AcuuWeather meteorologist Joe Bastardi has a question about two datasets and asks: If it is darn warm, how come there is so much sea ice?
Bastardi asks a simple question: how can we have above normal temperatures in the Arctic and the Antarctic and continue to add to the global sea ice trend? After all we’ve been told by media stories that both the Arctic and the Antarctic continue to melt at a frenetic pace. But it looks like this year we’ll see another Arctic recovery as we’ve seen in 2008 and 2009.
Bastardi also wonders about something we routinely ask about here at WUWT: data adjustments. GISS seems to be stuck with Arctic positive anomaly, yet the sea ice isn’t cooperating. Of course just having a positive temperature anomaly doesn’t guarantee melt, but members of the public who are less discerning, who look at red hot color presentations like GISS puts out, usually can’t tell the difference.
For reference here are the images Joe uses in his presentation. I’m going to help out a bit too with some simple comparisons.
First The GISS Dec-Feb 2010 Global Surface Anomaly as Joe presents it in his video:
Note that in the warmest places in the Arctic according to GISS, there are few if any land thermometers:
Above: map of GHCN2 land stations (thanks to commenter Carrick at Lucia’s)
Note the cross section of the GISS data, most of the warmth is at the Arctic where there are no thermometers. The Antarctic comes in a close second, though it has a few thermometers at bases on the perimeter of the continent plus a couple at and near the center. Note the flat plateaus are each pole.
The effects of interpolation become clearer when you do a 250 km map instead of 1200 km:
All of the sudden, the hot Arctic disappears. It disappears because there are no thermometers there as demonstrated by the cross section image which stops at about 80N.
Interestingly, the global surface anomaly also drops, from 0.80°C at 1200km of interpolation to 0.77°C with an interpolation of 250km.
One of the things that I and many other people criticize GISS for is the use of the 1951-1980 base period which they adopted as their “standard” base period. That period encompasses a lot of cool years, so anomalies plotted against that base period will tend to look warmer.
This famous GISS graph of surface temperatures from weather stations, shown worldwide in media outlets, is based on the 1951-1980 period:
Uncertainty bars (95% confidence limits) are shown for both the annual and five-year means, account only for incomplete spatial sampling of data.”]
GISS doesn’t provide a utility to replot the graph above with a different base period on their webpage here http://data.giss.nasa.gov/gistemp/graphs/ but I can demonstrate what would happen to the GISS global maps using a different base period by using their plot selector here http://data.giss.nasa.gov/gistemp/maps/
Watch what happens when we use the same base period as the UAH satellite data, which is 1979-2009. The 1200km interpolated global temperature anomaly for Dec-Jan-Feb 2010 drops more than half to 0.38°C from 0.80°C. That number is not so alarming now is it? As for the graphic, the flaming red is still there in the same places because the anomaly map colors always stay the same, no matter what the absolute temperature scale is. In the first map with the 1951-1980 base period, the max positive anomaly was 6.4°C for 1200km and 8.8°C for 250km, while in the one below with the 1979-2009 base period the max positive anomaly of 7.1C If colors were assigned to absolute temperatures, this map would look cooler than it’s counterpart with the 1951-1980 base period.
And here’s the 250km presentation, note that the global surface temp drops to 0.34°C
So it is clear, with the GISS anomaly presentation, you can look at it many different ways, and get many different answers. Who decides then which maps and graphs with what base periods and interpolations get sent out in press releases? Jim? Gavin?, Reto? Consensus over coffee at Monks?
The answer as to what base period GISS chooses in temperature anomaly maps to present to the public is easily answered by looking at their main page here: http://data.giss.nasa.gov/gistemp/
Here’s a thumbnail of the page, and the full size version of the second graph from the top, note the caption on the top of the graph:
Clearly, they prefer the base period of 1951-1980 as the default base period for the public presentation [as well as 1200 km smoothing] and by choosing that, the GISS results look a lot more alarming than they might be if a different base period was used, such as the 1979-2009 period used by UAH and RSS.
