Volcanic Eruptions

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A. Robock - One of the best experts on this subject based on the ideXlab platform.

  • northern hemisphere winter warming and summer monsoon reduction after Volcanic Eruptions over the last millennium
    Journal of Geophysical Research, 2017
    Co-Authors: Brian Zambri, A. Robock, Allegra N. Legrande, Joanna Slawinska
    Abstract:

    Observations show that all recent large tropical Volcanic Eruptions (1850-present) were followed by surface winter warming in the first Northern Hemisphere (NH) winter after the eruption. Recent studies show that climate models produce a surface winter warming response in the first winter after the largest Eruptions, but require a large ensemble of simulations to see significant changes. It is also generally required that the eruption be very large, and only two such Eruptions occurred in the historical period: Krakatau in 1883 and Pinatubo in 1991. Here we examine surface winter warming patterns after the 10 largest Volcanic Eruptions between 850 and 1850 in the Paleoclimate Modeling Intercomparison Project 3 last millennium simulations and in the Community Earth System Model Last Millennium Ensemble. These Eruptions were all larger than those since 1850. Though the results depend on both the individual models and the forcing data set used, we have found that models produce a surface winter warming signal in the first winter after large Volcanic Eruptions, with higher temperatures over NH continents and a stronger polar vortex in the lower stratosphere. We also examined NH summer precipitation responses in the first year after the Eruptions, and find clear reductions of summer Asian and African monsoon rainfall.

  • Climatic Impacts of Volcanic Eruptions
    The Encyclopedia of Volcanoes, 2015
    Co-Authors: A. Robock
    Abstract:

    Abstract Large Volcanic Eruptions inject sulfur gases into the stratosphere. The resulting stratospheric sulfate aerosol clouds last for several months to a couple years. Volcanic clouds produce global cooling, and are the most important natural cause of climate change from decades to millennia. Regional responses include winter warming of Northern Hemisphere continents following major tropical Eruptions and weakening of summer Asian and African monsoons following tropical and Northern Hemisphere high latitude Eruptions. Volcanic clouds also produce stratospheric ozone depletion. The very large Toba eruption 74,000 years ago may have caused a human genetic bottleneck. Volcanic Eruptions serve as an analog warning us of the dangers of anthropogenic stratospheric inputs from geoengineering or nuclear war.

  • ocean response to Volcanic Eruptions in coupled model intercomparison project 5 simulations
    Journal of Geophysical Research, 2014
    Co-Authors: Yanni Ding, A. Robock, Georgiy L. Stenchikov, James A Carton, Gennady A Chepurin, Lori T Sentman, John P Krasting
    Abstract:

    We examine the oceanic impact of large tropical Volcanic Eruptions as they appear in ensembles of historical simulations from eight Coupled Model Intercomparison Project Phase 5 models. These models show a response that includes lowering of global average sea surface temperature by 0.1–0.3 K, comparable to the observations. They show enhancement of Arctic ice cover in the years following major Volcanic Eruptions, with long-lived temperature anomalies extending to the middepth and deep ocean on decadal to centennial timescales. Regional ocean responses vary, although there is some consistent hemispheric asymmetry associated with the hemisphere in which the eruption occurs. Temperature decreases and salinity increases contribute to an increase in the density of surface water and an enhancement in the overturning circulation of the North Atlantic Ocean following these Eruptions. The strength of this overturning increase varies considerably from model to model and is correlated with the background variability of overturning in each model. Any cause/effect relationship between Eruptions and the phase of El Nino is weak.

  • The Latest on Volcanic Eruptions and Climate
    Eos Transactions American Geophysical Union, 2013
    Co-Authors: A. Robock
    Abstract:

    What was the largest Volcanic eruption on Earth since the historic Mount Pinatubo eruption on 15 June 1991? Was the Toba super­eruption 74,000 years ago—the largest in the past 100,000 years—responsible for a human genetic bottleneck or a 1000-year-long glacial advance? What role did small Volcanic Eruptions play in the reduced global warming of the past decade? What caused the Little Ice Age? Was the April 2010 Eyjafjallajokull eruption in Iceland important for climate change? What do Volcanic Eruptions teach us about new ideas on geoengineering and nuclear winter? These are some of the questions that have been answered since the review article by Robock [2000]. Reviews by Forster et al. [2007] and Timmreck [2012] go into some of these topics in much greater detail.

