scholarly journals Simulation of Historic Glacier Variations with a Simple Climate-Glacier Model

1988 ◽  
Vol 34 (118) ◽  
pp. 333-341 ◽  
Author(s):  
Johannes Oerlemans
Keyword(s):  
Volcanic Activity ◽  
Climate Model ◽  
Ring Width ◽  
Volcanic Eruptions ◽  
Solar Variability ◽  
Surface Radiation ◽  
Greenhouse Warming ◽  
Radiation Balance ◽  
Equilibrium Line Altitude ◽  
Modelling Studies

AbstractGlacier variations during the last few centuries have shown a marked coherence over the globe. Characteristic features are the maximum stand somewhere in the middle of the nineteenth century, and the steady retreat afterwards (with some minor interruptions depending on the particular region). In many papers, qualitative statements have been made about the causes of these fluctuations. Lower temperatures associated with solar variability and/or volcanic activity are the most popular explanations. In particular, the statistical relation between glacier activity and major volcanic eruptions appears to be strong.In this paper, an attempt is made to simulate recent glacier fluctations with a physics-based model. A simple climate model, calculating perturbations of surface-radiation balance and air temperature (not necessarily in phase!), is coupled to a schematic time-dependent glacier model. The climate model is forced by volcanic activity (Greenland acidity and/or Lamb’s dust-veil index) and greenhouse warming. Solar variability was not considered, because its effect on climate has still not been demonstrated in a convincing way. The output is translated into variations in equilibrium-line altitude, driving the glacier model.The simulated variations in glacier length show good agreement with the observed record, but the amplitude is too small. This is improved when mass-balance gradients are assumed to be larger in warmer climates. Compared to recently published modelling studies of particular glaciers, in which series of local parameters (e.g. tree-ring width and temperature) were used as forcing, the present simulation is better. This suggests that the radiation balance is a decisive factor with regard to glacier variations on longer time-scales. The model experiments lend support to the results of Porter (1986), who concluded from a more qualitative study that a strong relation exists between periods of increased volcanic activity and glacier advances.A comparison of some selected runs shows that, according to the present model, the greenhouse warming would be responsible for about 50% of the glacier retreat observed over the last 100 years.

scholarly journals Simulation of Historic Glacier Variations with a Simple Climate-Glacier Model

1988 ◽  
Vol 34 (118) ◽  
pp. 333-341 ◽  
Author(s):  
Johannes Oerlemans
Keyword(s):  
Volcanic Activity ◽  
Climate Model ◽  
Ring Width ◽  
Volcanic Eruptions ◽  
Solar Variability ◽  
Surface Radiation ◽  
Greenhouse Warming ◽  
Radiation Balance ◽  
Equilibrium Line Altitude ◽  
Modelling Studies

Abstract Glacier variations during the last few centuries have shown a marked coherence over the globe. Characteristic features are the maximum stand somewhere in the middle of the nineteenth century, and the steady retreat afterwards (with some minor interruptions depending on the particular region). In many papers, qualitative statements have been made about the causes of these fluctuations. Lower temperatures associated with solar variability and/or volcanic activity are the most popular explanations. In particular, the statistical relation between glacier activity and major volcanic eruptions appears to be strong. In this paper, an attempt is made to simulate recent glacier fluctations with a physics-based model. A simple climate model, calculating perturbations of surface-radiation balance and air temperature (not necessarily in phase!), is coupled to a schematic time-dependent glacier model. The climate model is forced by volcanic activity (Greenland acidity and/or Lamb’s dust-veil index) and greenhouse warming. Solar variability was not considered, because its effect on climate has still not been demonstrated in a convincing way. The output is translated into variations in equilibrium-line altitude, driving the glacier model. The simulated variations in glacier length show good agreement with the observed record, but the amplitude is too small. This is improved when mass-balance gradients are assumed to be larger in warmer climates. Compared to recently published modelling studies of particular glaciers, in which series of local parameters (e.g. tree-ring width and temperature) were used as forcing, the present simulation is better. This suggests that the radiation balance is a decisive factor with regard to glacier variations on longer time-scales. The model experiments lend support to the results of Porter (1986), who concluded from a more qualitative study that a strong relation exists between periods of increased volcanic activity and glacier advances. A comparison of some selected runs shows that, according to the present model, the greenhouse warming would be responsible for about 50% of the glacier retreat observed over the last 100 years.

