Glacier National Park Summer Drought Reconstruction ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE CONTRIBUTORS WHEN USING THIS DATA!!!!! NAME OF DATA SET: Glacier National Park Summer Drought Reconstruction LAST UPDATE: 2/2006 (Original receipt by WDC Paleo) CONTRIBUTOR: G.T. Pederson, Montana State University IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2006-008. SUGGESTED DATA CITATION: Pederson, G.T. et al. 2006. Glacier National Park Summer Drought Reconstruction. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2006-008. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Pederson, G.T., S.T. Gray, D.B. Fagre, and L.J. Graumlich. 2006. Long-Duration Drought Variability and Impacts on Ecosystem Services: A Case Study from Glacier National Park, Montana. Earth Interactions, Volume 10, Paper 4, January 2006. ABSTRACT: Instrumental climate records suggest that summer precipitation and winter snowpack in Glacier National Park (Glacier NP), Montana, vary significantly over decadal to multidecadal time scales. Because instrumental records for the region are limited to the twentieth century, knowledge of the range of variability associated with these moisture anomalies and their impacts on ecosystems and physical processes are limited. The authors developed a reconstruction of summer (June-August) moisture variability spanning A.D. 1540-2000 from a multispecies network of tree-ring chronologies in Glacier NP. Decadal-scale drought and pluvial regimes were defined as any event lasting 10 yr or greater, and the significance of each potential regime was assessed using intervention analysis. Intervention analysis prevents single intervening years of average or opposing moisture conditions from ending what was otherwise a sustained moisture regime. The reconstruction shows numerous decadal-scale shifts between persistent drought and wet events prior to the instrumental period (before A.D. 1900). Notable wet events include a series of three long-duration, high-magnitude pluvial regimes spanning the end of the Little Ice Age (A.D. 1770-1840). Though the late-nineteenth century was marked by a series of >10 yr droughts, the single most severe dry event occurred in the early-twentieth century (A.D. 1917-41). These decadal-scale dry and wet events, in conjunction with periods of high and low snowpack, have served as a driver of ecosystem processes such as forest fires and glacial dynamics in the Glacier NP region. Using a suite of paleoproxy reconstructions and information from previous studies examining the relationship between climate variability and natural processes, the authors explore how such persistent moisture anomalies affect the delivery of vital goods and services provided by Glacier NP and surrounding areas. These analyses show that regional water resources and tourism are particularly vulnerable to persistent moisture anomalies in the Glacier NP area. Many of these same decadal-scale wet and dry events were also seen among a wider network of hydroclimatic reconstructions along a north-south transect of the Rocky Mountains. Such natural climate variability can, in turn, have enormous impacts on the sustainable provision of natural resources over wide areas. Overall, these results highlight the susceptibility of goods and services provided by protected areas like Glacier NP to natural climate variability, and show that this susceptibility will likely be compounded by the effects of future human-induced climate change. GEOGRAPHIC REGION: Northwestern Montana, Northern Rocky Mountains, USA PERIOD OF RECORD: 1540 - 2000 AD DESCRIPTION: Reconstruction of Summer Drought based on tree-ring chronologies in Glacier National