Anomalies can show anything you want based of choosing the base period. For example, a simple thought experiment. I could choose a base period from 11,000 years ago, during the last ice age, and plot maps and graphs of today’s temperatures against that base period. Would we see red? You betcha.
Here’s a graph that shows reconstructed northern hemisphere temps at the end of the last ice age 11k years ago, they were about 4.5°C cooler than today. Granted it’s not a global temp, but close enough for government work.
So if I used a 30 year slice of temperature 11,000 years before the present as a baseline period, our GISTEMP map would look something like this:
Obviously the map above is not an accurate representation, just a visual guesstimate. The more excitable who frequent here will likely cry foul at my abuse of the image. But it does illustrate how choices of colors and baseline periods can have a distinct effect on the final visual. Using a cold baseline period in the past (in this case 4.5°C globally cooler than the present) makes the present look broiling hot.
Anomalies are all about the starting choices made by people. Nature doesn’t give a hoot about anomalies. Generally, people don’t either. Imagine if your local TV weather forecaster gave tomorrow’s forecast in anomalies rather than absolute temperatures. He might say something like:
It’s going to be a hot one folks! Tomorrow we’ll have a high temperature that is 0.8C warmer than the 1951-1980 historical baseline for this city. Dress accordingly.
Useful isn’t it? Even more useful if he’s the weatherman in Svalbaard and people anticipating a heat wave go out in shorts and tank tops in mid February.
While anomalies are fine for illustrating many things, including temperature, bear in mind it’s all about the starting conditions chosen by the individuals doing the analysis. It’s all about choosing a baseline “normal”, which is subjective.
So when Joe Bastardi looks at the GISS map of the world, sees red, and wonders why we have a growing ice presence, the answer is in the choice of baseline and the choice of colors used to calculate and represent the anomaly.
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Phil. (08:52:06) :,
Joe is standing at the top of the hill looking down. You’re still standing at the bottom of the hill looking up. Come on up, the air is fine. 😉
Maybe somebody pointed this out, but folks at NASA ought to know that you cannot accurately represent data on the sphere with a Mercator style flat projection. In astrophysics, the Aitoff Equal Area Projection is used. This distorts the surface of the sphere on to a roughtly ellipsoidal plane — but it maintains equal areas in the distortion and the human eye responds to the area strongly when forming a perception of planar density. And please stop interpolating — interpolation does not create data.
Anu (08:35:24) :
Arctic ice is still way below the 1979 to 2000 average extent:
http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png
But small respites from the frenetic pace of melting is welcome.
———–
REPLY: Dear Anu, please take a deep, relaxing breath and try to relax.
Reviewing the link you provided (which I also post regularly), we see that the trend of Arctic sea ice extent is approaching levels where it is statistically indistinguishable from the years prior to 2007, when Arctic winds moved much of the ice out of the basin (per Anthony’s post a few days ago).
Arctic ice is recovering nicely, and as discussed above, the severe lack of measurement accuracy in the Arctic throws your argument about the “frenetic pace of melting” in doubt.
Hypothetically speaking, the temps at those hotspots could be -30 but if baseline was -33, they would still be shown in red?
The answer is the anomaly is a difference between measurements and an arbitrary baseline. The amount of the anomaly depends upon what baseline is used and how the temperature is measured and/or estimated. It could be well below the freezing point of seawater and still be recorded as an anomaly.
The colors chosen make it appear the Arctic is feverish, while most of us would consider it still damn cold.
Climate is more than temperature. How is the cloud cover? Amount of sunlight? Precipitation? The temperature anomaly map tells us none of these things.
Joe Bastardi (08:49:25) :
Yes, something is terribly amiss with GISS.
Nothing is quite as bad as GISS. I can use some CRU station data, but GISS is a basket case.
Joe, Joe, just got the answer to your dilemma from some of the AGW proponents themselves in so many words: “Mother Nature just doesn’t know what the @ur momisugly$#% she is doing, NASA does!”
Welcome to OZ, Joe! ;-()
Richard M said (to RR Kampken):
“Are you really claiming that we won’t see a huge increase in “older” ice this summer?”