Evidence of volcanic activity in the growth rings of trees at the Tacaná volcano, Mexico–Guatemala border

2020 ◽  
Vol 50 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Teodoro Carlón Allende ◽  
José Luis Macías ◽  
Manuel E. Mendoza ◽  
José Villanueva Díaz
Keyword(s):  
Tree Growth ◽  
Volcanic Activity ◽  
Ring Width ◽  
Volcanic Eruptions ◽  
Growth Rings ◽  
Growth And Survival ◽  
Ash Layer ◽  
Tacaná Volcano ◽  
First Time ◽  
Santa Maria

Volcanic activity can have a significant effect on the growth and survival of trees. The objective of our research was to analyze the effects of the 1855–1856 eruption of the Tacaná volcano and the ashfall from the 1902 eruption of the Santa María volcano, Guatemala, on the radial growth of trees at Tacaná. Dendrochronological sampling was carried out on sites covered by Pinus hartwegii Lindl., and a ring-width chronology was built using 102 increment cores from 75 trees. The ring-width chronology shows two statistically significant suppression events. One of these events occurred from 1857 to 1868 and was potentially caused by the historic eruption of Tacaná (1855–1856). The second suppression event occurred from 1903 to 1908, during which tree growth was affected 1 year after the ashfall caused by the 1902 eruption of Santa María. The growth suppression did not have the same magnitude in all sampled trees and may be related to the thickness of the ash layer deposited around each tree. For the first time, we show that tree growth at Tacaná is reduced by ashfall from volcanic eruptions. Our results may contribute to the evaluation of risks associated with the volcanic activity of the Tacaná volcano.

scholarly journals Effects of Memory Biases on Variability of Temperature Reconstructions

2019 ◽  
Vol 32 (24) ◽  
pp. 8713-8731 ◽  
Author(s):  
Lucie J. Lücke ◽  
Gabriele C. Hegerl ◽  
Andrew P. Schurer ◽  
Rob Wilson
Keyword(s):  
Tree Ring ◽  
Climate Models ◽  
Climate Model ◽  
Ring Width ◽  
Volcanic Eruptions ◽  
Ice Age ◽  
Detection And Attribution ◽  
Reconstructed Temperature ◽  
Tree Ring Data ◽  
The Difference

Abstract Quantifying past climate variation and attributing its causes improves our understanding of the natural variability of the climate system. Tree-ring-based proxies have provided skillful and highly resolved reconstructions of temperature and hydroclimate of the last millennium. However, like all proxies, they are subject to uncertainties arising from varying data quality, coverage, and reconstruction methodology. Previous studies have suggested that biological-based memory processes could cause spectral biases in climate reconstructions. This study determines the effects of such biases on reconstructed temperature variability and the resultant implications for detection and attribution studies. We find that introducing persistent memory, reflecting the spectral properties of tree-ring data, can change the variability of pseudoproxy reconstructions compared to the surrogate climate and resolve certain model–proxy discrepancies. This is especially the case for proxies based on ring-width data. Such memory inflates the difference between the Medieval Climate Anomaly and the Little Ice Age and suppresses and extends the cooling in response to volcanic eruptions. When accounting for memory effects, climate model data can reproduce long-term cooling after volcanic eruptions, as seen in proxy reconstructions. Results of detection and attribution studies show that signals in reconstructions as well as residual unforced variability are consistent with those in climate models when the model fingerprints are adjusted to reflect autoregressive memory as found in tree rings.

