North Pacific Troposphere Annual Volcanic Sulfate Loading Reconstruction ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE CONTRIBUTORS WHEN USING THIS DATA!!!!! NAME OF DATA SET: North Pacific Troposphere Annual Volcanic Sulfate Loading Reconstruction LAST UPDATE: 4/2007 (Original receipt by WDC Paleo) CONTRIBUTORS: Kaplan Yalcin, Cameron P. Wake, and Karl J. Kreutz IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2007-040 SUGGESTED DATA CITATION: Yalcin, K., et al. 2007. Eclipse Icefield Volcanic Aerosol Reconstruction. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2007-040. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Yalcin, K., C.P. Wake, K.J. Kreutz, M.S. Germani, and S.I. Whitlow. 2007. Ice core paleovolcanic records from the St. Elias Mountains, Yukon, Canada. J. Geophys. Res., 112, D08102, doi: 10.1029/2006JD007497, 2007. ABSTRACT: We previously reported a record of regionally significant volcanic eruptions in the North Pacific using an ice core from Eclipse Icefield (St. Elias Mountains, Yukon, Canada). The acquisition of two new ice cores from Eclipse Icefield, along with the previously available Eclipse Icefield and Mount Logan Northwest Col ice cores, allows us to extend our record of North Pacific volcanism to 550 years before present using a suite of four ice cores spanning an elevation range of 3–5 km. Comparison of volcanic sulfate flux records demonstrates that the results are highly reproducible, especially for the largest eruptions such as Katmai (A.D. 1912). Correlation of volcanic sulfate signals with historically documented eruptions indicates that at least one-third of the eruptions recorded in St. Elias ice cores are from Alaskan and Kamchatkan volcanoes. Although there are several moderately large (volcanic explosivity index (VEI) >= 4) eruptions recorded in only one core from Eclipse Icefield, the use of multiple cores provides signals in at least one core from all known VEI >= 4 eruptions in Alaska and Kamchatka since A.D. 1829. Tephrochronological evidence from the Eclipse ice cores documents eruptions in Alaska (Westdahl, Redoubt, Trident, and Katmai), Kamchatka (Avachinsky, Kliuchevoskoi, and Ksudach), and Iceland (Hekla). Several unidentified tephra-bearing horizons, with available geochemical evidence suggesting Alaskan and Kamchatkan sources, were also found. We present a reconstruction of annual volcanic sulfate loading for the North Pacific troposphere based on our ice core data, and we provide a detailed assessment of the atmospheric and climatic effects of the Katmai eruption. ADDITIONAL REFERENCES: Yalcin, K., C.P. Wake, K.J. Kreutz, M.S. Germani, and S.I. Whitlow. 2006. Ice core evidence for a second volcanic eruption around 1809 in the Northern Hemisphere. Geophysical Research Letters, 33, L14706, doi:10.1029/2006GL026013. Yalcin, K., C.P. Wake, S. Kang, K.J. Kreutz, and S.I. Whitlow, Seasonal and spatial variability in snow chemistry at Eclipse Icefield, Yukon, Canada. Annals of Glaciology, 43, 230-238, 2006. Yalcin, K., C.P. Wake, S. Whitlow, and K. Kreutz. 2006. A 1000-year record of forest fire activity from Eclipse Icefield, Yukon, Canada. The Holocene, 16, 200-209. Yalcin, K., C.P. Wake and M. Germani. 2003. A 100-year record of North Pacific volcanism in an ice core from Eclipse Icefield, Yukon Territory, Canada. Journal of Geophysical Research 108, 10.1029/2002JD00244. Wake, C., K. Yalcin, and N. Gundestrup. 