# northamerica_usa_ak044 - Usibelli below treeline - 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:
#
# Description/Documentation lines begin with #
# Data lines have no #
#
# Archive: Tree Rings
#--------------------
# Contribution_Date
#	Date: 2016-01-07
#--------------------
# Title
#	Study_Name: northamerica_usa_ak044 - Usibelli below treeline - 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.
#--------------------
# Funding_Agency
#	Funding_Agency_Name: Swiss National Science Foundation
#	Grant:
#--------------------
# Site_Information
#	Site_Name: Usibelli below treeline
#	Location:
#	Country: United States
#	Northernmost_Latitude: 63.9
#	Southernmost_Latitude: 63.9
#	Easternmost_Longitude: -148.67
#	Westernmost_Longitude: -148.67
#	Elevation: 762 m
#--------------------
# Data_Collection
#	Collection_Name: northamerica_usa_ak044B
#	Earliest_Year: 1832
#	Most_Recent_Year: 1996
#	Time_Unit: y_ad
#	Core_Length:
#	Notes: {"sensitivity":"temperature"}{"T1":"6.33156295802"}{"T2":"18.1237411492"}{"M1":"0.0225088323454"}{"M2":"0.392447357168"}
#--------------------
# Species
#	Species_Name: white spruce
#	Species_Code: PCGL
#--------------------
# Chronology:
#
#
#
#--------------------
# 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
1832	1.077
1833	0.92
1834	0.471
1835	0.499
1836	0.648
1837	0.696
1838	0.756
1839	0.757
1840	0.784
1841	1.177
1842	0.858
1843	1.026
1844	0.773
1845	0.64
1846	0.735
1847	0.794
1848	0.792
1849	0.585
1850	0.635
1851	0.616
1852	0.692
1853	0.829
1854	0.815
1855	0.954
1856	0.815
1857	0.737
1858	0.722
1859	0.939
1860	1.119
1861	1.104
1862	0.915
1863	0.782
1864	0.774
1865	0.801
1866	0.722
1867	0.853
1868	0.752
1869	0.682
1870	0.848
1871	0.966
1872	0.749
1873	0.884
1874	0.99
1875	0.962
1876	1.084
1877	1.151
1878	1.027
1879	1.19
1880	1.312
1881	1.427
1882	1.167
1883	1.181
1884	1.371
1885	1.167
1886	1.27
1887	0.726
1888	0.877
1889	0.961
1890	1.164
1891	1.3
1892	1.07
1893	1.119
1894	0.811
1895	0.657
1896	0.816
1897	0.99
1898	0.938
1899	0.827
1900	1.017
1901	1.05
1902	1.131
1903	0.915
1904	1.008
1905	0.849
1906	1.223
1907	1.054
1908	1.01
1909	0.926
1910	0.749
1911	0.999
1912	0.913
1913	1.083
1914	1.081
1915	0.666
1916	0.601
1917	1.154
1918	1.21
1919	0.787
1920	1.252
1921	1.529
1922	1.013
1923	1.185
1924	0.82
1925	1.12
1926	0.854
1927	0.874
1928	0.712
1929	0.928
1930	1.001
1931	0.869
1932	1.074
1933	0.923
1934	1.116
1935	1.235
1936	1.176
1937	0.744
1938	0.655
1939	1.026
1940	0.653
1941	0.875
1942	1.034
1943	1.085
1944	0.877
1945	0.847
1946	1.101
1947	1.047
1948	1.2
1949	0.83
1950	0.889
1951	0.618
1952	0.91
1953	1.007
1954	0.944
1955	1.033
1956	0.873
1957	0.853
1958	0.597
1959	0.982
1960	1.116
1961	0.87
1962	0.93
1963	0.669
1964	0.9
1965	0.885
1966	1.213
1967	1.068
1968	1.228
1969	0.926
1970	0.76
1971	1.284
1972	0.857
1973	0.615
1974	0.925
1975	1.023
1976	1.307
1977	1.073
1978	0.773
1979	1.133
1980	1.168
1981	1.178
1982	1.662
1983	0.964
1984	0.883
1985	1.132
1986	1.197
1987	1.011
1988	1.022
1989	0.87
1990	1.004
1991	0.924
1992	1.057
1993	0.795
1994	0.882
1995	1.09
1996	1.246