The unidentified volcanic eruption of ~1809: why it remains a climatic cold case

Author(s):  
Claudia Timmreck ◽  
Matthew Toohey ◽  
Davide Zanchettin ◽  
Stefan Brönnimann ◽  
Elin Lundstadt ◽  
...  

<p>The  "1809 eruption” is one of the most recent unidentified volcanic eruptions with a global climate impact. Even though the eruption ranks as the 3rd largest since 1500 with an eruption magnitude estimated to be two times that of the 1991 eruption of Pinatubo, not much is known of it from historic sources. Based on a compilation of instrumental and reconstructed temperature time series, we show here that tropical temperatures show a significant drop in response to the ~1809 eruption, similar to that produced by the Mt. Tambora eruption in 1815, while the response of Northern Hemisphere (NH) boreal summer temperature is spatially heterogeneous.  Here, we present the sensitivity of the climate response simulated by the MPI Earth system model to a range of volcanic forcing estimates constructed using estimated volcanic stratospheric sulfur injections (VSSI) and uncertainties from ice core records. Three of the forcing reconstructions represent a tropical eruption with approximately symmetric hemispheric aerosol spread but different forcing magnitudes, while a fourth reflects a hemispherically asymmetric scenario without volcanic forcing in the NH extratropics. Observed and reconstructed post-volcanic surface NH summer temperature anomalies lie within the range of all the scenario simulations. Therefore, assuming the model climate sensitivity is correct, the VSSI estimate is accurate within the uncertainty bounds. Comparison of observed and simulated tropical temperature anomalies suggests that the most likely VSSI for the 1809 eruption would be somewhere between 12 -19 Tg of sulfur. Model results show that NH large-scale climate modes are sensitive to both volcanic forcing strength and its spatial structure.  While spatial correlations between the N-TREND NH temperature reconstruction and the model simulations are weak in terms of the ensemble mean model results, individual model simulations show good correlation over North America and Europe, suggesting the spatial heterogeneity of the 1810 cooling could be due to internal climate variability. </p>


2021 ◽  
Author(s):  
Claudia Timmreck ◽  
Matthew Toohey ◽  
Davide Zanchettin ◽  
Stefan Brönnimann ◽  
Elin Lundstadt ◽  
...  

Abstract. The 1809 eruption is one of the most recent unidentified volcanic eruptions with a global climate impact. Even though the eruption ranks as the 3rd largest since 1500 with an eruption magnitude estimated to be two times that of the 1991 eruption of Pinatubo, not much is known of it from historic sources. Based on a compilation of instrumental and reconstructed temperature time series, we show here that tropical temperatures show a significant drop in response to the ~1809 eruption, similar to that produced by the Mt. Tambora eruption in 1815, while the response of Northern Hemisphere (NH) boreal summer temperature is spatially heterogeneous. We test the sensitivity of the climate response simulated by the MPI Earth system model to a range of volcanic forcing estimates constructed using estimated volcanic stratospheric sulfur injections (VSSI) and uncertainties from ice core records. Three of the forcing reconstructions represent a tropical eruption with approximately symmetric hemispheric aerosol spread but different forcing magnitudes, while a fourth reflects a hemispherically asymmetric scenario without volcanic forcing in the NH extratropics. Observed and reconstructed post-volcanic surface NH summer temperature anomalies lie within the range of all the scenario simulations. Therefore, assuming the model climate sensitivity is correct, the VSSI estimate is accurate within the uncertainty bounds. Comparison of observed and simulated tropical temperature anomalies suggests that the most likely VSSI for the 1809 eruption would be somewhere between 12–19 Tg of sulfur. Model results show that NH large-scale climate modes are sensitive to both volcanic forcing strength and its spatial structure. While spatial correlations between the N-TREND NH temperature reconstruction and the model simulations are weak in terms of the ensemble mean model results, individual model simulations show good correlation over North America and Europe, suggesting the spatial heterogeneity of the 1810 cooling could be due to internal climate variability.