2002. The climate signal recorded in the oxygen isotope, accumulation, and major ion time-series from the Eclipse Ice Core, Yukon Territory. Annals of Glaciology 35, 416-422. Yalcin, K. and C.P. Wake. 2001. Anthropogenic signals recorded in an ice core from Eclipse Icefield, Yukon Territory. Geophysical Research Letters 28, 4487-4490, doi: 10.1029/2001GL013037. GEOGRAPHIC REGION: Northwest Canada, St. Elias Mountains, Yukon PERIOD OF RECORD: 1450 - 2002 AD FUNDING SOURCE: U.S. National Science Foundation DESCRIPTION: A 160 m ice core (Core 1) was recovered from Eclipse Icefield in 1996 [Yalcin and Wake, 2001; Yalcin et al., 2003]. Two additional ice cores, 345 m (Core 2) and 130 m (Core 3) in length, were recovered in 2002 [Yalcin et al., 2006]. All three ice cores were continuously sampled at 10 to 15 cm resolution for major ions and stable isotopes. Above the firn-ice transition, core was scraped on an acrylic lathe system under a laminar flow bench using a titanium scraper so that all surface and sub-surface contamination from the drilling process was removed. Below the firn-ice transition, the core was continuously sampled in 10 cm segments using a discrete melting system that was also used to sample the GISP2 ice core. The top 60 m of Core 2 was sampled on a continuous melting system with a nickel head so that co-registered samples could also be collected for trace metal analysis. Thinning of annual layers in the lower 120 m of Core 2 required higher resolution sampling to establish an annually dated chronology. Therefore, Core 2 was resampled at 2 to 6 cm resolution continuously for stable isotopes and around select high sulfate horizons for major ions. Samples were analyzed for major ions (Na+, NH4+, K+, Mg2+, Ca2+, Cl-, NO3-, SO42-) at the University of New Hampshire Climate Change Research Center via ion chromatography using a 0.5 ml sample loop. The cation system used a 4 mm Dionex CS12A column with Dionex CSRS-ultra suppressor in auto suppression recycle mode with 20 mM MSA eluent. The anion system used a 4 mm Dionex AS11 column with a Dionex ASRS-ultra suppressor in auto suppression recycle mode with 6 mM NaOH eluent. An aliquot of each sample was analyzed at the University of Maine Stable Isotope Laboratory with a Multiprep CO2 equilibration system coupled to a VG SIRA mass spectrometer for Delta 18O (precision ± 0.05‰) and a Eurovector Cr pyrolosis unit coupled to a GV Isoprime mass spectrometer for Delta D (precision ± 0.5‰). Chronology of the Eclipse ice core is based on multi-parameter annual layer counting of seasonal oscillations in the stable isotope and major ion records (especially Na+ and NH4+). Age control on the chronology established via annual layer counting is provided by the AD 1961, 1963 and 1986 137Cs reference horizons as well as sulfate reference horizons provided by the following major volcanic eruptions: Katmai (AD 1912), Tambora (AD 1815), Laki (AD 1783), and Kuwae (AD 1453). Additional volcanic reference horizons are provided by tephrochronological identification of known high northern latitude volcanic eruptions (as discussed in Yalcin et al., 2007). Dating error is estimated based on the number of independently dated reference horizons (radioactivity, volcanic eruptions), and ranges from +/- 1 year from AD 1912-2002 and from AD 1783-1815, +/- 2 years from AD 1815-1912, and up to +/- 5 years (1%) from AD 1453-1783 due to the lack of independently dated horizons between the Laki and Kuwae eruptions. The resulting time scales indicate that Core 1 covers the period AD 1894-1996, Core 2 