A new paper just published in the Geophysical Review Letters finds a significant correlation between the Atlantic Multidecadal Oscillation (AMO) and the water temperature of the Barents Sea.
This was made possible by a significant network of hydrographical stations in the Barents Sea which resulted in a 230,000 temperature profiles used in this analysis. The hint in the conclusion (which the authors stop short of defining) is that the pattern of data, seen below, might be linked to the recent pattern of Arctic sea ice melt and some partial recovery seen in the last two years. Their figure 2 below, certainly seems to suggest a strong correlation between water temperature in the Barents Sea and the AMO index.
The paper is:
Levitus, S., G. Matishov, D. Seidov, and I. Smolyar (2009), Barents Sea multidecadal variability, Geophys. Res. Lett., 36, L19604, doi:10.1029/2009GL039847.
We present area-averaged time series of temperature for the 100–150 m depth layer of the Barents Sea from 1900 through 2006. This record is dominated by multidecadal variability on the order of 4C which is correlated with the Atlantic Multidecadal Oscillation Index.
Introduction:
The thermohaline regime of the Arctic Ocean is determined by several key processes—the inflow of Atlantic Water (AW) through two gateways—the Fram Strait [Schauer et al., 2004; Walczowski and Piechura, 2006] and the Barents Sea (BS) [Furevik, 2001], air-sea interaction in the Arctic, river runoff [Peterson et al., 2002], and Pacific water inflow through the Bering Strait [Jones et al., 2008; Woodgate and Aagaard, 2005; Woodgate et al., 2006]. If the BS, as one of the gateways to the Arctic, is warming, there is a possibility that this warming may be amplified in the Siberian Arctic Seas due to reduced seasonal sea ice cover resulting from the ice-albedo feedback effect. Temperaturesalinity anomalies of the water comprising the boundary currents of the Arctic may propagate towards the interior of the Arctic as thermohaline intrusions [Carmack et al., 1997; McLaughlin et al., 2009]. Recent analyses emphasize strong interannual to decadal variability of the Arctic Ocean [e.g., Dmitrenko et al., 2008a, 2008b; Polyakov et al., 2008] that depend or may depend on the interplay of the above mentioned climatic elements. Alekseev et al. [2003] provide a detailed review of Arctic Ocean variability. [3] Observations and climate models suggest that certain teleconnections and feedbacks link interannual to decadal variability between the Arctic Ocean and other geographic regions. The most prominent feedbacks identified so far are the linkages between Arctic climate variability and the North Atlantic Oscillation (NAO)/Arctic Oscillation (AO). Both the NAO and AO are characterized by vacillations of the atmospheric pressure systems of mid-latitude highs and high-latitude lows, with the ocean-atmosphere interactions in the northern North Atlantic being the lead factor in the NAO [Visbeck et al., 2001]. There is evidence of links between the NAO and the circulation patterns of the Arctic Ocean characterized by multidecadal oscillations with periods of 10 to 40–60 years [Mysak, 2001]. A discussion of the robustness of correlations between the NAO and other effects with BS climate dynamics was given by Goosse and Holland [2005]. Using the Community Climate System Model, version 2 (CCSM-2), they found a persistent correlation between the thermal history of the model BS and the history of model AW inflow. Their model runs showed that variability in air-sea exchange and heat transport in the BS dominate in forcing Arctic surface air temperature variability suggesting an important role of the BS in Arctic climate dynamics. In addition to the recent multidecadal decrease in the extent of Arctic sea ice cover there has been a dramatic drop during 2007. This sudden decrease does not appear to be directly related to the NAO or AO [Zhang et al., 2008; Overland et al., 2008]. [4]
The BS is perhaps the only Arctic sea where presently available in situ observations are sufficient for unambiguous detection and analysis of long-term ocean climate variability. Because it remains ice-free almost throughout the year, the BS is covered by a well-developed observational network of standard sections [Matishov et al., 1998] (Figure 1a) accompanied by a large number of historical and recent ocean profiles that are not part of this network (Figure 1b) that are available in the World Ocean Database (WOD) [Boyer et al., 2006] (data available at www.nodc.noaa.gov). The BS serves as a transit zone between the upper layer warm water masses of the Atlantic Ocean and cold waters of the Eastern and inner Arctic. Therefore ocean conditions and long-term climatic trends in the BS may be indicative of the overall climate change in the Arctic Ocean, or at least in its eastern half. Our goal is to document the long-term thermohaline history of the BS that may be important for better understanding and prediction of possible changes in the Arctic Ocean.
