# northamerica_usa_co574w - Niwot Ridge C - 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:
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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_co574w - Niwot Ridge C - 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: Niwot Ridge C
#	Location:
#	Country: United States
#	Northernmost_Latitude: 40.05
#	Southernmost_Latitude: 40.05
#	Easternmost_Longitude: -105.55
#	Westernmost_Longitude: -105.55
#	Elevation: 3400 m
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# Data_Collection
#	Collection_Name: northamerica_usa_co574wB
#	Earliest_Year: 1727
#	Most_Recent_Year: 1982
#	Time_Unit: y_ad
#	Core_Length:
#	Notes: {"sensitivity":"temperature"}{"T1":"4.22705114322"}{"T2":"15.8075484736"}{"M1":"0.022553844968"}{"M2":"0.476814788656"}
#--------------------
# Species
#	Species_Name: Engelmann spruce
#	Species_Code: PCEN
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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
1727	0.767
1728	1.165
1729	1.021
1730	0.941
1731	0.913
1732	1.11
1733	1.127
1734	0.905
1735	0.807
1736	0.691
1737	0.66
1738	0.931
1739	0.96
1740	0.853
1741	0.812
1742	0.865
1743	0.938
1744	0.901
1745	0.95
1746	1.083
1747	1.034
1748	0.838
1749	1.157
1750	1.137
1751	0.983
1752	0.874
1753	1.258
1754	1.114
1755	0.914
1756	0.886
1757	1.032
1758	1.04
1759	1.134
1760	1.004
1761	1.019
1762	1.315
1763	0.954
1764	1.073
1765	1.11
1766	1.027
1767	1.2
1768	1.172
1769	1.012
1770	0.847
1771	1.001
1772	1.025
1773	1.235
1774	1.188
1775	0.873
1776	0.919
1777	1.042
1778	0.892
1779	0.953
1780	1.084
1781	0.965
1782	0.923
1783	0.999
1784	1.314
1785	1.141
1786	0.84
1787	1.044
1788	0.777
1789	0.801
1790	0.859
1791	0.921
1792	1.124
1793	0.826
1794	1.016
1795	1.018
1796	1.217
1797	1.152
1798	1.21
1799	1.14
1800	0.963
1801	1.259
1802	1.155
1803	1.025
1804	1.12
1805	0.826
1806	0.863
1807	0.948
1808	0.741
1809	0.855
1810	0.715
1811	0.969
1812	1.183
1813	0.994
1814	0.975
1815	1.004
1816	1.103
1817	0.965
1818	0.866
1819	0.869
1820	0.841
1821	0.991
1822	0.906
1823	0.855
1824	0.811
1825	0.949
1826	0.968
1827	0.798
1828	1.027
1829	1.167
1830	1.229
1831	1.238
1832	1.276
1833	1.364
1834	0.985
1835	0.958
1836	1.098
1837	1.212
1838	1.252
1839	1.189
1840	1.03
1841	1.209
1842	1.078
1843	1.233
1844	1.248
1845	0.863
1846	0.848
1847	0.772
1848	1.146
1849	1.152
1850	0.921
1851	0.649
1852	0.859
1853	0.824
1854	0.861
1855	0.913
1856	1.061
1857	0.652
1858	0.761
1859	0.824
1860	0.904
1861	0.843
1862	0.931
1863	0.959
1864	1.138
1865	0.881
1866	0.693
1867	0.711
1868	0.53
1869	0.799
1870	0.929
1871	0.982
1872	0.679
1873	1.016
1874	0.779
1875	0.855
1876	1.105
1877	0.841
1878	0.763
1879	0.714
1880	0.609
1881	1.112
1882	0.586
1883	0.739
1884	0.806
1885	0.983
1886	0.9
1887	0.746
1888	0.808
1889	0.693
1890	0.522
1891	0.732
1892	0.801
1893	0.593
1894	0.868
1895	0.98
1896	0.799
1897	1.014
1898	1.035
1899	0.907
1900	0.783
1901	0.832
1902	0.657
1903	0.842
1904	0.809
1905	0.875
1906	0.701
1907	1.163
1908	1.226
1909	1.328
1910	1.274
1911	1.151
1912	1.117
1913	1.206
1914	1.188
1915	1.043
1916	1.065
1917	1.139
1918	1.095
1919	1.047
1920	1.003
1921	1.223
1922	1.12
1923	1.175
1924	1.29
1925	1.14
1926	1.165
1927	1.271
1928	1.322
1929	1.296
1930	1.332
1931	1.341
1932	1.27
1933	1.309
1934	0.858
1935	0.837
1936	1.082
1937	1.012
1938	1.154
1939	1.102
1940	1.153
1941	0.855
1942	1.053
1943	0.918
1944	0.951
1945	0.829
1946	1.045
1947	1.043
1948	0.972
1949	1.173
1950	1.084
1951	1.384
1952	1.172
1953	0.74
1954	0.704
1955	0.821
1956	0.896
1957	0.958
1958	0.999
1959	0.928
1960	1.038
1961	1.035
1962	1.099
1963	1.045
1964	1.309
1965	1.183
1966	1.048
1967	0.8
1968	0.912
1969	1.064
1970	0.942
1971	1.01
1972	1.105
1973	1.066
1974	1.034
1975	1.058
1976	0.936
1977	0.992
1978	0.877
1979	0.897
1980	0.808
1981	0.78
1982	0.665