____
Don’t know what he was saying, but you should define what you mean by “huge” and also, it can only increase to a point in the summer…before it melts…but as a percentage of the total ice, no doubt the older multi-year ice will make a come back this summer, and relative to the very low levels of older ice we saw the past few years, the increase will be “huge”, but relative to the historic levels of multi-year ice, going back more than just a few years, the amount will still be less…and a warm summer in the arctic will melt a lot of it, regardless.
Hmmm….
For one thing you have completely sidetracked the truth that in his video Bastari clearly does not undertand that the graphic he is working with is of temperature anomalies. He states sarcastically at the end that ” water must now be freezing at 34 degrees ” He clearly thinks the graphic shows absolute warmth. That a professional “long-range forcaster” is not intimately familiar with the nature of a graphic that NASA puts out monthly shows what a clown he truly is.
To your point that choosing the baseline period will effect the size and (positive/negative) sign of the anomoly compared to it…. well… DUH.
So? Since the current decade from 1999 to 2009 is the warmest decade in the modern record it would seem that most months in that decade and future months are going to appear warmer… its just a matter of how warm. Its true that if we were to choose 1979-2009 as our baseline, current graphics would appear “less red”. You seem to be insinuating that the choice of the base years of 1951-1980 is a choice made in order to make these graphics look “more warm”… but you don’t really provide any evidence for that other than the fact you don’t like the choice because that period showed some slight cooling the record. I don’t really know the history in the choice but I suspect that since global warming science really expanded in the 80’s, its a historical artifact of these anomaly graphics that has been retained since that period. The fact that people like yourself want to refer to 1979-2009 instead actually demonstrates that you would like to hide or diminish the effect of these anomaly graphics by refering to a warmer period… that you find the truth that there is very significant warming since 1959-80 really inconvenient… and want to hide that truth….to the extent that you can.
The fact remains that the globe is warming and that the vast majority of climate scientists maintain that it will continue to warm as long as we alter the greenhouse gas composition of our atmosphere.
“how can we have above normal temperatures in the Arctic and the Antarctic and continue to add to the global sea ice trend?”
It’s possible if you live in the land behind the looking glass. Anything’s possible, if you just report on it, it makes it true, and if you put it in an IPCC Assessment Report, it gains the truth content of tautology.
Thnks for this copious post. However, without being sarcastic, I’ve made my own research as to the connection between increased energy and electricity consumption, average temperatures and the occurence of ice: since the 1950s not only has energy consumption and hence, due to it being mostly fossile fuel, CO2 emission increased. AT THE SAME TIME ice has multiplied in living rooms and kitchens. It got so bad that the average US refrigerator now comes with an ice crusher built in. So, don’t fret, it’s perfectly normal that ice occurences and sightings increase with warming.
Don’t see the problem – just look at the daily-updated JAXA Arctic sea ice graph in the right-hand column – 2010 is EXACTLY in the middle of the 2002-2009 spread.
Do the Japanese do one for the Antarctic, too..?
John F. Hultquist (23:15:31) :
(…) Next year should see the use of this new period as the normal. They have made it high, now we will see what they can do to keep their anomalies above average.
You wouldn’t be the first to consider that little problem. Don’t worry though, I’m fairly sure a plausible set of “corrections” to the offending data will be found. (especially if we have entered a cooling period)
Those suggesting that base lines don’t matter
Take a look at this station. Does it matter (for this station alone) what period we choose for our base? Using ’30-’60 means that we have had 6/7 decades of “blue” anomalies and ’60-’90 means we have been warming alarmingly for the last thirty years.
Let’s play “trends”. To a scientist in 1970 looking at the “trend” where will we be in 1990? To a scientist in 1990 (or 1910) where will we be in 2010?
Note: (to the criminally contrary) Reykjavik is not offered as proof or otherwise of “global warming”. But is Reykjavik “warmer” or “colder”?
D’OH.
That color bar is NOT on a linear scale. Talk about misleading!
R. Gates (07:13:33),
A classic example of psychological projection:
The basic alarmist conjecture is that a rise in CO2 will cause runaway global warming and climate catastrophe [CO2=CAGW]. That must be the conjecture, because if, as the planet is showing us, CO2 does not cause temperature to rise measurably, then there is no crisis, and the CAGW conjecture can be disregarded as falsified.
