On data losses -vs- geography in Cowtan and Way 2013: data dropout may account for most of the recent observed differences

At Climate Audit, Roman M. has a very interesting analysis that shows the surface grid cell losses from HadCRUT4 in C&W. It hones in on the issue of why the temperature differences from 2005 are much more significant than the earlier part of the record. Data loss seems to be recently seasonally large, especially in the Antarctic, something C&W seems not to have considered important enough to dedicate more than a passing note about. Roman’s analysis was made possible by the fact that C&W provided data and code here, something not so common these days, so some props are in order.

He writes: 

The cells lost as a percentage of all possible cell values (missing or not) is 2.32%, approximately the value given in the paper. However, the percentage of cells containing temperatures (representing the real reduction of information) lost through anomalisation is 3.34%. The monthly distribution of the losses can be seen in the following graph. The change in the pattern shortly before 2005 could be related to Steve’s observations in his earlier post on CA.

cells_lost

[CA Figure 2]

Which grid cells are losing the information?

cell_frequency

[CA Figure 3]

It is quite obvious that the losses occurred in those areas which were already short of temperature information thereby exacerbating the problems inherent in trying to create a reliable reconstruction of the gridded temperatures in the polar regions. I would suggest that the paper’s observation that “coverage is very slightly reduced” understates the impact of these reductions by ignoring the geography of where they occur.

Based on the two graphs shown above, and in particular the plot of frequency of grid cell loss, I left some comments at CA which I think give insight into the reason for the loss and I repeat them here for wider consideration.

===============================================================
From CA Figure 2 above, it appears that the breakpoint observed in this graph Steve produced a few days ago,


Figure 2. Delta between CW Hybrid (basis 1961-1990) and HadCRUT4.

Owes its 2005 up shift primarily to an increased loss of cells starting about that time.

===============================================================

In CA Figure 3 above, there are two red bands of missing cells. The Arctic band is weaker than the Antarctic one, which is quite pronounced. Note also how the southern limit of the Antarctic band follows the shoreline of the continent almost perfectly. Roman asked if there was a seasonal component.

I think the geography difference and sea ice can explain much of this. Observe this graph from NSIDC:


Above: Sea ice climatologies: Arctic and Antarctic sea ice concentration climatology from 1981-2010, at the approximate seasonal maximum and minimum levels based on passive microwave satellite data. Image provided by National Snow and Ice Data Center, University of Colorado, Boulder.

Note the difference in seasonality of sea ice extent between poles. It is far more dramatic in Antarctica.

We know that for HadCRUT is both land and ocean data.

For the Arctic, there are few manned bases not on land, and a lot of the data in the Arctic ocean is brought in from buoys. The manned Arctic bases on land are supplied almost exclusively by airplane, and they operate 24/7/365 thanks to being supplied. There are no significant fuel/distance limits to aircraft operations since they can hopscotch north. There are no surface readings taken during transport by aircraft. The sea ice extent doesn’t affect the operation of the bases, the aircraft, and mostly doesn’t affect the buoys, though some losses do occur. Sea ice does affect some data gathered by ships though. Only a few icebreakers operate in winter.

In the southern hemisphere, it is an entirely different story.

The sea ice when it reaches maximum in September, creates an nearly impenetrable barrier between the open sea and bases on the periphery of the Antarctic continent. Ships generally can’t operate in this zone during winter. And what little supply occurs (if it occurs) is by aircraft. The bases hunker down for the winter and continue to operate, as do the AWS stations on the continent.

So IMHO, that bright red ring in Roman’s figure 3 above showing frequency of grid cell loss circumventing Antarctica represents the sea ice barrier and loss during those months when ships cannot operate.

As we know, sea ice extent in the Arctic is decreasing, while increasing in the Antarctic. See this graph from NSIC:


Above Arctic and Antarctic Sea Ice Extent Anomalies, 1979-2012: Arctic sea ice extent underwent a strong decline from 1979 to 2012, but Antarctic sea ice underwent a slight increase, although some regions of the Antarctic experienced strong declining trends in sea ice extent. Thick lines indicate 12-month running means, and thin lines indicate monthly anomalies. Image provided by National Snow and Ice Data Center, University of Colorado, Boulder.

