The sulfur- and halogen-rich super eruption Los Chocoyos and its impacts on climate and environment

Abstract. The super-eruption of Los Chocoyos, newly dated to 80.6 kyrs ago, in Guatemala was one of the largest volcanic events of the past 100 000 years. Recent petrologic data show that the eruption released very large amounts of climate-relevant sulfur and ozone destroying chlorine and bromine gases. Using the recently released Earth System Model CESM2(WACCM6) we simulate the impacts of the sulfur- and halogen-rich Los Chocoyos (~ 15° N) eruption on the pre-industrial Earth System for the eruption month January. Our model results show that enhanced modeled sulfate burden and aerosol optical depth (AOD) persists for five years, while the volcanic halogens stay elevated for nearly 15 years. As a consequence the eruption leads to a collapse of the ozone layer with global mean column ozone values dropping to 50 DU (80 % decrease) leading to a 550 % increase in surface UV over the first five years with potential impacts on the biosphere. The volcanic eruption shows an asymmetric hemispheric response with enhanced aerosol, ozone, UV, and climate signals over the Northern Hemisphere (NH). Surface climate is impacted globally due to peak AOD of > 6 leading to a maximum surface cooling of > 6 K, precipitation and terrestrial net primary production (NPP) decreases of > 25 %, and sea ice area increases of 40 % in the first three years. Locally, a wetting (> 100 %) and strong increase of NPP (> 700 %) over Northern Africa is simulated in the first five years related to a southwards shift of the Inter-Tropical Convergence Zone to the southern tropics. The ocean responds with El-Niño conditions in the first two years which are masked by the strong volcanic induced surface cooling. Recovery to pre-eruption ozone levels and climate takes 15 and 30 years respectively. The long lasting surface cooling is sustained by sea ice/ocean changes in the Arctic showing an immediate sea ice area increase followed by a decrease of poleward ocean heat transport at 60° N lasting up to 20 years. In contrast, when simulating Los Chocoyos conventionally, including sulfur and neglecting halogens, we simulate larger sulfate burden and AOD, more pronounced surface climate changes and an increase of column ozone. Comparing our aerosol chemistry ESM results to other super-eruption simulations with aerosol climate models we find a higher surface climate impact per injected sulfur amount than previous studies for our different sets of model experiments, since CESM2(WACCM6) creates smaller aerosols with a longer lifetime partly due to the interactive aerosol chemistry. As the model uncertainties for the climate response to super eruptions are very large observational evidence from paleo archives and a coordinated model intercomparison would help to improve our understanding of the climate and environment response.

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The potential impacts of a sulfur- and halogen-rich supereruption such as Los Chocoyos on the atmosphere and climate

Atmospheric Chemistry and Physics ◽

10.5194/acp-20-6521-2020 ◽

2020 ◽

Vol 20 (11) ◽

pp. 6521-6539 ◽

Cited By ~ 1

Author(s):

Hans Brenna ◽

Steffen Kutterolf ◽

Michael J. Mills ◽

Kirstin Krüger

Keyword(s):

