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Yeah. I hear you. Springfield has gotten the shaft worse than St. Louis these past several years. By the way, I went to high school in Republic so I'm very familiar with the area.

Euro has some snow...more on the east side of MO than the west, but Springfield is still in the ballpark right now for some accumulation at least as modeled.

Preliminary numbers show that the annual mean extents for the NH finished second lowest behind 2016. SH was similar...it finished second lowest behind 2017. The SH is whole different beast, but the fact that we had 2018 end badly lends a bit of credence to the idea that 2017 may not have a fluke. I wonder if we're beginning to observe the paradigm shift down there too. Any thoughts csnavy?

0Z UKMET looks intriguing as well; perhaps more so than the Euro even.

And combined SH and NH sea ice extents are now 2nd lowest. And aside from a couple of brief blips global sea ice has remained below 2σ from the mean for about 2.5 years now. And much of that time it was actually 3σ below the mean.

I looked at the data this morning. Assuming I didn't miscalculate at the current pace 2018 is on track to have the 2nd lowest annual mean sea ice extent. The top 3 lowest would be 2016, 2018, and 2017.

November mean extent came in at 9.81e6. This is lower than my estimation of 9.9e6 from my earlier post. Extents are hugging the lower interdecile range of the 1981-2010 average. Even assuming we hit the climatological average for December of 12.8e6 (I don't see how that's possible at this point) then 2018 will easily land in the top 5 lowest for annual mean extent. If December comes in at a more modest (but still high by recent standards) 12.4e6 then 2018 could make a run for the second lowest behind only 2016.

I believe this figure is in reference to TSI which is incident radiation normal to the beam angle. To get the integrated radiation over the entire Earth you have to multiple by Earth's cross sectional area. Conveniently the cross sectional area of a sphere is 1/4 the surface area. That means the power going into the geosphere is actually 1360 / 4 = 340 W/m2. So you need to take that -8.0 W/m2 and divide it by 4 as well. This gives us a normalized value of -2.0 W/m2 of force that's being applied. Note that Zharkova's super grand solar minimum claim is 4x the magnitude of the Maunder Minimum (a fact she acknowledges). So will this hypothetical Modern Minimum really be 4x as deep as the Maunder Minimum? Maybe. But, I'm not going to hold my breath. Furthermore, I believe this is the maximal effect. It's not the mean forcing you'd derive if you integrated the radiation reduction over the several decades in which the minimum is taking place. Remember, it will slope down on the entry and slope up on the exit. And of course, this in no way turns off the CO2 effect. It's persistent positive radiative forcing effect is still very much in play. And it will remain in play (unless we go to a negative CO2 emissions regime) for 100s or even 1000s of years easily outlasting this hypothetical grand minimum.

Again...no one is suggesting that the total effect of CO2 is larger than the total effect of the Sun. What we are saying is that the change in the effect of CO2 is larger than the change in effect from the Sun relative to the preindustrial era. Also, the Rahmstorf study regarding a hypothetical grand minimum and it's effect on the climate isn't the only one available for you to review. I posted 3 others above. Finally, if you're going to include oceanic composition in your list then it would be imperative to also include atmospheric composition. Afterall, the Stefan/Boltzmann law tells us that the Earth should be radiating with a temperature of 255K, but because our atmosphere traps heat it actually radiates at 288K which is a +33K effect. The atmosphere matters...a lot. Changes in its composition can and do have a measurable effect.

CO2 like most polyatomic molecules really does have it's molecular vibration modes activated by photons with wave number 667. This process converts quantized photon energy into thermal energy. And it's been confirmed by laboratory experiments going as far back as Tyndall in the mid 1800's, modern infrared spectroscopy, paleoclimate records, and fully explained by molecular physics and quantum mechanics. This is reality and it's been known for over 150 years. My phrasing "all other things being equal" is a nod to the fact that there are many physical processes that act as agents to force global heat uptake changes beyond just greenhouse gases and solar radiation. It's the net effect of all of them that determines the magnitude and direction of the "force" placed on the climate system.