2021 ◽  
Vol 17 (4) ◽  
pp. 1455-1482
Author(s):  
Claudia Timmreck ◽  
Matthew Toohey ◽  
Davide Zanchettin ◽  
Stefan Brönnimann ◽  
Elin Lundstad ◽  
...  

Abstract. The “1809 eruption” is one of the most recent unidentified volcanic eruptions with a global climate impact. Even though the eruption ranks as the third largest since 1500 with a sulfur emission strength estimated to be 2 times that of the 1991 eruption of Pinatubo, not much is known of it from historic sources. Based on a compilation of instrumental and reconstructed temperature time series, we show here that tropical temperatures show a significant drop in response to the ∼ 1809 eruption that is similar to that produced by the Mt. Tambora eruption in 1815, while the response of Northern Hemisphere (NH) boreal summer temperature is spatially heterogeneous. We test the sensitivity of the climate response simulated by the MPI Earth system model to a range of volcanic forcing estimates constructed using estimated volcanic stratospheric sulfur injections (VSSIs) and uncertainties from ice-core records. Three of the forcing reconstructions represent a tropical eruption with an approximately symmetric hemispheric aerosol spread but different forcing magnitudes, while a fourth reflects a hemispherically asymmetric scenario without volcanic forcing in the NH extratropics. Observed and reconstructed post-volcanic surface NH summer temperature anomalies lie within the range of all the scenario simulations. Therefore, assuming the model climate sensitivity is correct, the VSSI estimate is accurate within the uncertainty bounds. Comparison of observed and simulated tropical temperature anomalies suggests that the most likely VSSI for the 1809 eruption would be somewhere between 12 and 19 Tg of sulfur. Model results show that NH large-scale climate modes are sensitive to both volcanic forcing strength and its spatial structure. While spatial correlations between the N-TREND NH temperature reconstruction and the model simulations are weak in terms of the ensemble-mean model results, individual model simulations show good correlation over North America and Europe, suggesting the spatial heterogeneity of the 1810 cooling could be due to internal climate variability.



2021 ◽  
Author(s):  
Zhihong Zhuo ◽  
Herman Fuglestvedt ◽  
Matthew Toohey ◽  
Michael J. Mills ◽  
Kirstin Krüger

<p>Major volcanic eruptions increase sulfate aerosols in the stratosphere. This causes a large-scale dimming effect with significant surface cooling and stratosphere warming. However, the climate impact differs for tropical and extratropical eruptions, and depends on the eruption season and height, and volcanic volatiles injections. In order to study different volcanic aerosol forcing and their climate impact, we perform simulations based on the fully coupled Community Earth System Model version 2 (CESM2) with the version 6 of the Whole Atmosphere Community Climate Model (WACCM6) with prognostic stratospheric aerosol and chemistry. In this study, explosive eruptions at 14.6 N and 63.6 N in January and July injecting 17 MT and 200 MT SO<sub>2</sub> at 24 km with and without halogens are simulated, in line with Central American Volcanic Arc and Icelandic volcanic eruptions. Simulated changes in the stratospheric sulfate and halogen burdens, and related impacts on aerosol optical depth, radiation, ozone and surface climate are analyzed. These simulated volcanic eruption cases will be compared with simulations based on the aerosol-climate model MAECHAM5-HAM.</p>



2005 ◽  
Vol 1 (2) ◽  
pp. 137-153 ◽  
Author(s):  
S. L. Weber

Abstract. The Northern Hemisphere temperature response to volcanic and solar forcing is studied using first a set of simulations with an intermediate-complexity climate model, driven by reconstructed forcings. Results are than compared with those obtained from the seven high-resolution reconstructed temperature records for the last millenium that are at present available. Focus of the analysis is on the timescale dependence of the response. Results between the model and the proxy-based reconstructions are remarkably consistent. The response to solar forcing is found to equilibrate at interdecadal timescales, reaching an equilibrium value for the regression of 0.2-0.3°C per W/m2. The time interval between volcanic eruptions is typically shorter than the dissipation timescale of the climate system, so that the response to volcanic forcing never equilibrates. As a result, the regression on the volcanic forcing is always lower than the equilibrium value and goes to zero for the longest temporal scales. The trends over the pre-anthropogenic period are found to be relatively large in all reconstructed temperature records compared to their interdecadal-centennial variability. This is at variance with a recent claim that reconstructed temperature records underestimate climatic variations at multi-centennial scales.