  • Correction to “Volcanic Eruptions and climate”
    Reviews of Geophysics, 2007
    Co-Authors: A. Robock
    Abstract:

    [1] In the paper ‘‘Volcanic Eruptions and climate’’ by Alan Robock (Reviews of Geophysics, 38(2), 191–219, 2000), two errors have been found on page 197. [2] While preparing for a presentation on the 25th anniversary of the April 1982 El Chichon Volcanic eruption, I found the original slide used for Plate 4 and discovered that it had been developed in July 1982 rather than the date of April 1983 given in the paper. I had had copies made of this slide and erroneously had used the date on a copy of the slide rather than the original date when writing the paper. Therefore the corrected caption should read as follows: [3] Plate 4. Sunset over Lake Mendota in Madison, Wisconsin, in July 1982, three months after the El Chichon eruption. Photograph by A. Robock. [4] On the same page as Plate 4, the statement, ‘‘The famous 1893 Edvard Munch painting, ‘The Scream,’ shows a red Volcanic sunset over the Oslo harbor produced by the 1892 Awu eruption,’’ is incorrect with regard to the eruption that produced the red and yellow sky. As pointed out subsequently by Olson et al. [2004], it was the memory of the spectacular sunsets from the 1883 Krakatau eruption that inspired Munch to use a Volcanic sunset 10 years later in ‘‘The Scream.’’

Gavin A. Schmidt - One of the best experts on this subject based on the ideXlab platform.

  • climatic response to high latitude Volcanic Eruptions
    Journal of Geophysical Research, 2005
    Co-Authors: Luke D. Oman, A. Robock, Georgiy L. Stenchikov, Gavin A. Schmidt, Reto Ruedy
    Abstract:

    [1] Strong Volcanic Eruptions can inject large amounts of SO2 into the lower stratosphere, which over time, are converted into sulfate aerosols and have the potential to impact climate. Aerosols from tropical Volcanic Eruptions like the 1991 Mount Pinatubo eruption spread over the entire globe, whereas high-latitude Eruptions typically have aerosols which remain in the hemisphere in which they where injected. This causes their largest radiative forcing to be extratropical, and the climate response should be different from that of tropical Eruptions. We conducted a 20-member ensemble simulation of the climate response to the Katmai eruption (58°N) of 6 June 1912 using the NASA Goddard Institute for Space Studies ModelE climate model. We also produced an additional 20-member ensemble for a 3 times Katmai (3x Katmai) eruption to see the impact the strength of the eruption has on the radiative as well as the dynamical responses. The results of these simulations do not show a positive Arctic Oscillation response like past simulations of tropical Volcanic Eruptions, but we did find significant cooling over southern Asia during the boreal winter. The first winter following Katmai and the second winter following 3x Katmai showed strong similarities in lower stratospheric geopotential height anomalies and sea level pressure anomalies, which occurred when the two cases had similar optical depth perturbations. These simulations show that the radiative impact of a high-latitude Volcanic eruption was much larger than the dynamical impact at high latitudes. In the boreal summer, however, strong cooling over the Northern Hemisphere landmasses caused a decrease in the Asian monsoon circulation with significant decreases of up to 10% in cloud cover and warming over northern India. Thus the main dynamical impact of high-latitude Eruptions is in the summer over Asia.

  • Climatic response to high‐latitude Volcanic Eruptions
    Journal of Geophysical Research, 2005
    Co-Authors: Luke D. Oman, A. Robock, Georgiy L. Stenchikov, Gavin A. Schmidt, Reto Ruedy
    Abstract:

    [1] Strong Volcanic Eruptions can inject large amounts of SO2 into the lower stratosphere, which over time, are converted into sulfate aerosols and have the potential to impact climate. Aerosols from tropical Volcanic Eruptions like the 1991 Mount Pinatubo eruption spread over the entire globe, whereas high-latitude Eruptions typically have aerosols which remain in the hemisphere in which they where injected. This causes their largest radiative forcing to be extratropical, and the climate response should be different from that of tropical Eruptions. We conducted a 20-member ensemble simulation of the climate response to the Katmai eruption (58°N) of 6 June 1912 using the NASA Goddard Institute for Space Studies ModelE climate model. We also produced an additional 20-member ensemble for a 3 times Katmai (3x Katmai) eruption to see the impact the strength of the eruption has on the radiative as well as the dynamical responses. The results of these simulations do not show a positive Arctic Oscillation response like past simulations of tropical Volcanic Eruptions, but we did find significant cooling over southern Asia during the boreal winter. The first winter following Katmai and the second winter following 3x Katmai showed strong similarities in lower stratospheric geopotential height anomalies and sea level pressure anomalies, which occurred when the two cases had similar optical depth perturbations. These simulations show that the radiative impact of a high-latitude Volcanic eruption was much larger than the dynamical impact at high latitudes. In the boreal summer, however, strong cooling over the Northern Hemisphere landmasses caused a decrease in the Asian monsoon circulation with significant decreases of up to 10% in cloud cover and warming over northern India. Thus the main dynamical impact of high-latitude Eruptions is in the summer over Asia.

