# northamerica_usa_ak047 - Firth River - 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
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# Contribution_Date
#	Date: 2016-01-07
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# Title
#	Study_Name: northamerica_usa_ak047 - Firth River - 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: Firth River
#	Location:
#	Country: United States
#	Northernmost_Latitude: 68.1
#	Southernmost_Latitude: 68.1
#	Easternmost_Longitude: -141.1
#	Westernmost_Longitude: -141.1
#	Elevation: 100 m
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# Data_Collection
#	Collection_Name: northamerica_usa_ak047B
#	Earliest_Year: 1802
#	Most_Recent_Year: 2002
#	Time_Unit: y_ad
#	Core_Length:
#	Notes: {"sensitivity":"temperature"}{"T1":"4.12225486614"}{"T2":"17.4670069158"}{"M1":"0.0220645914799"}{"M2":"0.348669700261"}
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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
1802	0.967
1803	1.058
1804	1.006
1805	0.982
1806	1.166
1807	1.161
1808	1.298
1809	1.177
1810	1.273
1811	1.233
1812	1.041
1813	1.196
1814	0.726
1815	0.871
1816	0.772
1817	0.845
1818	0.824
1819	0.65
1820	0.7
1821	0.664
1822	0.759
1823	0.939
1824	1.156
1825	1.011
1826	1.192
1827	0.773
1828	1.391
1829	1.146
1830	0.922
1831	0.873
1832	1.04
1833	1.019
1834	1.118
1835	0.909
1836	1.18
1837	0.885
1838	0.967
1839	0.801
1840	1.333
1841	1.017
1842	0.878
1843	1.048
1844	1.018
1845	0.8
1846	1.166
1847	1.089
1848	1.349
1849	0.9
1850	0.756
1851	0.692
1852	0.633
1853	0.855
1854	0.82
1855	1.001
1856	0.797
1857	0.802
1858	1.012
1859	1.067
1860	0.998
1861	1.03
1862	1.093
1863	1.228
1864	0.726
1865	1.051
1866	1.02
1867	1.056
1868	0.846
1869	0.957
1870	0.88
1871	0.702
1872	0.87
1873	0.614
1874	0.567
1875	1.022
1876	0.895
1877	0.768
1878	0.7
1879	0.887
1880	0.946
1881	0.565
1882	0.863
1883	0.661
1884	0.689
1885	0.832
1886	0.839
1887	0.674
1888	0.852
1889	0.745
1890	0.664
1891	0.843
1892	0.464
1893	0.769
1894	0.957
1895	1.423
1896	1.367
1897	1.446
1898	1.145
1899	1.113
1900	1.266
1901	1.328
1902	1.056
1903	1.086
1904	1.161
1905	0.949
1906	1.145
1907	1.028
1908	1.021
1909	1.248
1910	1.362
1911	1.252
1912	0.917
1913	1.062
1914	1.209
1915	1.073
1916	1.014
1917	0.878
1918	0.643
1919	1.004
1920	0.886
1921	1.03
1922	0.831
1923	1.999
1924	1.217
1925	1.344
1926	1.286
1927	1.255
1928	1.09
1929	1.024
1930	1.177
1931	0.781
1932	0.791
1933	0.83
1934	0.878
1935	1.195
1936	0.963
1937	1.006
1938	0.888
1939	0.799
1940	0.745
1941	0.878
1942	1.081
1943	1.087
1944	1.147
1945	1.199
1946	1.307
1947	1.021
1948	1.08
1949	0.815
1950	1.34
1951	0.906
1952	1.102
1953	1.128
1954	1.499
1955	1.163
1956	1.072
1957	1.127
1958	1.191
1959	1.044
1960	1.051
1961	1.109
1962	1.1
1963	0.96
1964	0.968
1965	1.167
1966	1.09
1967	0.905
1968	1.075
1969	0.976
1970	0.814
1971	0.831
1972	1.124
1973	0.854
1974	0.815
1975	1.073
1976	0.699
1977	0.753
1978	0.869
1979	0.741
1980	1.032
1981	0.765
1982	1.463
1983	0.985
1984	0.971
1985	1.093
1986	1.036
1987	0.834
1988	0.8
1989	0.758
1990	0.79
1991	0.499
1992	1.046
1993	0.559
1994	0.395
1995	0.726
1996	1.011
1997	0.872
1998	1.04
1999	0.905
2000	1.002
2001	0.861
2002	0.468