It’s not called the “hokey stick” for nothing.
The e-mail is below.
from: “Rob Wilson”
reply-to: “Rob Wilson”
subject: Re: 1816 tropical SSTs
to: “Phil Jones”
no the Nature paper is a TR based NH extra-tropical temperature
reconstruction that I wrote
with Rosanne D’Arrigo.
Essentially a substantial update (1250 years in length) to the original
Jacoby and D’Arrigo
The coral paper is a different beast. I am leaning towards JGR for submission
as I don’t
think it has the restrictive word length of GRL.
I can send you the last draft of the coral paper if you like, although I hope
to tighten it
in the next week or so.
For the coral reconstruction, I did not include the New Caledonia data.
I set up a fairly stringent screening procedure for the coral data – i.e.
only those series
that correlated significantly with local annual SSTs using both unfiltered
differenced time-series were used for later analysis.
The new Caledonia data did not pass this test. This is, in fact, a problem
with many of the
coral data-sets – the long term trends in these data might be related to
rather than SST. However, due to strong linear trends, there is often a
correlation with local SST using unfiltered series, which is purely an
artefact of trend.
Hence my use of 1st difference transforms to identify a ‘pure’ temperature
signal. The new
Caledonia data did not correlate significant with local SSTs at these high
hence, using my empirical approach, I could not rationalise the record to be
Although a strict interpretation of the new Caledonia O18 record as a
would indicate cooler conditions around the 1810-1820 period, I do not think
interpretation is entirely correct. Also, through this period, the lowest
index value is
1814, not 1816. 1885 is an inferred cool year which could tie in nicely with
It is also interesting to note that many of the coral records utilised by
Mike Mann also
failed my screening procedure.
The attached figure shows normalised series of the 5 coral records that go
back to 1801 in
my ‘SST sensitive’ data-set. The y-axis has been inverted as the series are
correlated to SSTs.
Only one record (MAL = Malindi: western Indian Ocean – Julia Cole) shows an
year in 1816.
As I state in the paper – lots of potential for corals, but there is simply
not enough data
prior to 1850 to derive particularly robust reconstructions.
just say if you want a copy of the paper
hope this helps