  • dynamic winter climate response to large tropical Volcanic Eruptions since 1600
    Journal of Geophysical Research, 2004
    Co-Authors: Gavin A. Schmidt, Drew T Shindell, Michael E Mann, G Faluvegi
    Abstract:

    [1] We have analyzed the mean climate response pattern following large tropical Volcanic Eruptions back to the beginning of the 17th century using a combination of proxy-based reconstructions and modern instrumental records of cold-season surface air temperature. Warm anomalies occur throughout northern Eurasia, while cool anomalies cover northern Africa and the Middle East, extending all the way to China. In North America, the northern portion of the continent cools, with the anomalies extending out over the Labrador Sea and southern Greenland. The analyses confirm that for two years following Eruptions the anomalies strongly resemble the Arctic Oscillation/Northern Annular Mode (AO/NAM) or the North Atlantic Oscillation (NAO) in the Atlantic-Eurasian sector. With our four-century record, the mean response is statistically significant at the 95% confidence level over much of the Northern Hemisphere land area. However, the standard deviation of the response is larger than the mean signal nearly everywhere, indicating that the anomaly following a single eruption is unlikely to be representative of the mean. Both the mean response and the variability can be successfully reproduced in general circulation model simulations. Driven by the solar heating induced by the stratospheric aerosols, these models produce enhanced westerlies from the lower stratosphere down to the surface. The climate response to Volcanic Eruptions thus strongly suggests that stratospheric temperature and wind anomalies can affect surface climate by forcing a shift in the AO/NAM or NAO.

Drew T Shindell - One of the best experts on this subject based on the ideXlab platform.

  • dynamic winter climate response to large tropical Volcanic Eruptions since 1600
    Journal of Geophysical Research, 2004
    Co-Authors: Gavin A. Schmidt, Drew T Shindell, Michael E Mann, G Faluvegi
    Abstract:

    [1] We have analyzed the mean climate response pattern following large tropical Volcanic Eruptions back to the beginning of the 17th century using a combination of proxy-based reconstructions and modern instrumental records of cold-season surface air temperature. Warm anomalies occur throughout northern Eurasia, while cool anomalies cover northern Africa and the Middle East, extending all the way to China. In North America, the northern portion of the continent cools, with the anomalies extending out over the Labrador Sea and southern Greenland. The analyses confirm that for two years following Eruptions the anomalies strongly resemble the Arctic Oscillation/Northern Annular Mode (AO/NAM) or the North Atlantic Oscillation (NAO) in the Atlantic-Eurasian sector. With our four-century record, the mean response is statistically significant at the 95% confidence level over much of the Northern Hemisphere land area. However, the standard deviation of the response is larger than the mean signal nearly everywhere, indicating that the anomaly following a single eruption is unlikely to be representative of the mean. Both the mean response and the variability can be successfully reproduced in general circulation model simulations. Driven by the solar heating induced by the stratospheric aerosols, these models produce enhanced westerlies from the lower stratosphere down to the surface. The climate response to Volcanic Eruptions thus strongly suggests that stratospheric temperature and wind anomalies can affect surface climate by forcing a shift in the AO/NAM or NAO.

Georgiy L. Stenchikov - One of the best experts on this subject based on the ideXlab platform.

