by Bob Tisdale
The Royal Netherlands Meteorological Institute (KNMI) has added the Hadley Centre’s new Sea Surface Temperature (SST) dataset HADSST3 to their Climate Explorer. (Thanks to Dr. Geert Jan van Oldenborgh for the update.) The following post is a quick introduction to the revisions to their global SST data. We’ll take a look at the individual ocean basins in a future post.
The new dataset was introduced in a two-part Kennedy et al (2011) paper:
And:
Note: The HADSST3 data ends in December 2006. Hopefully the Hadley Centre will be able to update the data in the near future.
Figure 1 is a time-series graph that compares the new HADSST3 Global SST data to its predecessor HADSST2. The data have been smoothed with 13-month running-average filters to reduce the noise and the seasonal signal. The largest correction occurs in 1945 to account for the discontinuity presented in the Thomson et al (2008) paper Identifying Signatures of Natural Climate Variability in Time Series of Global-Mean Surface Temperature: Methodology and Insights.
Figure 1
By subtracting the Global HADSST2 data from the HADSST3 data, Figure 2, the magnitude of the correction at that time becomes apparent. The Hadley Centre appears also to have increased the response to the 1883 eruption of Krakatoa, and reduced the rise from 1920 to 1940.
Figure 2
The long-term linear trends of the Global HADSST3 data are basically the same as HADSST2 at about 0.335 deg C per Century, as shown in Figure 3.
Figure 3
Let’s take a look at the trends during the two 20thCentury (plus) warming epochs and the mid-century cooling period. From January 1975 to December 2006, Figure 4, the global HADSST2 and HADSST3 linear trends are basically the same at 0.16 deg C per decade.
Figure 4
The corrections made to the early warming period, Figure 5, has reduced the linear trend for the period of January 1910 to December 1941 from 0.165 deg C per decade for the global HADSST2 data to 0.137 deg C per decade for the HADSST3 data.
Figure 5
The biggest change, of course, occurs during the mid 20thCentury cooling period. Figure 6 illustrates the Global SST anomalies for the two HADSST datasets for the period of January 1941 to December 1975. By correcting the discontinuity in 1945 and gradually aligning the data again in the early 1970s, the linear trend has dropped drastically from -0.008 deg C per decade for HADSST2 to -0.033 deg C per decade for the global HADSST3 data.
Figure 6
And that’s the period the IPCC models have difficulty reproducing. Figure 7 is a comparison of the global HADSST3 data to the IPCC Multi-Model Mean (20C3M) for the mid-century cooling era.
Figure 7
SOURCE
The IPCC Multi-Model Mean TOS data and the data for the two Hadley Centre SST datasets are available through the KNMI Climate Explorer:
http://climexp.knmi.nl/selectfield_obs.cgi?someone@somewhere
This [ http://i53.tinypic.com/14eb2xk.jpg ] is a grave claim that demands rigorous challenge by EOP (Earth Orientation Parameter) experts. A proper challenge will take years – perhaps many years. I do not accept the claim.
mrdarcy_pemberley says: “From an IPCC perspective, break out the bubbly for they will be happy with Bullets 1, 2, and 4.”
They should not be happy with 4. The models show no skill at hindcasting the rise in SST anomalies during the early warming period.
http://i56.tinypic.com/3g55f.jpg
For the early warming period, the global SST trend for the multi-model mean is 0.035 deg C per decade while the observations show the rise was 0.137 deg C per decade.
Bob Tisdale says: “They should not be happy with 4. The models show no skill at hindcasting the rise in SST anomalies during the early warming period.”
As my spouse often qualifies my responses using the term, “should” is the operative word in that statement. Personally, I agree the discrepancy between the datasets for the first, short-term warming period in the last century casts further doubt on the models’ abilities. However, the difference is such that it’ll be lost in the scientific “chaff” that the AGW proponents would throw at the comparison of the datasets. “After all, the long-term trend is reaffirmed by both datasets, right?”
This is overly simple but easily saleable to the global public.
If pressed, though, the IPCC will likely (1) emphasize the “smallness” of the difference (statistical significance is immaterial when the planet’s fate is at stake), (2) attribute the discrepancy to the vagaries in the recording of the data (there’s always a range of error associated with human-initiated input, which must be tolerated), (3) and the more trustworthy data (because it incorporates these things called… satellites) is entirely affirmed, as reflected in the second, short-term warming trend.
While we know it would be affirmed regardless given the baseline, that nuance is lost on the global public.
So, on the whole, I believe the IPCC is “happy” with Bullet 4 because its supports the “storytelling” they enjoy vis-à-vis their summaries for policymakers.
So the planet is warming.
sceptical said on July 13, 2011 at 9:46 pm:
Yup, in general, since the Little Ice Age, as we’ve been saying. Glad to know you’ve been paying attention. ☺
whilst talking about the planet warming….
I think I have pretty much eliminated the probability / possibility that the warming – or even part of the warming – is due to an increase in carbon dioxide or other GHG’s.
http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming
not so?
However, when arguing with myself on this, I think we cannot get past the reasoning that all those planes,rockets, traffic, electricity and fuel (including nuclear) that we burn and use must be adding some warmth to atmosphere.
the real problem is to find some kind of formula that would calculate the part of the warming that is man made.
I think it simply has to be based on the total energy consumed versus the atual energy coming in from the sun, no matter how small that portion that may be?