So the Arctic has become more accessible to ships on the periphery of seasonal sea ice boundary, while the Antarctic has become less accessible to ships during the last decade.

As for the seasonal component note the differences in the minimums vs the maximums:


Sea ice extent for the month when its at its minimum (i.e. the end of local summer) Source: James Hansen http://www.columbia.edu/~mhs119/UpdatedFigures/

This looks like a simple case of access to surface measurement having increasing bipolar difference, something the satellites don’t have a problem with beyond 80N and 80S.

===============================================================

As for the high missing grid cell frequencies in Africa and Asia, I’d wager they are late/missing reports. The plot of frequency for those regions center on many countries where political unrest in common. The one black cell in Russia is an oddity. Roman do you know what stations are under that cell?

[RomanM: No, that information is not contained in the paper’s data and it would be a tough task to chase it down on my computer, Sorry.]

===============================================================

As Bob Tisdale points out in theis WUWT post:

Figure 4

This breakpoint may be related to loss of seasonal measurements in Antarctica, note that in this Cryosphere Today graph, most of the ice extent anomalies post 2005 are positive.

seaice.anomaly.antarctic[1]

This increase in Antarctic sea ice may translate into less seasonal ship traffic (and less measurements) in the Antarctic coastal zone during that time.

57 thoughts on “On data losses -vs- geography in Cowtan and Way 2013: data dropout may account for most of the recent observed differences

  1. But how about Arctic amplification? Where does that fit in?
    REPLY: It doesn’t, even C&W say it may not have even happened until post 2005. This discussion is about data and stats and what happened after 2005. Stop thread bombing here with this question “Gunther Kisrchbaum” – Anthony

  2. Antarctic sea ice is relatively thin because almost all of it melts out during summer, so no thick multi-year ice. How could more thin ice translate into less seasonal ship traffic? Icebreakers generally don’t have problems with 2 meter thick ice, so there must be another reason for less seasonal ship traffic (money, rough weather, katabatic winds)?

    REPLY: “Gunther”, it is more like economic reality, US icebreaker fleet is broken, they have to use the Russians.

    http://www.stripes.com/news/pacific/japan/us-uses-russian-icebreaker-to-get-fuel-supplies-to-antarctica-1.168398

    Plus it is more than that, regular ship traffic, including research ships, don’t operate in those months around Antarctica. They aren’t equipped for icebraking. – Anthony

  3. Okay – if you live in Canada and know about her Arctic and her Arctic Islands we are quite familiar with the lack of temp gauges in that particular part of the world. On the other hand, we are also familiar with humans living in the Arctic region for tens of thousands of years so it was never a frozen waste land since the first human walked across the ice bridge. Inuit developed and used kayaks to hunt on Arctic waters and have for ten thousand years. I don’t get why there is such intense interest in the Arctic as if each ice pan had to be accounted for as if natural variations has never occurred in the historical past and present. Our citizens have lived there and still do and still fish and hunt the Arctic waters as they have done for thousands of years. Yet, there is not this hue and cry and minute by minute gashing of teeth over the Antarctic. I don’t get it.

  4. @ Alberta lad: Ah come on dude. The Antarctic doesn’t fit the story line. And in Alberta where we live it is REALLY warm today so Global Warming must be real. Couldn’t be the Chinook Winds that we all know and Love/Hate could it? Those things our great grand parents talked about but our grandchildren are told it’s AGW? Just Joshing. I don’t know whether to put my snow suit on or just jeans and a jacket today cause it’s plus 7 C outside … and two days ago it was 25 C below. Wish it would just stay below zero. That two feet of snow I have outside gets a bit heavy and sloppy in these silly Chinooks. Didn’t even light a fire today. Too cold to ski last week, too warm this week. WEATHER. SNAFU.

  5. Talking of missing data you have to wonder how they missed this, until now?

    Austrian Meteorologists Stupefied Into Silence! Data From Alps Show Marked Cooling Over Last 2-3 Decades!
    NoTricksZone – By P Gosselin on 22. November 2013
    ………According to an expert review conducted by the Zentralanstalt für Meteorologie und Geodynamik (ZAMG), the Austrian state weather service, using weather data from the last 20 years or more: “Winters there indeed are shown to have gotten colder over the last 20 years, and in some places quite massively. The last two winters at Kitzbühel were in fact the coldest of the last 20 years.”…………….

