't blame Ball for re-releasing his warmed-over piece; the man has to keep his pro-pollution dollars coming in, as he's no longer a practicing scientist, so he needs to pen any denialist rants he can. But I do blame those who claim to have intellectual honesty for relying solely on such tripe.
Your remarks just reinforce what I think many here already know. You use character assassination because you can't take the facts where you want to go. Doing what you do, the character assassination, makes you into a very small and pathetic person.
Again with the ad hominem attacks directed at me? I'm sorry; I thought you and I were engaged in a somewhat productive conversation.
Guess not. So my final word before I leave you to your thoughts: questioning the credibility of someone called as an expert witness is in no way "character assassination". Now, Bell lost all his climate credibility years ago when he sold it to Big Oil and Big Gas; if someone wishes to use Bell's antiscience opinions to validate their own in a public forum, I have the right--in fact, I have the duty--to highlight Bell's loss of credibility.
My point is that while modern-day tornado assessments are adjusted for bias due to substandard construction practices or materials, 40 years ago when the Fujita scale was new, that didn't seem to be the case--and even less so when that scale was applied to buildings that had been destroyed two decades or more earlier.
I guess the scale really is a but too subjective, or was in the earlier days of its use. Many historic hurricanes have had Saffir-Simpson numbers retroactively applied to them based on limited contemporary accounts, so while they're certainly not all in error, I've a feeling some likely are.
The whole "no damage so no rating" thing seems a bit too subjective, as well; it's as if the NHC said, "Yeah, that hurricane had a two-mile-wide eye, a central pressure of 890 mb, and winds of 200 mph--but it stayed over open ocean and didn't hit anything, so let's just call it, say, a Cat 1." ;-)
I do hope, as you say, that storm-chasers with proper instrumentation, in concert with better knowledge and understanding of tornadoes, will go a long way toward helping us get a far better picture of the things in the future.
U.S. News & World Report Article...
And that's precisely the point we "alarmists" have been trying to raise for years anytime someone claims that CO2 levels and temperatures have risen or fallen rapidly in the past: the fossil record shows that every single one of those rapid rises in CO2 and temperature throughout earth's history has been accompanied by extinctions of a lesser or greater degree. Now, does anyone except for a few apocalypticans and survivalists really want to help usher in such an event?
Another chart that needs to be rescaled upwards and not downwards I see.
So you believe a natural cycle caused it, and there was no negative feedback to snuff out the warming from CO2. Okay. How this this different from what skeptics are claiming, that natural factors are the primary driver of today's Global Climate?
You seem to be missing my point. I have never said that the negative feedbacks will cause cooling in the co2 system. I said that the warming effect of co2 will be cancelled out by the negative feedbacks. To show proof of this, I will use a graph that MikeSTL himself presented.
Note that the lower range of the GCC feedback, is equal to the forcing from co2. I have demonstrated multiple times that the net effect of clouds is cooling, but I will do so once more.
So the negative feedback of the clouds, is equal, or even more powerful than the actual forcing of Carbon Dioxide.
I must critique the Water Vapour graph, however, and I explain from an earlier post:
--------
...Clouds and water vapour are not different feedbacks. This is what happens when there are warmer oceans- they release more water vapour- which is true. However, the AGW theory missed a key piece of the puzzle in basic meteorology.
Evaporation is caused when water is exposed to air and the liquid molecules turn into water vapor, which rises up and forms clouds.
http://en.wikipedia.org/wiki/Evaporation
The water vapour forms clouds. So most of the water vapour is lost in the process of cloud formation. The positive water vapour feedback that CAGW advocates like to throw around a lot, is not there.
h/t to cyclonebuster- this is NOAA data.
Where is the supposed increase in SH if water vapour is supposed to increase due to increased co2?
--------
The negative feedbacks would cancel the warming from the co2, so there would be no forcing from co2. Co2 would not cause cooling.
OBVIOUSLY climate variations in the past were natural. Man wasn't around, or at least didn't have enough of an impact, to significantly alter climate before the industrial revolution.
This is entirely different from skeptics claims because in the past we are not entirely sure what may have caused an ice age, or warm period; however, now days we can measure natural things.
Clearly in the last 50 years, earth has been hit by no significant asteroids, there have been no super volcanoes, solar output has not increased, and earth has not undergone any cycles in orbit pattern.
And yet earth is still warming. So it has to be man or a natural oscillation. However, if it were because of the PDO or AMO or some other oscillation, we would see temperatures cycle. So far, temps have only continued up
I'm not missing your point at all. For CO2's feedback loops to cancel out the warming created through the GHG theory, you would need a net total effect of all of CO2's feedbacks to be cooling.
