# northamerica_usa_ak6 - Starrigawan  Old Sitka - 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_ak6 - Starrigawan  Old Sitka - 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: Starrigawan  Old Sitka
#	Location:
#	Country: United States
#	Northernmost_Latitude: 57.13
#	Southernmost_Latitude: 57.13
#	Easternmost_Longitude: -135.38
#	Westernmost_Longitude: -135.38
#	Elevation: 5 m
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# Data_Collection
#	Collection_Name: northamerica_usa_ak6B
#	Earliest_Year: 1800
#	Most_Recent_Year: 1985
#	Time_Unit: y_ad
#	Core_Length:
#	Notes: {"sensitivity":"temperature"}{"T1":"4.36973550847"}{"T2":"16.5607380709"}{"M1":"0.022227653922"}{"M2":"0.414791183072"}
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# 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
1800	0.916
1801	1.321
1802	1.531
1803	1.401
1804	1.579
1805	1.331
1806	1.124
1807	1.269
1808	1.238
1809	0.96
1810	0.68
1811	0.478
1812	0.576
1813	0.553
1814	0.477
1815	0.713
1816	0.795
1817	0.586
1818	0.688
1819	0.788
1820	0.684
1821	0.599
1822	0.694
1823	0.674
1824	0.694
1825	0.693
1826	0.403
1827	0.518
1828	0.628
1829	0.646
1830	0.847
1831	0.815
1832	0.751
1833	0.563
1834	0.604
1835	0.703
1836	0.634
1837	0.55
1838	0.607
1839	0.569
1840	0.509
1841	0.591
1842	0.628
1843	0.698
1844	0.648
1845	0.613
1846	0.629
1847	0.593
1848	0.743
1849	0.58
1850	0.629
1851	0.782
1852	0.783
1853	0.93
1854	0.82
1855	0.911
1856	0.869
1857	1.059
1858	0.998
1859	0.9
1860	1.061
1861	0.947
1862	0.724
1863	0.868
1864	0.909
1865	0.93
1866	0.844
1867	0.906
1868	0.7
1869	0.908
1870	0.972
1871	0.862
1872	0.862
1873	0.922
1874	1.015
1875	1.022
1876	0.804
1877	1.013
1878	1.081
1879	1.049
1880	0.959
1881	1.104
1882	1.082
1883	1.389
1884	1.254
1885	1.094
1886	1.396
1887	1.085
1888	1.401
1889	1.277
1890	1.404
1891	1.442
1892	1.59
1893	1.425
1894	1.336
1895	1.313
1896	1.337
1897	1.348
1898	1.549
1899	1.381
1900	1.447
1901	1.379
1902	1.543
1903	1.299
1904	0.9
1905	1.148
1906	1.17
1907	1.215
1908	1.235
1909	1.194
1910	0.843
1911	1.018
1912	1.151
1913	1.319
1914	1.473
1915	1.569
1916	1.092
1917	1.09
1918	1.208
1919	1.219
1920	1.163
1921	1.225
1922	0.992
1923	1.142
1924	1.059
1925	1.058
1926	1.059
1927	1.045
1928	0.983
1929	1.161
1930	1.132
1931	1.24
1932	1.17
1933	1.281
1934	1.029
1935	1.022
1936	0.987
1937	0.756
1938	0.937
1939	1.013
1940	1.1
1941	1.103
1942	1.181
1943	1.168
1944	1.054
1945	0.961
1946	1.049
1947	0.848
1948	0.921
1949	0.806
1950	0.978
1951	0.799
1952	0.753
1953	0.815
1954	0.666
1955	0.84
1956	0.922
1957	1.073
1958	1.083
1959	0.927
1960	0.931
1961	0.888
1962	0.886
1963	0.994
1964	0.898
1965	0.81
1966	0.804
1967	0.781
1968	0.664
1969	0.628
1970	0.627
1971	0.714
1972	0.545
1973	0.747
1974	0.718
1975	0.611
1976	0.682
1977	0.814
1978	0.865
1979	0.926
1980	1.048
1981	0.947
1982	0.826
1983	1.013
1984	1.04
1985	1.015