Discussion:
Average BS temperature trends in the 100–150 layer agree with previous findings that the Arctic has warmed during the past 30 years. These trends align closely with spectacular surface air temperature increase over the entire Arctic and with the rapid sea ice retreat [Arguez et al., 2007]) since the end of the 1990s. Since the late 1970s the temperature of the 100–150 m layer of the BS increased by
approximately 4°C as part of multidecadal variability that is correlated with the AMO Index for the past 100 years. [10] However, despite good qualitative agreement between the BS oceanic climate trends and other climate tendencies in the Arctic, we must draw attention to some caveats inherent to our work. First, there is some uncertainty in ‘‘connecting the dots’’ between a warmer BS and reduced sea ice cover in the central Arctic—the presumed link between the two observables, which is yet to be explained. One of the plausible explanations would be to link AW throughflow in the BS to a lower rate of seasonal sea ice growth in winter in the BS [Wu et al., 2004] and further downstream of the throughflow. However, AW sinks and thus may not have that much impact downstream on ice cover. Recent results suggest that the advection of warming near-surface water from the North Pacific Ocean to the Arctic Ocean through the Bering Strait may play a significant role in Arctic sea-ice retreat [Woodgate et al., 2006]. Thermohaline intrusions of relatively warm water from the Arctic boundary currents into the Arctic interior [McLaughlin et al., 2009] may play a role. Aerosols may also play a role [Shindell, 2007]. [11] Prior to about 1970, there was generally above average sea ice cover, with the maximum extent observed in the late 1960s. Since the late 1970s sea ice extent has decreased substantially [Comiso et al., 2008], whereas, simultaneously, AW has become warmer and perhaps more abundant in the BS. The warmer air and the gradual decrease of albedo of thinning ice in summer would cause melting from above. Additionally, the sea ice decrease may be due to heating from below, when the water mixing channels heat stored in subsurface layers toward the sea ice base. More and warmer AW may contribute to shortening or complete elimination of seasonal sea ice presence in some part of central and eastern Arctic. It is still not clear whether, or how much, subsurface AW has directly contributed to the substantial ice melting that has been observed during last 20 years in the central Arctic; another plausible explanation for an AW role in this process may be the BS impact on the Arctic climate via ocean-air interaction [Goosse and Holland, 2005]. (See also the comment on possible role of Bering Straight inflow above.)
Leif Svalgaard was kind enough to alert me to this paper, and he has a copy available for viewing here (PDF)
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“If the BS, as one of the gateways to the Arctic, is warming, there is a possibility that this warming may be amplified in the Siberian Arctic Seas due to reduced seasonal sea ice cover resulting from the ice-albedo feedback effect.”
LOL! I’d say the BS has been warming up for a while now. Finally, a rational explanation for ice loss! This no doubt will cause the Arctic ice to completely disappear soon, because BS never stops.
REPLY: I knew this would happen with the abbreviations used, let’s leave these sort of jokes aside and focus on the information. – Anthony
Could someone please teach me about the difference between the temperature on the left ordinate T(deg C) and that on the right ordinate AMO index (also in degC)?
I have long (mistakenly?) thought that the range of seawater temperature change hardly exceeds 1 degC and generally within 0.5 degC even fora long period, as exemplified(?) by the 130-year NCDC data:
http://www.junkscience.com/MSU_Temps/NCDCabsOcean1880.html
Thanks in advance.
this is close to perfect correlation. this puzzle appears to be solved.
judging from their latet press releases, the NSIDC though still hasn’t arrived at the state of science yet. they should, if they don’t want to be regarded incompetent or useless or even worse.
My sincerest apologies, Anthony. I promise to behave.
Best Regards,
jdj
As long as the trees in Yamal don’t freeze to death, I’m happy…
It seems there was a global warming in the ’30s-’40s!!! Funny how people were more worried about fascism than AGW then. It seems that history is repeating itself. Could we almost see a correlation with the rise of socialism/fascism and temperature curves?
The Oceanics have won yet again.
The answer is staring us in the face.
First Place Prize goes to: The Oceans.
Second Third, and so-on….to be decided later.
CO2 comes in at 99th place. Congrats to C02 for getting across the finish line.
