Status: this preprint was under review for the journal CP but the revision was not accepted.
Volcanic imprint in the North Atlantic climate variability as recorded by stable water isotopes of Greenland ice cores
Hera Guðlaugsdóttir,Jesper Sjolte,Árný Erla Sveinbjörnsdóttir,and Hans Christian Steen-Larsen
Abstract. Volcanic eruptions are important drivers of climate variability on both seasonal and multi-decadal time scales as a result of atmosphere-ocean coupling. While the direct response after equatorial eruptions emerges as the positive phase of the North Atlantic Oscillation in the first two years after an eruption, less is known about high latitude northern hemisphere eruptions. In this study we assess the difference between equatorial and high latitude volcanic eruptions through the reconstructed atmospheric circulation and stable water isotope records of Greenland ice cores for the last millennia (1241–1979 CE), where the coupling mechanism behind the long-term response is addressed. The atmospheric circulation is studied through the four main modes of climate variability in the North Atlantic, the Atlanti Ridge (AtR), Scandinavian Blocking (ScB) and the positive and negative phase of the North Atlantic Oscillation (NAO+/NAO−). We report a difference in the atmospheric circulation response after equatorial eruptions compared to the response after high latitude eruptions, where NAO+ and AtR seem to be more associated with equatorial eruptions while NAO- and ScB seems to follow high latitude eruptions. This response is present during the first five years and then again in years 8–12 after both equatorial and high latitude eruptions. Such a prolonged response is evidence of an ocean-atmosphere coupling that is initiated through different mechanisms, where we suspect sea ice to play a key role.
How to cite. Guðlaugsdóttir, H., Sjolte, J., Sveinbjörnsdóttir, Á. E., and Steen-Larsen, H. C.: Volcanic imprint in the North Atlantic climate variability as recorded by stable water isotopes of Greenland ice cores, Clim. Past Discuss. [preprint], https://doi.org/10.5194/cp-2019-99, 2019.
Received: 08 Aug 2019 – Discussion started: 06 Sep 2019
In the North Atlantic four modes of climate variability dominate weather. Here we assess how these modes are affected after both equatorial and high latitude eruptions, known to influence temperature in the atmosphere. Main results show that the modes associated with extreme weather events tend to follow high latitude eruptions as opposed to equatorial eruptions. These modes have also become more frequent as a result of anthropogenic warming, providing an insight into the dominating mechanism.
In the North Atlantic four modes of climate variability dominate weather. Here we assess how...