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.
Dirk (04:41:55) :
Can anyone help me with this analysis:
I suggest that you go over to Chiefio’s Site http://chiefio.wordpress.com/ and read through his Temperature analysis. He not supplies the graphs but all the data as well so that you can do your own analysis.
This strikes at the heart of AGW: Are anomalies useful?
Increasingly, it seems making large claims based on small anomalies results in claims that are not meaningful.
I’m having a hard time making sense of the “interpolation” on the Dec-Jan-Feb 2010 anomaly vs 1951-1980.
Looking at Canada, it looks like central, northern, and western Canada should be in the red (2-4 deg) range at the highest in the 1200km map based on the 250km map. Instead, it’s almost all in the 4-6 deg range.
There are also grids in western Canada and Alaksa which show as 1-2 deg anomalies (or lower) in the 250km map that get over-ridden as 2-4 deg in the 1200km map. Any algorithmic processing that brings that about would seem to be nonsense.
Another problem that has been discussed elsewhere is that the maps presented always choose a projection with severe distortion of area at the poles. Those maps are going to look scary because large areas of a rectangular projection are red, however due to the earth in reality being a sphere, the areas represented are going to be much smaller. The entire top and bottom coordinate rows could probably be represented by a single square, and yet in this highly-distorted rectangular projection, that single square becomes an entire row of red temperatures. It’s dishonest to present the world temperature anomaly to the public in this manner, particularly with 3D representation of the earth so easy to show people now.
I think the main problem I have with the GISS mapping is the representation of the poles as huge. I think it should be appropriately sized and scaled instead of making the arctic look like it is 4 times the size of North America.
Anthony,
It really doesn’t matter if the current anomaly is 0.8, 0.32, or -999999.32, since we are concerned with the trend. The standard GISS temp graph looks identical rebaselined to any baseline; all that changes are the units on the y-axis. Here is GISSTemp relative to 1979-1998 if you are interested: http://i81.photobucket.com/albums/j237/hausfath/Picture208.png
Wrt the global anomaly maps, the scale chosen is a lot more relevant to the resulting image than the baseline. The main reason why GISS uses a 1951-1980 baseline is because they produced their first temp series prior to 1990, and thus couldn’t use a 1961-1990 one. They decided changing the baseline to correspond with that used by HadCRUT would be more confusing since all their prior publications use 1951-1980, and the choice of the baseline is completely irrelevent to the trend (and which years are the warmest/coolest, etc.).
Mia culpa, selected the wrong column in excel, that one was 1951-1980. Here is 1979-1998: http://i81.photobucket.com/albums/j237/hausfath/Picture209.png
They are identical save for the y-axis units, which is the point.
REPLY: Bastardi didn’t focus on trends and neither did I, the issue has to do with the graphic presentation, which I think is visually flawed.
On the issue of why GISS can’t move their baseline forward, I understand where you are coming from, but the fact is that it still affects the outcome of the final public presentation which gets splashed all over the world media. So it is not irrelevant. I think GISS could do a better job and I think the excuse of “we did it before 1990” is a lame excuse, especially since NCDC provides anomaly plots with a baseline of 1901-2000, for example. They have data that goes back prior to 1900 and they are able to present it without cherry picking a 30 year period because “that’s what we started with”.
If GISS really wants to produce an accurate representation to the public, they’ll provide a more balanced visual presentation.
WRT the anomaly graph, does the magnitude of the anomaly (not the whole offset) not depend on the baseline period used to create the anomaly points? So for example, wouldn’t the more recent points be lower if created using a 1979-2009 baseline. The map demonstration I provided certainly seems to indicate it would by the change of the global anomaly value in the upper right. Your correct plot shows a drop in magnitude also. GISS should provide a tool for the public.
I agree the trend is unchanged, but my point (and Joe’s) is about the monthly scare stories that come from the magnitude. and the color presentations of the anomalies. – Anthony
Re: HumanityRules (Mar 23 22:46),
” This seems very weak.
You can complain about colour schemes and so forth but it’s trends that matter and I think you know that”
There is a very nice trend going on in Alaska. Every community in Alaska with at least 1,000 residents now has a paved Class I commercial airport.
Last I checked with the FAA the runway at Point Barrow is currently undergoing expansion.
The good old days of taking off and landing on a grass/gravel/ice airstrip in some broken down propeller plane in Alaska are slowly giving way to nice 6500 foot long commercial runways and traveling in the comfort and convenience of a Boeing 737.