  6. NevenA: “But how about Arctic amplification?”

    You mean the thing that happens quite regularly and has nothing to do with CO2?

    Here are the top 3 latitude bands near the arctic (HADCRUT4). The big fluctuations were much larger in the past.

  7. Oh Wayne – that was funny. It got down to -33C up in oil sands country for two night – yep, you’re correct, climate change.

  8. I thought the purpose of the paper was to infill the missing areas – not selectively infill the missing areas sometimes in select areas.

    Certainly leaves open the possibility of systematic error. Which is what one should be wary of with Skeptical Science team authors.

  9. Antartica may have less shipping for several reasons.
    Lower population ie, they only people living there are researchers. Why risk a ship when it is easier and cheaper to stock up and wait out winter?
    The winter winds are savage. “Below 40 there is no law, below 50, there is no God”
    Even flying into the area is fraught with peril.

    Oh and it has no polar bears floating on photoshoped bits of ice for WWF and Greenpeace to complain about.

  10. I looked at Arctic and Antarctic trends of UAH, RSS and HadCRUT4 from 1997 to 2012, to see if it was even possible to increase HadCRUT4 global trend by swapping UAH or RSS data for HadCRUT4 data in the Arctic and Antarctic. This is what I found-

    UAH Arctic gives 0.8 C, or 0.53C/decade.
    RSS Arctic gives 0.65 C, or 0.43C/decade.
    UAH Antarctic gives 0.0 C
    RSS Antarctic gives 0.0 C
    HadCRUT4 Arctic gives 1.0 C, or 0.67C/decade.
    HadCRUT4 Antarctic gives 0.4 C, or 0.27C/decade.
    So, subbing UAH for HadCRUT4 in Arctic lowers trend from 0.67C/dec to 0.53C/dec.
    Subbing UAH for HadCRUT4 in Antarctic lowers trend from 0.4C/dec to 0C/dec.
    It does not seem plausible that the HadCRUT4 hybrid trend can be higher than HadCRUT4.

  11. Jimbo says:November 23, 2013 at 3:00 pm
    “Talking of missing data you have to wonder how they missed this, until now?”

    They didn’t miss it. Here is a plot of HADCRUT etc seasonal trends against latitude for the last 16 years. Note the very large DJF dip in latitudes 40-50. A lot has been written about recent cooler European winters.

  12. Nick Stokes says:
    November 23, 2013 at 4:32 pm
    >>>>>
    Not as funny as usual, Nick. Please tell us again about CO2 raising global temps. That is what makes us laugh.

  13. As I noted on the thread at Climate Audit:
    I would tend to agree with Anthony that the loss of sea surface temperature data in the Southern Ocean is likely the result of sea ice gains there. In fact, that was my first thought when I saw the map in the post.

    And as Anthony also noted, that also likely explains some of the seasonality of the missing data.
    # # #
    Second comment:
    ICOADS is the source data for the HADSST3 data. I would hope the ICOADS data is also declining proportionally in the Southern Ocean.

    Satellite-enhanced sea surface temperature data show cooling there over the past 30+ years:

    The graph is from the most-recent update:

    http://bobtisdale.wordpress.com/2013/11/11/october-2013-sea-surface-temperature-sst-anomaly-update/

  14. Nick Stokes;
    Note the very large DJF dip in latitudes 40-50.
    >>>>>>>>>>>>>>>>>>>>

    Not also that the larger that dip is, and assuming that 60-70 stays the same, the higher a number you get when extrapolating to 80-90. Only in climate science could a cooling of one area amidst a temperature set that on average is not changing, can the absurd claim be made that this must mean that the unobserved areas are warming faster than previously thought.

    Which changes the statement that I made when this piece of cow pie first got published. In the unlikely event that the paper holds up, what it shows is that some places where it is so cold that everything is frozen and nothing lives are now slightly less so cold that everything is frozen and nothing lives.

  15. “This increase in Antarctic sea ice may translate into less seasonal ship traffic (and less measurements) in the Antarctic coastal zone during that time.”
    Less traffic is fine, but it should be fewer measurements. Fewer is used for discrete quantities.

