Northern North American Tree-Ring Evidence for Regional Temperature Changes after Major Volcanic Events

摘要: Maximum latewood density data from trees at thirteen temperature-sensitive sites along the northern treeline of North America are used to evaluate spatial patterns response four known volcanic events just prior period modern observations: in 1640, 1783, 1815 and 1835. A previously unknown event is also postulated for 1699. This tree-ring parameter because it shows a stronger more consistent short-term, temperature-related signal than ring width. Normalized departures following these vary sign magnitude region region, with coldest summer conditions inferred Northwest Territories 1641, Alaska Quebec Labrador 1816 1836. For as well other events, low values often among most extreme on record their respective locations. We suggest that regional variations tree growth reflect cooling induced by volcanism distribution influenced atmospheric circulation patterns.