Chris
Norfolk, VA, USA
Why not try to correlate AMO index to Global mean temperatures?
Look at the graph! AMO seems like a perfect proxy for global temps…
Removing the AMO effect, there is not much space left for CO2.
Funny as there are still “scientists” believing in the aerosol cooling in 50-70ties, even ocean multidecadal cycles being the reason are known almost 10 years.
Arctic sea temperatures were higher in 40ties than in 2000s, so much to unprecedented warming.
Now that is just plain spooky – I was just reading this piece on Norwegian Cod as I refreshed the page on WUWT.
Perhaps some kind reader could help me out with this one. Wouldn’t Arctic Ice cover in Winter (and summer?) have the effect of keeping both the circulating Atlantic and Pacific waters ‘warm’ by setting up an insulating barrier? Retaining the more of the energy gained in the NH summer than would be the case if the Arctic was open water. Does the energy retention through Ice insulation outweigh the albedo effect overall? Is Arctic Ice a non-linear mechanism for retaining energy?
Przybylak (2000) and Polaykov et al. (2003) work showed the same correlations for the Arctic basin wide temperature and surface US temperature trends.
Polyakov, I., Walsh, D., Dmitrenko, I., Colony, R.L. and Timokhov, L.A. 2003. Arctic Ocean variability derived from historical observations. Geophysical Research Letters 30: 10.1029/2002GL016441.
Polyakov, I., Alekseev, G.V., Timokhov, L.A., Bhatt, U.S., Colony, R.L., Simmons, H.L., Walsh, D., Walsh, J.E. and Zakharov, V.F., 2004. Variability of the Intermediate Atlantic Water of the Arctic Ocean over the Last 100 Years. Journal of Climate 17: 4485-4497
Przybylak, R., 2000, Temporal And Spatial Variation Of Surface Air Temperature Over The Period Of Instrumental Observations In The Arctic, Intl Journal of Climatology, 20: 587–614
tokyoboy: You asked, “Could someone please teach me about the difference between the temperature on the left ordinate T(deg C) and that on the right ordinate AMO index (also in degC)?”
The difference between the two scales implies (to me, at least) that the depth-averaged temperature (not anomaly) of the Barents Sea amplifies the variations of the AMO, which is calculated by the reference (NOAA ESRL) as detrended SST anomalies of the North Atlantic.
Very interesting, thank you Anthony for posting this and Leif for giving access to the full article.
So AMO has a 60 year period and it looks like it is falling again to the negative territory while at the same time arctic ice is recovering? Is it really this simple, every 60 years there is a minimum in arctic sea ice extend and the last minimum was 2007?
It looks like AMO is another index to follow.
Jonas: You wrote, “Why not try to correlate AMO index to Global mean temperatures? Look at the graph! AMO seems like a perfect proxy for global temps…”
It’s widely accepted that the AMO plays a role in Global Temperature variations. Even RealClimate notes it:
http://www.realclimate.org/index.php/archives/2004/11/atlantic-multidecadal-oscillation-amo/
Thanks to Leif for hosting the full .pdf
Here’s the takehome bit for me, very interesting.
“A recent shift toward a warmer BS (Figure 3a) is dramatic and
may have important climatic consequences. A sharp increase
in temperature without an accompanying equally
sharp increase in salinity below the mixed surface layer
leads to a weakened seasonal pycnocline. A weaker pycnocline
means easier downward mixing of fresher but colder
surface water in winter and therefore a substantial release of
heat from sea to air.”
Hmm, warmer winters in the N.H. eh?
The AMO index (in degC) appears to be essentially the same as in the 2005 Sutton et al Science article:
http://www.sciencemag.org/cgi/content/full/309/5731/115
However, I still has not grasped what the “degC” for AMO index means, though it definitely may not be the real temperature.
Help me again please.
The left is the average sea temperature at a depth of 100m or so and the right hand side is complicated but basically a measure of the changing patterns of Sea Surface Temperatures (SST’s) in the North Atlantic over time. I’m sure somebody like Bob Tisdale has a more accurate description though.
I think the problem with your narrow band of sea temperatures is that it looks to be a monthly average derived from SST’s over 90S to 90N (the entire planet) and so doesn’t relate very well to the ‘local’ (and 3D) subject of the paper.
Looking at long standing stations in Iceland and Norway via GISS station selector there seems nothing “spectacular” about SAT in the current part of the cycle. Does anyone have an non PPV copy of the Arguez et al.,2007 paper?