2005 ◽  
Vol 1 (1) ◽  
pp. 9-17 ◽  
Author(s):  
S. L. Weber

Abstract. The Northern Hemisphere temperature response to volcanic and solar forcing in the time interval 1000–1850 AD is studied using first a set of simulations with an intermediate-complexity climate model, driven by reconstructed forcings. Results are then compared with those obtained from the seven high-resolution reconstructed temperature records for the last millenium that are at present available. Focus of the analysis is on the timescale dependence of the response. Results between the model and the proxy-based reconstructions are remarkably consistent. The response to solar forcing is found to equilibrate at interdecadal timescales, reaching an equilibrium value for the regression of 0.2–0.3°C per W/m2. The time interval between volcanic eruptions is typically shorter than the dissipation timescale of the climate system, so that the response to volcanic forcing never equilibrates. As a result, the regression on the volcanic forcing is always lower than the equilibrium value and goes to zero for the longest temporal scales. The trends over the pre-anthropogenic period are found to be relatively large in all reconstructed temperature records, given the trends in the reconstructed forcing and the equilibrium value for the regression. This is at variance with a recent claim that reconstructed temperature records underestimate climatic variations at multi-centennial timescales.



2021 ◽  
Author(s):  
Michael Sigl ◽  
Florian Adolphi ◽  
Andrea Burke ◽  
Jihong Cole-Dai ◽  
Hubertus Fischer ◽  
...  

<p>Extratropical volcanic eruptions are commonly thought to be less effective at driving large-scale surface cooling than tropical eruptions, and only the latter are commonly thought to be able to distribute sulfate globally. Here, we test both of these assumptions using a network of ice cores from the polar regions of Antarctica and Greenland covering the past 15’000 years and climate-aerosol modeling. We employ state-of-the-art analyses of trace elements, cryptoptephra and sulphur isotopes (Burke et al., 2019) to gain new insights into the timing of past eruptions, their stratospheric sulphur mass injections and subsequent sulphate aerosol lifecycle. We use this information to estimate the climate impact potential due to negative radiative forcing caused by Earth’s largest volcanic eruptions since the last Glacial. Our analysis encompasses over 1’000 eruptions and include the caldera-forming eruptions of Okmok II (Alaska, 43 BCE, VEI=6, 53°N; McConnell et al., 2020), Aniakchak II (Alaska, 1600s BCE, VEI=6, 57°N), Crater Lake (Mazama, Oregon, 5600s BCE, VEI=7, 43°N) and Laacher See (Germany, c. 13 ka BP, VEI=6, 50°N).</p><p>We use our reconstructed radiative forcing and the coupled earth system models MPI-ESM1.2 and CESM (version 1.2.2) to analyze the climatic impact caused by these eruptions and compare the simulated temperature response with temperature reconstructions based on ultra-long tree-ring chronologies. Finally, based on these comparisons, we propose a number of stratigraphic age tie-points to anchor ice-core chronologies from Greenland (GICC05) and Antarctica (WD2014) to the absolute dated tree-ring chronology. We thereby aim to improve proxy synchronization throughout the Holocene -- a prerequisite for detection and attribution studies -- and invite the paleo-climate community to update climate proxy records based on ice cores to the latest chronologies.    </p><p>The European Research Council Grant 820047 under the European Union’s Horizon 2020 research and innovation program funded the research project THERA - Timing of Holocene Volcanic eruptions and their radiative aerosol forcing. </p><p><strong> </strong></p><p><strong>References:</strong></p><p>Burke, A., Moore, K. A., Sigl, M., Nita, D. C., McConnell, J. R., and Adkins, J. F.: Stratospheric eruptions from tropical and extra-tropical volcanoes constrained using high-resolution sulfur isotopes in ice cores, <em>Earth Planet Sc Lett</em>, 521, 113-119, 2019.</p><p>McConnell, J. R., Sigl, M., Plunkett, G., Burke, A., Kim, W., Raible, C. C., Wilson, A. I., Manning, J. G., Ludlow, F. M., Chellman, N. J., Innes, H. M., Yang, Z., Larsen, J. F., Schaefer, J. R., Kipfstuhl, S., Mojtabavi, S., Wilhelms, F., Opel, T., Meyer, H., and Steffensen, J. P.: Extreme climate after massive eruption of Alaska’s Okmok volcano in 43 BCE and effects on the late Roman Republic and Ptolemaic Kingdom, <em>Proceedings of the National Academy of Sciences</em>, 117, 15443-15449, 2020.</p>



Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 136
Author(s):  
Yahya Darmawan ◽  
Huang-Hsiung Hsu ◽  
Jia-Yuh Yu

This study aims to explore the contrasting characteristics of large-scale circulation that led to the precipitation anomalies over the northern parts of Sumatra Island. Further, the impact of varying the Asian–Australian Monsoon (AAM) was investigated for triggering the precipitation variability over the study area. The moisture budget analysis was applied to quantify the most dominant component that induces precipitation variability during the JJA (June, July, and August) period. Then, the composite analysis and statistical approach were applied to confirm the result of the moisture budget. Using the European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Anaysis Interim (ERA-Interim) from 1981 to 2016, we identified 9 (nine) dry and 6 (six) wet years based on precipitation anomalies, respectively. The dry years (wet years) anomalies over the study area were mostly supported by downward (upward) vertical velocity anomaly instead of other variables such as specific humidity, horizontal velocity, and evaporation. In the dry years (wet years), there is a strengthening (weakening) of the descent motion, which triggers a reduction (increase) of convection over the study area. The overall downward (upward) motion of westerly (easterly) winds appears to suppress (support) the convection and lead to negative (positive) precipitation anomaly in the whole region but with the largest anomaly over northern parts of Sumatra. The AAM variability proven has a significant role in the precipitation variability over the study area. A teleconnection between the AAM and other global circulations implies the precipitation variability over the northern part of Sumatra Island as a regional phenomenon. The large-scale tropical circulation is possibly related to the PWC modulation (Pacific Walker Circulation).



2011 ◽  
Vol 24 (12) ◽  
pp. 2963-2982 ◽  
Author(s):  
Andrea Alessandri ◽  
Andrea Borrelli ◽  
Silvio Gualdi ◽  
Enrico Scoccimarro ◽  
Simona Masina

Abstract This study investigates the predictability of tropical cyclone (TC) seasonal count anomalies using the Centro Euro-Mediterraneo per i Cambiamenti Climatici–Istituto Nazionale di Geofisica e Vulcanologia (CMCC-INGV) Seasonal Prediction System (SPS). To this aim, nine-member ensemble forecasts for the period 1992–2001 for two starting dates per year were performed. The skill in reproducing the observed TC counts has been evaluated after the application of a TC location and tracking detection method to the retrospective forecasts. The SPS displays good skill in predicting the observed TC count anomalies, particularly over the tropical Pacific and Atlantic Oceans. The simulated TC activity exhibits realistic geographical distribution and interannual variability, thus indicating that the model is able to reproduce the major basic mechanisms that link the TCs’ occurrence with the large-scale circulation. TC count anomalies prediction has been found to be sensitive to the subsurface assimilation in the ocean for initialization. Comparing the results with control simulations performed without assimilated initial conditions, the results indicate that the assimilation significantly improves the prediction of the TC count anomalies over the eastern North Pacific Ocean (ENP) and northern Indian Ocean (NI) during boreal summer. During the austral counterpart, significant progresses over the area surrounding Australia (AUS) and in terms of the probabilistic quality of the predictions also over the southern Indian Ocean (SI) were evidenced. The analysis shows that the improvement in the prediction of anomalous TC counts follows the enhancement in forecasting daily anomalies in sea surface temperature due to subsurface ocean initialization. Furthermore, the skill changes appear to be in part related to forecast differences in convective available potential energy (CAPE) over the ENP and the North Atlantic Ocean (ATL), in wind shear over the NI, and in both CAPE and wind shear over the SI.