Hmm...I think there may still be some confusion here. When we say "forcing" we are talking about a perturbation or anomaly above or below a reference point. For example, a solar grand maximum might have +1.0 W/m2 of "forcing" relative to a long term average. A solar grand minimum might have -1.0 W/m2 of "forcing" relative to the same long term average. Likewise, CO2 "forcing" is relative to a reference point. Typically we use the 280 ppm preindustrial concentration as the reference point. There's actually a coincidental and rather convenient temporal alignment of these two reference points as a result of the Sun being midway between the Maunder Minimum and Modern Maximum just before the CO2 concentrations spiked up from 280 ppm. A "forcing" in this context is a change. We aren't saying that the total effect of CO2 is more powerful than the total effect of the Sun. What we are saying is that the change in the CO2 effect is bigger than the change in the Sun effect today. So if the Sun goes -1.0 W/m2 and CO2 goes +2.0 W/m2 and all other things remain equal then the net effect is +1.0 W/m2. This is because the change in the CO2 effect was bigger than the change in the Sun effect.

That is not what bluewave or anyone has claimed. The claim is that Sun (like any main sequence star) is relatively stable in regards to it's luminosity. The variability in the radiative forcing is relatively small despite the magnitude of the radiative forcing being large. The change in radiative forcing of CO2 dominates over the change in radiative forcing of the Sun. Again, it's the change in the effects that are crucial in understanding the change in radiative forcing and thus the change in the heat uptake by the geosphere. Note that I have underlined change to drive home the point that it is the change in the system that puts pressure on the climate and ultimately the Arctic sea ice extents to also change. For example, if the Sun were to experience a change of 0.25% in it's integrated luminosity then this is equivalent to 1360 W/m2 * 0.0025 / 4 = 0.85 W/m2 of forcing. But, a doubling of CO2 results in 5.35 * ln(560/280) = 3.7 W/m2 of forcing. That's more than 4x the effect. Plus, solar grand minimums are relatively short term compared to the long term impacts of CO2 which take 100s or even 1000s of years to die off to preindustrial levels. Note that a -0.25% change in TSI is considered to be on the high end of the forcing change for a hypothetical grand minimum.

And it's not just Rahmstorf that came to the conslusion that grand minimums will have minimal effect. You also have Meehl 2013, Anet 2013, and Jones 2012. Yes a hypothetical grand minimum will suppress the warming, but it won't stop it and it will only be temporary. Once the Sun comes out of its quiescent state that mitigation effect completely disappears.

Yeah. I agree. We try should to figure why this year's refreeze is more aggressive than in recent years. We should strive to figure out every little nuance of weather/climate no matter how detailed and trivial. I'm sure solar cycles play a role. I just don't know how much. As with most things related to the climate its rarely ever just one thing. It's usually the net effect of a lot of stuff that makes for the best discriminator of climate behavior. For example, although a solar min by itself might not have much of an impact if it is phased precisely with a particular ENSO, AMO, and/or PDO cycle then the effect is magnified. My naive assumption is that solar cycles should have a bigger impact in the summer than the winter due to the fact that the poles receive relatively little solar insolation in the winter to begin with. But, I've learned over the years that my naive assumptions can be dead wrong. In fact, it's not unreasonable to think the link between sea ice extents and solar cycles is more indirect owing to the fact that the upper atmosphere is far more sensitive to the cycles than the troposphere. And of course, there are likely inertial lags between the peaks of the solar cycles and the peaks of the responses in the various elements of the climate system. I wouldn't be surprised if solar cycles have the complete opposite effect of what you'd expect as well. Anyway, I did a quick google search and I found this very recent paper right away and it's not even behind a paywall...yay! I must confess...I haven't actually read it yet. I'll try to do that later today. https://www.nature.com/articles/s41598-018-22854-0 This study investigates the role of the eleven-year solar cycle on the Arctic climate during 1979–2016. It reveals that during those years, when the winter solar sunspot number (SSN) falls below 1.35 standard deviations (or mean value), the Arctic warming extends from the lower troposphere to high up in the upper stratosphere and vice versa when SSN is above. The warming in the atmospheric column reflects an easterly zonal wind anomaly consistent with warm air and positive geopotential height anomalies for years with minimum SSN and vice versa for the maximum. Despite the inherent limitations of statistical techniques, three different methods – Compositing, Multiple Linear Regression and Correlation – all point to a similar modulating influence of the sun on winter Arctic climate via the pathway of Arctic Oscillation. Presenting schematics, it discusses the mechanisms of how solar cycle variability influences the Arctic climate involving the stratospheric route. Compositing also detects an opposite solar signature on Eurasian snow-cover, which is a cooling during Minimum years, while warming in maximum. It is hypothesized that the reduction of ice in the Arctic and a growth in Eurasia, in recent winters, may in part, be a result of the current weaker solar cycle.