AD 1000-2002, and Core 3 AD 1910-2002. Because the Core 2 chronology is not annually resolved prior to AD 1450, we limit our discussion of volcanic signals to the period AD 1450-2002. We used two methods to identify volcanic SO42- signals in our record (Figure 3): empirical orthogonal function (EOF) decomposition and estimation of non-volcanic sulfate using a robust spline. Applying EOF analysis to the suite of ions measured in the Eclipse ice cores (excluding NH4+) reveals that, for all three cores, EOF 5 is loaded solely with SO42- and describes 3.9-5.3% of the total variance in the dataset, but 11.9-20.3% of the variance in the sulfate time series. Volcanic eruptions have been identified as the source of this SO42- [Yalcin et al., 2003]. To assess the atmospheric effects and possible climatic implications of the volcanic eruptions recorded in the Eclipse ice cores; we provide estimates of volcanic aerosol loading derived from the Eclipse glaciochemical data. Since most of the volcanic signals identified by the Eclipse EOF analysis can be matched to a previously documented eruption, we believe that the EOF 5 time series provides a continuous proxy of volcanic SO42- deposition. To convert glaciochemical concentrations to estimates of volcanic aerosol loading, we use a modern analog approach to derive a multiplier from a volcanic eruption whose actual aerosol loading is known from satellite data. A total production estimate of 9 x 1011 g of SO2 for the AD 1989 eruption of Redoubt, Alaska was derived from petrologic work and direct measurements of the gas emissions from Redoubt during and after its eruptive sequence using fixed wing aircraft, which equates to 1.35 x 1012 g of SO42- aerosols. Coupled with tephrochronological identification of fallout from the AD 1989 Redoubt eruption in the Eclipse ice core, this has allowed us to derive estimates of sulfate aerosol loading from the time series of volcanic sulfate deposition at Eclipse by using the ratio of sulfate deposited at Eclipse by the Redoubt eruption to the total SO2 produced by that eruption. The Eclipse ice cores (Cores 1 and 3) record 1.17+0.16 µg cm-2 of volcanic (EOF 5) SO42- deposition from the Redoubt eruption. From this information we derived a multiplier of 1.18+0.16 x 1012 relating the Eclipse volcanic sulfate flux (µg cm-2) to total sulfate aerosol loading (g) from the eruption. We then used this multiplier to convert our time series of volcanic sulfate deposition at Eclipse into an estimate of annual volcanic sulfate aerosol loading for the Gulf of Alaska troposphere. Spatial variability in volcanic sulfate deposition represents a source of uncertainty in our reconstruction. We can address this issue using the multiple cores available from Eclipse Icefield, allowing more robust aerosol loading estimates to be made. In reconstructing volcanic sulfate aerosol loading we use the mean volcanic sulfate deposition in the Eclipse cores available for that year, and use the range of volcanic sulfate deposition for that year to estimate our uncertainty. Uncertainty in the multiplier relating volcanic sulfate deposition in the ice core to volcanic aerosol mass loading (due to variability in volcanic sulfate deposition from the Redoubt eruption that we used to derive out multiplier) introduces an uncertainty of +14% in our estimates. Variability in annual volcanic sulfate deposition in individual cores introduces an additional uncertainty of +39% for a cumulative uncertainty of +53% in our