I sure would be nice to have had Satellites and the Argo network available in 1930!
Manfred (22:47:47) “this is close to perfect correlation. this puzzle appears to be solved.”
It would be surprising if the correlation was not that good. [Let’s keep in mind the definition of the AMO.] The main point of the paper must be something else… (I’ll take a look when I have a minute…)
This brings us straight back to oceanic variability again as the primary climate driver.
I’ve refined my ideas a little more and this is the latest version in a relatively smplified form:
“I propose something slighty different and perhaps I can explain it this way:
1) The Earth system is not a single unit. If we ignore land as relatively insignificant we are left with oceans and air. I propose that both ocean and air process solar energy at different speeds and moreover they process it independently save that the oceans drive the whole system and the air has to adjust to what the oceans do.
2) Furthermore the processing of solar energy by both oceans and air is variable. That is the critical issue in creating a variable climate over time. If it were not so then climate would be very much more stable than it is with a virtually fixed latitudinal position for the air circulation systems and climate variation being limited only to a basic level of chaotic variability.
3) The oceans appear to vary substantially over several time scales as regards the rate at which they release energy to the air. The evidence for that is the ENSO cycle, the observed 30 year phase shifts and I suspect a further cycle of 500 years or so.
4) The evidence that those variations go beyond a basic level of chaotic variability is those cyclical latitudinal shifts in the air circulation systems which always follow changes in SSTs on at least the 3 time scales we have evidence for.
5) It is important that changes in air temperatures do not seem to be able to either heat up the oceans or significantly affect the variable rates of energy release from the oceans. The evaporative process combined with the penetrative weakness of infra red longwave seems to be a big enough obstacle to such a process such that I can find no suggestion anywhere other than at Realclimate that the air can ever warm the ocean on any significant time scale.
6) That is important because if the air cannot warm the oceans then the composition of the air cannot change the equilibrium temperature set by sun and oceans. In turn the ocean surfaces prevent the air from warming because water always dictates the temperature of the air above.
7) That means that something else has to happen to the extra energy in the air instead. If it cannot warm the oceans and yet the radiative balance between solar energy in and radiative energy out has to be maintained then all that is left is for it to be ejected faster to space in order to maintain the radiative balance and if that happens then no change in the equilibrium temperature of the Earth can occur.
8) So what we have here is a system that receives a certain amount of energy from the sun and radiates the same amount out to space. No significant imbalance occurs despite large changes in the rate of energy release by the oceans and significant changes in the speed of the hydrological cycle via changes in the air circulation systems.
9) The only logical solution is that the variation in energy flow from the oceans is countered by an equal and opposite variation in energy flow through the air. Since the air cannot warm the oceans any extra energy in the air from any cause has to be dealt with by the same process. Warmer ocean surfaces cause increased evaporation and once the energy in the extra water vapour is in the air from that cause then the change in the speed of the hydro cycle deals with it routinely. It would do the same for increased evaporation caused by extra CO2 but on a far far smaller scale.
There is much observational evidence to confirm what I say. Ongoing climate events in the real world must serve as my proof because there is no conceivable laboratory experiment that could replicate the entire system.
Models could do it but first they must incorporate the full scale of variability of oceanic energy release with an accurate response by the air and a full scale representation of the behaviour of the air at the air/space boundary as well. At present they are limited to guesses about ENSO but have nothing adequate about any other oceanic cycles and nothing about air circulation shifts apart from seasonal changes and a simple observation that warming moves them poleward.
They must also model the air circulation systems correctly as regulators of energy transmission at both the sea/air interface and the air/space interface. The air/space interface is currently governed by fixed equations which take no account of observations that the air circulations have a substantial energy flow regulating effect even at the thinnest upper levels
In view of what Leif Svalgaard says about the smallness of solar variations I’m coming round to the opinion that virtually all climate change that we observe is simply internal variability induced by the oceans and countered in the air all occurring around a relatively stable equilibrium set by sun and oceans.
I don’t see any reason why the variations from the peak of the Mediaeval Warm Period to the bottom of the Little Ice Age and all lesser variations could not be accommodated within the term ‘relatively stable’ in terms of the planet even if not in terms of human sensibilities.
All one has to do is insert that third level of ocean cycling at 500 year intervals along wih the ENSO and PDO irregularities and that covers everything ever observed during the current interglacial.
