A New Volcanic Stratospheric Sulfate Aerosol Forcing Emulator (EVA_H): Comparison With Interactive Stratospheric Aerosol Models

Aubry, Thomas J.; Toohey, Matthew; Marshall, Lauren; Schmidt, Anja; Jellinek, M.

doi:10.1029/2019jd031303

Cited by 31 publications

(29 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition to temperature responses, several studies have noted a decrease in global precipitation following the Pinatubo eruption (Robock and Liu, 1994;Broccoli et al, 2003;Gillett et al, 2004;Barnes et al, 2016). The CanESM5 ensemble mean shows a global precipitation decrease of 0.05 mm d −1 1 year after the eruption, consistent with previous studies.…”

Section: Climate Responsesupporting

confidence: 88%

Quantifying CanESM5 and EAMv1 sensitivities to Mt. Pinatubo volcanic forcing for the CMIP6 historical experiment

et al. 2020

View full text Add to dashboard Cite

Abstract. Large volcanic eruptions reaching the stratosphere have caused marked perturbations to the global climate including cooling at the Earth's surface, changes in large-scale circulation and precipitation patterns and marked temporary reductions in global ocean heat content. Many studies have investigated these effects using climate models; however, uncertainties remain in the modelled response to these eruptions. This is due in part to the diversity of forcing datasets that are used to prescribe the distribution of stratospheric aerosols resulting from these volcanic eruptions, as well as uncertainties in optical property derivations from these datasets. To improve this situation for the sixth phase of the Coupled Model Intercomparison Project (CMIP6), a two-step process was undertaken. First, a combined stratospheric aerosol dataset, the Global Space-based Stratospheric Aerosol Climatology (GloSSAC; 1979–2016), was constructed. Next, GloSSAC, along with information from ice cores and Sun photometers, was used to generate aerosol distributions, characteristics and optical properties to construct a more consistent stratospheric aerosol forcing dataset for models participating in CMIP6. This “version 3” of the stratospheric aerosol forcing has been endorsed for use in all contributing CMIP6 simulations. Recent updates to the underlying GloSSAC from version 1 to version 1.1 affected the 1991–1994 period and necessitated an update to the stratospheric aerosol forcing from version 3 to version 4. As version 3 remains the official CMIP6 input, quantification of the impact on radiative forcing and climate is both relevant and timely for interpreting results from experiments such as the CMIP6 historical simulations. This study uses two models, the Canadian Earth System Model version 5 (CanESM5) and the Energy Exascale Earth System Model (E3SM) Atmosphere Model version 1 (EAMv1), to estimate the difference in instantaneous radiative forcing in simulated post-Pinatubo climate response when using version 4 instead of version 3. Differences in temperature, precipitation and radiative forcings are generally found to be small compared to internal variability. An exception to this is differences in monthly temperature anomalies near 24 km altitude in the tropics, which can be as large as 3 ∘C following the eruption of Mt. Pinatubo.

show abstract

Section: Climate Responsesupporting

confidence: 88%

Quantifying CanESM5 and EAMv1 sensitivities to Mt. Pinatubo volcanic forcing for the CMIP6 historical experiment

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Progress in representing volcanic forcing (Aubry et al, ; Toohey & Sigl, ), as well as improvements in model resolution and processes (e.g., active stratospheric chemistry) in PMIP4 (Kageyama et al, ) may lead to closer model‐data matches in future work. Regardless of these factors, our analysis suggests that a critical ingredient of minimizing the model‐reconstruction mismatch is to evaluate simulated temperature at the times and places where it is recorded by the proxy sensors (Anchukaitis et al, ).…”

Section: Discussionmentioning

confidence: 99%

Resolving the Differences in the Simulated and Reconstructed Temperature Response to Volcanism