Modelling aspects of the sulfate aerosol evolution after recent volcanic activity

2021 ◽  
Author(s):  
Christina Brodowsky ◽  
Timofei Sukhodolov ◽  
Aryeh Feinberg ◽  
Michael Höpfner ◽  
Thomas Peter ◽  
...  
Keyword(s):  
Volcanic Activity ◽  
Climate Model ◽  
Volcanic Eruptions ◽  
Stratospheric Aerosol ◽  
Sulfate Aerosol ◽  
Global Climate Models ◽  
Volcanic Plume ◽  
Free Running ◽  
Volcanic Emission ◽  
The Impact

<p>Volcanic activity is one of the main natural climate forcings and therefore an accurate representation of volcanic aerosols in global climate models is essential. However, direct modelling of sulfur chemistry, sulfate aerosol microphysics and transport is a complex task involving many uncertainties including those related to the volcanic emission magnitude, vertical shape of the plume, and observations of atmospheric sulfur. This study aims to investigate some of these uncertainties and to analyse the performance of the aerosol-chemistry-climate model SOCOL-AERv2 for three medium-sized volcanic eruptions from Kasatochi in 2008, Sarychev in 2009 and Nabro in 2011. In particular, we investigate the impact of different estimates for the initial volcanic plume height and its SO2 content on the stratospheric aerosol burden. The influence of internal model variability and of modelled dynamics is addressed by three free-running simulations and two nudged simulations at different vertical resolutions. Comparing the modelled evolution of the stratospheric aerosol loading and its spread with the Brewer-Dobson-Circulation (BDC) to satellite measurements reveals in general a very good performance of SOCOL-AERv2 during the considered period. However, the large spread in emission estimates logically leads to significant differences in the modelled aerosol burden. This spread results from both the uncertainty in the total emitted mass of sulfur as well as its vertical distribution relative to the tropopause. An additional source of modelled uncertainty is the tropopause height, which varies among the free-running simulations. Furthermore, the validation is complicated by disagreement between different observational datasets. Nudging effects on the tropospheric clouds were found to affect the tropospheric SO2 oxidation paths and the cross-tropopause transport, leading to increased background burdens both in the troposphere and the stratosphere. This effect can be reduced by nudging only horizontal winds but not temperature. A higher vertical resolution of 90 levels (as opposed to 39 in the standard version) increases the stratospheric residence time of sulfate aerosol after low-latitude eruptions by reducing the diffusion speed out of the tropical reservoir. We conclude that the model's uncertainties can be largely defined by both its set-up as by the volcanic emission parameters.</p>

Reconstruction of maximum temperature on Zhegu Mountain, western Sichuan Plateau (China)

2020 ◽  
Vol 81 ◽  
pp. 1-14
Author(s):  
M Keyimu ◽  
Z Li ◽  
Y Zhao ◽  
Y Dong ◽  
B Fu ◽  
...  
Keyword(s):  
Tree Growth ◽  
Ring Width ◽  
Volcanic Eruptions ◽  
Southwestern China ◽  
Maximum Temperature ◽  
Driving Mechanism ◽  
Western Sichuan ◽  
Relationship Analysis ◽  
Decadal Scale ◽  
Thermal Variability