estimates of volcanic sulfate aerosol loading. Full details of these calculations and a discussion of the assumptions and uncertainties in this approach are provided in Yalcin et al., 2007. For the period 1895-2001 where multiple cores are available, the loadings presented below are the mean estimate from the available cores. We also include the minimum and maximum estimate from individual cores. For the period 1894-1450, only one core is available. All loadings are in terragrams (Tg) SO42- aerosols (1 Tg = 10^12 g). DATA: North Pacific Troposphere Annual Volcanic Sulfate Loading Reconstruction Column 1: Year AD Column 2: Tropospheric Volcanic SO42- aerosol loading (unit: Tg SO42-) Column 3: Minimum estimate from multiple cores (unit: Tg SO42-) Column 4: Maximum estimate from multiple cores (unit: Tg SO42-) Year Loading Min Max 2001 0.48 0.42 0.55 2000 0.49 0.42 0.55 1999 0.5 0.43 0.57 1998 0.17 0.14 0.19 1997 0.3 0.26 0.34 1996 0.29 0.25 0.33 1995 0.22 0.19 0.25 1994 0.5 0.14 0.95 1993 0.89 0.64 1.18 1992 0.53 0.39 0.69 1991 0.74 0.6 0.88 1990 0.86 0.72 1.01 1989 1.18 0.61 1.88 1988 0.05 0.01 0.1 1987 0.16 0.08 0.26 1986 0.51 0.26 0.81 1985 0.38 0.05 0.8 1984 0.14 0.01 0.29 1983 0.05 0.01 0.11 1982 0.53 0.37 0.71 1981 0.19 0.03 0.38 1980 0.63 0.22 1.13 1979 0.58 0.4 0.78 1978 0.83 0.55 1.16 1977 0.7 0.59 0.81 1976 1.06 0.39 1.89 1975 2.36 0.33 4.93 1974 0.51 0.19 0.9 1973 4.2 3.23 5.3 1972 1.3 0.78 1.93 1971 0.32 0.17 0.51 1970 0.83 0.38 1.4 1969 0.67 0.51 0.85 1968 0.32 0.09 0.49 1967 0.2 0.02 0.4 1966 0.35 0.17 0.67 1965 0.64 0.22 1.33 1964 2.48 0.62 5.95 1963 2.49 2 2.93 1962 0.81 0.5 1.2 1961 1.25 0.58 1.81 1960 2.07 0.72 3.84 1959 1.76 0.06 3.96 1958 1.49 0.99 1.94 1957 2.53 1.16 5.1 1956 1.34 0.52 2.21 1955 0.79 0.44 1.19 1954 0.66 0.4 0.89 1953 1.66 1.11 2.25 1952 2.06 0.83 3.47 1951 0.46 0.3 0.76 1950 0.35 0.09 0.78 1949 0.55 0.24 0.81 1948 1 0.54 1.56 1947 0.67 0.11 1.24 1946 0.66 0.42 0.98 1945 0.86 0.27 1.76 1944 0.63 0.3 1.07 1943 1.04 0.74 1.49 1942 0.68 0.45 0.9 1941 0.48 0.25 0.8 1940 1.02 0.71 1.37 1939 1.52 0.67 2.41 1938 0.69 0.55 0.9 1937 0.65 0.38 0.88 1936 0.49 0.23 0.69 1935 1.44 0.86 1.97 1934 0.23 0 0.53 1933 0.62 0.33 0.98 1932 1 0.73 1.32 1931 0.76 0.51 1.09 1930 1.55 1.07 2.07 1929 1.92 1.36 2.38 1928 0.86 0.39 1.59 1927 0.29 0.04 0.56 1926 0.87 0.2 1.56 1925 0.95 0.55 1.29 1924 0.77 0.57 1.02 1923 1.86 0.66 4.22 1922 0.87 0.45 1.72 1921 0.72 0.52 0.91 1920 0.75 0.35 1.08 1919 0.87 0.46 1.2 1918 2.46 1.97 3 1917 2.42 1.81 3 1916 1.58 1.2 2.06 1915 1.01 0.41 1.56 1914 1.03 0.75 1.51 1913 4.02 2.98 5.06 1912 11.68 9.1 14.79 1911 0.49 0.35 0.67 1910 0.59 0.33 0.99 1909 0.42 0.28 0.59 1908 1.37 1.07 1.71 1907 2.61 1.84 3.5 1906 0.61 0.45 0.79 1905 0.52 0.37 0.7 1904 1.49 1.05 2.01 1903 1.03 0.77 1.32 1902 0.46 0.16 0.83 1901 0.22 0.19 0.25 1900 0.53 0.2 0.94 1899 0.11 0.04 0.19 1898 0.3 0.12 0.53 1897 0.67 0.24 1.21 1896 0.3 0.23 0.38 1895 0.64 0.52 0.77 1894 0.14 1893 0.16 1892 1.1 1891 0.82 1890 0.3 1889 0.88 1888 0.12 1887 0.06 1886 1.07 1885 0.73 1884 2.72 1883 1.7 1882 0.05 1881 0.24 1880 0.4 1879 0.11 1878 0.17 1877 0.34 1876 0.16 1875 0 1874 1.17 1873 0.77 1872 1.41 1871 0.29 1870 0.23 1869 0.03 1868 0.28 1867 0.21 1866 0.25 1865 0.15 1864 0.35 1863 0.69 1862 1.83 1861 4.73 1860 0.07 1859 1.57 1858 1.17 1857 2.28 1856 0.32 1855 0.82 1854 1.34 1853 0.5 1852 0.31 1851 0.29 1850 0.66 1849 0.1 1848 0.41 1847 0.33 1846 1.21 1845 0.84 1844 0.12 1843 0.24 1842 0.69 1841 0.2 1840 0.03 1839 0.94 1838 0.34 1837 1.04 1836 3.21 1835 