Park. Reconstructed parameter is Mean Summer Deficit (precipitation - potential evapotranspiration [Thornthwaite, 1948] for June-August) at Kalispell, Montana on the boundary of Glacier National Park. FUNDING SOURCES: U.S. Geological Survey - Northern Rocky Mountain Science Center, National Science Foundation (#0082376). DATA: Kalispell, Montana Mean Summer (June-August) Deficit (precipitation - potential evapotranspiration) in mm. Reconstruction and Observed Year Recon Observed 1540 -153.479 1541 -223.16 1542 -209.51 1543 -147.019 1544 -214.347 1545 -256.609 1546 -244.174 1547 -226.356 1548 -194.132 1549 -191.277 1550 -201.372 1551 -179.002 1552 -200.817 1553 -250.678 1554 -187.006 1555 -235.716 1556 -185.106 1557 -182.565 1558 -206.424 1559 -184.636 1560 -228.46 1561 -233.553 1562 -255.454 1563 -183.818 1564 -195.636 1565 -193.594 1566 -272.628 1567 -242.217 1568 -237.899 1569 -229.82 1570 -240.726 1571 -228.401 1572 -189.976 1573 -207.96 1574 -207.218 1575 -250.223 1576 -160.997 1577 -187.661 1578 -160.147 1579 -216.423 1580 -284.274 1581 -246.445 1582 -201.789 1583 -238.223 1584 -223.287 1585 -197.829 1586 -229.066 1587 -171.467 1588 -242.736 1589 -192.932 1590 -166.408 1591 -152.17 1592 -267.364 1593 -217.783 1594 -204.972 1595 -235.04 1596 -166.882 1597 -161.787 1598 -197.259 1599 -227.853 1600 -164.628 1601 -266.521 1602 -240.853 1603 -247.554 1604 -280.81 1605 -286.646 1606 -273.103 1607 -222.009 1608 -204.091 1609 -265.814 1610 -207.601 1611 -193.064 1612 -220.355 1613 -210.194 1614 -254.861 1615 -199.392 1616 -178.988 1617 -284.911 1618 -191.646 1619 -247.326 1620 -232.564 1621 -209.854 1622 -232.472 1623 -179.626 1624 -206.184 1625 -197.795 1626 -277.084 1627 -217.341 1628 -259.988 1629 -255.546 1630 -248.226 1631 -227.474 1632 -164.043 1633 -253.18 1634 -259.941 1635 -237.624 1636 -213.915 1637 -234.931 1638 -308.323 1639 -220.339 1640 -221.865 1641 -256.868 1642 -184.426 1643 -202.42 1644 -200.921 1645 -187.553 1646 -214.21 1647 -200.822 1648 -209.897 1649 -228.02 1650 -185.834 1651 -218.322 1652 -253.55 1653 -187.738 1654 -219.316 1655 -199.598 1656 -273.06 1657 -202.535 1658 -210.495 1659 -224.476 1660 -249.726 1661 -220.808 1662 -239.524 1663 -229.134 1664 -291.146 1665 -233.676 1666 -256.536 1667 -195.093 1668 -189.526 1669 -225.043 1670 -230.874 1671 -242.745 1672 -168.576 1673 -221.908 1674 -132.909 1675 -195.673 1676 -207.477 1677 -106.545 1678 -147.207 1679 -206.348 1680 -166.367 1681 -215.349 1682 -241.479 1683 -273.625 1684 -189.967 1685 -228.143 1686 -226.11 1687 -286.152 1688 -239.594 1689 -246.773 1690 -201.096 1691 -238.117 1692 -228.791 1693 -257.515 1694 -209.815 1695 -225.154 1696 -249.122 1697 -234.642 1698 -235.184 1699 -217.732 1700 -223.198 1701 -203.571 1702 -231.476 1703 -189.289 1704 -182.66 1705 -185.367 1706 -199.292 1707 -186.942 1708 -178.882 1709 -196.691 1710 -154.853 1711 -184.695 1712 -145.162 1713 -207.042 1714 -144.855 1715 -174.187 1716 -155.793 1717 -212.192 1718 -230.662 1719 -297.068 1720 -205.065 1721 -219.01 1722 -294.046 1723 -180.049 1724 -252.781 1725 -220.803 1726 -244.167 1727 -226.072 1728 -166.753 1729 -182.746 1730 -225.087 1731 -209.326 1732 -175.346 1733 -233.624 1734 -234.863 1735 -236.45 1736 -210.73 1737 -215.388 1738 -183.701 1739 -207.553 1740 -222.937 1741 -197.469 1742 -237.912 1743 -241.304 1744 -213.854 1745 -294.379 1746 -216.799 1747 -167.119 1748 -240.86 1749 -206.608 1750 -245.571 1751 -188.855 1752 -208.092 1753 -149.652 1754 -266.135 1755 -241.232 1756 -242.02 1757 -281.019 1758 -255.656 1759 -255.078 1760 -233.522 1761 -216.586 1762 -248.774 1763 -261.942 1764 -224.63 1765 -279.389 1766 -229.502 1767 -200.977 1768 -224.531 1769 -229.144 1770 -185.492 1771 -214.313 