  16. Anthony is correct, the U.S. ice breaking capability is embarrassingly very poor right now. The USCG Polar Sea sat tied to the dock for years and was only saved from scrapping recently by the intervention of senators from Washington and Alaska. The USCG Polar Star just completed a two year overhaul which will buy another eight years of service. Our next largest icebreaker, (and only) medium sized USCG Healy, would probably not even attempt to enter two meter ice.

    The Antarctic eats icebreakers. The only large Argentine icebreaker, ARA Almirante Irizar, suffered a serious fire in 2007, and has been in drydock ever since. The UK icebreaker, HMS Endurance, almost sank off Chile in 2008 due to improper maintenance, and has been docked ever since.

  17. mobihci says:
    November 23, 2013 at 4:24 pm

    “the icebreaker Australian Antarctic supply ship has had trouble both getting down there and back the last couple of years, stuck in too much ice.”

    Yeah, looks like the summer ice that NevenA talks about can’t melt fast enough for the crew of Aurora Australis.

    Present position shown on this map:

    https://secure3.aad.gov.au/proms/public/schedules/voyageTrack.cfm?season=1314

    Was due into Davis 27 Oct, arrived 07 Nov.

    Schedule for return to Hobart was 16 Nov, last position stationary not far out from Davis so the whole 2013-14 Antarctic program looks like a bit of a shambles.

    Wonder what forecasts they are basing their planning on? Hope it is not from Tim Flannery’s Climate Commission.

    Also haven’t seen Christine Milne on the ABC yet blaming this all on global warming.

  18. Please connect the dots for me. Does this mean that this Cowtan study is bogus, justified, or what?

  19. chris y says:
    November 23, 2013 at 4:21 pm
    UAH Arctic gives 0.8 C, or 0.53C/decade.
    HadCRUT4 Arctic gives 1.0 C, or 0.67C/decade.
    So, subbing UAH for HadCRUT4 in Arctic lowers trend from 0.67C/dec to 0.53C/dec.
    It does not seem plausible that the HadCRUT4 hybrid trend can be higher than HadCRUT4.

    I could certainly be wrong here and I am sure that I will be corrected if I am, but my understanding is this: HadCRUT4 Arctic may well be 0.67C/decade, but it may only go from latitude 70 to 75 for example. And if there are no readings from 75 to 82.5 for example, HadCRUT4 would leave that part blank. But Cowtan and Way would assume that latitude 75 to 82.5 would be 0.53C/decade for that region. And since this is higher than the global average of 0.046C/decade, the trend goes up. Am I on the right track here?

  20. @Wayne and AlbertaLad

    I have used both your short term data sets (creating thereby a temperature data set ensemble) and projected a daytime temperature for Edmonton of 2085 Deg C on the 23rd of Nov 2014. This is alarming.

    Can I have my grant money now, please?

  21. Thank you Paul Homewood who says:

    Remember as well that RSS only covers to 70S, whereas they go to 82.5N.

    If anything , therefore, RSS is overestimating the warming trend.

    http://data.remss.com/msu/monthly_time_series/RSS_Monthly_MSU_AMSU_Channel_TLT_Anomalies_Land_and_Ocean_v03_3.txt

    This helps explain a tiny piece of the puzzle why the satellite readings keep saying that we are above the anomaly month after month after month (albeit slightly but still above) when I see record cold everywhere. (OK, not everywhere yet enough places the anomaly readings don’t make sense to me). People (on these blogs) keep telling me that although there is record cold in oh so many places causing untold pain, death, and destruction– the globe is still warming because other areas on the globe are warmer than the areas that are colder….I went on Dr. Spencer’s blog and asked about it. Although folks there were patient in their explanations, I still have a sense that it doesn’t quite ring true. I have been suspecting tampering with the satellites and then the satellites that were not operating correctly–was the reason we keep showing readings above the 30 year anomalies when I can ‘t see how.

    Your observation gives me a small sense that maybe I’m not so crazy after all for questioning the satellite anomalies….

  22. davidmhoffer says: November 23, 2013 at 5:01 pm
    “Not also that the larger that dip is, and assuming that 60-70 stays the same, the higher a number you get when extrapolating to 80-90″

    I don’t think anyone is basing Arctic trends on extrapolation from mid-latitudes. C&W use kriging over relatively short distances. I got similar results by just infilling missing cells with the average from their own latitude band, instead of with the global average, as is implicitly done when the cells are omitted). There’s a bit of crossover between the very highest latitudes, when whole bands are actually near empty. But for latitudes below 80, there isn’t use of lower latitude data. Just proper weighting.