1.5 1834 0.05 1833 0.63 1832 4.28 1831 1.95 1830 0.07 1829 0.8 1828 0.85 1827 0.35 1826 0.33 1825 0.94 1824 0.88 1823 0.89 1822 0.78 1821 0.02 1820 2.18 1819 0.28 1818 0.14 1817 1.14 1816 3.97 1815 3.21 1814 0.15 1813 0.26 1812 0.27 1811 0.71 1810 2.48 1809 1.44 1808 1.01 1807 0.25 1806 0.68 1805 0.32 1804 0.95 1803 1.23 1802 0.31 1801 3.5 1800 0.34 1799 0.67 1798 3.02 1797 2.6 1796 0.75 1795 0.07 1794 0.27 1793 0.43 1792 0.32 1791 0.08 1790 0.12 1789 0.1 1788 0.02 1787 1.35 1786 0.59 1785 0.42 1784 5.17 1783 1.96 1782 0.14 1781 0.2 1780 0.32 1779 0.39 1778 0.29 1777 1.16 1776 0.65 1775 0.08 1774 0.1 1773 0 1772 0 1771 1.49 1770 0 1769 0.55 1768 0.98 1767 0.36 1766 0.27 1765 0.89 1764 0.81 1763 0.13 1762 1.33 1761 0.63 1760 0 1759 0.51 1758 0 1757 0.18 1756 0.12 1755 0 1754 1.1 1753 0.18 1752 0 1751 0 1750 0.52 1749 0 1748 1.3 1747 0.02 1746 0.11 1745 0.28 1744 0 1743 0 1742 0.91 1741 0 1740 0.18 1739 0.58 1738 0.8 1737 2.88 1736 1.51 1735 0.13 1734 0.05 1733 0.52 1732 0.02 1731 0 1730 0.11 1729 0 1728 2.82 1727 1.66 1726 0.01 1725 0.36 1724 0 1723 0.33 1722 0.18 1721 0.56 1720 0.14 1719 0.32 1718 1.2 1717 0.2 1716 0.47 1715 0.6 1714 0.07 1713 0.15 1712 0.4 1711 1.61 1710 0.8 1709 0.19 1708 2.21 1707 0.74 1706 0.04 1705 0 1704 0.18 1703 0.28 1702 0.97 1701 0.13 1700 1.3 1699 0.2 1698 0.47 1697 0.12 1696 0.48 1695 0 1694 0.48 1693 0.05 1692 0.73 1691 0 1690 0.53 1689 0.96 1688 0.72 1687 0.53 1686 5.16 1685 1.18 1684 0.34 1683 0 1682 0.18 1681 0.49 1680 2.69 1679 1.76 1678 1.25 1677 0.4 1676 0.15 1675 0.36 1674 0 1673 0.77 1672 2.12 1671 0.9 1670 0.36 1669 0 1668 1.9 1667 0.25 1666 1.28 1665 0.88 1664 0.29 1663 0.58 1662 0.93 1661 0.07 1660 0.56 1659 4.42 1658 0.08 1657 0.29 1656 1.08 1655 1 1654 0.76 1653 1.66 1652 0.9 1651 0.57 1650 1.44 1649 0.16 1648 4.35 1647 2.1 1646 0.25 1645 0.75 1644 2.4 1643 0 1642 0.23 1641 3.44 1640 0.43 1639 0 1638 0.05 1637 0 1636 2.78 1635 1.04 1634 0 1633 0.43 1632 0.58 1631 2.29 1630 5.94 1629 1.43 1628 2.86 1627 1.04 1626 0.6 1625 0.54 1624 1.4 1623 0 1622 0.71 1621 0.1 1620 2.36 1619 1.83 1618 1.65 1617 0.11 1616 1.68 1615 0.61 1614 0 1613 0 1612 0.59 1611 0.03 1610 0 1609 0.21 1608 0.16 1607 0 1606 0 1605 0.4 1604 0 1603 0.31 1602 0.41 1601 0.19 1600 0 1599 0 1598 0 1597 0.15 1596 0.15 1595 0 1594 0.08 1593 0.43 1592 0 1591 0 1590 0.08 1589 0.21 1588 3.15 1587 3.82 1586 0 1585 0.38 1584 0 1583 0 1582 0 1581 2.61 1580 0 1579 1.08 1578 0.45 1577 0.52 1576 0.23 1575 1.3 1574 0.03 1573 0.2 1572 0.22 1571 0.54 1570 1.27 1569 0.48 1568 0 1567 0 1566 0.25 1565 0 1564 0 1563 0.61 1562 0.34 1561 0 1560 0.15 1559 0 1558 0 1557 0.48 1556 0 1555 4.14 1554 0 1553 0.8 1552 0 1551 0.54 1550 0 1549 0.06 1548 0.35 1547 0.63 1546 0 1545 0 1544 0 1543 0 1542 0 1541 0 1540 0 1539 0 1538 0.06 1537 0 1536 1.05 1535 0.49 1534 0.59 1533 0.47 1532 0 1531 0 1530 0.38 1529 0 1528 0.72 1527 2.67 1526 0 1525 1.47 1524 0.29 1523 0 1522 0 1521 0.02 1520 0 1519 0 1518 0.64 1517 0.38 1516 1.66 1515 5.65 1514 0.47 1513 0 1512 0 1511 0 1510 0 1509 0 1508 0.15 1507 0 1506 5.24 1505 0.1 1504 0.84 1503 1.82 1502 0.51 1501 0 1500 0 1499 0 1498 0.65 1497 0.17 1496 2.36 1495 1.13 1494 0.38 1493 1.71 1492 1.17 1491 0 1490 0 1489 0 1488 1.48 1487 0.43 1486 0 1485 0.27 1484 0 1483 0 1482 0 1481 0.24 1480 0 1479 0 1478 0.3 1477 0.53 1476 0 1475 0 1474 0 1473 0 1472 0 1471 0 1470 0 1469 0.06 1468 0.35 1467 0.48 1466 0.12 1465 0 1464 7.12 1463 5.43 1462 1.61 1461 1.68 1460 0.68 1459 2.92 1458 0 1457 0 1456 0 1455 0.32 1454 1.6 1453 2.38 1452 0.55 1451 0.23 1450 0