Assuming extent gains increase by the 1981-2010 rate November will end with a mean of about 9.9e6 km^2. Then if we assume extents jump up and exactly match the 1981-2010 average (unlikely IMHO) then December will end with a mean of 12.8e6 km^2. This puts the final tally for 2018 at at mean 10.41e6 km^2. It would still be the 5th lowest annual mean just barely behind 2012 at 10.406e6 and 2017 at 10.393e6. Note that the top 5 would all be 2012 and later. So although the fast refreeze is interesting in it's own right it needs to be considered in context here. Unless someone has a convincing argument it's premature to think this is the start of a new era where sea ice extents begin a long term secular increase especially considering that we have a mountain of evidence that suggests sea ice extents will stagnate at best through the 2030's or just continue to decline.

It does seem like there has been an extended run of generally quiescent weather in the midwest the last few years.

Even assuming higher freeze rates than have occurred recently persist for the remainder of the year then 2018 will still end with an annual mean < 10.5e6 km^2. That would be 4 years in a row now. To put this in perspective the IPCC AR3 report from 2001 suggested that the first occurrence of < 10.5e6 km^2 might not happen until 2040. Well it actually happened in 2007 about 33 years ahead of computer simulations available at the time. And yet we're about to experience 4 in a row of this happening well ahead of the expected first occurence. Furthermore they say "The simulations of ice extent decline over the past 30 years are in good agreement with the observations, lending confidence to the subsequent projections which show a substantial decrease of Arctic sea-ice cover leading to roughly 20% reduction in annual mean Arctic sea-ice extent by the year 2050." Note that a 20% reduction of the annual mean is about ~10.0e6 km^2. I just don't see how it's possible that we can make it to 2050 before the annual mean drops below 10.0e6 km^2. My point is two-fold. First, it's winter. The refreeze is expected. Just because it's happening faster now relative to recent years in no way means the longterm decline has suddenly reversed. And second, the expectation for the longterm decline has been severely underestimated by the IPCC at least in their earlier publications. So you'll have to forgive me for being skeptical that we'll also make past 2050 before the Arctic goes ice-free (defined as < 1.0e6 km^2) at least once in the summer. Sure, we might make it that long, but I'm not going to hold my breath.

Can you clarify the difference between EDEX Service Access and EDEX Priority access? Also, for those that don't know AWIPS is actually a pretty useful tool. There is a Windows version now which I haven't played around with yet. But I can tell you that AWIPS installs quite nicely in a CentOS 7 instance running inside VMWare. You just need to have "enable 3D graphics" ticked in the VMWare settings.

I only mean that CO2 is adjusting the overall energy budget by perturbing some of the longwave channels as opposed to the other channels. As a result its effect is more pronounced on the Qout side than the Qin side due to its spectral behavior in relation to the precise nature of the Earth/Sun radiation fluxes. I'm not sure what your point was about "there is NO balance never". Anyway, we're starting to digress here as the physical process behind polyatomic molecule's propensity to trap heat isn't directly related to the subject of this thread. We're trying to discuss Arctic sea ice extents here. If you have questions or comments regarding other topics of climate change maybe it would be better to post them in another thread? There's a whole forum dedicated to this.

It's true. The 2007 summer minimum was lower than in 2018. However, if you integrate the sea ice extents over the entire year and assuming 2018 follows the 2017 trajectory the remainder of the year (a reasonable assumption) you'll find that 2018 results in less ice than in 2007. Except that's really moot anyway. Keep in mind that when we say "decline" we are talking about a longterm secular decrease in sea ice extents. We are not in any way implying that every year will necessarily be lower than the previous. Natural variation is still very much in play. And we aren't necessarily even focused on just the summer minimum. The winter maximum and, of course, the yearly mean are equally important metrics. Regarding your second point there may be some confusion as to what a greenhouse gas does. CO2 and other polyatomic molecules (like H20, CH4, and CFCs) aren't sources of heat. What they do is disrupt the balance between Qin (the incoming shortwave radiation) and Qout (the outgoing longwave radiation). This imbalance creates a net positive gain in heat uptake in the geosphere (90% goes into the hydrosphere) until a new equilibrium is achieved such that Qin = Qout once again. It's really not much different at a conceptual level with the insulation in your home. All other things being equal your house will achieve an equilibrium at a lower temperature if there is no insulation. Again, CO2 is not a source of heat. What it does is impede the transmission of heat.