Sea Ice ◽

Primary Production ◽

Net Primary Production ◽

Earth System Model ◽

System Model ◽

Earth System ◽

Surface Cooling ◽

Aerosol Chemistry ◽

Surface Climate ◽

Column Ozone

Abstract. The supereruption of Los Chocoyos (14.6∘ N, 91.2∘ W) in Guatemala ∼84 kyr ago was one of the largest volcanic events of the past 100 000 years. Recent petrologic data show that the eruption released very large amounts of climate-relevant sulfur and ozone-destroying chlorine and bromine gases (523±94 Mt sulfur, 1200±156 Mt chlorine, and 2±0.46 Mt bromine). Using the Earth system model (ESM) of the Community Earth System Model version 2 (CESM2) coupled with the Whole Atmosphere Community Climate Model version 6 (WACCM6), we simulated the impacts of the sulfur- and halogen-rich Los Chocoyos eruption on the preindustrial Earth system. Our simulations show that elevated sulfate burden and aerosol optical depth (AOD) persists for 5 years in the model, while the volcanic halogens stay elevated for nearly 15 years. As a consequence, the eruption leads to a collapse of the ozone layer with global mean column ozone values dropping to 50 DU (80 % decrease) and leading to a 550 % increase in surface UV over the first 5 years, with potential impacts on the biosphere. The volcanic eruption shows an asymmetric-hemispheric response with enhanced aerosol, ozone, UV, and climate signals over the Northern Hemisphere. Surface climate is impacted globally due to peak AOD of >6, which leads to a maximum surface cooling of >6 K, precipitation and terrestrial net primary production decrease of >25 %, and sea ice area increases of 40 % in the first 3 years. Locally, a wetting (>100 %) and strong increase in net primary production (NPP) (>700 %) over northern Africa is simulated in the first 5 years and related to a southward shift of the Intertropical Convergence Zone (ITCZ) to the southern tropics. The ocean responds with pronounced El Niño conditions in the first 3 years that shift to the southern tropics and are coherent with the ITCZ change. Recovery to pre-eruption ozone levels and climate takes 15 years and 30 years, respectively. The long-lasting surface cooling is sustained by an immediate increase in the Arctic sea ice area, followed by a decrease in poleward ocean heat transport at 60∘ N which lasts up to 20 years. In contrast, when simulating Los Chocoyos conventionally by including sulfur and neglecting halogens, we simulate a larger sulfate burden and AOD, more pronounced surface climate changes, and an increase in column ozone. By comparing our aerosol chemistry ESM results to other supereruption simulations with aerosol climate models, we find a higher surface climate impact per injected sulfur amount than previous studies for our different sets of model experiments, since the CESM2(WACCM6) creates smaller aerosols with a longer lifetime, partly due to the interactive aerosol chemistry. As the model uncertainties for the climate response to supereruptions are very large, observational evidence from paleo archives and a coordinated model intercomparison would help to improve our understanding of the climate and environment response.

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Aerosols and their impacts on future Arctic climate change under different emission projections in the GISS-E2.1 Earth system model

10.5194/egusphere-egu21-2566 ◽

2021 ◽

Author(s):

Ulas Im ◽

Kostas Tsigaridis ◽

Gregory S. Faluvegi ◽

Peter L. Langen ◽

Joshua P. French ◽

...

Keyword(s):

Sea Ice ◽

Earth System Model ◽

System Model ◽

The Arctic ◽

Earth System ◽

Anthropogenic Aerosols ◽

Emission Reductions ◽

Air Temperatures ◽

The Future ◽

Emission Projections

In order to study the future aerosol burdens and their radiative and climate impacts over the Arctic (>60 &#176;N), future (2015-2050) simulations have been carried out using the GISS-E2.1 Earth system model. Different future anthrpogenic emission projections have been used from the Eclipse V6b and the Coupled Model Intercomparison Project Phase 6 (CMIP6) databases. Results showed that&#160;Arctic BC, OC and SO42- burdens decrease significantly in all simulations following the emission projections, with the CMIP6 ensemble showing larger reductions in Arctic aerosol burdens compared to the Eclipse ensemble. For the 2030-2050 period, both the Eclipse Current Legislation (CLE) and the Maximum Feasible Reduction (MFR) ensembles simulated an aerosol top of the atmosphere (TOA) forcing of -0.39&#177;0.01 W m-2, of which -0.24&#177;0.01 W m-2 were attributed to the anthropogenic aerosols. The CMIP6 SSP3-7.0 scenario simulated a TOA aerosol forcing of -0.35 W m-2 for the same period, while SSP1-2.6 and SSP2-4.5 scenarios simulated a slightly more negative TOA forcing (-0.40 W m-2), of which the anthropogenic aerosols accounted for -0.26 W m-2. The 2030-2050 mean surface air temperatures are projected to increase by 2.1 &#176;C and 2.4 &#176;C compared to the 1990-2010 mean temperature according to the Eclipse CLE and MFR ensembles, respectively, while the CMIP6 simulation calculated an increase of 1.9 &#176;C (SSP1-2.6) to 2.2 &#176;C (SSP3-7.0). Overall, results show that even the scenarios with largest emission reductions lead to similar impact on the future Arctic surface air temperatures compared to scenarios with smaller emission reductions, while scenarios with no or little mitigation leads to much larger sea-ice loss, implying that even though the magnitude of aerosol reductions lead to similar responses in surface air temperatures, high mitigation of aerosols are still necessary to limit sea-ice loss.&#160;

