# northamerica_usa_co527 - Big Elk Meadows - 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_co527 - Big Elk Meadows - 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: Big Elk Meadows
#	Location:
#	Country: United States
#	Northernmost_Latitude: 40.22
#	Southernmost_Latitude: 40.22
#	Easternmost_Longitude: -105.42
#	Westernmost_Longitude: -105.42
#	Elevation: 2438 m
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# Data_Collection
#	Collection_Name: northamerica_usa_co527B
#	Earliest_Year: 1818
#	Most_Recent_Year: 1983
#	Time_Unit: y_ad
#	Core_Length:
#	Notes: {"sensitivity":"moisture"}{"T1":"4.49222022964"}{"T2":"15.9605263082"}{"M1":"0.0231159473655"}{"M2":"0.50415808396"}
#--------------------
# Species
#	Species_Name: ponderosa pine
#	Species_Code: PIPO
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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
1818	1.18
1819	1.19
1820	1.082
1821	0.463
1822	0.889
1823	0.386
1824	0.499
1825	0.823
1826	1.02
1827	1.126
1828	1.348
1829	1.195
1830	1.008
1831	0.993
1832	1.003
1833	1.062
1834	1.165
1835	1.142
1836	1.168
1837	1.168
1838	1.197
1839	1.138
1840	0.932
1841	1.132
1842	0.698
1843	1.007
1844	1.023
1845	0.996
1846	0.541
1847	0.628
1848	0.662
1849	0.855
1850	0.703
1851	0.525
1852	0.701
1853	0.921
1854	0.934
1855	0.77
1856	0.69
1857	0.782
1858	1.088
1859	0.875
1860	0.851
1861	0.633
1862	0.908
1863	0.838
1864	0.886
1865	0.845
1866	1.045
1867	1.052
1868	1.067
1869	1.192
1870	1.019
1871	0.81
1872	0.967
1873	0.813
1874	1.057
1875	1.26
1876	1.338
1877	1.228
1878	1.414
1879	1.105
1880	0.499
1881	0.973
1882	0.918
1883	1.17
1884	0.943
1885	0.836
1886	0.975
1887	0.639
1888	0.893
1889	1.382
1890	1.005
1891	1.472
1892	1.291
1893	0.823
1894	1.613
1895	1.387
1896	1.049
1897	1.476
1898	1.324
1899	1.119
1900	1.147
1901	1.222
1902	0.921
1903	1.172
1904	1.215
1905	0.993
1906	1.133
1907	1.207
1908	1.074
1909	1.212
1910	0.93
1911	0.867
1912	1.179
1913	1.015
1914	1.221
1915	1.27
1916	1.08
1917	0.861
1918	1.039
1919	0.681
1920	0.92
1921	1.13
1922	0.585
1923	1.268
1924	0.896
1925	0.643
1926	0.955
1927	0.766
1928	0.979
1929	0.61
1930	0.712
1931	0.659
1932	0.404
1933	0.639
1934	0.597
1935	0.717
1936	0.694
1937	0.957
1938	1.149
1939	0.76
1940	1.074
1941	1.258
1942	1.192
1943	1.129
1944	0.941
1945	1.067
1946	0.741
1947	1.391
1948	0.98
1949	1.157
1950	0.997
1951	1.121
1952	1.224
1953	1.077
1954	0.229
1955	0.919
1956	0.843
1957	0.923
1958	1.025
1959	0.937
1960	0.992
1961	1.175
1962	1.17
1963	0.725
1964	0.476
1965	0.884
1966	0.485
1967	1.171
1968	1.01
1969	1.431
1970	1.35
1971	1.079
1972	1.309
1973	0.96
1974	0.901
1975	1.284
1976	0.93
1977	0.524
1978	0.92
1979	1.054
1980	0.93
1981	1.154
1982	1.417
1983	1.414