Historical temperature reconstructions at high altitudes are still insufficient in southwestern China, which is considered one of the most sensitive areas to climate change in the world. Here we developed a tree ring-width chronology of Faxon fir Abies fargesii var. faxoniana at the upper timber line on Zhegu Mountain, Miyaluo Scenic Area, western Sichuan, China. The climate-tree growth relationship analysis indicated temperature as the dominant regulator on radial tree growth in this region. The reconstruction of aggregated maximum temperature (TMX) of autumn and winter for the period 1856-2016 was achieved with a linear regression model that accounted for 43.6% of the actual variability in the common time series (1954-2016). The reconstruction identified 4 warm periods and 3 cold periods. Similarities of warm and cold periods with previously published reconstructions from nearby sites indicated the reliability of our reconstruction. The significant positive correlation between TMX reconstruction and the Asian-Pacific Oscillation index and the Atlantic Multi-decadal Oscillation index suggested a linkage between large-scale climate circulations and the thermal variability at a multi-decadal scale on the western Sichuan Plateau. We also found that solar activity exerted a strong influence on decadal temperature variability in this region. The cold periods were matched well with historical large volcanic eruptions. Our results strengthen the historical climatic information in southwestern China and contribute to further understanding the regional thermal variability as well as its driving mechanism.

scholarly journals Near-real-time volcanic cloud monitoring: insights into global explosive volcanic eruptive activity through analysis of Volcanic Ash Advisories

2021 ◽  
Vol 83 (2) ◽  
Author(s):  
S. Engwell ◽  
L. Mastin ◽  
A. Tupper ◽  
J. Kibler ◽  
P. Acethorp ◽  
...  
Keyword(s):  
Real Time ◽  
Volcanic Activity ◽  
Volcanic Ash ◽  
Source Parameters ◽  
Volcanic Eruptions ◽  
Volcanic Hazards ◽  
Process Data ◽  
Cloud Monitoring ◽  
Satellite Sensors ◽  
Volcanic Cloud

AbstractUnderstanding the location, intensity, and likely duration of volcanic hazards is key to reducing risk from volcanic eruptions. Here, we use a novel near-real-time dataset comprising Volcanic Ash Advisories (VAAs) issued over 10 years to investigate global rates and durations of explosive volcanic activity. The VAAs were collected from the nine Volcanic Ash Advisory Centres (VAACs) worldwide. Information extracted allowed analysis of the frequency and type of explosive behaviour, including analysis of key eruption source parameters (ESPs) such as volcanic cloud height and duration. The results reflect changes in the VAA reporting process, data sources, and volcanic activity through time. The data show an increase in the number of VAAs issued since 2015 that cannot be directly correlated to an increase in volcanic activity. Instead, many represent increased observations, including improved capability to detect low- to mid-level volcanic clouds (FL101–FL200, 3–6 km asl), by higher temporal, spatial, and spectral resolution satellite sensors. Comparison of ESP data extracted from the VAAs with the Mastin et al. (J Volcanol Geotherm Res 186:10–21, 2009a) database shows that traditional assumptions used in the classification of volcanoes could be much simplified for operational use. The analysis highlights the VAA data as an exceptional resource documenting global volcanic activity on timescales that complement more widely used eruption datasets.

scholarly journals The role of tropical volcanic eruptions in exacerbating Indian droughts

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Suvarna Fadnavis ◽  
Rolf Müller ◽  
Tanusri Chakraborty ◽  
T. P. Sabin ◽  
Anton Laakso ◽  
...  
Keyword(s):  
El Niño ◽  
Climate Model ◽  
El Nino ◽  
Volcanic Eruptions ◽  
Summer Monsoon Rainfall ◽  
Indian Region ◽  
Volcanic Plume ◽  
Kelvin Wave ◽  
Central Pacific ◽  
Climate Model Simulations

AbstractThe Indian summer monsoon rainfall (ISMR) is vital for the livelihood of millions of people in the Indian region; droughts caused by monsoon failures often resulted in famines. Large volcanic eruptions have been linked with reductions in ISMR, but the responsible mechanisms remain unclear. Here, using 145-year (1871–2016) records of volcanic eruptions and ISMR, we show that ISMR deficits prevail for two years after moderate and large (VEI > 3) tropical volcanic eruptions; this is not the case for extra-tropical eruptions. Moreover, tropical volcanic eruptions strengthen El Niño and weaken La Niña conditions, further enhancing Indian droughts. Using climate-model simulations of the 2011 Nabro volcanic eruption, we show that eruption induced an El Niño like warming in the central Pacific for two consecutive years due to Kelvin wave dissipation triggered by the eruption. This El Niño like warming in the central Pacific led to a precipitation reduction in the Indian region. In addition, solar dimming caused by the volcanic plume in 2011 reduced Indian rainfall.