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An Internal Atmospheric Process Determining Summertime Arctic Sea Ice Melting in the Next Three Decades: Lessons Learnt from 5 Large Ensembles and CMIP5 Simulations

10.5194/egusphere-egu2020-4729 ◽

2020 ◽

Author(s):

Daniel Topal ◽

Qinghua Ding ◽

Jonathan Mitchell ◽

Ian Baxter ◽

Mátyás Herein ◽

...

Keyword(s):

Sea Ice ◽

Arctic Sea Ice ◽

The Arctic ◽

Cmip5 Models ◽

Ice Melting ◽

Surface Cooling ◽

Atmospheric Process ◽

Sst Variability ◽

Arctic Sea ◽

Large Ensembles

Arctic sea ice melting processes in summer due to internal atmospheric variability have recently received considerable attention. A regional barotropic atmospheric process over Greenland and the Arctic Ocean in summer (June-July-August), featuring either a year-to-year change or a low-frequency trend toward geopotential height rise, has been identified as an essential contributor to September sea ice loss, in both observations and the CESM1 Large Ensemble (CESM-LE) of simulations [1-2]. This local melting is further found to be sensitive to remote sea surface temperature (SST) variability in the East Central Pacific [3]. Here, we utilize five available single-model large ensembles and 31 CMIP5 models&#8217; pre-industrial control simulations to show that the same atmospheric process, resembling the observed one and the one found in the CESM-LE, also dominates internal sea ice variability on interannual to interdecadal time scales in pre-industrial, historical and future scenarios, regardless of the modeling environment. However, all models exhibit limitations in replicating the correct magnitude of the observed local atmosphere-sea ice coupling and its sensitivity to remote tropical SST variability. These biases cast a shadow over models&#8217; credibility in simulating interactions of sea ice variability with the Arctic and global climate systems. Further efforts toward identifying possible causes of these model limitations may provide profound implications for alleviating the biases and improving interannual and decadal time scale sea ice prediction and future sea ice projection.&#160;[1] Ding, Q., and Coauthors, (2017): Influence of high-latitude atmospheric circulation changes on summertime Arctic sea ice. Nat. Climate Change, 7, 289-295.[2] Ding, Q., and Coauthors, (2019): Fingerprints of internal drivers of Arctic sea ice loss in observations and model simulations. Nat. Geosci., 12, 28&#8211;33.[3] Baxter, I., and Coauthors, (2019):&#160;How tropical Pacific surface cooling contributed to accelerated sea ice melt from 2007 to 2012 as ice is thinned by anthropogenic forcing.&#160;J. Climate, 32, 8583&#8211;8602 https://doi.org/10.1175/JCLI-D-18-0783.1&#160;

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Effects of sea ice cover on satellite-detected primary production in the Arctic Ocean

Biology Letters ◽

10.1098/rsbl.2016.0223 ◽

2016 ◽

Vol 12 (11) ◽

pp. 20160223 ◽

Cited By ~ 35

Author(s):

Mati Kahru ◽

Zhongping Lee ◽

B. Greg Mitchell ◽

Cynthia D. Nevison

Keyword(s):

