Volcanic Impacts Dominate Bidecadal-Multidecadal Temperature Variations During the Late Holocene in Northern Fennoscandia

摘要

abstract_textpA reconstruction of summer temperatures during two millennia in Northern Fennoscandia has been studied and 79 abrupt cold periods have been identified. Data regarding the volcanic eruptions are not a priori used. During 1750-2000 all of the abrupt, cold periods could posteriori be connected to candidate years of volcanic eruptions. It is concluded that the 79 abrupt cold periods are mainly, if not all, postvolcanic ones. Local impact of weaker, less global (Icelandic) or some unknown eruptions is evident in the results. In addition to the short cold periods, we found 42 longer bidecadal-multidecadal oscillations during 50-1980 AD. The short abrupt cold periods and the longer oscillations were characterized as the atmospheric and oceanic responses to volcanic eruptions, respectively. The volcanic activity has clearly been a dominant contributor to the temperature variations in Northern Fennoscandia during the two last millennia./p/abstract_text