  • ocean response to Volcanic Eruptions in coupled model intercomparison project 5 simulations
    Journal of Geophysical Research, 2014
    Co-Authors: Yanni Ding, A. Robock, Georgiy L. Stenchikov, James A Carton, Gennady A Chepurin, Lori T Sentman, John P Krasting
    Abstract:

    We examine the oceanic impact of large tropical Volcanic Eruptions as they appear in ensembles of historical simulations from eight Coupled Model Intercomparison Project Phase 5 models. These models show a response that includes lowering of global average sea surface temperature by 0.1–0.3 K, comparable to the observations. They show enhancement of Arctic ice cover in the years following major Volcanic Eruptions, with long-lived temperature anomalies extending to the middepth and deep ocean on decadal to centennial timescales. Regional ocean responses vary, although there is some consistent hemispheric asymmetry associated with the hemisphere in which the eruption occurs. Temperature decreases and salinity increases contribute to an increase in the density of surface water and an enhancement in the overturning circulation of the North Atlantic Ocean following these Eruptions. The strength of this overturning increase varies considerably from model to model and is correlated with the background variability of overturning in each model. Any cause/effect relationship between Eruptions and the phase of El Nino is weak.

  • Stratosphere troposphere coupling: the influence of Volcanic Eruptions
    2011
    Co-Authors: Matthew Toohey, Kirstin Krüger, Stefanie Gleixner, Claudia Timmreck, H. F. Graf, Marco A. Giorgetta, A. Karpechko, Doreen Metzner, Hauke Schmidt, Georgiy L. Stenchikov
    Abstract:

    Stratospheric sulfate aerosols produced by major Volcanic Eruptions modify the radiative and dynamical properties of the troposphere and stratosphere through their reflection of solar radiation and absorption of infrared radiation. At the Earth's surface, the primary consequence of a large eruption is cooling, however, it has long been known that major tropical Eruptions tend to be followed by warmer than usual winters over the Northern Hemisphere (NH) continents. This Volcanic "winter-warming" effect in the NH is understood to be the result of changes in atmospheric circulation patterns resulting from heating in the stratosphere, and is often described as positive anomalies of the Northern Annular Mode (NAM) that propagate downward from the stratosphere to the troposphere. In the southern hemisphere, climate models tend to also predict a positive Southern Annular Mode (SAM) response to Volcanic Eruptions, but this is generally inconsistent with post-eruption observations during the 20th century. We review present understanding of the influence of Volcanic Eruptions on the large scale modes of atmospheric variability in both the Northern and Southern Hemispheres. Using models of varying complexity, including an aerosol-climate model, an Earth system model, and CMIP5 simulations, we assess the ability of climate models to reproduce the observed post-eruption climatic and dynamical anomalies. We will also address the parametrization of Volcanic Eruptions in simulations of the past climate, and identify possibilities for improvement

  • arctic oscillation response to Volcanic Eruptions in the ipcc ar4 climate models
    Journal of Geophysical Research, 2006
    Co-Authors: Georgiy L. Stenchikov, A. Robock, Kevin Hamilton, Ronald J Stouffer, V Ramaswamy, B D Santer, Hansf Graf
    Abstract:

    [1] Stratospheric sulfate aerosol particles from strong Volcanic Eruptions produce significant transient cooling of the troposphere and warming of the lower stratosphere. The radiative impact of Volcanic aerosols also produces a response that generally includes an anomalously positive phase of the Arctic Oscillation (AO) that is most pronounced in the boreal winter. The main atmospheric thermal and dynamical effects of Eruptions typical of the past century persist for about two years after each eruption. In this paper we evaluate the Volcanic responses in simulations produced by seven of the climate models included in the model intercomparison conducted as part of the preparation of the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4). We consider global effects as well as the regional circulation effects in the extratropical Northern Hemisphere focusing on the AO responses forced by Volcanic Eruptions. Specifically we analyze results from the IPCC historical runs that simulate the evolution of the circulation over the last part of the 19th century and the entire 20th century using a realistic time series of atmospheric composition (greenhouse gases and aerosols). In particular, composite anomalies over the two boreal winters following each of the nine largest low-latitude Eruptions during the period 1860–1999 are computed for various tropospheric and stratospheric fields. These are compared when possible with observational data. The seven IPCC models we analyzed use similar assumptions about the amount of Volcanic aerosols formed in the lower stratosphere following the Volcanic Eruptions that have occurred since 1860. All models produce tropospheric cooling and stratospheric warming as in observations. However, they display a considerable range of dynamic responses to Volcanic aerosols. Nevertheless, some general conclusions can be drawn. The IPCC models tend to simulate a positive phase of the Arctic Oscillation in response to Volcanic forcing similar to that typically observed. However, the associated dynamic perturbations and winter surface warming over Northern Europe and Asia in the post-volcano winters is much weaker in the models than in observations. The AR4 models also underestimate the variability and long-term trend of the AO. This deficiency affects high-latitude model predictions and may have a similar origin. This analysis allows us to better evaluate Volcanic impacts in up-to-date climate models and to better quantify the model Arctic Oscillation sensitivity to external forcing. This potentially could lead to improving model climate predictions in the extratropical latitudes of the Northern Hemisphere.