I'm trying to tell you CO2's feedbacks are not understood well enough to outright make that claim, and additionally, there is no correlation between high CO2 levels and cooling. If anything, it's the opposite. Meaning there is no causal evidence, nor correlation evidence.
Ok, you made your point, the net effect of clouds is cooling. But what about the other dozens of CO2 feedback loops?
See what I mean, yet? CO2's feedbacks are not understood well enough to claim they cause cooling, and enough cooling to further cancel out the warming effect brought on by the GHG theory.
Hmmm, I could've swore we discussed this just last evening (shortly before you became frustrated and expressed your desire to shoot me in the head). Here's the formula I presented then. Learn it. Know it. Live it:
More CO2 = greater plant growth.
More CO2 = greater heat.
Greater heat = lower crop yields.
Lower crop yields due to heat > CO2-caused growth.
Therefore:
CO2 = lower crop yields.
Aye preguntas?
Okay, so you didn't wish to discuss science with civility? That's too bad; I was really hoping for something more productive. Ah, well.
(BTW, if saying you'd "like to enlarge a photo of my head and use it for target practice" isn't a threat, you should call up the U.S. Secret Service and tell them you wish to do that with the President, then let us know how that works out for you.)
Scientific American Article...
Rules of the Road
1. Please do not carry on personal disputes in the blogs.
2. Threats, intimidation, especially that which extends into the real world will be dealt with by extreme action.
3. Foul language is not allowed.
4. Please avoid topics that would be considered adults only. Many children come to this site looking for information about the weather.
5. Do not circumvent administrative action by creating new users, etc.
6. No spam.
You are correct that man couldn't have possibly impacted the Ice Age 450 million years ago. But CO2 is CO2. Man Made or not. The effects of CO2 do not change if they come from an automobile, or they come from volcanoes. The point is, is that the increase in co2 was not strong enough 450 million years ago to prevent an Ice Age, regardless if they were man-made or not.
Yes, and they were going up at the same pace when humans could not possibly have been impacting the climate.
I believe we have gone over this in a previous post. The positive feedbacks that you had listed, I replied here:
----------
The Increase in Parts per Million of Methane has decreased significantly, to near no trend.
As for Desertification... that is actually a negative feedback, if what you say about the feedback of co2 causing more deserts, is true. Generally, there is more moisture for it to get warmer. Why? The moisture in the air traps heat, and thus, warms the surface faster. A popular misconception is that "deserts are extremely hot." Some deserts are bone chillingly cold during the night, since there is no moisture in the air to retain the heat. With decreasing amounts of moisture in the air, places that were warm, will then become cooler, since there is no more moisture to trap the heat.
How would co2 create deforestation? If anything, higher concentrations of co2 would make more plant life grow faster.
http://www.youtube.com/watch?v=P2qVNK6zFgE
-----------
Post 310.
Do you have any other positive feedbacks to add on, since you mentioned that "there are dozens of other feedbacks?"
Could you list some more feedbacks that co2 creates that either you or me have not listed yet?
Not that it will ever happen, but it would be so refreshing if just once any
denialist"skeptic" would post something here (or anywhere) written by a) a practicing scientist who's b) writing in his or her area of expertise, and who c) isn't employed by Big Oil or any other industry making tens of billions of dollars in annual profits off of the current fossil fuel paradigm, and d) hasn't taken antiscience stances in other areas.Oh, I so wish there was a way to put money on this; I'd go all-in on the IPCC prediction without so much as a moment's hesitation. Of course, Morner isn't likely to be around to pay off; he'll be 102 in 2040 if still alive. But I plan on being here, when we'll all look back at predictions like Morner's with a curious mixture of nostalgia, and resentment over just how very wrong he and others of his ilk were.
No problem, Cat5! :) It is good for objective readers to look at the predictions, (and the data), and then make reasonable conclusions.
We shall see in time.
The extent has actually increased over the past day. It is not the dispersing of the thicker ice, because the Sea Ice Area is flat as well.
What is remarkable about this, is that the Ice increased during the time of a -AO. However, one can only look at the temperature of the Arctic Basin and see why the ice has increased in extent.
Cooler air has moved into the Arctic Basin...
...and that cooler air is poised to stay for at least the next few days.
Could you list some more feedbacks that co2 creates that either you or me have not listed yet?Snowlover, this argument is going in a circle, and it's getting ridiculous.