1772 -204.261 1773 -198.985 1774 -197.044 1775 -210.855 1776 -178.786 1777 -198.123 1778 -223.782 1779 -204.632 1780 -148.003 1781 -180.561 1782 -156.788 1783 -185.906 1784 -239.307 1785 -155.552 1786 -194.625 1787 -129.382 1788 -154.904 1789 -172.522 1790 -185.301 1791 -171.981 1792 -242.519 1793 -226.236 1794 -212.493 1795 -215.95 1796 -204.434 1797 -178.438 1798 -246.08 1799 -242.303 1800 -111.526 1801 -201.951 1802 -224.235 1803 -117.983 1804 -184.14 1805 -121.75 1806 -185.53 1807 -148.48 1808 -195.159 1809 -161.648 1810 -161.014 1811 -215.313 1812 -221.13 1813 -169.843 1814 -225.143 1815 -213.972 1816 -192.714 1817 -223.974 1818 -142.933 1819 -154.381 1820 -194.952 1821 -151.866 1822 -297.636 1823 -232.277 1824 -195.609 1825 -195.715 1826 -192.757 1827 -187.269 1828 -140.182 1829 -170.5 1830 -265.005 1831 -214.529 1832 -187.383 1833 -186.348 1834 -174.309 1835 -205.443 1836 -176.619 1837 -212.202 1838 -126.743 1839 -156.149 1840 -198.05 1841 -232.761 1842 -219.419 1843 -225.294 1844 -213.893 1845 -176.398 1846 -221.621 1847 -192.734 1848 -248.679 1849 -212.067 1850 -198.96 1851 -271.263 1852 -215.76 1853 -244.1 1854 -217.36 1855 -235.35 1856 -210.177 1857 -173.639 1858 -207.104 1859 -192.156 1860 -172.909 1861 -255.318 1862 -235.115 1863 -231.716 1864 -217.255 1865 -187.411 1866 -271.74 1867 -222.129 1868 -318.835 1869 -220.283 1870 -232.638 1871 -249.554 1872 -238.916 1873 -297.098 1874 -279.692 1875 -220.099 1876 -219.413 1877 -222.976 1878 -222.493 1879 -237.114 1880 -232.937 1881 -213.817 1882 -222.647 1883 -247.319 1884 -198.964 1885 -182.901 1886 -205.024 1887 -188.96 1888 -264.448 1889 -225.048 1890 -201.079 1891 -198.752 1892 -241.282 1893 -261.043 1894 -240.326 1895 -229.745 1896 -260.88 1897 -215.031 1898 -222.39 1899 -144.107 1900 -164.618 -233 1901 -216.591 -233 1902 -196.686 -178 1903 -181.347 -230 1904 -242.151 -258 1905 -251.797 -239 1906 -197.26 -245 1907 -186.905 -134 1908 -192.206 -198 1909 -202.546 -161 1910 -225.039 -279 1911 -210.475 -169 1912 -152.801 -186 1913 -194.83 -221 1914 -221.109 -213 1915 -156.219 -189 1916 -198.434 -119 1917 -282.2 -245 1918 -247.699 -254 1919 -294.542 -284 1920 -252.884 -224 1921 -296.169 -280 1922 -256.19 -297 1923 -271.497 -236 1924 -251.298 -192 1925 -254.612 -245 1926 -230.27 -252 1927 -248.376 -247 1928 -201.138 -186 1929 -260.942 -309 1930 -245.444 -248 1931 -240.334 -296 1932 -228.982 -267 1933 -223.311 -265 1934 -240.91 -250 1935 -288.198 -262 1936 -257.518 -293 1937 -242.786 -239 1938 -300.424 -273 1939 -237.781 -215 1940 -263.784 -274 1941 -230.595 -264 1942 -176.97 -125 1943 -197.158 -207 1944 -218.655 -238 1945 -216.793 -242 1946 -207.56 -246 1947 -176.35 -111 1948 -202.374 -119 1949 -114.189 1950 -181.392 -145 1951 -255.451 -185 1952 -214.381 -197 1953 -218.905 -204 1954 -175.275 -138 1955 -251.562 -230 1956 -219.376 -150 1957 -227.269 -255 1958 -247.511 -274 1959 -226.935 -275 1960 -215.954 -270 1961 -285.745 -321 1962 -235.021 -276 1963 -211.779 -188 1964 -195.308 -144 1965 -187.373 -156 1966 -212.802 -162 1967 -274.457 -289 1968 -231.166 -191 1969 -201.503 -221 1970 -259.177 -246 1971 -240.212 -186 1972 -210.753 -240 1973 -277.618 -295 1974 -231.336 -278 1975 -190.646 -197 1976 -187.023 -145 1977 -137.403 -239 1978 -181.13 -208 1979 -257.256 -293 1980 -167.921 -179 1981 -221.102 -184 1982 -210.831 -173 1983 -181.344 -183 1984 -267.314 -264 1985 -219.67 -262 1986 -198.943 -243 1987 -198.531 -166 1988 -274.628 -279 1989 -188.884 -190 1990 -239.427 -197 1991 -204.181 -212 1992 -167.522 -165 1993 -109.899 -20 1994 -205.591 -283 1995 -165.562 -113 1996 -206.829 -263 1997 -224.407 -188 1998 -170.985 -187 1999 -178.013 -234 2000 -251.934 -277 2001 -210 2002 -230 2003 -323