# northamerica_usa_ak009 - Slana Bei Tok - 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_ak009 - Slana Bei Tok - 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: Slana Bei Tok
#	Location:
#	Country: United States
#	Northernmost_Latitude: 62.83
#	Southernmost_Latitude: 62.83
#	Easternmost_Longitude: -143.92
#	Westernmost_Longitude: -143.92
#	Elevation: 600 m
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# Data_Collection
#	Collection_Name: northamerica_usa_ak009B
#	Earliest_Year: 1776
#	Most_Recent_Year: 1983
#	Time_Unit: y_ad
#	Core_Length:
#	Notes: {"sensitivity":"moisture"}{"T1":"4.37827816784"}{"T2":"12.568697255"}{"M1":"0.0235131231585"}{"M2":"0.572928417922"}
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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)
#
##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
1776	1.268
1777	1.322
1778	0.639
1779	0.77
1780	0.642
1781	0.7
1782	0.491
1783	0.485
1784	0.442
1785	0.438
1786	0.523
1787	0.608
1788	0.689
1789	0.868
1790	0.73
1791	0.687
1792	0.7
1793	0.806
1794	0.855
1795	0.785
1796	0.77
1797	0.632
1798	0.722
1799	0.619
1800	0.775
1801	0.829
1802	1.079
1803	0.883
1804	0.791
1805	0.861
1806	1.16
1807	0.883
1808	0.834
1809	0.632
1810	0.724
1811	0.791
1812	0.727
1813	0.666
1814	0.637
1815	0.636
1816	0.701
1817	0.512
1818	0.642
1819	0.617
1820	0.713
1821	0.759
1822	0.826
1823	0.88
1824	0.799
1825	0.888
1826	1.006
1827	1.204
1828	1.162
1829	1.177
1830	0.968
1831	0.92
1832	1.216
1833	1.13
1834	1.098
1835	1.198
1836	1.22
1837	1.294
1838	1.179
1839	0.993
1840	0.996
1841	1.242
1842	1.267
1843	1.296
1844	1.344
1845	1.055
1846	1.335
1847	1.138
1848	1.41
1849	1.126
1850	1.233
1851	1.217
1852	1.356
1853	1.389
1854	1.589
1855	1.609
1856	1.282
1857	1.422
1858	1.515
1859	1.422
1860	1.484
1861	1.416
1862	1.564
1863	1.531
1864	1.437
1865	1.361
1866	1.295
1867	1.364
1868	1.203
1869	1.212
1870	1.187
1871	1.191
1872	0.987
1873	1.068
1874	1.093
1875	1.147
1876	1.185
1877	1.144
1878	1.203
1879	1.104
1880	1.056
1881	1.307
1882	1.319
1883	1.132
1884	1.365
1885	1.09
1886	1.173
1887	0.922
1888	0.981
1889	0.821
1890	1.004
1891	1.114
1892	1.047
1893	1.174
1894	1.172
1895	1.047
1896	0.97
1897	0.885
1898	0.998
1899	1.041
1900	0.923
1901	1.101
1902	1.304
1903	0.973
1904	0.825
1905	1.082
1906	0.933
1907	0.865
1908	0.999
1909	0.884
1910	0.769
1911	0.888
1912	0.622
1913	0.931
1914	0.771
1915	0.924
1916	0.813
1917	0.865
1918	0.892
1919	0.563
1920	0.75
1921	0.814
1922	0.778
1923	0.964
1924	0.745
1925	0.902
1926	0.884
1927	1.003
1928	0.861
1929	1.166
1930	1.207
1931	1.053
1932	1.073
1933	1.195
1934	1.013
1935	1.027
1936	1.074
1937	0.934
1938	0.979
1939	1.17
1940	0.905
1941	0.894
1942	0.946
1943	0.677
1944	0.668
1945	0.619
1946	0.649
1947	0.696
1948	0.79
1949	0.63
1950	0.595
1951	0.599
1952	0.673
1953	0.658
1954	0.468
1955	0.582
1956	0.652
1957	0.678
1958	0.861
1959	1.133
1960	1.135
1961	1.185
1962	1.179
1963	1.006
1964	1.152
1965	0.879
1966	0.982
1967	0.771
1968	0.744
1969	0.549
1970	0.652
1971	0.872
1972	0.795
1973	0.812
1974	1.003
1975	1.13
1976	1.146
1977	0.967
1978	0.965
1979	1.1
1980	0.948
1981	1.092
1982	1.132
1983	0.956