The validity of the suggestion of that third 500 year level of oceanic variability is provided by the observation that during the LIA the ITCZ was at the equator.
As far as I can tell the latitudinal shift in air circulaton systems is the tell tale sign of a change in the rate of oceanic energy emission. It is the ‘fingerprint’ of an ocean cycle.
That would seem to square the circle and remove any need for external forcing, even solar.
All that is then left is to investigate whether I am right about the powerlessness of changes in the air alone to alter an equilibrium set by sun and oceans.
Hence my focus on the IR downwelling versus increased evaporation issue.
Models can be made to work with equations if they are tortured to produce the required result ex post facto.
The main omissions in current climatology are to ignore the oceanic role in setting and maintaining AND CHANGING the Earth’s temperature and failing to recognise that the speed of the hydro cycle changes in response to those oceanic forcings.In 1988 when this all started no one acknowledged the significance of ENSO events globally or the existence of 30 year phase shifts let alone a 500 year ocean cycle. Believing that the composition of the air sets the equilibrium temperature is reasonable only until one realises that the rate of energy release from the oceans is not stable.
Unstable oceans introduce variablity at the sea/air interface which alters the air circulation. Changes in the air circulation introduce variability at the air/space interface which help to prevent the destabilisation that would otherwise be caused by that oceanic variability. None of this is recognised by the models.
Once one does fit those phenomena into the system it all falls into place without abusing any accepted physical laws or principles and all observed climate phenomena can be seen as inevitable by-products of internal variability.”
hy anthony,
have a look at this graph:
http://i37.tinypic.com/24wvyth.png
it shows the t trend in the alpine region (only one station here shown today) for 100a. the hole warming of almost 2,0°C can be explained by changes in circulation types. ironicly the PIK (Rahmstorf & Co) have datasets of cirulation types for each day beginning in 1880 (ed. southwest=warmingaverage 3,21°C, northeast=coolingaverage -2,45°C, there are 30 different circulation forms definated). we bild an average for every day and can show, that there is a significant trend in more warming circulation forms and less cool types. the graph shows in black the messured temp. (year average) and in red the warming caused by circulation trends. we now go on to do this with 100 station in middel europe and our first results show, that we do not need any radiation forcing to explain the hole warming in the 20th. century.
when we finish the paper, we will tell you. are you interested in?
(sorry about my english, i´m from austria and not realy used to write in your language…)
Stephen Wilde: You wrote, “The evidence for that is the ENSO cycle, the observed 30 year phase shifts and I suspect a further cycle of 500 years or so.”
Refering to the Mann reconstruction from Jones et al (2001), the time span of the low frequency changes in NINO3 SST anomalies varies from 21 to 39 years.
Refer to:
http://bobtisdale.blogspot.com/2009/03/low-frequency-enso-oscillations.html
Do you have a reconstruction on which you’re basing your 500-year cycle?
My late Father in Law was”volunteered” to help deliver a load of Sherman tanks to
Murmansk.- 1944 in January.He commented on the ice free nature of the Barents
Sea.So it may have been a warmish period.Later that year he had the pleasure of
getting a little tour of Europe, courtesy of General Patton….
It wasn’t warm then…
Stephen Wilde (03:31:57) :
This brings us straight back to oceanic variability again as the primary climate driver.
Driver does not seem to be the best definition here. The perfect oscillator would be more fitting.
Sun big. Earth small.
This debate reminds me of a more heated form of cosmology.
Only cosmology is in search of the components to arrive at it’s answer. Climatology seeks to jettison as many components as possible.
Re: savethesharks (23:30:05) :
Unfortunately CO2 has been disqualified due to too many false starts.
rbateman (04:39:36) : This brings us straight back to oceanic variability again as the primary climate driver.
Driver does not seem to be the best definition here. The perfect oscillator would be more fitting. Sun big. Earth small.
Sure. Even a perfectly constant (big) sun can initiate and sustain many oscillations her on (small) earth. This is for example equivalent to the reaction–diffusion systems that display a wide range of oscillatory behaviors, including the formation of traveling waves and wave-like phenomena as well as other self-organized patterns like stripes, hexagons or more intricate structure like dissipative solitons.
http://en.wikipedia.org/wiki/Reaction–diffusion_system
Possibly the nonlinear oscillations here on earth may be present on many time scales, from days, to years and centuries.