# Greenland Ice Cores 1,250 Year d18O, Accumulation, and North Atlantic Jet Stream Reconstruction
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#               World Data Service for Paleoclimatology, Boulder
#                                   and
#                      NOAA Paleoclimatology Program
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# Template Version 3.0
# Encoding: UTF-8
# NOTE: Please cite original publication, online resource and date accessed when using this data.
# If there is no publication information, please cite Investigator, title, online resource and date accessed.
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# Description/Documentation lines begin with #
# Data lines have no #
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# Online_Resource: https://www.ncdc.noaa.gov/paleo/study/33773
#      Description: NOAA Landing Page
# Online_Resource: https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/osman2021/summit2021accum.txt
#      Description: NOAA location of the template
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# Data_Type: Ice Cores
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# Dataset_DOI:
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# Parameter_Keywords: accumulation
#---------------------------------------
# Contribution_Date
#    Date: 2021-09-17
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# File_Last_Modified_Date
#    Date: 2021-09-17
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# Title
#    Study_Name: Greenland Ice Cores 1,250 Year d18O, Accumulation, and North Atlantic Jet Stream Reconstruction
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# Investigators
#      Investigators: Osman, M.B.; Coats, S.; Das, S.B.; McConnell, J.R.; Chellman, N.
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# Description_Notes_and_Keywords
#        Description: Previously unpublished raw (i.e., unsmoothed, unaveraged) d18O of precipitation and annually accumulated snowfall ice core measurements for 14/45 ice core records described in Osman et al. (2021, PNAS).  Information on the source and accessibility of the remaining (previously published) ice core records are provided in Table S1 of  the "Supplementary Information" of Osman et al. (2021, PNAS).
#         Provided Keywords: Greenland, North Atlantic, jet stream, water isotope, accumulation, ice core
#---------------------------------------
# Publication
# Authors: Matthew B. Osman, Sloan Coats, Sarah B. Das, Joseph R. McConnell, and Nathan Chellman
# Published_Date_or_Year: 2021-09-21
# Published_Title: North Atlantic jet stream projections in the context of the past 1,250 years
# Journal_Name: Proceedings of the National Academy of Sciences of the United States of America 
# Volume: 118
# Edition: e2104105118
# Issue: 38
# Pages: 
# Report_Number: 
# DOI: 10.1073/pnas.2104105118
# Online_Resource: https://www.pnas.org/content/118/38/e2104105118
# Full_Citation: 
# Abstract: Reconstruction of the North Atlantic jet stream (NAJ) presents a critical, albeit largely unconstrained, paleoclimatic target. Models suggest northward migration and changing variance of the NAJ under 21st-century warming scenarios, but assessing the significance of such projections is hindered by a lack of long-term observations. Here, we incorporate insights from an ensemble of last-millennium water isotope–enabled climate model simulations and a wide array of mean annual water isotope (δ18O) and annually accumulated snowfall records from Greenland ice cores to reconstruct North Atlantic zonal-mean zonal winds back to the 8th century CE. Using this reconstruction we provide preobservational constraints on both annual mean NAJ position and intensity to show that late 20th- and early 21st-century NAJ variations were likely not unique relative to natural variability. Rather, insights from our 1,250 year reconstruction highlight the overwhelming role of natural variability in thus far masking the response of midlatitude atmospheric dynamics to anthropogenic forcing, consistent with recent large-ensemble transient modeling experiments. This masking is not projected to persist under high greenhouse gas emissions scenarios, however, with model projected annual mean NAJ position emerging as distinct from the range of reconstructed natural variability by as early as 2060 CE.