2021 ◽  
Author(s):  
Rafael Castro ◽  
Tushar Mittal ◽  
Stephen Self

<p>The 1883 Krakatau eruption is one of the most well-known historical volcanic eruptions due to its significant global climate impact as well as first recorded observations of various aerosol associated optical and physical phenomena. Although much work has been done on the former by comparison of global climate model predictions/ simulations with instrumental and proxy climate records, the latter has surprisingly not been studied in similar detail. In particular, there is a wealth of observations of vivid red sunsets, blue suns, and other similar features, that can be used to analyze the spatio-temporal dispersal of volcanic aerosols in summer to winter 1883. Thus, aerosol cloud dispersal after the Krakatau eruption can be estimated, bolstered by aerosol cloud behavior as monitored by satellite-based instrument observations after the 1991 Pinatubo eruption. This is one of a handful of large historic eruptions where this analysis can be done (using non-climate proxy methods). In this study, we model particle trajectories of the Krakatau eruption cloud using the Hysplit trajectory model and compare our results with our compiled observational dataset (principally using Verbeek 1884, the Royal Society report, and Kiessling 1884).</p><p>In particular, we explore the effect of different atmospheric states - the quasi-biennial oscillation (QBO) which impacts zonal movement of the stratospheric volcanic plume - to estimate the phase of the QBO in 1883 required for a fast-moving westward cloud. Since this alone is unable to match the observed latitudinal spread of the aerosols, we then explore the impact of an  umbrella cloud (2000 km diameter) that almost certainly formed during such a large eruption. A large umbrella cloud, spreading over ~18 degrees within the duration of the climax of the eruption (6-8 hours), can lead to much quicker latitudinal spread than a point source (vent). We will discuss the results of the combined model (umbrella cloud and correct QBO phase) with historical accounts and observations, as well as previous work on the 1991 Pinatubo eruption. We also consider the likely impacts of water on aerosol concentrations and the relevance of this process for eruptions with possible significant seawater interactions, like Krakatau. We posit that the role of umbrella clouds is an under-appreciated, but significant, process for beginning to model the climatic impacts of large volcanic eruptions.</p>



2016 ◽  
Author(s):  
Davide Zanchettin ◽  
Myriam Khodri ◽  
Claudia Timmreck ◽  
Matthew Toohey ◽  
Anja Schmidt ◽  
...  

Abstract. The enhancement of the stratospheric aerosol layer by volcanic eruptions induces a complex set of responses causing global and regional climate effects on a broad range of timescales. Uncertainties exist regarding the climatic response to strong volcanic forcing identified in coupled climate simulations that contributed to the fifth phase of the Climate Model Intercomparison Project (CMIP5). In order to better understand the sources of these model diversities, the model intercomparison project on the climate response to volcanic forcing (VolMIP) has defined a coordinated set of idealized volcanic perturbation experiments to be carried out in alignment with the CMIP6 protocol. VolMIP provides a common stratospheric aerosol dataset for each experiment to eliminate differences in the applied volcanic forcing, and defines a set of initial conditions to determine how internal climate variability contributes to determining the response. VolMIP will assess to what extent volcanically-forced responses of the coupled ocean-atmosphere system are robustly simulated by state-of-the-art coupled climate models and identify the causes that limit robust simulated behavior, especially differences in the treatment of physical processes. This paper illustrates the design of the idealized volcanic perturbation experiments in the VolMIP protocol and describes the common aerosol forcing input datasets to be used.



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