Eastern Mediterranean Spring/Summer Precipitation Reconstruction ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE CONTRIBUTORS WHEN USING THIS DATA!!!!! NAME OF DATA SET: Eastern Mediterranean Spring/Summer Precipitation Reconstruction LAST UPDATE: 2/2007 (Original receipt by WDC Paleo) CONTRIBUTOR: Ramzi Touchan, The University of Arizona IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2007-020 SUGGESTED DATA CITATION: Touchan, R., et al. 2007. Eastern Mediterranean Spring/Summer Precipitation Reconstruction. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2007-020. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Touchan, R., E. Xoplaki, G. Funkhouser, J. Luterbacher, M.K. Hughes, N. Erkan, Ü. Akkemik, and J. Stephan. 2005. Reconstructions of Spring/Summer Precipitation for the Eastern Mediterranean from Tree-Ring Widths and its Connection to Large-Scale Atmospheric Circulation. Climate Dynamics, 25:75-98. ABSTRACT: This study represents the first large-scale systematic dendroclimatic sampling focused on developing chronologies from different species in the eastern Mediterranean region. Six reconstructions were developed from chronologies ranging in length from 115 years to 600 years. The first reconstruction (1885–2000) was derived from principal components (PCs) of 36 combined chronologies. The remaining five, 1800–2000, 1700–2000, 1600–2000, 1500–2000 and 1400–2000 were developed from PCs of 32, 18, 14, 9, and 7 chronologies, respectively. Calibration and verification statistics for the period 1931–2000 show good levels of skill for all reconstructions. The longest period of consecutive dry years, defined as those with less than 90% of the mean of the observed May–August precipitation, was 5 years (1591–1595) and occurred only once during the last 600 years. The longest reconstructed wet period was 5 years (1601–1605 and 1751–1755). No long term trends were found in May–August precipitation during the last few centuries. Regression maps are used to identify the influence of large-scale atmospheric circulation on regional precipitation. In general, tree-ring indices are influenced by May–August precipitation, which is driven by anomalous below (above) normal pressure at all atmospheric levels and by convection (subsidence) and small pressure gradients at sea level. These atmospheric conditions also control the anomaly surface air temperature distribution which indicates below (above) normal values in the southern regions and warmer (cooler) conditions north of around 40°N. A compositing technique is used to extract information on large-scale climate signals from extreme wet and dry summers for the second half of the twentieth century and an independent reconstruction over the last 237 years. Similar main modes of atmospheric patterns and surface air temperature distribution related to extreme dry and wet summers were identified both for the most recent 50 years and the last 237 years. Except for the last few decades, running correlation analyses between the major European-scale circulation patterns and eastern Mediterranean spring/summer precipitation over the last 237 years are non-stationary and insignificant, suggesting that local and/or sub-regional geographic factors and processes are important influences on treering variability over the last few centuries. GEOGRAPHIC REGION: Eastern Mediterranean PERIOD OF RECORD: 1400 - 2000 AD FUNDING SOURCES: National Science Foundation (USA), Earth System History (Grant No. 0075956). Elena Xoplaki was partially supported by Fifth Framework Programme of the European Union (project SOAP), the Swiss Science Foundation (NCCR Climate) and US National Science Foundation, Earth System History (Grant No. 0075956). Juerg Luterbacher was supported by the Swiss Science Foundation (NCCR Climate). DESCRIPTION: Late