#---------------------------------------
# Publication
# Authors: Joseph R. McConnell, Nathan J. Chellman, Andrew I. Wilson, Andreas Stohl, Monica M. Arienzo, Sabine Eckhardt, Diedrich Fritzsche, Sepp Kipfstuhl, Thomas Opel, Philip F. Place, and Jorgen Peder Steffensen
# Published_Date_or_Year: 2019-07-23
# Published_Title: Pervasive Arctic lead pollution suggests substantial growth in medieval silver production modulated by plague, climate, and conflict
# Journal_Name: Proceedings of the National Academy of Sciences of the United States of America (PNAS)
# Volume: 116
# Edition: 30
# Issue: 
# Pages: 14910-14915
# Report_Number: 
# DOI: 10.1073/pnas.1904515116 
# Online_Resource: 
# Full_Citation: 
# Abstract: Lead pollution in Arctic ice reflects large-scale historical changes in midlatitude industrial activities such as ancient lead/silver production and recent fossil fuel burning. Here we used measurements in a broad array of 13 accurately dated ice cores from Greenland and Severnaya Zemlya to document spatial and temporal changes in Arctic lead pollution from 200 BCE to 2010 CE, with interpretation focused on 500 to 2010 CE. Atmospheric transport modeling indicates that Arctic lead pollution was primarily from European emissions before the 19th-century Industrial Revolution. Temporal variability was surprisingly similar across the large swath of the Arctic represented by the array, with 250- to 300-fold increases in lead pollution observed from the Early Middle Ages to the 1970s industrial peak. Superimposed on these exponential changes were pronounced, multiannual to multidecadal variations, marked by increases coincident with exploitation of new mining regions, improved technologies, and periods of economic prosperity; and decreases coincident with climate disruptions, famines, major wars, and plagues. Results suggest substantial overall growth in lead/silver mining and smelting emissions - and so silver production - from the Early through High Middle Ages, particularly in northern Europe, with lower growth during the Late Middle Ages into the Early Modern Period. Near the end of the second plague pandemic (1348 to ~1700 CE), lead pollution increased sharply through the Industrial Revolution. North American and European pollution abatement policies have reduced Arctic lead pollution by >80% since the 1970s, but recent levels remain ~60-fold higher than at the start of the Middle Ages.
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# Funding_Agency
#    Funding_Agency_Name: US National Science Foundation
#    Grant: OPP-1205196, 909541, 1023672, 1204176, 1406219, 2041281
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# Site_Information
# Site_Name: Summit2010
# Location: North America>Greenland
# Northernmost_Latitude: 72.8
# Southernmost_Latitude: 72.8
# Easternmost_Longitude: -38.5
# Westernmost_Longitude: -38.5
# Elevation: 3258
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# Data_Collection
#   Collection_Name: Summit2021accum
#   First_Year: 1743
#   Last_Year: 2009
#   Time_Unit: Year CE
#   Core_Length: 
#   Notes: 
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# Chronology_Information 
# Chronology: 
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# Variables
# Data variables follow that are preceded by "##" in columns one and two.
# Variables list, one per line, shortname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data)
# 
## age_CE	age,,,year Common Era,,Ice cores,,,N,Year midpoint (CE)
## accumulation	accumulation rate,bulk ice,,kilogram per square meter per year,annual,Ice cores,,,N,annual flux (jan-dec) aqueous
# 
#------------------------