scholarly journals Volcanic activity sparks the Arctic Oscillation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Weizheng Qu ◽  
Fei Huang ◽  
Jinping Zhao ◽  
Ling Du ◽  
Yong Cao
Keyword(s):  
Volcanic Activity ◽  
Volcanic Eruption ◽  
Arctic Oscillation ◽  
Polar Vortex ◽  
Volcanic Eruptions ◽  
The Arctic ◽  
Vortex System ◽  
Significant Fluctuation ◽  
The Arctic Oscillation

AbstractThe parasol effect of volcanic dust and aerosol caused by volcanic eruption results in the deepening and strengthening of the Arctic vortex system, thus stimulating or strengthening the Arctic Oscillation (AO). Three of the strongest AOs in more than a century have been linked to volcanic eruptions. Every significant fluctuation of the AO index (AOI = ΔH_middle latitudes − ΔH_Arctic) for many years has been associated with a volcanic eruption. Volcanic activity occurring at different locations in the Arctic vortex circulation will exert different effects on the polar vortex.

Why does the climate response to greenhouse warming and greenhouse cooling differ? 

2021 ◽  
Author(s):  
Jennifer Kay ◽  
Jason Chalmers
Keyword(s):  
Carbon Dioxide ◽  
Radiative Forcing ◽  
Climate Model ◽  
Temperature Response ◽  
Greenhouse Warming ◽  
Climate Response ◽  
Cloud Feedbacks ◽  
Surface Climate ◽  
Carbon Dioxide Concentrations ◽  
Radiative Feedbacks

<p>While the long-standing quest to constrain equilibrium climate sensitivity has resulted in intense scrutiny of the processes controlling idealized greenhouse warming, the processes controlling idealized greenhouse cooling have received less attention. Here, differences in the climate response to increased and decreased carbon dioxide concentrations are assessed in state-of-the-art fully coupled climate model experiments. One hundred and fifty years after an imposed instantaneous forcing change, surface global warming from a carbon dioxide doubling (abrupt-2xCO2, 2.43 K) is larger than the surface global cooling from a carbon dioxide halving (abrupt-0p5xCO2, 1.97 K). Both forcing and feedback differences explain these climate response differences. Multiple approaches show the radiative forcing for a carbon dioxide doubling is ~10% larger than for a carbon dioxide halving. In addition, radiative feedbacks are less negative in the doubling experiments than in the halving experiments. Specifically, less negative tropical shortwave cloud feedbacks and more positive subtropical cloud feedbacks lead to more greenhouse 2xCO2 warming than 0.5xCO2 greenhouse cooling. Motivated to directly isolate the influence of cloud feedbacks on these experiments, additional abrupt-2xCO2 and abrupt-0p5xCO2 experiments with disabled cloud-climate feedbacks were run. Comparison of these “cloud-locked” simulations with the original “cloud active” simulations shows cloud feedbacks help explain the nonlinear global surface temperature response to greenhouse warming and greenhouse cooling. Overall, these results demonstrate that both radiative forcing and radiative feedbacks are needed to explain differences in the surface climate response to increased and decreased carbon dioxide concentrations.</p>

Revisiting the Krakatau 1883 Volcanic Aerosol Dispersal 

2021 ◽  
Author(s):  
Rafael Castro ◽  
Tushar Mittal ◽  
Stephen Self
Keyword(s):  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Volcanic Eruptions ◽  
Climate Impact ◽  
Volcanic Plume ◽  
Quasi Biennial Oscillation ◽  
Aerosol Cloud ◽  
Pinatubo Eruption ◽  
The Impact

<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>

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