# northamerica_usa_ak085 - Dalton Highway Mile Post 235 - 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_ak085 - Dalton Highway Mile Post 235 - 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: Dalton Highway Mile Post 235
#	Location:
#	Country: United States
#	Northernmost_Latitude: 68.03
#	Southernmost_Latitude: 68.03
#	Easternmost_Longitude: -149.68
#	Westernmost_Longitude: -149.68
#	Elevation: 810 m
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# Data_Collection
#	Collection_Name: northamerica_usa_ak085B
#	Earliest_Year: 1849
#	Most_Recent_Year: 2005
#	Time_Unit: y_ad
#	Core_Length:
#	Notes: {"sensitivity":"temperature"}{"T1":"4.35488950676"}{"T2":"17.6983752307"}{"M1":"0.0220997633504"}{"M2":"0.356290616215"}
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# Species
#	Species_Name: white spruce
#	Species_Code: PCGL
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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)
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##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
1849	0.926
1850	0.776
1851	0.969
1852	0.937
1853	1.117
1854	1.372
1855	1.6
1856	0.937
1857	1.144
1858	1.046
1859	0.828
1860	0.728
1861	0.849
1862	0.856
1863	0.716
1864	0.568
1865	0.871
1866	0.86
1867	0.939
1868	0.604
1869	0.493
1870	0.676
1871	0.512
1872	0.616
1873	0.86
1874	0.973
1875	0.984
1876	1.251
1877	1.21
1878	1.052
1879	1.222
1880	1.126
1881	1.122
1882	1.456
1883	0.935
1884	1.017
1885	1.451
1886	1.179
1887	0.957
1888	1.07
1889	1.319
1890	1.189
1891	1.332
1892	1.074
1893	0.978
1894	1.113
1895	1.525
1896	1.341
1897	1.411
1898	0.934
1899	0.631
1900	0.696
1901	0.839
1902	1.05
1903	0.95
1904	0.899
1905	0.754
1906	1.235
1907	0.98
1908	1.148
1909	1.092
1910	0.997
1911	1.181
1912	0.806
1913	1.122
1914	0.923
1915	0.949
1916	0.871
1917	1.019
1918	1.088
1919	0.479
1920	0.888
1921	0.979
1922	0.545
1923	1.174
1924	0.837
1925	0.999
1926	0.942
1927	0.967
1928	0.887
1929	1.081
1930	1.0
1931	0.8
1932	0.829
1933	0.609
1934	0.81
1935	0.931
1936	1.023
1937	0.932
1938	0.86
1939	1.103
1940	0.79
1941	1.001
1942	1.041
1943	1.104
1944	1.162
1945	0.918
1946	1.084
1947	0.9
1948	0.869
1949	0.671
1950	1.023
1951	0.892
1952	1.202
1953	0.986
1954	1.26
1955	1.221
1956	0.95
1957	1.175
1958	1.241
1959	1.032
1960	1.375
1961	1.101
1962	1.171
1963	0.935
1964	1.108
1965	1.015
1966	0.95
1967	1.086
1968	1.173
1969	0.653
1970	0.65
1971	1.019
1972	0.965
1973	0.677
1974	0.717
1975	0.857
1976	0.856
1977	1.179
1978	0.932
1979	0.947
1980	1.236
1981	0.941
1982	1.275
1983	0.996
1984	1.141
1985	1.109
1986	0.984
1987	0.779
1988	0.918
1989	0.888
1990	1.025
1991	1.069
1992	1.127
1993	0.579
1994	0.686
1995	0.849
1996	1.184
1997	1.278
1998	1.223
1999	1.103
2000	1.072
2001	1.054
2002	0.81
2003	0.864
2004	0.964
2005	0.669