  • climatic response to high latitude Volcanic Eruptions
    Journal of Geophysical Research, 2005
    Co-Authors: Luke D. Oman, A. Robock, Georgiy L. Stenchikov, Gavin A. Schmidt, Reto Ruedy
    Abstract:

    [1] Strong Volcanic Eruptions can inject large amounts of SO2 into the lower stratosphere, which over time, are converted into sulfate aerosols and have the potential to impact climate. Aerosols from tropical Volcanic Eruptions like the 1991 Mount Pinatubo eruption spread over the entire globe, whereas high-latitude Eruptions typically have aerosols which remain in the hemisphere in which they where injected. This causes their largest radiative forcing to be extratropical, and the climate response should be different from that of tropical Eruptions. We conducted a 20-member ensemble simulation of the climate response to the Katmai eruption (58°N) of 6 June 1912 using the NASA Goddard Institute for Space Studies ModelE climate model. We also produced an additional 20-member ensemble for a 3 times Katmai (3x Katmai) eruption to see the impact the strength of the eruption has on the radiative as well as the dynamical responses. The results of these simulations do not show a positive Arctic Oscillation response like past simulations of tropical Volcanic Eruptions, but we did find significant cooling over southern Asia during the boreal winter. The first winter following Katmai and the second winter following 3x Katmai showed strong similarities in lower stratospheric geopotential height anomalies and sea level pressure anomalies, which occurred when the two cases had similar optical depth perturbations. These simulations show that the radiative impact of a high-latitude Volcanic eruption was much larger than the dynamical impact at high latitudes. In the boreal summer, however, strong cooling over the Northern Hemisphere landmasses caused a decrease in the Asian monsoon circulation with significant decreases of up to 10% in cloud cover and warming over northern India. Thus the main dynamical impact of high-latitude Eruptions is in the summer over Asia.

  • Climatic response to high‐latitude Volcanic Eruptions
    Journal of Geophysical Research, 2005
    Co-Authors: Luke D. Oman, A. Robock, Georgiy L. Stenchikov, Gavin A. Schmidt, Reto Ruedy
    Abstract:

    [1] Strong Volcanic Eruptions can inject large amounts of SO2 into the lower stratosphere, which over time, are converted into sulfate aerosols and have the potential to impact climate. Aerosols from tropical Volcanic Eruptions like the 1991 Mount Pinatubo eruption spread over the entire globe, whereas high-latitude Eruptions typically have aerosols which remain in the hemisphere in which they where injected. This causes their largest radiative forcing to be extratropical, and the climate response should be different from that of tropical Eruptions. We conducted a 20-member ensemble simulation of the climate response to the Katmai eruption (58°N) of 6 June 1912 using the NASA Goddard Institute for Space Studies ModelE climate model. We also produced an additional 20-member ensemble for a 3 times Katmai (3x Katmai) eruption to see the impact the strength of the eruption has on the radiative as well as the dynamical responses. The results of these simulations do not show a positive Arctic Oscillation response like past simulations of tropical Volcanic Eruptions, but we did find significant cooling over southern Asia during the boreal winter. The first winter following Katmai and the second winter following 3x Katmai showed strong similarities in lower stratospheric geopotential height anomalies and sea level pressure anomalies, which occurred when the two cases had similar optical depth perturbations. These simulations show that the radiative impact of a high-latitude Volcanic eruption was much larger than the dynamical impact at high latitudes. In the boreal summer, however, strong cooling over the Northern Hemisphere landmasses caused a decrease in the Asian monsoon circulation with significant decreases of up to 10% in cloud cover and warming over northern India. Thus the main dynamical impact of high-latitude Eruptions is in the summer over Asia.

Kirstin Krüger - One of the best experts on this subject based on the ideXlab platform.