Sea Ice ◽

Primary Production ◽

Arctic Ocean ◽

Barents Sea ◽

Net Primary Production ◽

Arctic Sea Ice ◽

The Arctic ◽

Primary Input ◽

High Productivity ◽

The Arctic Ocean

The influence of decreasing Arctic sea ice on net primary production (NPP) in the Arctic Ocean has been considered in multiple publications but is not well constrained owing to the potentially large errors in satellite algorithms. In particular, the Arctic Ocean is rich in coloured dissolved organic matter (CDOM) that interferes in the detection of chlorophyll a concentration of the standard algorithm, which is the primary input to NPP models. We used the quasi-analytic algorithm (Lee et al . 2002 Appl. Opti. 41 , 5755−5772. ( doi:10.1364/AO.41.005755 )) that separates absorption by phytoplankton from absorption by CDOM and detrital matter. We merged satellite data from multiple satellite sensors and created a 19 year time series (1997–2015) of NPP. During this period, both the estimated annual total and the summer monthly maximum pan-Arctic NPP increased by about 47%. Positive monthly anomalies in NPP are highly correlated with positive anomalies in open water area during the summer months. Following the earlier ice retreat, the start of the high-productivity season has become earlier, e.g. at a mean rate of −3.0 d yr −1 in the northern Barents Sea, and the length of the high-productivity period has increased from 15 days in 1998 to 62 days in 2015. While in some areas, the termination of the productive season has been extended, owing to delayed ice formation, the termination has also become earlier in other areas, likely owing to limited nutrients.

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Comparison of sea ice kinematics at different resolutions modeled with a grid hierarchy in the Community Earth System Model (version 1.2.1)

Geoscientific Model Development ◽

10.5194/gmd-14-603-2021 ◽

2021 ◽

Vol 14 (1) ◽

pp. 603-628

Author(s):

Shiming Xu ◽

Jialiang Ma ◽

Lu Zhou ◽

Yan Zhang ◽

Jiping Liu ◽

...

Keyword(s):

High Resolution ◽

Sea Ice ◽

Earth System Model ◽

System Model ◽

The Arctic ◽

Small Scale ◽

Earth System ◽

Atmospheric Circulation Patterns ◽

Community Earth System Model ◽

Climate Studies

Abstract. High-resolution sea ice modeling is becoming widely available for both operational forecasts and climate studies. In traditional Eulerian grid-based models, small-scale sea ice kinematics represent the most prominent feature of high-resolution simulations, and with rheology models such as viscous–plastic (VP) and Maxwell elasto-brittle (MEB), sea ice models are able to reproduce multi-fractal sea ice deformation and linear kinematic features that are seen in high-resolution observational datasets. In this study, we carry out modeling of sea ice with multiple grid resolutions by using the Community Earth System Model (CESM) and a grid hierarchy (22, 7.3, and 2.4 km grid stepping in the Arctic). By using atmospherically forced experiments, we simulate consistent sea ice climatology across the three resolutions. Furthermore, the model reproduces reasonable sea ice kinematics, including multi-fractal spatial scaling of sea ice deformation that partially depends on atmospheric circulation patterns and forcings. By using high-resolution runs as references, we evaluate the model's effective resolution with respect to the statistics of sea ice kinematics. Specifically, we find the spatial scale at which the probability density function (PDF) of the scaled sea ice deformation rate of low-resolution runs matches that of high-resolution runs. This critical scale is treated as the effective resolution of the coarse-resolution grid, which is estimated to be about 6 to 7 times the grid's native resolution. We show that in our model, the convergence of the elastic–viscous–plastic (EVP) rheology scheme plays an important role in reproducing reasonable kinematics statistics and, more strikingly, simulates systematically thinner sea ice than the standard, non-convergent experiments in landfast ice regions of the Canadian Arctic Archipelago. Given the wide adoption of EVP and subcycling settings in current models, it highlights the importance of EVP convergence, especially for climate studies and projections. The new grids and the model integration in CESM are openly provided for public use.

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Multi-Scale Sea Ice Kinematics Modeling with a Grid Hierarchy in Community Earth System Model (version 1.2.1)

10.5194/gmd-2020-160 ◽

2020 ◽

Author(s):

Shiming Xu ◽

Jialiang Ma ◽

Lu Zhou ◽

Yan Zhang ◽

Jiping Liu ◽

...

