CRU : Projects : SO&P : Data
SO&P: Proxy data
The World Data Center for Paleoclimatology, run by the National Climatic Data
Centre (NCDC, formerly run by the National Geophysical Data Centre, NGDC),
make many raw and calibrated proxy data series available through their
web
site. It is not the purpose of this SO&P web site to reproduce such
a comprehensive data base. Only subsets or selections assembled specifically
for SO&P, and records
that are not available at WDC-Paleoclimatology, will be placed here.
"Schweingruber" tree-ring network chronologies.
- The "Schweingruber" network consists of 387 chronologies from across
the northern hemisphere, from locations selected to have greatest sensitivity
of tree-growth to growing-season temperature. The data files available here
are tree-ring width and maximum latewood density. See Briffa et al. (2001,
2002a, 2002b) for analysis of this network.
-
Briffa KR, Osborn TJ, Schweingruber FH, Harris IC, Jones PD, Shiyatov SG,
Vaganov EA (2001) Low-frequency temperature variations from a norther tree
ring density network. Journal of Geophysical Research
106, 2929-2941.
-
Briffa KR, Osborn TJ, Schweingruber FH, Jones PD, Shiyatov SG and Vaganov EA
(2002a) Tree-ring width and density data around the Northern Hemisphere:
part 1, local and regional climate signals.
The Holocene 12, 737-757.
-
Briffa KR, Osborn TJ, Schweingruber FH, Jones PD, Shiyatov SG and Vaganov EA
(2002b) Tree-ring width and density data around the Northern Hemisphere:
part 2, spatio-temporal variability and associated climate patterns.
The Holocene 12, 759-789.
-
The individual raw measurements, from some 10,000 tree cores, are not
available
from this website. All tree cores from each site and species have been
cross-dated, standardised to remove the age-related component of tree growth,
and combined into 387 site/species chronologies. The standardisation
used a detrending-type method, as explained in Briffa et al. (2002a, 2002b),
that also removes multi-century climate variations. These data should,
therefore, be used mainly for inter-annual and inter-decadal time scale
studies. The "age-band decomposition" method of Briffa et al. (2001)
has not been applied at the individual chronology level, so chronologies
without loss of multi-century time scale climate variations are not
available.
-
Data format. The data files are ASCII, with a header to describe the
data layout, missing code etc. The header contains the list of years
(i.e., the time coordinate) because this is not repeated for each
chronology. After the header, each chronology is stored one at a time,
beginning with a header giving location and genus/species, followed
by the data time series, followed by a time series of values between 0 and
1, which is the number of tree cores with data in each year expressed as a
fraction of the maximum number of tree cores at that site.
-
Click here
to download the gzip'd alltrw.dat.gz TREE-RING-WIDTH data file
(size 0.4 Mb).
-
Click here
to download the gzip'd allmxd.dat.gz TREE-RING-DENSITY data file
(size 0.4 Mb).
Mann et al. (1998) multi-proxy network.
-
Mann ME, Bradley RS and Hughes MK (1998) Global-scale temperature patterns
and climate forcing over the past six centuries. Nature 392,
779-787.
-
Mann et al. (1998) used a network of many different types of proxy data to
perform their reconstructions of global temperature patterns.
-
These data are accessible from this anonymous ftp site:
ftp://holocene.evsc.virginia.edu/pub/MBH98/
DENDRODB data base of tree core measurements and chronologies.
-
As part of the work funded by SO&P, partner CNRS/UDESAM at the CEREGE
laboratory, Antoine Nicault, Simon Brewer and Joel Guiot have created
a tree-ring data base from earlier work on the FORMAT data base.
-
This new data base, DENDRODB, has been filled with data from more than
600 tree-ring sites from Euroasia. 256 sites have tree-ring width
chronologies of 300 years or longer, and 90 sites have tree-ring density
chronologies of 300 years or longer. (Note that there is a partial overlap
with the chronologies in the Schweingruber network, especially for the
density chronologies, but many more ring-width series are available here.)
-
The DENDRODB data base is now freely accessible to all SO&P project staff and others.
-
The DENDRODB data base is accessed via a web interface:
http://servpal.cerege.fr/webdbdendro/
Last updated: August 2008, Tim Osborn