  • Global ozone depletion and increase of UV radiation caused by pre-industrial tropical Volcanic Eruptions
    Scientific Reports, 2019
    Co-Authors: Hans Brenna, Steffen Kutterolf, Kirstin Krüger
    Abstract:

    Large explosive tropical Volcanic Eruptions inject high amounts of gases into the stratosphere, where they disperse globally through the large-scale meridional circulation. There is now increasing observational evidence that Volcanic halogens can reach the upper troposphere and lower stratosphere. Here, we present the first study that combines measurement-based data of sulfur, chlorine and bromine releases from tropical Volcanic Eruptions with complex coupled chemistry climate model simulations taking radiative-dynamical-chemical feedbacks into account. Halogen model input parameters represent a size-time-region-wide average for the Central American Eruptions over the last 200 ka ensuring a comprehensive perspective. The simulations reveal global, long-lasting impact on the ozone layer affecting atmospheric composition and circulation for a decade. Column ozone drops below 220 DU (ozone hole conditions) in the tropics, Arctic and Antarctica, increasing biologically active UV by 80 to 400%. Our model results could potentially be validated using high-resolution proxies from ice cores and pollen records.

  • disproportionately strong climate forcing from extratropical explosive Volcanic Eruptions
    Nature Geoscience, 2019
    Co-Authors: Matthew Toohey, Kirstin Krüger, Claudia Timmreck, Hauke Schmidt, Michael Sigl, Markus Stoffel, Rob Wilson
    Abstract:

    Extratropical Volcanic Eruptions are commonly thought to be less effective at driving large-scale surface cooling than tropical Eruptions. However, recent minor extratropical Eruptions have produced a measurable climate impact, and proxy records suggest that the most extreme Northern Hemisphere cold period of the Common Era was initiated by an extratropical eruption in 536 ce. Using ice-core-derived Volcanic stratospheric sulfur injections and Northern Hemisphere summer temperature reconstructions from tree rings, we show here that in proportion to their estimated stratospheric sulfur injection, extratropical explosive Eruptions since 750 ce have produced stronger hemispheric cooling than tropical Eruptions. Stratospheric aerosol simulations demonstrate that for Eruptions with a sulfur injection magnitude and height equal to that of the 1991 Mount Pinatubo eruption, extratropical Eruptions produce time-integrated radiative forcing anomalies over the Northern Hemisphere extratropics up to 80% greater than tropical Eruptions, as decreases in aerosol lifetime are overwhelmed by the enhanced radiative impact associated with the relative confinement of aerosol to a single hemisphere. The model results are consistent with the temperature reconstructions, and elucidate how the radiative forcing produced by extratropical Eruptions is strongly dependent on the eruption season and sulfur injection height within the stratosphere. Explosive Volcanic Eruptions in the extratropics have cooled the climate in their hemisphere more than tropical Eruptions, suggests an analysis of reconstructions since ad 750 and simulations with an atmosphere–aerosol model.

  • Stratosphere troposphere coupling: the influence of Volcanic Eruptions
    2011
    Co-Authors: Matthew Toohey, Kirstin Krüger, Stefanie Gleixner, Claudia Timmreck, H. F. Graf, Marco A. Giorgetta, A. Karpechko, Doreen Metzner, Hauke Schmidt, Georgiy L. Stenchikov
    Abstract:

    Stratospheric sulfate aerosols produced by major Volcanic Eruptions modify the radiative and dynamical properties of the troposphere and stratosphere through their reflection of solar radiation and absorption of infrared radiation. At the Earth's surface, the primary consequence of a large eruption is cooling, however, it has long been known that major tropical Eruptions tend to be followed by warmer than usual winters over the Northern Hemisphere (NH) continents. This Volcanic "winter-warming" effect in the NH is understood to be the result of changes in atmospheric circulation patterns resulting from heating in the stratosphere, and is often described as positive anomalies of the Northern Annular Mode (NAM) that propagate downward from the stratosphere to the troposphere. In the southern hemisphere, climate models tend to also predict a positive Southern Annular Mode (SAM) response to Volcanic Eruptions, but this is generally inconsistent with post-eruption observations during the 20th century. We review present understanding of the influence of Volcanic Eruptions on the large scale modes of atmospheric variability in both the Northern and Southern Hemispheres. Using models of varying complexity, including an aerosol-climate model, an Earth system model, and CMIP5 simulations, we assess the ability of climate models to reproduce the observed post-eruption climatic and dynamical anomalies. We will also address the parametrization of Volcanic Eruptions in simulations of the past climate, and identify possibilities for improvement