Wednesday, January 18, 2012

2043.txt

cc: k.heywoodatXYZxyz.ac.uk
date: Fri Jun 27 12:14:13 2008
from: Phil Jones <p.jonesatXYZxyz.ac.uk>
subject: Re: SST Undergraduate Dissertation
to: John.MatthewsatXYZxyz.ac.uk

Robin,
Our links are back.
[1]http://www.cru.uea.ac.uk/cru/data/temperature/
and the last linked document at the bottom of the page, 17Mb.
Cheers
Phil
Robin,
Happy to do this, but there are a number of papers you ought to read.
I'll give you a few links to look at. We have been doing a lot of
work in this area over about the last 25 years.
The CRU web site seems to be down, so I'll send one link later when it's back.
There shouldn't be much of a difference between ERSST and HadSST2. I suspect
some of the differences you've noticed relate to whether bucket-type corrections
were incorporated or not, or whether there were recent changes made to incorporate
satellite measurements. It is important to get version numbers on these datasets.
You mention various types of buckets, however most measurements now (at least
since the 1950s) have been made using engine intakes and insulated buckets.
The paper I've attached is the latest one on the Hadley Centre dataset. This shouldn't
be that different from HadISST, but the latter is spatially infilled, so it can be used
for driving GCMs. HadISST is Rayner et al. (2003) in the atatched.
What Rayner et al 2006 have done is the generally accepted adjustments that have
to be made. Versions of ERSST have also had these adjustments made. There is
a new version of ERSST due out very soon in J. Climate by Smith and Reynolds.
What you'd need to do in a project would be to get the raw measurements for the
ship track you followed from ICOADS. [2]http://icoads.noaa.gov/ . Worth getting
the air temperatures as well, as they have a different set of problems. With data
from the 1970s onwards the raw values should include the measurement method.
There will also be loads of drifters in the region in recent years and maybe some
fixed buoys. These measure SSTs slightly different from ships. ICOADS is all
unadjusted (i.e. as measured data).
What would be a useful aspect to look at is the recent problem of fewer ship
obs and many more drifting buoys. Attached is a paper that mentions this in
its final sentence, and a ppt from John Kennedy at the Met Office.
All issues with SSTs can generally only be solved with large sample numbers,
so the numbers of obs you have are unlikely to be enough, hence my suggestion
to get the ICOADS data.
Cheers
Phil


At 16:48 26/06/2008, you wrote:

Dr Jones,
I am a final year ENV student in Geophysical Sciences and have just
returned from my year abroad in North America (at the University of
British Columbia, UBC). Over the past six weeks I have been on a research
cruise across the central equatorial Pacific from Tahiti to Hawaii. I will
be using the data I collected along the ship's transect for my
undergraduate dissertation. I wish my final year project to be around the
theme of comparing different historical methodologies of measuring Sea
Surface Temperatures (SSTs). Originally I planned to do a climate
modelling project under Dr Tim Lenton.
I wish to contribute to the debate surrounding whether global warming is
more likely to lead to El Nino-like or La Nina-like conditions in the
tropical Pacific. It has been noted that the NOAA ERSST and the UK Hadley
Centre HadISST datasets show opposite and incompatible trends in SST for
this region over the past century. It has been suggested that the main
discrepancies between these two records (which occur around the 1930s and
1980s) could be the result of methodological changes in SST measurement.
I understand that you have been involved with correcting SST records for
historical changes in measurement techniques. The abstract for the
research paper I completed on ship is attached. I was taking measurements
of the temperature of surface seawater sampled in wood, canvas and
Zubrycki buckets. The purpose was to discover whether the different bucket
types (all used historically for SST measurements) would influence the SST
recorded.
My contact at UEA with regards this project has been Dr Karen Heywood.
Whilst she is willing to act as my supervisor, perhaps you would be more
suitable due to your previous research experience on this topic. I will
not be returning to UEA until the start of the autumn semester (around
September 22nd), but wish to work on my project in the meantime. My UEA
advisor is Dr Jenni Barclay.
Thanks for your time,
Robin Matthews

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
NR4 7TJ
UK
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