# northamerica_usa_tn027 - Porter's Creek - 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_tn027 - Porter's Creek - 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: Porter's Creek
#	Location:
#	Country: United States
#	Northernmost_Latitude: 35.67
#	Southernmost_Latitude: 35.67
#	Easternmost_Longitude: -82.38
#	Westernmost_Longitude: -82.38
#	Elevation: 1005 m
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# Data_Collection
#	Collection_Name: northamerica_usa_tn027B
#	Earliest_Year: 1809
#	Most_Recent_Year: 1997
#	Time_Unit: y_ad
#	Core_Length:
#	Notes: {"sensitivity":"temperature"}{"T1":"3.49883190974"}{"T2":"17.944627043"}{"M1":"0.0229196409621"}{"M2":"0.490177419336"}
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# Species
#	Species_Name: tuliptree
#	Species_Code: LITU
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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
1809	0.993
1810	1.322
1811	1.046
1812	0.72
1813	0.662
1814	0.87
1815	1.093
1816	1.044
1817	1.001
1818	1.053
1819	0.704
1820	0.458
1821	0.544
1822	0.67
1823	0.894
1824	1.152
1825	1.105
1826	1.522
1827	1.478
1828	1.605
1829	1.171
1830	1.334
1831	1.032
1832	0.975
1833	1.064
1834	1.184
1835	0.873
1836	0.866
1837	0.594
1838	0.933
1839	0.546
1840	0.882
1841	0.697
1842	0.771
1843	0.9
1844	0.859
1845	1.056
1846	0.812
1847	0.996
1848	1.094
1849	1.258
1850	1.177
1851	1.43
1852	1.149
1853	1.237
1854	0.489
1855	0.853
1856	0.819
1857	0.95
1858	0.567
1859	0.688
1860	0.791
1861	0.563
1862	0.61
1863	0.588
1864	0.633
1865	0.498
1866	0.786
1867	0.612
1868	0.796
1869	0.717
1870	0.673
1871	0.677
1872	0.823
1873	0.794
1874	0.611
1875	1.158
1876	1.638
1877	1.353
1878	1.537
1879	0.883
1880	1.51
1881	1.237
1882	1.821
1883	1.063
1884	1.586
1885	1.266
1886	1.068
1887	1.255
1888	1.04
1889	1.347
1890	1.411
1891	1.096
1892	1.073
1893	0.944
1894	1.039
1895	0.887
1896	1.029
1897	1.405
1898	0.879
1899	0.768
1900	0.824
1901	1.001
1902	1.017
1903	1.158
1904	0.814
1905	0.974
1906	1.138
1907	1.074
1908	0.647
1909	0.885
1910	0.875
1911	0.842
1912	0.858
1913	1.026
1914	0.528
1915	1.098
1916	1.169
1917	0.959
1918	0.666
1919	0.75
1920	0.792
1921	0.596
1922	1.312
1923	1.451
1924	1.01
1925	0.791
1926	0.501
1927	0.607
1928	1.018
1929	0.63
1930	0.489
1931	0.438
1932	0.748
1933	0.696
1934	0.953
1935	0.931
1936	0.63
1937	1.197
1938	1.131
1939	1.212
1940	0.845
1941	0.764
1942	1.098
1943	1.038
1944	0.613
1945	0.786
1946	0.879
1947	1.022
1948	1.005
1949	1.152
1950	1.364
1951	1.275
1952	1.325
1953	1.34
1954	1.283
1955	0.894
1956	1.073
1957	1.076
1958	1.094
1959	0.876
1960	1.101
1961	0.848
1962	0.927
1963	0.752
1964	1.052
1965	0.586
1966	0.781
1967	0.716
1968	0.866
1969	0.761
1970	0.571
1971	0.745
1972	1.04
1973	1.029
1974	1.282
1975	1.329
1976	1.016
1977	0.882
1978	0.798
1979	0.765
1980	1.296
1981	0.949
1982	1.24
1983	1.344
1984	0.964
1985	1.558
1986	0.701
1987	1.144
1988	0.799
1989	1.092
1990	0.932
1991	1.396
1992	1.155
1993	1.073
1994	0.701
1995	1.023
1996	1.191
1997	1.07