  23. geran says: “Not as funny as usual, Nick….”

    Bear in mind that there are apparently TWO Nick Stokes. One of them is fairly sentient and usually worth reading.

  24. Nick Stokes;
    I don’t think anyone is basing Arctic trends on extrapolation from mid-latitudes. C&W use kriging over relatively short distances.
    >>>>>>>>>>>>>>>>

    Sorry, I didn’t make my point well. It doesn’t matter if the distance is long or short. My point was that cooling can result in a temperature gradient that gives you an unrealistic value when extended to neighbouring areas. The precise same is true of warming. Temperatures fluctuate in both directions by large amounts in just meters. The reason NOT to use techniques like this one is that they are ultimately models for what the modeler thinks is happening, they are not measurements. For the areas of earth where we have on going measurements, there has been no significant warming. It is unreasonable to suggest that the arctic regions are any different without actual measurement data to suggest same.

    Further, it is utterly daft to average temperature data in this manner in the first place. At -60 C, a temperature commonly reached in the Antarctic, it takes only 2.2 w/m2 to raise the temperature by a single degree. But at +30C, a temperature commonly reached in temperate zones and the tropics, it takes 6.3 w/m2 to raise temps by a single degree.

    Do you not admit that this is a problem? That even a large rise in a tiny area of the world, the arctic regions, could be completely and totally off set by even a small amount of cooling over a much larger area in warmer climes. The energy balance of the planet could well be negative, and we’d never be able to detect it by measuring the temps in the missing cells in the arctic, let alone by estimating them from some bizarre fantasy that results in a trend in opposition to what we are measuring in the rest of the planet.

  25. “jorgekafkazar says:
    November 23, 2013 at 9:11 pm

    geran says: “Not as funny as usual, Nick….”

    Bear in mind that there are apparently TWO Nick Stokes. One of them is fairly sentient and usually worth reading.”

    Maybe one of them is from the racehorse latitudes.

  26. “extent in the Arctic is decreasing, while increasing in the Antarctic.”

    Not exactly.

    See NSIDC data here, here, here, here, here – data used for creating the graphs were retrieved on Thursday and are available here, original data source here.

    I note that the NSIDC hemispherical pictures for the 2005/2013 global monthly maximum (daily this year on Nov 2 – this month – the highest daily global sea ice extent since 1999 which oddly went completely unnoticed by our climate watchdogs) are for obvious reasons not available yet, so I did only the comparisons for the yearly global sea ice minimum in the February and for NH only.
    SH is out of question – but if one wants I can of course do the pictures – the numbers for February yearly global minimum are
    FEB 2005: extent 2.9 mil. sq. km, concentration 1.9 mil. sq. km
    FEB 2013: extent: 3.8 mil. sq. km, concentration 2.5 mil. sq. km
    Area increase differences: +23.6% and +24% respectively for the SH (for NH +2% and +3% respectively – yes, there is the sea ice area increase since 2005 global monthly minimum at the NH)
    I will revisit the NSIDC data next month to do the November maximum pictures – but the recent record global maximum and the trends give quite a hint what will most likely happen…

    The CW13 no-data analysis is straight away falsified by the real data which actually do cover the polar regions – the sea ice extent data – because a claim there is a significant global warming trend (moreover in the same period where the “CW13 hybrid” starts to diverge from the HadCRUT4) is absolutely not believable. (I note that unlike with other global climate indicators, measuring sea-ice is relatively easy, accurate and with very rarely missing coverage in the space age -see the NSIDC coverage metadata in the linked spreadsheet or at the original location.)

    There is no scientific reason to believe there is a significant warming trend in the global surface temperatures for the last ~decade – and even much less because of a bias in the global surface temperature anomaly data due to insufficient coverage in the polar regions.

    In fact the global sea-ice extent data give quite a very compelling evidence to the contrary.

    And data is what counts in the science, which has the method based on falsification not confirmation bias. If the real data don’t agree with a hypothesis it is in the overwhelming majority of cases the hypothesis which is falsified, not the data.