Here's everything I found wrong with your arguments in that post
1. CO2 levels have never been 10 times higher than the present values.
Take your pick in whatever graph you'd like, none of them show co2 values ten times the present as you've been claiming
oh wait, here's one
but clearly this image is hoax, as it doesn't even REMOTELY correlate to any of the other co2 graphs.
So your idea that CO2 levels were 10 times higher and temps were cooling, is terribly wrong.
If anything, CO2 levels seem to correlate very well with temperatures.
2. Let's play along with CO2 being 10 times higher. You claim that's what caused the cooling at the time. That's a logical fallacy - false cause. You fail to explain how it's CO2's fault. You say it's the feedback loops, but clearly that isn't true. The total effects of all of CO2's feedback loops has never been proven to be cooling. Some negative feedback loops cause cooling. Other positive feedback loops cause warming. You can't go outright and claim the total of all these is cooling.
3. You seem to believe CO2 and natural oscillations are the only thing which can dictate temperatures on earth.
4. Temperatures began rising around 1850 accoding to your graphs. If you've ever taken a US history course, you would know that this is almost exactly when the industrial revolution began. (in the early 19th century around the 1830s and 1840s is when the revolution is said to have occurred).
5. #4 means that man could of had an impact at this time.
6. You mention desertification as a negative feedback. Cool. That's one down, and dozens more feedback loops to go. You want some? Deforestation, Arctic sea ice, coral bleaching, methane release from deep seas, methane release from frozen tundra, melting of glaciers, ocean's dissolving less co2 as a result of warmer temps, etc.
Here's a list
Link
None of these are all perfectly understood, and not to mention there are plenty we are yet to discover.
to finally conclude these ridiculously repetitive discussions..
1. CO2 has never been 10 times the level of present values. Throughout as far back as our ice core samples take us, CO2 levels have, for the most part, correlated very well with temperatures.
2. co2's feedback loops are not understood well enough to say whether or not the total effect of all these feedback loops cancels out the warming created through greenhouse gas theory.
3. ARGO data has not found any climate trends. One study showed warming, the other cooling. Both are studies done from late 03 to 2008 - five years is not enough time.
4. Natural oscillations affect the distribution of heat in Earth's system. This can lead to positive feedbacks to create more warming over the arctic. However, the opposite is also true when the oscillation is in it's opposite phase which can cause positive feedbacks to increase sea ice (ie: some additional ice is formed by cooler temps due to the negative phase. As a result, the ice further cools regional temps by raising albedo. This creates more ice).
Meanwhile,
1. Earth is still warming
2. Man is still contributing
National Oceanic and Atmospheric Administration
National Climatic Data Center
Many lines of scientific evidence show the Earth's climate is changing. This page presents the latest information from several independent measures of observed climate change that illustrate an overwhelmingly compelling story of a planet that is undergoing global warming. It is worth noting that increasing global temperature is only one element of observed global climate change. Precipitation patterns are also changing; storms and other extremes are changing as well.
How do we know the Earth's climate is warming?
Thousands of land and ocean temperature measurements are recorded each day around the globe. This includes measurements from climate reference stations, weather stations, ships, buoys and autonomous gliders in the oceans. These surface measurements are also supplemented with satellite measurements. These measurements are processed, examined for random and systematic errors, and then finally combined to produce a time series of global average temperature change. A number of agencies around the world have produced datasets of global-scale changes in surface temperature using different techniques to process the data and remove measurement errors that could lead to false interpretations of temperature trends. The warming trend that is apparent in all of the independent methods of calculating global temperature change is also confirmed by other independent observations, such as the melting of mountain glaciers on every continent, reductions in the extent of snow cover, earlier blooming of plants in spring, a shorter ice season on lakes and rivers, ocean heat content, reduced arctic sea ice, and rising sea levels.
Simulated global temperature in experiments that include human influences (pink line), and model experiments that included only natural factors (blue line). The black line is observed temperature change.
Time will tell, but I know where I'm putting my money
I wasn't trying to end the GW debate, I know that won't end. I was trying to put an end to the side debate snowlover and I have been having for over a week now
The CO₂ data in that graph agrees pretty well with the GEOCARB III reconstructions.
That being said, I think it is very difficult to make comparisons to today's climate to that of 500 million years ago. To many factors, known and unknown, are different. The fact that CO₂ levels were high while temperatures were low is interesting, but not a deal-breaker for either side in my opinion.
Viewing: 451 - 501
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 — Blog Index