Off topic:
See another conflict of interest.
cheers
What a treasure trove of information in Joe’s video archive….
http://www.accuweather.com/video/68856143001/global-warmth-getting-ready-to-collapse.asp?channel=vblog_bastardi
Freedman at the Washington Post has ironically come out with an article today touting these very figures.
http://voices.washingtonpost.com/capitalweathergang/2010/03/nasa_projects_2010_will_likely.html#more
I regularly monitor the temp gauges that surround the Arctic Ice. During Winter, it is cold enough to freeze water, plants, and unprotected organic life forms, with room to spare. In the Summer it is warm enough to melt, rather slowly, but melt nonetheless, the aforesaid ice, flora and fauna, with not a lot of room to spare. I’ve been watching this for 5 years and it is the same every year. As far as the temps on the ice flow (it is not a cap, it is an ice flow), it’s temperature can rather easily be mathematically calculated from the amount of axial tilt to the Sun’s infrared known parameters and bracketed by the land temps and micro-climate zones that surround the flow. A degree here or there is well within the “pad” that describes the range. Won’t make much difference.
I have also been monitoring the surface wind. Now that is quite another story. That is until the damned temperature freezes the wind gauge in place, or the wind itself blows the thing onto its side.
Me thinks Hansen needs something more exciting to do, Watching ice freeze and melt can addle the mind.
The reason Dr. Hansen uses the baseline period of 1951 to 1980 is that he started analyzing temperature anomalies in 1981 – hardly a good year to consider a baseline of 1979 to 2009.
———-
Science 28 August 1981:
Vol. 213. no. 4511, pp. 957 – 966
Climate Impact of Increasing Atmospheric Carbon Dioxide
J. Hansen , D. Johnson , A. Lacis , S. Lebedeff , P. Lee , D. Rind , and G. Russell
Atmospheric physicists at the NASA Institute for Space Studies, Goddard Space Flight Center, New York 10025
The global temperature rose by 0.2°C between the middle 1960’s and 1980, yielding a warming of 0.4°C in the past century. This temperature increase is consistent with the calculated greenhouse effect due to measured increases of atmospheric carbon dioxide. Variations of volcanic aerosols and possibly solar luminosity appear to be primary causes of observed fluctuations about the mean trend of increasing temperature. It is shown that the anthropogenic carbon dioxide warming should emerge from the noise level of natural climate variability by the end of the century, and there is a high probability of warming in the 1980’s. Potential effects on climate in the 21st century include the creation of drought-prone regions in North America and central Asia as part of a shifting of climatic zones, erosion of the West Antarctic ice sheet with a consequent worldwide rise in sea level, and opening of the fabled Northwest Passage.
http://www.sciencemag.org/cgi/content/abstract/213/4511/957
The color schemes, grid size, baselines (and map projection with no control points) are chosen to be emotive. They damn well know what they’re doing. They’re adults – stumping for a cause, shaping displays for a desired outcome. Its really shameful.
AND – the rest of the Climate ‘Science’ Community (save a few brave souls) have silently sat by and allowed this persist unchallenged. Judith – this is no evil oil company conspiracy – its the US Government, and you all are complicit in this in my view. Talk about monied interests. Sheesh. Where are the honest scientists?
Great post Anthony.
I would love to see a chart of the number of days above 32 degrees vs latitude to further expose the assertion that atmosphere composition and temperature control everything in the Arctic. I believe that ice still melts at 0 degrees (STP)?
There are two issues I want to make refference to in my comment, as there was one of the quotes in this article that drew my attention: “Anomalies are all about the starting choices made by people. Nature doesn’t give a hoot about anomalies.” So, first of all, I agree that we are definitely on the wrong track regarding mankind, due to the climate changes which can’t be denied anymore, they are a fact, they are affecting everyone of us, our future on this planet. However, while reading on this matter, I actually found out that, according to many scientists, these “anomalies” that we’re currently experimenting are in fact the normal state of the planet, and the true “anomaly” was the period of warm, steady, somewhat peacefull climate.
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.
——————–
http://nsidc.org/images/arcticseaicenews/20100303_Figure3.png
Ice extent is “recovering” only in relation to the lowest data points. And this doesn’t take into account the thinning of the Arctic Ice, as measured by ICESat:
http://www.sciencedaily.com/releases/2009/07/090708103212.htm
And soon, Cryosat:
http://news.bbc.co.uk/2/hi/science/nature/8568285.stm
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.
The other source of exaggeration in polar temperatures on the GISS maps is the chosen map projection, which grossly overstates the polar area, so adds a lot more red. I wrote a post showing this years ago:
http://www.climate-skeptic.com/2008/02/more-on-chartsm.html
The funny part is the tool I found to re-project the map to an equal area projection was on the GISS site!
For the record, I know the answer and it has to do with exactly what Anthony
added. But I want viewers to go dig and find out for themselves. To do that, one must raise the question first… and hopefully the rationale, objective viewer can make the connection that something is amiss here.