Keyword(s):

High Resolution ◽

Sea Ice ◽

Earth System Model ◽

System Model ◽

The Arctic ◽

Earth System ◽

Multi Scale ◽

Kinematics Modeling ◽

Community Earth System Model ◽

Climate Studies

Abstract. High-resolution sea ice modeling is becoming widely available for both operational forecasts and climate studies. Sea ice kinematics is the most prominent feature of high-resolution simulations, and with rheology models such as Viscous-Plastic, current models are able to reproduce multi-fractality and linear kinematic features in satellite observations. In this study, we carry out multi-scale sea ice modeling with Community Earth System Model (CESM) by using a grid hierarchy (22 km, 7.3 km, and 2.5 km grid stepping in the Arctic). By using atmospherically forced experiments, we simulate consistent sea ice climatology across the 3 resolutions. Furthermore, the model reproduces reasonable sea ice kinematics, including multi-fractal deformation and scaling properties that are temporally changing and dependent on circulation patterns and forcings (e.g., Arctic Oscillation). With the grid hierarchy, we are able to evaluate the model's effective spatial resolution regarding the statistics of kinematics, which is estimated to be about 6 to 7 times that of the grid's native resolution. Besides, we show that in our model, the convergence of the Elastic-Viscous-Plastic (EVP) rheology scheme plays an important role in reproducing reasonable kinematics statistics, and more strikingly, simulates systematically thinner sea ice than the standard, non-convergent experiments in landfast ice regions of Canadian Arctic Archipelago. Given the wide adoption of EVP and subcycling settings in current models, it highlights the importance of EVP convergence especially for climate studies and projections. The new grids and the model integration in CESM are openly provided for public use.

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Processes Controlling Arctic and Antarctic Sea Ice Predictability in the Community Earth System Model

Journal of Climate ◽

10.1175/jcli-d-18-0348.1 ◽

2018 ◽

Vol 31 (23) ◽

pp. 9771-9786 ◽

Cited By ~ 6

Author(s):

Ana C. Ordoñez ◽

Cecilia M. Bitz ◽

Edward Blanchard-Wrigglesworth

Keyword(s):

Sea Ice ◽

Mixed Layer ◽

Ocean Dynamics ◽

System Model ◽

The Arctic ◽

Earth System ◽

Ice Volume ◽

Antarctic Sea Ice ◽

The Antarctic ◽

Area And Volume

Sea ice predictability is a rapidly growing area of research, with most studies focusing on the Arctic. This study offers new insights by comparing predictability between the Arctic and Antarctic sea ice anomalies, focusing on the effects of regional differences in ice thickness and ocean dynamics. Predictability in simulated regional sea ice area and volume is investigated in long control runs of an Earth system model. Sea ice area predictability in the Arctic agrees with results from other studies, with features of decaying initial persistence and reemergence because of ocean mixed layer processes and memory in thick ice. In pan-Arctic averages, sea ice volume and the area covered by thick ice are the best predictors of September area for lead times greater than 2 months. In the Antarctic, area is generally the best predictor of future area for all times of year. Predictability of area in summer differs between the hemispheres because of unique aspects of the coupling between area and volume. Generally, ice volume only adds to the predictability of summer sea ice area in the Arctic. Predictability patterns vary greatly among different regions of the Arctic but share similar seasonality among regions of the Antarctic. Interactive ocean dynamics influence anomaly reemergence differently in the Antarctic than the Arctic, both for the total and regional area. In the Antarctic, ocean dynamics generally decrease the persistence of area anomalies, reducing predictability. In the Arctic, the presence of ocean dynamics improves ice area predictability, mainly through mixed layer depth variability.

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The Interplay of Recent Vegetation and Sea Ice Dynamics—Results From a Regional Earth System Model Over the Arctic

Geophysical Research Letters ◽

10.1029/2019gl085982 ◽

2020 ◽

Vol 47 (6) ◽

Cited By ~ 2

Author(s):

W. Zhang ◽

R. Döscher ◽

T. Koenigk ◽

P.A. Miller ◽

C. Jansson ◽

...

Keyword(s):

Sea Ice ◽

Earth System Model ◽

System Model ◽

The Arctic ◽

Earth System ◽

Ice Dynamics ◽

Sea Ice Dynamics

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Sensitivity of organic carbon fluxes from Arctic coastal erosion to climate change

10.5194/egusphere-egu21-13268 ◽

2021 ◽

Author(s):

David Marcolino Nielsen ◽

Patrick Pieper ◽

Victor Brovkin ◽

Paul Overduin ◽

Tatiana Ilyina ◽

...