spring/summer (May–August) precipitation reconstruction based on 42 tree-ring sites sampled from Turkey, Syria, Lebanon, Cyprus, and Greece. The sites range in elevation from 400m to 2,400 m a.s.l. Species sampled were Cedrus libani, Cedrus brevifolia, Juniperus excelsa, Pinus brutia, Pinus nigra, Pinus sylvestris, Pinus leukodermis, and Abies cilicica. The reconstruction was calibrated on the mean May–August precipitation of the region covering latitudes 34.5N–40N and longitudes 20E–40E. The different chronology sets were transformed to uncorrelated predictors by projecting them to their principal components (PCs) prior to developing the regression equation. Predictors for the final reconstruction models were selected from the PCs by a forward stepwise regression procedure. Regression against the first PC accounts for 40% of the variance of 1400-2000AD May-August precipitation. Some of the tree ring data utilized in this study have been archived with the International Tree ring Data Bank: http://www.ncdc.noaa.gov/paleo/treering.html DATA: YEAR May-August precipitation reconstruction 1400 66.45 1401 86.32 1402 86.33 1403 66.18 1404 82.33 1405 82.72 1406 59.02 1407 76.15 1408 88.4 1409 78.51 1410 72.37 1411 94.78 1412 68.86 1413 71.97 1414 60.3 1415 91.72 1416 78.95 1417 81.88 1418 74.92 1419 59.75 1420 78.5 1421 73.67 1422 71.72 1423 92.3 1424 77.81 1425 87.31 1426 78.11 1427 70.14 1428 88.13 1429 114.39 1430 62.99 1431 89.99 1432 83.51 1433 90.95 1434 50.83 1435 62.95 1436 43.93 1437 80.49 1438 71.02 1439 70.13 1440 41.46 1441 90.16 1442 119.71 1443 78.68 1444 65.86 1445 48.89 1446 74.19 1447 57.42 1448 89.13 1449 102.46 1450 83.01 1451 53.3 1452 72.76 1453 69.56 1454 63.13 1455 81.44 1456 75.42 1457 70.62 1458 85.91 1459 108.03 1460 68.54 1461 69.52 1462 65.03 1463 57.96 1464 93.15 1465 70.47 1466 76.5 1467 64.41 1468 58.82 1469 63.96 1470 81.76 1471 88.92 1472 90.85 1473 91.74 1474 70.1 1475 99.03 1476 74.08 1477 48.31 1478 58.56 1479 52.08 1480 75.58 1481 92.75 1482 72.87 1483 70.59 1484 78.5 1485 70.58 1486 73.46 1487 69.42 1488 61.87 1489 60.21 1490 76.91 1491 67.35 1492 77.43 1493 77.3 1494 70.36 1495 50.75 1496 96.38 1497 78.24 1498 69.38 1499 74 1500 84.83 1501 62.61 1502 74.04 1503 89.85 1504 93.44 1505 48.72 1506 81.05 1507 101.4 1508 84.59 1509 61.56 1510 86.08 1511 82.33 1512 55.92 1513 81.77 1514 83.39 1515 61.07 1516 84.01 1517 53.51 1518 83.26 1519 115.39 1520 72.59 1521 80.49 1522 79.26 1523 92.7 1524 80.39 1525 80.09 1526 70.13 1527 73.78 1528 77.07 1529 63.36 1530 78.63 1531 63.8 1532 98.56 1533 93.6 1534 109.78 1535 92.67 1536 67.89 1537 66.98 1538 81.33 1539 112.96 1540 48 1541 80.77 1542 58.93 1543 78.58 1544 75.17 1545 98.79 1546 69.14 1547 88.98 1548 54.36 1549 56.97 1550 99.15 1551 65.65 1552 84.93 1553 80.91 1554 90.36 1555 92.2 1556 99.95 1557 42.13 1558 57.73 1559 109.16 1560 63.92 1561 55.64 1562 74.07 1563 75.49 1564 104.96 1565 130.82 1566 97.48 1567 42.04 1568 79.79 1569 80.21 1570 59.38 1571 66.89 1572 71.51 1573 76.21 1574 105.59 1575 78.95 1576 92.61 1577 77.73 1578 74.43 1579 66.69 1580 71.68 1581 64.45 1582 61.8 1583 83.7 1584 96.95 1585 50.07 1586 110.83 1587 78.5 1588 67.2 1589 89.38 1590 85.22 1591 64.3 1592 62.76 1593 64.81 1594 63.45 1595 55.92 1596 71.81 1597 69.88 1598 74.46 1599 72.77 1600 51.23 1601 88.08 1602 89.81 1603 89.19 1604 92.35 1605 88.92 1606 77.01 1607 40.14 1608 50.83 1609 74.32 1610 101.44 1611 69.81 1612 72.51 1613 46.52 1614 62.63 1615 88.3 1616 90.38 1617 74.84 1618 77.51 1619 66.5 1620 76.34 1621 108.7 1622 70.82 1623 74.06 1624 52.05 1625 73.8 1626 85.87 1627 52.57 1628 64.17 1629 104.34 1630 100.29 1631 101.18 1632 59.73 1633 59.91 1634 96.48 1635 74.73 1636 94.36 1637 77.73 1638 91.78 1639 75.64 1640 97.81 1641 95.3 1642 73.79 1643 79.76 1644 57.98 1645 66.85 1646 95.84 1647 76.7 1648 94.68 1649 72.14 1650 