Again its a simply argument.. lets watch the temp with the change of the PDO and in the coming years, the amo, and see if we are where we were back at the start of the satellite era, the late 70s, which by the way was the END of the last cold PDO and in the middle of a cold AMO, which common sense tells us would be colder!
BTW Thanks Ant-nee..I have to keep the videos short(tough for me, lol)
Willis Eschenbach (03:06:44) :
Well, I got to wondering just what temperature sensors we do have in the Arctic. It seemed to me that reaching out to 250 km, Hansen couldn’t be covering that much above 80°N … and it turns out he’s not.
Figure W1. Coverage of the area north of 80°N, showing 250 km radius areas around ground temperature stations.
Here’s your two miscellaneous factoids for today. A 1200 km radius circle is about the same size as the 80° N circle shown in the figure. It encompasses an area about three times the size of Alaska … and GISS is claiming that one single solitary temperature station is representative of that whole area.
Not.
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Nice graphics !
But you are missing the point that “temperature anomaly” is not the same as “temperature”. Yes, if you wanted weather forecasts for the Arctic, the coverage is pretty sparse. However, temperature anomalies are highly correlated over substantial geographical distances. This is why all the planetary datasets on warming speak of “anomalies” wrt some baseline average, rather than average temperatures. This fact underlies the GISS estimates of polar temperatures:
We analyze surface air temperature data from available meteorological stations with principal focus on the period 1880-1985. The temperature changes at mid- and high latitude stations separated by less than 1000 km are shown to be highly correlated; at low latitudes the correlation falls off more rapidly with distance for nearby stations.
The Journal of Geophysical Research paper describing why this methodology is good enough, in the absence of very expensive additional
observation stations and 90 deg inclination polar orbit satellites, is here.
If you can cite any research showing high resolution measurements in the Arctic (perhaps a few summers of ice breaker temperature measurements) proving this to be in error, please do so. Perhaps the Russians have done such studies.
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.
Why wonder about “a growing ice presence” when the data shows a steady decline over the last three decades (the satellite record) for the months in question?
Dec -3.3%
Jan -3.2%
Feb -2.9%
http://nsidc.org/cgi-bin/bist/bist.pl?annot=1&legend=1&scale=75&tab_cols=2&tab_rows=3&config=seaice_extent_trends&submit=Refresh&hemis0=N&img0=trnd&hemis1=N&img1=plot&mo0=12&year0=2010&mo1=01&year1=2010
GISS seems to be stuck with Arctic positive anomaly…….
Note that in the warmest places in the Arctic according to GISS, there are few if any land thermometers:
Not only GISS, UAH shows the same trend for the NPole, the last three months referred to in the graphs (DJF) show large positive anomalies, and is independent of station density.
Dec 09 1.98
Jan 10 1.66
Feb 10 2.32
Here is a BBC article connecting low solar activity and cold winters. Not joking-the BBC.
http://www.bbc.co.uk/blogs/paulhudson/2010/03/-i-am-indebted-to.shtml
” If it warms up about four more degrees as forecast by The Met office, we will no doubt have an ice age. ” ~S Goddard
Ahhh, hah, ha haaa… that one got me ; ) Good one~
Now with these investigations going on at CRU IPCC and such why don’t the investigators call in some of the more prominent skeptics? Oh stupid me I know why.
I find it interesting as we develope into a more so called educated urban society, we seem to be getting stupider.
Alexander (01:54:45) : No roses in UK?
How darned hot do they think it is going to get? For example Fort Worth has several public displays, such as this:
http://dallas.about.com/od/recreation/ig/Oval-Rose-Garden/index_g.htm
The oval rose garden at the Fort Worth Botanic Gardens is a great place to view roses that grow well in this area and get an idea of what will look good in your landscape.
Ian H (00:47:48) : who cares what idiots think.
Suppose you were an idiot. And suppose you were a member of Congress. But I repeat myself. Mark Twain
Basil (04:58:20) : The WMO and time base for normals
That is interesting. I’ve been using the Western Regional Climate Center data set for the western USA for so long it didn’t occur to me that it was not a uniform practice. There (WRCC), in fact, they provide a 1971 – 2000 data set and one for 1961 – 1990. Links to these are shown in the left frame for the Seattle station here:
http://www.wrcc.dri.edu/cgi-bin/cliMAIN.pl?wa7488
esin (09:21:08) :
” If it warms up about four more degrees as forecast by The Met office, we will no doubt have an ice age. ” ~S Goddard
Ahhh, hah, ha haaa… that one got me ; ) Good one~
————-
Reply:
Laugh, my unsuspecting ones. Mother Nature will have the last laugh–the next ice age shows signs of beginning even as we speak. It isn’t “warming” that will do in the earth’s population.