To debunk Gates’ accusation that scientific skeptics take ‘the smallest bit of data’ and make it fit our ‘preconception,’ I will provide a wealth of contrary data below. If Mr Gates would like more data showing that the current climate is entirely explained by natural variability without adding the extraneous entity of CO2, I have it available for the asking.
Since Mr Gates is fixated as usual on the Arctic, let’s begin by looking at Arctic temperatures back to 1958: click. Notice that temperatures this year, last year, and for the last several decades look amazingly similar for this time of year [click on the years to compare].
What we are seeing at the poles is simply natural climate variability. Increases in temperature caused by carbon dioxide are so insignificant that they are too small to be measured, despite a one-third increase in carbon dioxide [almost all of which is not due to human activity, but rather, to the planet’s natural emergence from the LIA]. Note that as CO2 increases at the South Pole, the temperature is decreasing: click1, click2, click3, click4
Further, there is no correlation between rises in CO2 and subsequent rises in temperature: click1, click2, click3
Gates pounces on a few years of natural fluctuation like a chicken on a junebug, hoping to convince us that entirely natural climate variability is instead proof of approaching runaway global warming due to CO2. But let’s look at some longer timelines before accepting that cherry-picked assumption: click1, click2, click3, click4, click5
As we see, the current climate is benign, and well within the parameters of natural variability. Nothing unusual is happening.
The climate has been in a very long term gradual cooling trend, interrupted by episodes of temporary warming. On shorter time scales, the media regularly panics impressionable folks like Gates whenever the climate flips from a warming to cooling phase, or vice versa: click
Over the past several decades the North Pole has been ice free at times. But it is currently frozen over. How is that possible, since CO2 is rising?
The answer, of course, is that sea ice is primarily a function of winds and currents, not CO2 or temperature. A fraction of a degree rise in global temperature over the past century is not sufficient to melt the polar ice caps, which are far below freezing. The cause of the natural fluctuations is changes in winds, currents and precipitation.
CAGW was never a theory. It is actually a conjecture. To even rise to the status of a hypothesis, those promoting it must “open the books” on the raw data, code and methods they used to construct their hypothesis. But they refuse.
Since they hide these essentials, the reasonable conclusion is that they must know that their conjecture would become a falsified hypothesis. They seem to think it is better to be seen as being devious, rather than to be publicly falsified after the $billions they have taken to promote their CO2 scare. They have put themselves in a tough position, and no one but the gullible and credulous trusts them any more.
Smokey,
I misssed Gates post. I thought he summed up pretty well the problems with AGW. I did not realize Gates was trying to defend AGW by projecting AGW community practice on to skeptics.
Fascinating.
Your essay is excellent, by the way.
R. Gates (10:56:38) :
Richard M said (to RR Kampken):
“Are you really claiming that we won’t see a huge increase in “older” ice this summer?”
____
Don’t know what he was saying, but you should define what you mean by “huge” and also, it can only increase to a point in the summer…before it melts…but as a percentage of the total ice, no doubt the older multi-year ice will make a come back this summer, and relative to the very low levels of older ice we saw the past few years, the increase will be “huge”, but relative to the historic levels of multi-year ice, going back more than just a few years, the amount will still be less…and a warm summer in the arctic will melt a lot of it, regardless.
RR kampen was claiming a continued reduction in older ice simply because it had been declining. Obviously, looking closely at the data gives a different view. It appears we are mostly in agreement … except for your last sentence.
You need to look at typical Arctic summer temperatures. There is very little variance year to year. It will have little effect on the ice. Also, check out the concentration of the ice compared to 2007. You will see much more of it is around 100% ice. This will melt slower and we may be seeing a developing La Nina by that time. Not only that but ocean temperatures are probably more important than air temperatures. Of course, the winds will probably be the biggest factor, but all-in-all it’s looking good for another increase in ice extent this year.