Keyword(s):

Climate Change ◽

Organic Carbon ◽

Sea Ice ◽

Coastal Erosion ◽

Earth System Model ◽

System Model ◽

The Arctic ◽

Earth System ◽

Carbon Release ◽

Arctic Coast

When unprotected by sea-ice and exposed to the warm air and ocean waves, the Arctic coast erodes and releases organic carbon from permafrost to the surrounding ocean and atmosphere. This release is estimated to deliver similar amounts of organic carbon to the Arctic Ocean as all Arctic rivers combined, at the present-day climate. Depending on the degradation pathway of the eroded material, the erosion of the Arctic coast could represent a positive feedback loop in the climate system, to an extent still unknown. In addition, the organic carbon flux from Arctic coastal erosion is expected to increase in the future, mainly due to surface warming and sea-ice loss. In this work, we aim at addressing the following questions: How is Arctic coastal erosion projected to change in the future? How sensitive is Arctic coastal erosion to climate change?To address these questions, we use a 10-member ensemble of climate change simulations performed with the Max Planck Institute Earth System Model (MPI-ESM) for the Coupled Model Intercomparison Project phase 6 (CMIP6) to make projections of coastal erosion at a pan-Arctic scale. We use a semi-empirical approach to model Arctic coastal erosion, assuming a linear contribution of its thermal and mechanical drivers. The pan-Arctic carbon release due to coastal erosion is projected to increase from 6.9 &#177; 5.4 TgC/year (mean estimate &#177; two standard deviations from the distribution of uncertainties) during the historical period (mean over 1850 -1950) to between 13.1 &#177; 6.7 TgC/year and 17.2 &#177; 8.2 TgC/year in the period 2081-2100 following an intermediate (SSP2.4-5) and a high-end (SSP5.8-5) climate change scenario, respectively. The sensitivity of the organic carbon release from Arctic coastal erosion to climate warming is estimated to range from 1.52 TgC/year/K to 2.79 TgC/year/K depending on the scenario. Our results present the first projections of Arctic coastal erosion, combining observations and Earth system model (ESM) simulations. This allows us to make first-order estimates of sensitivity and feedback magnitudes between Arctic coastal erosion and climate change, which can lay out pathways for future coupled ESM simulations.&#160;

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Assessment of decadal variability in sea ice in the Community Earth System Model against a long-term regional observational record: implications for the predictability of an ice-free Arctic

Journal of Climate ◽

10.1175/jcli-d-20-0561.1 ◽

2021 ◽

Author(s):

Amélie Desmarais ◽

Bruno Tremblay

Keyword(s):

Sea Ice ◽

Decadal Variability ◽

Earth System Model ◽

System Model ◽

The Arctic ◽

Earth System ◽

Atlantic Sector ◽

The Pacific ◽

Community Earth System Model ◽

Observational Record

AbstractUncertainties in the timing of a seasonal ice cover in the Arctic Ocean depend on model physics and parameterizations, natural variability at decadal timescales and uncertainties in climate scenarios and forcings. We use the Gridded Monthly Sea-Ice Extent and Concentration, 1850 Onward product to assess the simulated decadal variability from the Community Earth System Model – Large Ensemble (CESM-LE) in the Pacific, Eurasian and Atlantic sector of the Arctic where a longer observational record exists. Results show that sea-ice decadal (8-16 years) variability in CESM-LE is in agreement with the observational record in the Pacific sector of the Arctic, underestimated in the Eurasian sector of the Arctic, specifically in the East-Siberian Sea, and slightly overestimated in the Atlantic sector of the Arctic, specifically in the Greenland Sea. Results also show an increase in variability at decadal timescales in the Eurasian and Pacific sectors during the transition to a seasonally ice-free Arctic, in agreement with the observational record although this increase is delayed by 10-20 years. If the current sea-ice retreat in the Arctic continues to be Pacific-centric, results from the CESM-LE suggest that uncertainty in the timing of an ice-free Arctic associated with natural variability is realistic, but that a seasonal ice cover may occur earlier than projected.

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