# northamerica_usa_ak17 - Fork Twin Creek  Kodiak Island - 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.
#
#
# Online_Resource:
#
# 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_ak17 - Fork Twin Creek  Kodiak Island - 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:
#--------------------
# Site_Information
#	Site_Name: Fork Twin Creek  Kodiak Island
#	Location:
#	Country: United States
#	Northernmost_Latitude: 57.6
#	Southernmost_Latitude: 57.6
#	Easternmost_Longitude: -152.32
#	Westernmost_Longitude: -152.32
#	Elevation: 25 m
#--------------------
# Data_Collection
#	Collection_Name: northamerica_usa_ak17B
#	Earliest_Year: 1762
#	Most_Recent_Year: 1985
#	Time_Unit: y_ad
#	Core_Length:
#	Notes: {"sensitivity":"temperature"}{"T1":"5.18979297887"}{"T2":"14.6598657627"}{"M1":"0.0225860332601"}{"M2":"0.500813788935"}
#--------------------
# Species
#	Species_Name: Sitka spruce
#	Species_Code: PCSI
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# Chronology:
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# Variables
#
# 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
#
#--------------------
# Data:
# Data lines follow (have no #)
# Data line format - tab-delimited text, variable short name as header
# Missing Values: nan
#
age	trsgi
1762	1.059
1763	1.169
1764	1.072
1765	1.243
1766	1.095
1767	1.206
1768	0.879
1769	0.89
1770	0.802
1771	1.02
1772	1.221
1773	1.129
1774	1.246
1775	1.279
1776	1.349
1777	1.458
1778	1.298
1779	1.331
1780	1.242
1781	0.916
1782	1.177
1783	0.992
1784	1.622
1785	1.218
1786	1.273
1787	1.049
1788	1.045
1789	0.766
1790	0.882
1791	0.976
1792	1.044
1793	1.122
1794	1.287
1795	1.403
1796	1.264
1797	1.231
1798	1.148
1799	1.191
1800	1.06
1801	1.07
1802	1.104
1803	1.348
1804	1.497
1805	1.264
1806	0.905
1807	0.835
1808	0.975
1809	0.722
1810	0.674
1811	0.291
1812	0.216
1813	0.288
1814	0.4
1815	0.85
1816	1.121
1817	1.318
1818	1.289
1819	1.114
1820	0.909
1821	0.913
1822	0.546
1823	0.577
1824	0.753
1825	0.519
1826	0.563
1827	0.898
1828	1.022
1829	1.167
1830	0.985
1831	0.785
1832	0.785
1833	0.619
1834	0.691
1835	1.003
1836	1.104
1837	0.955
1838	0.955
1839	1.02
1840	1.189
1841	1.445
1842	0.87
1843	0.883
1844	0.927
1845	0.913
1846	0.709
1847	0.521
1848	0.453
1849	0.662
1850	0.77
1851	1.056
1852	1.179
1853	0.904
1854	1.005
1855	0.851
1856	0.741
1857	0.917
1858	0.958
1859	0.859
1860	0.73
1861	0.671
1862	0.72
1863	0.875
1864	0.874
1865	1.007
1866	0.968
1867	0.838
1868	0.827
1869	0.588
1870	0.78
1871	0.788
1872	1.035
1873	1.059
1874	1.187
1875	0.906
1876	0.69
1877	0.845
1878	0.831
1879	0.931
1880	0.93
1881	0.948
1882	0.582
1883	0.809
1884	1.126
1885	1.15
1886	1.106
1887	1.012
1888	1.335
1889	0.952
1890	0.959
1891	0.805
1892	0.828
1893	0.966
1894	0.826
1895	1.083
1896	1.022
1897	0.892
1898	0.912
1899	1.072
1900	1.011
1901	1.157
1902	1.387
1903	1.352
1904	0.96
1905	1.06
1906	0.826
1907	0.996
1908	0.901
1909	0.924
1910	0.85
1911	0.862
1912	0.449
1913	0.476
1914	0.811
1915	1.417
1916	1.447
1917	2.006
1918	1.48
1919	1.032
1920	1.093
1921	1.16
1922	1.054
1923	1.089
1924	0.992
1925	0.991
1926	0.954
1927	0.968
1928	1.041
1929	1.041
1930	0.901
1931	0.767
1932	0.614
1933	0.952
1934	1.2
1935	1.155
1936	1.372
1937	1.096
1938	1.156
1939	1.438
1940	1.257
1941	1.209
1942	1.533
1943	1.768
1944	1.952
1945	1.78
1946	1.553
1947	1.77
1948	1.424
1949	1.377
1950	1.093
1951	0.901
1952	0.731
1953	0.613
1954	0.546
1955	0.594
1956	0.728
1957	0.862
1958	0.844
1959	1.106
1960	0.855
1961	0.937
1962	0.933
1963	0.912
1964	0.84
1965	0.722
1966	1.027
1967	1.153
1968	1.126
1969	0.926
1970	0.853
1971	0.998
1972	0.765
1973	0.775
1974	0.858
1975	0.794
1976	0.744
1977	0.72
1978	0.629
1979	0.911
1980	0.957
1981	1.107
1982	0.992
1983	0.904
1984	0.873
1985	0.85