Climate response to large, high‐latitude and low‐latitude volcanic eruptions in the Community Climate System Model

Abstract

[1] Explosive volcanism is known to be a leading natural cause of climate change. The second half of the 13th century was likely the most volcanically perturbed half-century of the last 2000 years, although none of the major 13th century eruptions have been clearly attributed to specific volcanoes. This period was in general a time of transition from the relatively warm Medieval period to the colder Little Ice Age, but available proxy records are insufficient on their own to clearly assess whether this transition is associated with volcanism. This context motivates our investigation of the climate system sensitivity to high-and low-latitude volcanism using the fully coupled NCAR Community Climate System Model (CCSM3). We evaluate two sets of ensemble simulations, each containing four volcanic pulses, with the first set representing them as a sequence of tropical eruptions and the second representing eruptions occurring in the mid-high latitudes of both the Northern and Southern hemispheres. The short-term, direct radiative impacts of tropical and high-latitude eruptions include significant cooling over the continents in summer and cooling over regions of increased sea-ice concentration in Northern Hemisphere (NH) winter. A main dynamical impact of moderate tropical eruptions is a winter warming pattern across northern Eurasia. Furthermore, both ensembles show significant reductions in global precipitation, especially in the summer monsoon regions. The most important long-term impact is the cooling of the high-latitude NH produced by multiple tropical eruptions, suggesting that positive feedbacks associated with ice and snow cover could lead to long-term climate cooling in the Arctic.

Climatic and societal impacts of a volcanic double event at the dawn of the Middle Ages

“…Consistency between the ice core records, MXD tree ring temperature reconstructions, and historical observations of the 536 event can be achieved under the scenario of a high latitude NH eruption producing a high altitude sulfur injection, consistent with contemporary observations of major tropical eruptions, but as yet not observed for extratropical eruptions. This result suggests that the climate impact of extratropical eruptions may not always be as minor compared to tropical eruptions as deduced from prior studies (e.g., Schneider et al 2009). Best agreement with ice core records of the ca.…”

“…While persistent decadal-scale cooling after 540 CE-apparent in some tree ring width records (e.g., D'Arrigo et al 2001;Larsen et al 2008)-is not reproduced by the model at the locations of the Scandinavian tree ring samples, decadal-scale anomalies of Arctic sea ice are produced, suggesting a possible mechanism for longer term climate response. If sea ice growth is an important mechanism in the prolongation of short-term volcanic radiative forcing into decadal scale climate responses (e.g., Schneider et al 2009;Schleussner and Feulner 2013;Lehner et al 2013), it may be that the characteristics of the 536/540 double event, which produced strong radiative forcing at NH high latitudes focused over a single decade, may have been especially effective at creating climate anomalies persisting well after the eruptions.…”

Volcano impacts on climate and biogeochemistry in a coupled carbon–climate model

“…It also indicates what fraction of the true volcano signal we expect to see in the real world, where we have no control case. Previous studies at higher resolution with the CCSM3 suggest that the model is able to capture the observed response to volcanoes (Schneider et al, 2009), but generally has difficulty in accurately capturing El Niño (Deser et al, 2006). This paper, similar to , does not consider the potentially important impacts of the addition of biogeochemically relevant species from a volcanic eruption, but only the response to the physical forcing.…”

“…The CCSM3's dynamical response to volcanic forcing has previously been investigated at higher spatial resolution, but uncoupled to the carbon cycle (Schneider et al, 2009), and there is a great deal of analysis available on the larger eruptions of the past century for other models (Shindell et al, 2004;Robock and Mao, 1995;Stenchikov et al, 2006). In the global average, we expect to see cooling after major eruptions due to the negative radiative forcing of the aerosol particles emitted by the volcano and subsequently dispersed.…”

“…A selection of eruptions (see Table 1) was made based on Robock and Mao (1992), and adjusted to facilitate comparison to other papers by choosing only the most commonly analyzed eruptions Robock and Liu, 1994;Shindell et al, 2004;Oman et al, 2005;Stenchikov et al, 2006;Schneider et al, 2009). Robock and Mao (1992) chose eruptions (Table 1) occurring between 1870-2000 that satisfied the criteria of VEI (volcanic explosivity index) ≥ 5 or DVI (dust veil index) ≥ 250.…”