Volcanic eruptions and long‐term temperature records: An empirical search for cause and effect

Abstract

AbstractThe ‘superposed epoch’ analysis method of compositing temperatures is employed to aid in the search for evidence of a drop in surface temperature due to large volcanic dust veils. The temperature records examined have been chosen from the archives at the National Center for Atmospheric Research according to the length and completeness of the record. Various groupings of the data stations are used as data bases and the strength of the ‘volcanic signal’ determined in the different cases. A seasonal (winter‐summer) investigation of the signal is also conducted. A significant dip in temperature can be found within a few years after the major eruption dates in most of the dust veil temperature superpositions, whereas the noise appears to vary randomly from superposition to superposition. The evidence points to a stronger, but less statistically significant, response to the effects of large volcanic dust veils in higher latitudes, although a definite conconclusion requires, among other things, a larger and more representative data base. The seasonal investigation reveals a stronger summer signal in the majority of cases.