# northamerica_usa_ak22 - Boulder Creek Alaska Near Haines - Breitenmoser Tree Ring Chronology Data
#-----------------------------------------------------------------------
#		World Data Center for Paleoclimatology, Boulder
#				and
#		NOAA Paleoclimatology Program
#-----------------------------------------------------------------------
# NOTE: Please cite Publication, and Online_Resource and date accessed when using these data.
# If there is no publication information, please cite Investigators, Title, and Online_Resource and date accessed.
#
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# Online_Resource:
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# Original_Source_URL:
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# Description/Documentation lines begin with #
# Data lines have no #
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# Archive: Tree Rings
#--------------------
# Contribution_Date
#	Date: 2016-01-07
#--------------------
# Title
#	Study_Name: northamerica_usa_ak22 - Boulder Creek Alaska Near Haines - Breitenmoser Tree Ring Chronology Data
#--------------------
# Investigators
#	Investigators:  Breitenmoser, P.; Bronnimann, S.; Frank, D.
#--------------------
# Description_and_Notes
#	Description: Data from Breitenmoser 2014 Journal of past Climate supplementary, see publication for ARSTAN standardization details
#--------------------
# Publication
#	Authors: Breitenmoser, P.; Bronnimann, S.; Frank, D.
#	Published_Date_or_Year: 2014-03-11
#	Published_Title: Forward modelling of tree-ring width and comparison with a global network of tree-ring chronologies
#	Journal_Name: Climate of the Past
#	Volume: 10 
#	Edition:
#	Issue:
#	Pages: 437-449
#	DOI: 10.5194/cp-10-437-2014
#	Online_Resource: www.clim-past.net/10/437/2014/
#	Full_Citation:
#	Abstract: We investigate relationships between climate and tree-ring data on a global scale using the process-based Vaganov–Shashkin Lite (VSL) forward model of tree-ring width formation. The VSL model requires as inputs only latitude, monthly mean temperature, and monthly accumulated precipitation. Hence, this simple, process-based model enables ring-width simulation at any location where monthly climate records exist. In this study, we analyse the growth response of simulated tree rings to monthly climate conditions obtained from the CRU TS3.1 data set back to 1901. Our key aims are (a) to assess the VSL model performance by examining the relations between simulated and observed growth at 2287 globally distributed sites, (b) indentify optimal growth parameters found during the model calibration, and (c) to evaluate the potential of the VSL model as an observation operator for data-assimilation-based reconstructions of climate from tree-ring width. The assessment of the growth-onset threshold temperature of approximately 4–6 C for most sites and species using a Bayesian estimation approach complements other studies on the lower temperature limits where plant growth may be sustained. Our results suggest that the VSL model skilfully simulates site level treering series in response to climate forcing for a wide range of environmental conditions and species. Spatial aggregation of the tree-ring chronologies to reduce non-climatic noise at the site level yielded notable improvements in the coherence between modelled and actual growth. The resulting distinct and coherent patterns of significant relationships between the aggregated and simulated series further demonstrate the VSL model’s ability to skilfully capture the climatic signal contained in tree-ring series. Finally, we propose that the VSL model can be used as an observation operator in data assimilation approaches to reconstruct past climate.
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# Funding_Agency
#	Funding_Agency_Name: Swiss National Science Foundation
#	Grant:
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# Site_Information
#	Site_Name: Boulder Creek Alaska Near Haines
#	Location:
#	Country: United States
#	Northernmost_Latitude: 59.35
#	Southernmost_Latitude: 59.35
#	Easternmost_Longitude: -135.77
#	Westernmost_Longitude: -135.77
#	Elevation: 45 m
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# Data_Collection
#	Collection_Name: northamerica_usa_ak22B
#	Earliest_Year: 1858
#	Most_Recent_Year: 1985
#	Time_Unit: y_ad
#	Core_Length:
#	Notes: {"sensitivity":"temperature"}{"T1":"4.41428604297"}{"T2":"16.4098933425"}{"M1":"0.0227484616162"}{"M2":"0.422821901536"}
#--------------------
# Species
#	Species_Name: Sitka spruce
#	Species_Code: PCSI
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# Chronology:
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# Variables
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# Data variables follow that are preceded by ## in columns one and two.
# Data line variables format:  Variables list, one per line, shortname-tab-longname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data)
#
##age	age, , ,years AD, , , , ,N
##trsgi	tree ring standardized growth index, tree ring, ,percent relative to mean growth, , Tree Rings, , ,N
#
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# Data:
# Data lines follow (have no #)
# Data line format - tab-delimited text, variable short name as header
# Missing Values: nan
#
age	trsgi
1858	0.969
1859	1.003
1860	0.946
1861	0.961
1862	0.918
1863	1.048
1864	1.022
1865	1.019
1866	1.052
1867	0.91
1868	1.039
1869	1.091
1870	1.165
1871	1.058
1872	1.141
1873	1.129
1874	1.247
1875	0.997
1876	0.769
1877	0.941
1878	1.014
1879	1.086
1880	1.032
1881	1.013
1882	1.006
1883	1.13
1884	1.154
1885	0.999
1886	1.296
1887	0.882
1888	0.807
1889	0.953
1890	1.125
1891	1.031
1892	0.936
1893	0.927
1894	0.89
1895	0.849
1896	0.798
1897	0.805
1898	0.842
1899	0.897
1900	1.056
1901	0.876
1902	1.01
1903	0.952
1904	0.866
1905	0.985
1906	0.94
1907	1.06
1908	0.999
1909	1.042
1910	1.052
1911	0.996
1912	1.03
1913	1.174
1914	1.143
1915	1.415
1916	1.023
1917	1.071
1918	0.964
1919	0.897
1920	0.956
1921	0.962
1922	0.875
1923	1.014
1924	0.864
1925	0.927
1926	0.96
1927	0.901
1928	0.987
1929	0.942
1930	1.056
1931	0.889
1932	0.879
1933	1.063
1934	1.121
1935	1.172
1936	1.043
1937	0.835
1938	0.878
1939	0.779
1940	0.845
1941	0.864
1942	0.997
1943	0.864
1944	0.881
1945	1.012
1946	1.133
1947	1.074
1948	0.877
1949	0.637
1950	0.936
1951	0.757
1952	0.839
1953	0.627
1954	0.391
1955	0.677
1956	0.917
1957	0.903
1958	0.783
1959	0.961
1960	1.189
1961	1.216
1962	1.265
1963	1.032
1964	1.154
1965	1.249
1966	1.166
1967	1.018
1968	1.001
1969	1.217
1970	1.023
1971	1.145
1972	0.935
1973	1.119
1974	1.111
1975	0.938
1976	1.07
1977	1.013
1978	0.943
1979	1.229
1980	1.055
1981	1.053
1982	1.096
1983	1.123
1984	1.241
1985	1.296