from: Phil Jones <p.jonesatXYZxyz.ac.uk>
subject: Re: SOI and NAO
to: Dennis Shea <sheaatXYZxyz.ucar.edu>
All is well at home. Hope you're well also and Kevin isn't working you
too hard - or passing on his troubles due to Landsea. I know he won't
be but he seems to have been dragged through the mill over it. At least the
two of us know what to expect later on in the IPCC process. I hope it
subsides and doesn't get to Ben Santer and Mike Mann proportions.
The issue with Mike is about to come to the surface again as a paper
will appear in GRL saying his curve is all wrong. The new curve is so
wrong it is unbelievable that even GRL appears to have been nobbled.
As for Darwin and Tahiti, several years ago I compared the two series
with what we had, what CPC had then and what the Australians had for
the two sites. All differences post 1931 probably resulted from this. For
Tahiti they are small except for 2hPa in 1936. For Darwin, only Sept82
can be considered large. I did the comparisons with Rob Allan who was
then at CSIRO (he's now at the HC in Exeter). I think we assumed the
Australians knew what the number should be.
I wouldn't have thought that NCEP-NCAR would be good enough to
resolve small differences. Doubt if ERA-40 would either.
I do recall doing a little more work on the early years at Tahiti, when
doing this paper.
K�nnen, G.P., Jones, P.D., Kaltofen, M.H. and Allan, R.J., 1998: Pre-1866 extensions of
the Southern Oscillation Index using early Indonesian and Tahitian meteorological
readings. J. Climate 11, 2325-2339.
Maybe that is why there are diffs with CPC and WMSC. Or maybe someone at CPC
made some changes.
Hope this helps.
At 16:20 01/02/2005, you wrote:
> don't think anyone answered your email of Dec 20. The person who
> responds to cruatXYZxyz.ac.uk has been off sick since the New Year. We think
> we've just found some of the emails that have come through.
I thought something was up. I have asked questions before and
received replys in prompt fashion.
> The base period for the SOI on our web site should be 1951-80. Are there
> any other questions?
THX ... Not really any specifics
This was some 'deep infrastructure' work related to
our section's WWW page: http://www.cgd.ucar.edu/cas/catalog/climind/
We download the CPC darwin/tahiti every month and we compute the SOI
using Trenberth (MWR, 1984).
Kevin wanted a detailed comparison of the CRU and
our [Climate Analysis Section] SOIs. Part of this
was a value-by-value check.
One thing I did was to print out values where the
differences were >0.2mb
I was hoping the the World Monthly SFc Station Climatology (WMSC)
would resolve any major differences. However, Wilbur Spangler
thought that this was not an independent dataset.
For more recent data (1950-pres) to possibly help resolve differences,
I interpolated the SLP given by Reanalysis.
eg: the 197907 interpolated reanalysis revealed that the CRU was correct.
Reanalysis showed the value to be approx 1014.? [forget exact number].
The funny thing to me is that in more recent years,
sometimes the CRU agrees with WMSC and in other time
and CPC agrees with the WMSC. Interpolation using reanalysis
does not help.
Hope all is well with you and your family!
(0) Darwin: 197205 CRU=1012.4 CPC=1013.7 Dif= -1.3 WMSC=1013.7
(1) Darwin: 197303 CRU=1007.4 CPC=1007.0 Dif= 0.4 WMSC=1007.0
(2) Darwin: 197310 CRU=1009.6 CPC=1010.0 Dif= -0.4 WMSC=1010.0
(3) Darwin: 197412 CRU=1006.5 CPC=1006.1 Dif= 0.4 WMSC=1005.6
(4) Darwin: 197811 CRU=1009.5 CPC=1009.1 Dif= 0.4 WMSC=1009.5
(5) Darwin: 197907 CRU=1014.6 CPC=1011.1 Dif= 3.5 WMSC=1011.1 *CRU [Re]
(6) Darwin: 198209 CRU=1014.3 CPC=1014.0 Dif= 0.3 WMSC=1014.3
(7) Darwin: 199010 CRU=1011.4 CPC=1010.9 Dif= 0.5 WMSC=1011.4
(0) Tahiti: 189601 CRU=1010.8 CPC=1011.8 Dif= -1.0 WMSC=1010.8
(1) Tahiti: 189602 CRU=1011.7 CPC=1012.7 Dif= -1.0 WMSC=1011.7
(2) Tahiti: 189603 CRU=1010.6 CPC=1011.6 Dif= -1.0 WMSC=1010.6
(3) Tahiti: 189604 CRU=1010.4 CPC=1011.4 Dif= -1.0 WMSC=1010.4
(4) Tahiti: 189608 CRU=1013.1 CPC=1014.1 Dif= -1.0 WMSC=1013.1
(5) Tahiti: 189609 CRU=1012.7 CPC=1013.7 Dif= -1.0 WMSC=1012.7
(6) Tahiti: 189610 CRU=1012.7 CPC=1013.7 Dif= -1.0 WMSC=1012.7
(7) Tahiti: 189611 CRU=1011.2 CPC=1012.2 Dif= -1.0 WMSC=1011.2
(8) Tahiti: 189612 CRU=1010.2 CPC=1011.2 Dif= -1.0 WMSC=1010.2
(9) Tahiti: 190504 CRU=1010.0 CPC=1008.0 Dif= 2.0 WMSC=1008.0
(10) Tahiti: 190505 CRU=1011.0 CPC=1008.1 Dif= 2.9 WMSC=1008.1
(11) Tahiti: 190506 CRU=1012.0 CPC=1010.2 Dif= 1.8 WMSC=1010.2
(12) Tahiti: 193604 CRU=1014.2 CPC=1012.2 Dif= 2.0 WMSC=1014.2
(13) Tahiti: 194012 CRU=1007.5 CPC=1009.5 Dif= -2.0 WMSC=1007.5
(14) Tahiti: 195810 CRU=1012.1 CPC=1012.4 Dif= -0.3 WMSC=1012.2
(15) Tahiti: 196306 CRU=1013.4 CPC=1013.1 Dif= 0.3 WMSC=1013.3
(16) Tahiti: 196903 CRU=1012.6 CPC=1012.3 Dif= 0.3 WMSC=1012.6
(17) Tahiti: 197702 CRU=1011.8 CPC=1012.1 Dif= -0.3 WMSC=1011.8
(18) Tahiti: 198106 CRU=1014.2 CPC=1014.5 Dif= -0.3 WMSC=1014.2
(19) Tahiti: 198109 CRU=1014.8 CPC=1014.5 Dif= 0.3 WMSC=1014.8
(20) Tahiti: 198204 CRU=1011.9 CPC=1012.2 Dif= -0.3 WMSC=1011.9
(21) Tahiti: 198304 CRU=1011.0 CPC=1010.4 Dif= 0.6 WMSC=1010.4
(22) Tahiti: 198411 CRU=1012.5 CPC=1012.8 Dif= -0.3 WMSC=1012.8
(23) Tahiti: 199704 CRU=1012.3 CPC=1012.8 Dif= -0.5 WMSC=1012.2
Prof. Phil Jones
Climatic Research Unit Telephone +44 (0) 1603 592090
School of Environmental Sciences Fax +44 (0) 1603 507784
University of East Anglia
Norwich Email p.jonesatXYZxyz.ac.uk