# northamerica_usa_ak029 - Water Supply - Breitenmoser Tree Ring Chronology Data
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#		World Data Center for Paleoclimatology, Boulder
#				and
#		NOAA Paleoclimatology Program
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# 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
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# Contribution_Date
#	Date: 2016-01-07
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# Title
#	Study_Name: northamerica_usa_ak029 - Water Supply - 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: Water Supply
#	Location:
#	Country: United States
#	Northernmost_Latitude: 60.12
#	Southernmost_Latitude: 60.12
#	Easternmost_Longitude: -149.47
#	Westernmost_Longitude: -149.47
#	Elevation: 305 m
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# Data_Collection
#	Collection_Name: northamerica_usa_ak029B
#	Earliest_Year: 1795
#	Most_Recent_Year: 1989
#	Time_Unit: y_ad
#	Core_Length:
#	Notes: {"sensitivity":"temperature"}{"T1":"4.29398788771"}{"T2":"17.8170063781"}{"M1":"0.0222261611587"}{"M2":"0.38598807413"}
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# Species
#	Species_Name: mountain hemlock
#	Species_Code: TSME
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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)
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##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
1795	1.278
1796	1.0
1797	1.58
1798	1.006
1799	0.972
1800	0.78
1801	1.244
1802	0.952
1803	0.739
1804	0.957
1805	1.01
1806	0.975
1807	1.023
1808	1.109
1809	0.784
1810	0.744
1811	0.573
1812	0.704
1813	0.578
1814	0.497
1815	1.174
1816	1.433
1817	1.265
1818	1.432
1819	1.116
1820	0.848
1821	0.834
1822	1.144
1823	0.79
1824	1.377
1825	1.398
1826	1.564
1827	1.041
1828	1.751
1829	1.622
1830	0.788
1831	0.527
1832	0.727
1833	1.106
1834	1.002
1835	1.604
1836	1.191
1837	1.445
1838	1.598
1839	1.673
1840	1.312
1841	1.349
1842	0.79
1843	0.929
1844	1.105
1845	1.247
1846	1.474
1847	1.114
1848	0.576
1849	0.326
1850	0.527
1851	0.613
1852	0.742
1853	0.685
1854	0.597
1855	0.534
1856	0.61
1857	0.595
1858	0.652
1859	0.645
1860	0.707
1861	0.747
1862	0.46
1863	0.609
1864	0.849
1865	1.063
1866	1.279
1867	1.051
1868	1.065
1869	1.106
1870	1.478
1871	1.391
1872	2.195
1873	1.676
1874	1.378
1875	1.368
1876	0.456
1877	0.456
1878	0.972
1879	1.258
1880	0.972
1881	1.293
1882	1.051
1883	1.037
1884	1.505
1885	1.127
1886	0.982
1887	0.624
1888	1.0
1889	1.054
1890	0.748
1891	0.765
1892	1.046
1893	1.046
1894	0.524
1895	0.233
1896	0.263
1897	0.254
1898	0.467
1899	0.495
1900	0.655
1901	0.827
1902	0.859
1903	0.603
1904	0.767
1905	1.114
1906	0.884
1907	0.781
1908	1.119
1909	1.055
1910	1.129
1911	1.289
1912	1.183
1913	1.297
1914	1.137
1915	1.678
1916	1.035
1917	1.343
1918	0.946
1919	1.029
1920	0.943
1921	1.094
1922	1.104
1923	1.392
1924	1.203
1925	1.194
1926	1.485
1927	0.784
1928	0.432
1929	0.365
1930	0.683
1931	1.014
1932	1.173
1933	1.446
1934	1.257
1935	1.361
1936	1.186
1937	0.646
1938	1.056
1939	0.838
1940	0.998
1941	1.588
1942	1.802
1943	1.602
1944	0.884
1945	0.556
1946	0.727
1947	1.302
1948	0.993
1949	1.063
1950	1.058
1951	0.838
1952	0.994
1953	1.065
1954	0.77
1955	0.663
1956	0.506
1957	0.943
1958	0.846
1959	0.996
1960	1.046
1961	1.203
1962	0.939
1963	1.009
1964	0.962
1965	1.007
1966	1.053
1967	0.781
1968	1.229
1969	0.966
1970	0.977
1971	0.776
1972	0.526
1973	0.35
1974	0.701
1975	0.632
1976	0.649
1977	0.822
1978	0.999
1979	1.273
1980	0.735
1981	1.18
1982	1.047
1983	1.104
1984	1.344
1985	1.132
1986	1.172
1987	0.871
1988	1.282
1989	1.059