Let me clarify something. Consensus is not itself a form of evidence. Rather it is born out of the abundance of evidence. Specifically it is the consilience of evidence from which a consensus is born. In other words the reality tends to land in the spot where there is the best overlap of available evidence. What I find often in the blogosphere is that they are brainwashing people into believing that consensus is bad and outlier is good. They do this in a variety of guises but the main issue is that they simply don't tell you about the abundance of evidence from which the consensus came and instead focus solely on outlier lines of evidence. Of course it doesn't help that evidence supporting the consensus is often misrepresented or misinterpreted and that the outlier evidence often has significant issues which is also not presented to you. This is actually a big problem with the internet today in general but specifically with climate science. The fact is that the Earth is going to experience a persistent net positive radiative forcing as a result of human activities (including but not limited to CO2). And baring any significant and unpredictable events like significant volcanic eruptions or other cataclysms the entire geosphere will respond with an increase in heat uptake and an increase in temperature. This will put longterm downward pressure on sea ice (especially in the Arctic region) resulting in ice-free conditions in the summer months with the most likely timing being around mid century assuming a business-as-usual representative climate pathway. Different RCPs yield different amounts of warming at different times. Dismissing the abundance of evidence (a mountain of evidence in fact) that has been collected over the last 150+ years isn't going to stop CO2 from producing a positive radiative forcing on the planet or stop the declining trend of Arctic sea ice extents.

I get that, but this thread is focused on Arctic sea ice. Judith Curry makes several points in her blog and none of them were directly related to sea ice. Don't get me wrong. They're good talking points, but they deserve their own thread. That way we can address each talking point via several posts without taking this thread too far off course. That's what the climate change subforum is for afterall. Post another thread and I'll participate as I get time.

Can you post a new thread? I was trying to avoid hijacking the Arctic Sea Ice thread to talk about non sea ice specific stuff.

From the NSIDC... "Why extent remains so low in the Barents Sea is not immediately clear from patterns of atmospheric circulation and temperature. October air temperatures at the 925 hPa level were only 1 to 3 degrees Celsius (2 to 5 degrees Fahrenheit) above average, associated with a trough of low pressure at sea level extending from Iceland into the region. While further investigation is warranted, this lack of ice growth may relate to the observed “Atlantification” of the Barents Sea, in which the cold, low density surface layer of the Arctic Ocean has weakened, allowing the heat from the warm Atlantic waters to more readily inhibit ice formation. It will be instructive to monitor ice growth rates in this area through the coming winter."

I guess where I was going with my post was that if we are to accept that sea ice was broadly lower in the holocene when temperature were also likely lower than that supports or is at least consistent with future sea ice decline predictions. Afterall, if we can show that sea ice was lower with lower temperatures in the past then there's no reason to think sea ice can't be at least equally as low or even lower with higher temperatures today. In other words, that's not really a good line of evidence to present if the point is to challenge sea ice decline predictions. Also, there may be some confusion as to what AGW actually is. Modern climate science has built a consensus around the idea that there are a lot of physical processes in play that modulate the climate and that these process ebb and flow with respect to their individual radiative forcings. AGW is just the moniker given to how the accepted model plays out in regards to the state of the climate system today. It doesn't ignore any physical process that is modulated wholly by natural cycles. It's just that the natural modulation has been dwarfed by the anthroprogenic modulation mainly after WWII. Remember, the laws of physics don't really care if a CO2 molecule was emitted by man or by nature. It still gets it's molecular vibrational modes activated and send radiation back to the surface all the same. It's the same with any greenhouse gas species or aerosol particle. They behave the same and with the same magnitude regardless of how they entered the atmosphere. That's why modern climate science theory can be applied equally to both the past and the present. Don't get me wrong. I'm not under any illusion that the current model is perfect. It isn't and it never will be. That's par for the course in any scientific discipline. However, the current model does have demonstrable explanatory and predictive power. It works very well all things considered. And if you remove a component (say CO2) from consideration the usefulness of the accepted model is weakened. Afterall, ignoring CO2 or even assuming the climate sensitivity to it is lower than the accepted consensus just makes it more difficult to explain both past and present climate change. If you have a proposal for lessening the radiative forcing or sensitivity of CO2 then it needs to be replaced with something else. Can that something else explain the faint young Sun problem? Can it explain the cooling stratosphere simultaneous with a warming troposphere? Can it explain heat uptake by the geosphere (mostly hydrosphere) in the presence of flat to declining total solar irradation? Nevermind that we'd still need a good reason to replace CO2 in the first place. Those are just some of the questions that need to be answered convincingly if you want to me dispense with 120 years of research culminating in a mountain of evidence that supports the idea that CO2 really can have a significant influence in climate change today.