    In this case the extensive real data crushingly falsify a hypothesis literally based on no data, moreover clearly postulated to significantly change the outcome of a real offical dataset (whatever we maybe think about the Hadley Center nad CRU at least based on real measurements and with still relatively conservative approach when compared to other global datasets as GISTEMP LOTI*) and moreover for such purpose – with quite clear intent to cast doubt about the current at very least flat global surface temperature trend – by inventing the infill temperature “data” – which already could be considered being on the edge of a fraud in the legal sense.

    Sorry to be so direct, but there is no significant global warming trend in the last ~decade whatsoever – a warming simply cannot cause water to freeze on hundreds of thousands square kilometer sea surface areas, it is physically impossible and therefore a hypothesis there is a global warming trend recently, moreover allegedly not measured due to insuficient surface temperature measurements coverage in the polar regions is absolutely implausible.

    ————————–
    If one wants to brush up on how it relates to the sea ice I recommend the final note from the Bob Tisdale’s article here which, to make this short, I allow myself to point out just one sentence from: “GISS masks (effectively deletes) sea surface temperature data anywhere sea ice has existed.”

  27. Antarctic ice while reported as thinner than arctic ice, is not the case for the entire run of ice. IE to get where you want to go you have to drive through a lot of connected ice. Why you might ask would that matter? well ice that is not frequently travelled by ships develops pressures based on exposed surface and how big the sheet is… at the meeting of pressure points you get ridges. Most ice breakers are capable of continuous breaking of unpressurized ice less than 6ft thick. pressure changes the game. Its why the Healy the U.S’s medium icebreaker can handle arctic ice but not Antarctic, not enough horsepower. No one tries the Antarctic in the Antarctic winter, you just wouldn’t make it, wicked high winds with a huge distance to break through, just too much pressure.

  28. Roman M. said (at CA),

    The cells lost as a percentage of all possible cell values (missing or not) is 2.32%, approximately the value given in the paper. However, the percentage of cells containing temperatures (representing the real reduction of information) lost through anomalisation is 3.34%. The monthly distribution of the losses can be seen in the following graph. The change in the pattern shortly before 2005 could be related to Steve’s observations in his earlier post on CA.

    – – – – – – –

    If I take anomalisation to be defined as the subtraction of a mean from a data set then I do not understand Roman M.’s statement ” [cell data] lost through anomalisation”.

    How does anomalisation lose data?

    John

  29. John Whitman says: November 23, 2013 at 11:27 pm
    “How does anomalisation lose data?”

    Because people generally seek a fixed base period for all data. And some cells don’t have enough data in that period and have to be dropped.

    The issue here is re-anomalization – HAD and UAH use different periods, so they wanted to change HAD to the UAH period (1981-2010, I think). So they had to drop HAD cells with no data in that period.

  30. Bottom line , and its very old one , your data is only ever as good as the method used to collect in the first place .
    The idea you can smear weather data over a large area to cover for ‘holes ‘ in collection , is a very odd one , given that local variations even over short distance of 10’s of miles can lead to differences in weather.

    Throw enough statistical power at it and you can ‘always compensate for errors’ has become mantra within science which ignores basic issues of data collection and data gathering which is used to be the bedrock of science.

    There is a irony that the increase in computing as allowed ‘tricks’ on data to be done quickly and easily, so the temptation is to try it and see what happens , while before it would have taken much time and effort and meant people would have really thought about it first . So the question is , are we really ‘better’ at this or are we just better at producing result data or no data ?

  31. Scott Scarborough says:
    November 23, 2013 at 6:16 pm
    Please connect the dots for me. Does this mean that this Cowtan study is bogus, justified, or what?
    =====================================================
    I am not sure Scott, but if Cowtan fails to extrapolate, 9due to missing information) in the strongly cooling Antarctic (.2 C from 2007 to present-See Bob Ts SST chart) S.H. ; but does further extrapolate warmer Ts in the N.H, while leaving the SH polar HadCRUT4 Antarctic positive 0.27C/decade, when RSS gives a flat trend, and SST a cooling, then the results would clearly lead to a biased warmer mean.

    Now further consider Davidmhoffers cogent comment, “At -60 C, a temperature commonly reached in the Antarctic, it takes only 2.2 w/m2 to raise the temperature by a single degree. But at +30C, a temperature commonly reached in temperate zones and the tropics, it takes 6.3 w/m2 to raise temps by a single degree.” Now further understand that the tropics have been virtually flat for the entire history of the CAGW theory. This further moves the average warming into ever higher latitudes, thus making the already well below CAGW projections of increased energy in the atmosphere due to assumed anthropogenic warming, even further off.