53.08 1651 83.11 1652 75.06 1653 78.07 1654 65.34 1655 77.51 1656 74.45 1657 84.59 1658 57.38 1659 87.25 1660 56.46 1661 106.2 1662 71.13 1663 96.26 1664 63.5 1665 108.34 1666 80.36 1667 87.02 1668 72.56 1669 81.94 1670 67.3 1671 72.04 1672 58.76 1673 78.18 1674 71.69 1675 57.09 1676 53.49 1677 84.45 1678 103.59 1679 54.43 1680 60.15 1681 110.46 1682 91.21 1683 68.4 1684 77.97 1685 52.12 1686 72.63 1687 67.93 1688 85.65 1689 98.4 1690 95.57 1691 81.22 1692 97.59 1693 56.03 1694 78.56 1695 72.61 1696 72.21 1697 90.51 1698 67.59 1699 82.23 1700 70.77 1701 72.45 1702 71.14 1703 64.34 1704 80.06 1705 69.11 1706 77.15 1707 76.19 1708 71.3 1709 107.07 1710 57.8 1711 64.06 1712 89.38 1713 71.51 1714 79.65 1715 50.19 1716 51 1717 85.99 1718 80.62 1719 91.23 1720 85.3 1721 87.93 1722 76.84 1723 68.22 1724 92.72 1725 47.66 1726 68.36 1727 92.84 1728 102.25 1729 70.92 1730 59.88 1731 69.4 1732 71.46 1733 77.34 1734 80.91 1735 85.44 1736 94.04 1737 72.38 1738 68.79 1739 84.42 1740 67.36 1741 57.86 1742 60.05 1743 90.14 1744 94.85 1745 86.58 1746 52.89 1747 92.32 1748 90.09 1749 69.86 1750 43.25 1751 100.8 1752 88.98 1753 92.27 1754 87.58 1755 119.18 1756 57.53 1757 74.97 1758 87.63 1759 64.23 1760 77.39 1761 73.56 1762 92.74 1763 62.19 1764 53.85 1765 74.66 1766 85.55 1767 75.99 1768 66 1769 86.31 1770 60.41 1771 92.12 1772 66.31 1773 79.73 1774 82.54 1775 65.13 1776 84.11 1777 73.47 1778 92.87 1779 52.13 1780 86.41 1781 67.18 1782 56.89 1783 96.01 1784 86.74 1785 75.23 1786 75.46 1787 72.09 1788 113.66 1789 71.96 1790 72.12 1791 88.48 1792 81.28 1793 75.79 1794 67 1795 94.39 1796 44.1 1797 64.5 1798 83.53 1799 70.23 1800 91.02 1801 84.02 1802 66.21 1803 88.27 1804 95.32 1805 85.52 1806 66.47 1807 80.33 1808 63.14 1809 100.13 1810 90.74 1811 90.31 1812 78.17 1813 63.67 1814 75.47 1815 71.77 1816 99.78 1817 75.02 1818 86.65 1819 63.75 1820 64.65 1821 95.64 1822 59.34 1823 72.11 1824 67.21 1825 76.53 1826 74.33 1827 126.98 1828 76.04 1829 77.07 1830 55.3 1831 82.56 1832 92.31 1833 75.84 1834 72.51 1835 102.92 1836 75.74 1837 78.23 1838 75.19 1839 72.32 1840 59.07 1841 94.34 1842 72.65 1843 69.91 1844 67.04 1845 82.98 1846 85.44 1847 69.78 1848 86.02 1849 73.16 1850 72.48 1851 56.46 1852 71.99 1853 72.37 1854 64.43 1855 96.98 1856 76.72 1857 83.89 1858 75.61 1859 91.91 1860 83.75 1861 68.92 1862 77.12 1863 60.9 1864 88.76 1865 95.33 1866 93.29 1867 65.81 1868 59.43 1869 68.27 1870 70.33 1871 79.65 1872 86.16 1873 83.18 1874 54.25 1875 77.03 1876 101.43 1877 87.32 1878 64.6 1879 68.08 1880 63.88 1881 96.42 1882 68.97 1883 90.17 1884 84 1885 98.5 1886 85.59 1887 49.92 1888 83.38 1889 90.17 1890 71.58 1891 81.1 1892 86.76 1893 51.19 1894 57.29 1895 83.72 1896 71.53 1897 107.68 1898 42.84 1899 76.81 1900 93.45 1901 107.36 1902 78.33 1903 75.81 1904 76.32 1905 70.54 1906 92.22 1907 56.38 1908 63.45 1909 57.59 1910 90.86 1911 63.75 1912 87.55 1913 94.52 1914 95.36 1915 70.55 1916 53.48 1917 88.88 1918 66.33 1919 96.45 1920 68.17 1921 92.08 1922 84.24 1923 65.34 1924 83.5 1925 75.69 1926 64.88 1927 54.82 1928 57.83 1929 66.67 1930 114.11 1931 82.53 1932 55.7 1933 73.14 1934 79.58 1935 54.23 1936 108.14 1937 79.22 1938 54.69 1939 85.44 1940 83.06 1941 69.53 1942 57.43 1943 84.6 1944 81.51 1945 57.24 1946 90.76 1947 98.99 1948 59.78 1949 53.28 1950 95.48 1951 107.01 1952 77.77 1953 72.62 1954 66.32 1955 63.71 1956 70.68 1957 75.25 1958 94.59 1959 81.97 1960 92.36 1961 64.53 1962 72.68 1963 88.9 1964 77.51 1965 58.82 1966 70.49 1967 76.92 1968 85.9 1969 67.42 1970 88.79 1971 67.12 1972 92.35 1973 66.31 1974 73.36 1975 113.52 1976 89.42 1977 90.61 1978 57.11 1979 97.3 1980 56.62 1981 78.35 1982 74.29 1983 81.47 1984 56.36 1985 76.53 1986 96.19 1987 71.71 1988 73.65 1989 79.42 1990 75.95 1991 85.47 1992 96.37 1993 68.58 1994 62.1 1995 71.57 1996 71.44 1997 80.83 1998 95.09 1999 89.25 2000 67.83