Anthony,
Odd that you mention the 1901-2000 baseline, since it gives results that are functionally identical to the 1951-1980 baseline: http://i81.photobucket.com/albums/j237/hausfath/Picture210.png
For the anomaly maps, I agree that it matters somewhat to the pattern of anomalies shown (since there could be regional differences in certain baselines and not others). My point was that the distribution of blue vs. red depends both on the scale chosen for red/blue as well as the baseline. The difference between the 1951-1980 and 1979-1998 anomaly maps in the original post isn’t really that noticeable, and changing the range of numbers associated with specific colors has a larger visual impact than changing the colors (e.g. make dark red start at 8 C instead of 4 C and it will look a lot cooler).
I guess my real question is: does any particular baseline pose a compelling case for use? E.g. is there any reason why 1961-1990 is particularly better than 1951-1980? If you accept the argument that anthropogenic forcing first start clearly dominating natural variability post-1975, it makes sense to have a baseline prior to the modern warming period. Or pick 1901-2000 if you want since it covers the whole century, but you will end up with annual anomalies that are almost identical to 1951-1980 (since the 1901-2000 mean is close to the 1951-1980 mean).
“Can anyone help me with this analysis:
http://tamino.wordpress.com/2010/02/25/false-claims-proven-false/”
From a quick once over :
He doesn’t link to the data sets used
He doesn’t disclose the methodology used to calculate his overall mean
There are no confidence limits or error bounds
There is no dicussion of variability
There is no discussion of data quality
There is no discussion of how missing data is processed in the overall mean calculation
There is no critique about assumptions, shortcomings and possible improvements in the analysis.
Sloppy, might be amusing if submitted in crayon by a kindergarten student…
Mr Goddard, Mr Watts, did I miss anything…?
To answer Bastardi’s question, anomalies 6.4 C above normal for February are still well below freezing in the arctic, so we wouldn’t expect it to have a huge impact on winter sea ice extent one way or another. Winter sea ice extents are probably more influenced by the magnitude of the prior summer melt than the temperatures during the depths of the current winter, as long as they do not exceed freezing.
Anomalies 6.4 C above normal for August would a much larger impact on sea ice extent.
>>>Ric Werme (06:30:06) :
>>>IT’S NOT A MERCATOR PROJECTION!!!!!
I get your point, but even if it is only a lat-long plot, it is still stretching the poles from an incy-wincy spot to a whacking great area the same as the equator.
The red spots at the poles still end up much bigger than they should be.
.
Although this post focuses on the polar extremes, it’s also interesting to note the lack of temperature readings in Africa/Middle East – the only other “red” section on the map. Is it just me, or does that red zone seem to almost “follow” the areas of low measurement sites? It’d be interesting to look at the raw data from some of the few sites in that area, because I’m guessing they get a lot of “weight” in the analysis being isolated, and even just one or two stations having unwarranted warming “adjustments” might lead to a dramatically different looking graph.
What’s also interesting is that Russia (with a strong cooling trend) has a fairly sparse data set, but its coverage is still nearly adequate/complete (see the 250 km plot).
Also, does this data suffer from the Antarctica “cherry picking” problem that was reported on WUWT a few months ago?
-Scott
Very interesting and educational .Thanks Joe Bastardi. We get nothing like this from the UK Met Office all we get is manmade global warming telling us we are going to have to prepare for climate change, the climate in the uk has changed very little over the last 100 years why would it change in the next 50 years.
Anu, you can’t be proposing that a comparison of ice thickness between 2004 and 2008 makes for climate warming?!?!?!? Okay. If you want to call weather pattern variation “climate”, fine. I think you are wrong but you have a right to your opinion. But that means you cannot complain when someone says that it has been cooling for 4 years and then tell them their observation cannot be correlated to climate change.
There is also a lot of cartographical tomfoolery with the projections these scientists use. Cylandrical projections are typical really poor for showing distribution areas (this looks like a Gall projection, close cousin of Mercator), a great global distribution projection is Goodes which would much more honest for presenting this data. Or at least a Robinson which almost halves the area distortion at the poles. http://en.wikipedia.org/wiki/Robinson_projection