    It appears ever more likely that the catestrophists are once again cherry picking their data, and using global averages to mean far more then they in reality mean, with regard to the predicted increase in global average T.

  32. Also consider that no only is the missing data localized to specific regions, but to specific seasons. As there can be, and usually is, a larger flux in some seasons, this can mean a greater potential error in results of missing data.

  33. Nick Stokes on November 24, 2013 at 1:15 am said,

    John Whitman says: November 23, 2013 at 11:27 pm

    “How does anomalisation lose data?”

    Because people generally seek a fixed base period for all data. And some cells don’t have enough data in that period and have to be dropped.

    The issue here is re-anomalization – HAD and UAH use different periods, so they wanted to change HAD to the UAH period (1981-2010, I think). So they had to drop HAD cells with no data in that period.

    – – – – – – – –

    Nick Stokes,

    Thanks for your info.

    John

  34. This brings back a memory:
    In December 1985, the southern hemisphere summer, the Antarctic supply ship “Nella Dan” was stuck in the ice. I was on board HMAS Stalwart that diverted from Manila to Hobart to load stores then we resupplied Macquarie Island.
    Doesn’t sound like the resupply ships are ice breakers.

  35. Minor English correction: “homes in”, not “hones in”. To remember: there are no honing pigeons (or torpedos).

    IanM

  36. Minor correction to the correction. “Hone in on” is now an accepted alteration, acceptable use even in the OED.

  37. Minor correction to the correction: “Hone in on” is an acceptable alteration, even according to the OED.

  38. Figure 2 from McIntyre’s post “Delta between CW Hybrid (basis 1961-1990) and HadCRUT4″ shows an incorrect slope for the trend since 2005 as I pointed out in Tisdale’s post here and on the original Climate Audit thread. Mistakes are forgivable, but continuing to propagate them once they’ve been pointed out is beyond sloppy.

  39. “Paul Homewood says:
    November 23, 2013 at 2:47 pm

    Remember as well that RSS only covers to 70S, whereas they go to 82.5N.

    If anything , therefore, RSS is overestimating the warming trend.

    http://data.remss.com/msu/monthly_time_series/RSS_Monthly_MSU_AMSU_Channel_TLT_Anomalies_Land_and_Ocean_v03_3.txt

    It is true that RSS only goes to 70S for channel TLT (lower troposphere), but RSS goes from 82.5N to 82.5S for channel TTT (total troposphere). In this connection, it is worth while to take a look at UAH’s “readme” page which, amongst other things, states,

    “ALSO BE CAUTIOUS USING LT AND MT OVER HIGH TERRAIN ( >1500 M)
    The areas of poor anomaly values are : Tibetian Plateau,
    Antarctica, Greenland and the narrow spine of the Andes.
    Depending on how much of these areas are neglected, the coverage
    should be about 97-98% of the globe.”

    http://vortex.nsstc.uah.edu/data/msu/docs/readme.msu

    In the light of this, it is possible that RSS’s channel TLT only goes to 70S because RSS realises that most of Antarctica from 70S to 90S is a very high plateau, so high that most of it is not within the lower troposphere for those latitudes.

  40. The arctic is only .42% of the globe. Assuming that the heat is concentrated there and is not trapped as latent heat from ice melt, how high are temps? What is the equalibrium temperature for the area? How fast is heat radiating away given how much temps are above equalibrium temp?

  41. aaron says:
    November 25, 2013 at 8:12 am
    The arctic is only .42% of the globe.
    Aaron, that 0.42% is only the part north of latitude 82.5 that RSS does not cover in the north.

  42. albertalad says:
    November 23, 2013 at 2:42 pm
    ” On the other hand, we are also familiar with humans living in the Arctic region for tens of thousands of years so it was never a frozen waste land since the first human walked across the ice bridge. Inuit developed and used kayaks to hunt on Arctic waters and have for ten thousand years.”
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    Not quite. If the extinction of Mammoths on Wrangel Island may be confidently attributed to human arrival, make that 4.7ky. –AGF

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