# Data:
# Data lines follow (have no #)
# Data line format - tab-delimited text, variable short name as header
# Missing_Values: 
#
age_CE	accumulation
2009.5	138.0
2008.5	203.1
2007.5	197.1
2006.5	243.2
2005.5	237.3
2004.5	240.3
2003.5	289.4
2002.5	243.4
2001.5	177.3
2000.5	268.5
1999.5	280.6
1998.5	179.4
1997.5	271.7
1996.5	228.6
1995.5	292.9
1994.5	203.6
1993.5	222.7
1992.5	179.6
1991.5	253.9
1990.5	246.9
1989.5	188.7
1988.5	246.0
1987.5	233.0
1986.5	213.9
1985.5	218.0
1984.5	196.9
1983.5	244.1
1982.5	201.0
1981.5	269.3
1980.5	195.0
1979.5	204.1
1978.5	244.3
1977.5	207.2
1976.5	247.5
1975.5	244.5
1974.5	204.3
1973.5	213.4
1972.5	211.4
1971.5	232.5
1970.5	193.3
1969.5	181.3
1968.5	241.7
1967.5	195.4
1966.5	192.4
1965.5	179.3
1964.5	257.9
1963.5	229.8
1962.5	293.3
1961.5	177.4
1960.5	172.4
1959.5	264.2
1958.5	233.0
1957.5	273.4
1956.5	173.5
1955.5	272.5
1954.5	226.1
1953.5	230.1
1952.5	311.0
1951.5	201.9
1950.5	179.8
1949.5	173.7
1948.5	233.3
1947.5	248.5
1946.5	251.6
1945.5	267.8
1944.5	277.9
1943.5	218.4
1942.5	193.1
1941.5	308.4
1940.5	193.2
1939.5	258.9
1938.5	227.6
1937.5	248.9
1936.5	158.9
1935.5	233.8
1934.5	249.0
1933.5	268.3
1932.5	264.3
1931.5	261.2
1930.5	196.5
1929.5	213.7
1928.5	256.3
1927.5	226.9
1926.5	216.8
1925.5	191.5
1924.5	198.6
1923.5	153.0
1922.5	247.3
1921.5	218.0
1920.5	255.5
1919.5	156.2
1918.5	159.2
1917.5	231.3
1916.5	262.8
1915.5	271.9
1914.5	182.7
1913.5	246.6
1912.5	212.2
1911.5	237.6
1910.5	318.9
1909.5	178.8
1908.5	227.5
1907.5	198.1
1906.5	200.2
1905.5	258.2
1904.5	210.4
1903.5	146.4
1902.5	286.8
1901.5	217.7
1900.5	280.7
1899.5	189.2
1898.5	267.6
1897.5	220.8
1896.5	225.0
1895.5	267.8
1894.5	249.5
1893.5	233.2
1892.5	189.4
1891.5	256.7
1890.5	240.4
1889.5	192.6
1888.5	297.6
1887.5	317.1
1886.5	190.7
1885.5	346.7
1884.5	152.0
1883.5	202.0
1882.5	247.9
1881.5	246.9
1880.5	174.5
1879.5	224.5
1878.5	315.4
1877.5	188.9
1876.5	240.0
1875.5	218.6
1874.5	215.6
1873.5	196.2
1872.5	268.8
1871.5	239.2
1870.5	222.9
1869.5	241.3
1868.5	248.5
1867.5	187.2
1866.5	192.3
1865.5	192.3
1864.5	230.2
1863.5	262.0
1862.5	248.7
1861.5	219.1
1860.5	248.8
1859.5	226.3
1858.5	188.4
1857.5	214.1
1856.5	238.7
1855.5	298.2
1854.5	239.8
1853.5	222.4
1852.5	207.1
1851.5	230.7
1850.5	244.1
1849.5	224.6
1848.5	288.2
1847.5	214.4
1846.5	233.9
1845.5	148.8
1844.5	241.2
1843.5	207.3
1842.5	193.0
1841.5	155.0
1840.5	172.5
1839.5	232.1
1838.5	269.2
1837.5	257.9
1836.5	217.9
1835.5	188.1
1834.5	243.7
1833.5	203.6
1832.5	256.1
1831.5	237.6
1830.5	256.2
1829.5	183.2
1828.5	253.2
1827.5	286.2
1826.5	228.6
1825.5	202.9
1824.5	205.0
1823.5	217.4
1822.5	225.7
1821.5	218.5
1820.5	214.4
1819.5	254.6
1818.5	209.3
1817.5	209.3
1816.5	182.5
1815.5	241.3
1814.5	152.7
1813.5	261.0
1812.5	209.5
1811.5	250.8
1810.5	194.1
1809.5	215.8
1808.5	273.6
1807.5	254.0
1806.5	211.7
1805.5	268.6
1804.5	198.4
1803.5	253.2
1802.5	222.2
1801.5	256.4
1800.5	232.6
1799.5	247.1
1798.5	167.5
1797.5	215.1
1796.5	275.2
1795.5	205.9
1794.5	282.5
1793.5	207.0
1792.5	202.9
1791.5	211.2
1790.5	204.0
1789.5	213.3
1788.5	176.1
1787.5	200.9
1786.5	281.7
1785.5	268.3
1784.5	272.5
1783.5	257.0
1782.5	190.7
1781.5	227.1
1780.5	189.8
1779.5	252.0
1778.5	230.3
1777.5	148.3
1776.5	193.0
1775.5	243.9
1774.5	304.1
1773.5	246.0
1772.5	168.2
1771.5	222.2
1770.5	255.5
1769.5	243.1
1768.5	255.6
1767.5	186.0
1766.5	189.1
1765.5	203.7
1764.5	231.8
1763.5	244.3
1762.5	220.5
1761.5	196.6
1760.5	192.4
1759.5	303.8
1758.5	192.5
1757.5	231.0
1756.5	232.1
1755.5	187.4
1754.5	200.9
1753.5	192.6
1752.5	213.5
1751.5	125.0
1750.5	239.5
1749.5	259.4
1748.5	256.3
1747.5	267.8
1746.5	195.9
1745.5	261.6
1744.5	151.2
1743.5	211.6