Zhu

Emile‐Geay

Hakim

et al. 2020

Geophysical Research Letters

View full text Add to dashboard Cite

Explosive volcanism imposes impulse-like radiative forcing on the climate system, providing a natural experiment to study the climate response to perturbation. Previous studies have identified disagreements between paleoclimate reconstructions and climate model simulations with respect to the magnitude and recovery from volcanic cooling, questioning the fidelity of climate model simulations, reconstructions, or both. Using the paleoenvironmental data assimilation framework of the Last Millennium Reanalysis, this study investigates the causes of the disagreements, using both real and simulated data. We demonstrate that discrepancies since 1600 CE can be largely resolved by assimilating tree-ring density records only, targeting growing season temperature instead of annual temperature, and performing the comparison at proxy locales. Simulations of eruptions earlier in the last millennium may also reflect uncertainties in forcing and modeled aerosol microphysics. Plain Language SummaryThe response to volcanic eruptions is a critical benchmark of the performance of climate models. Previous studies of the past millennium have identified discrepancies between model simulations and climate reconstructions regarding the temperature response to volcanic eruptions, raising concerns regarding the source of this mismatch and implications for both models and reconstructions. By evaluating the leading sources of differences between simulations and reconstructions, this study shows that accounting for known factors largely bridges the gap. Key Points:• We explore model-proxy disagreement on the temperature response to volcanic eruptions over the past millennium • Using paleoclimate data assimilation with both real and synthetic data, we show that this discrepancy is due to four main factors • Over the past 400 years, agreement is found for tree-ring density records at the places and season these proxies record Supporting Information:• Supporting Information S1

show abstract

“…In this example, annual SAOD values are calendar years. We do not convert EVA SAOD depending on the year after the eruption as the ESP‐dependent relationships account for a large amount of the variability in the SAOD to ERF conversion (Figure 1f) and the temporal evolution in the EVA reconstruction is based on a simple box model with decay timescales that are different to aerosol‐climate models that explicitly account for volcanic SO 2 emissions (Aubry et al, 2020; Zanchettin et al, 2016).…”

Section: Resultsmentioning

confidence: 99%

Large Variations in Volcanic Aerosol Forcing Efficiency Due to Eruption Source Parameters and Rapid Adjustments

Marshall

Smith

Forster

et al. 2020

Geophysical Research Letters

Self Cite

View full text Add to dashboard Cite

The relationship between volcanic stratospheric aerosol optical depth (SAOD) and volcanic radiative forcing is key for quantifying volcanic climate impacts. In their Fifth Assessment Report, the Intergovernmental Panel on Climate Change used one scaling factor between volcanic SAOD and volcanic forcing based on climate model simulations of the 1991 Mt. Pinatubo eruption, which may not be appropriate for all eruptions. Using a large ensemble of aerosol-chemistry-climate simulations of eruptions with different sulfur dioxide emissions, latitudes, emission altitudes, and seasons, we find that the effective radiative forcing (ERF) is on average 20% less than the instantaneous radiative forcing, predominantly due to a positive shortwave cloud adjustment. In our model, the volcanic SAOD-ERF relationship is non-unique and varies widely depending on time since an eruption, eruption latitude, and season due to differences in aerosol dispersion and incoming solar radiation. Our revised SAOD-ERF relationships suggest that volcanic forcing has been previously overestimated. Plain Language Summary Powerful explosive volcanic eruptions inject sulfur gases high into the atmosphere where they form a layer of sulfate aerosol particles that scatter sunlight back into space, decrease the transparency of the atmosphere, and cause surface cooling. The amount of sunlight that is scattered depends on the location of the layer of particles and particle size. We have used a complex climate model to quantify how eruptions of different magnitudes and occurring in different seasons and locations may affect the climate. We find that the relationship between the transparency of the atmosphere and the resulting climatic impact caused by volcanic sulfate aerosol particles depends on the amount of sunlight and the spread of the aerosol and therefore the time since the eruption, the eruption location, and the season. Our simulations also show that the eruptions reduce the cooling effect of clouds, which reduces the overall effectiveness of volcanoes at cooling the Earth's surface.

show abstract

A New Volcanic Stratospheric Sulfate Aerosol Forcing Emulator (EVA_H): Comparison With Interactive Stratospheric Aerosol Models

Cited by 31 publications

References 53 publications

Quantifying CanESM5 and EAMv1 sensitivities to Mt. Pinatubo volcanic forcing for the CMIP6 historical experiment

Quantifying CanESM5 and EAMv1 sensitivities to Mt. Pinatubo volcanic forcing for the CMIP6 historical experiment

Resolving the Differences in the Simulated and Reconstructed Temperature Response to Volcanism

Large Variations in Volcanic Aerosol Forcing Efficiency Due to Eruption Source Parameters and Rapid Adjustments

Contact Info

Product

Resources

About