Long-range transport of stratospheric aerosols in the Southern Hemisphere following the 2015 Calbuco eruption

Abstract. After 43 years of inactivity, the Calbuco volcano, which is located in the southern part of Chile, erupted on 22 April 2015. The space–time evolutions (distribution and transport) of its aerosol plume are investigated by combining satellite (CALIOP, IASI, OMPS), in situ aerosol counting (LOAC OPC) and lidar observations, and the MIMOSA advection model. The Calbuco aerosol plume reached the Indian Ocean 1 week after the eruption. Over the Reunion Island site (21° S, 55.5° E), the aerosol signal was unambiguously enhanced in comparison with background conditions, with a volcanic aerosol layer extending from 18 to 21 km during the May–July period. All the data reveal an increase by a factor of ∼  2 in the SAOD (stratospheric aerosol optical depth) with respect to values observed before the eruption. The aerosol mass e-folding time is approximately 90 days, which is rather close to the value ( ∼  80 days) reported for the Sarychev eruption. Microphysical measurements obtained before, during, and after the eruption reflecting the impact of the Calbuco eruption on the lower stratospheric aerosol content have been analyzed over the Reunion Island site. During the passage of the plume, the volcanic aerosol was characterized by an effective radius of 0.16 ± 0.02 µm with a unimodal size distribution for particles above 0.2 µm in diameter. Particle concentrations for sizes larger than 1 µm are too low to be properly detected by the LOAC OPC. The aerosol number concentration was ∼  20 times higher that observed before and 1 year after the eruption. According to OMPS and lidar observations, a tendency toward conditions before the eruption was observed by April 2016. The volcanic aerosol plume is advected eastward in the Southern Hemisphere and its latitudinal extent is clearly bounded by the subtropical barrier and the polar vortex. The transient behavior of the aerosol layers observed above Reunion Island between May and July 2015 reflects an inhomogeneous spatio-temporal distribution of the plume, which is controlled by the localization of these dynamical barriers.

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Long-range isentropic transport of stratospheric aerosols over Southern Hemisphere following the Calbuco eruption in April 2015

10.5194/acp-2017-544 ◽

2017 ◽

Cited By ~ 1

Author(s):

Nelson Bègue ◽

Damien Vignelles ◽

Gwenaël Berthet ◽

Thierry Portafaix ◽

Guillaume Payen ◽

...

Keyword(s):

Southern Hemisphere ◽

Transient Behavior ◽

Stratospheric Aerosol ◽

Aerosol Layer ◽

Reunion Island ◽

Volcanic Aerosol ◽

Réunion Island ◽

One Year ◽

The Impact ◽

Aerosol Plume

Abstract. After 43 years of inactivity, the Calbuco volcano which is located in the southern part of Chile erupted on 22 April 2015. The space-time evolutions (distribution and transport) of its aerosol plume are investigated by combining satellite (CALIOP, IASI, OMPS), in situ aerosol counting (LOAC OPC) and lidar observations, and the MIMOSA advection model. The Calbuco aerosol plume reached the Indian Ocean 1 week after the eruption. Over the Reunion Island site (21° S; 55.5° E), the aerosol signal was unambiguously enhanced in comparison with "background" conditions with a volcanic aerosol layer extending from 18 km to 21 km during the May–July period. All the data reveal an increase by a factor of ~ 2 in the SAOD (Stratospheric Aerosol Optical Depth) with respect to values observed before the eruption. The aerosol e-folding time is approximately 90 days. Microphysical measurements obtained before, during and after the eruption reflecting the impact of the Calbuco eruption on the lower stratospheric aerosol content have been analyzed over Reunion site. During the passage of the plume, the volcanic aerosol was characterized by an effective radius of 0.16 ± 0.02 µm with an unimodal lognormal size distribution and the aerosol number concentration appears 20 times higher than before and one year after the eruption. A tendency toward "background" conditions has been observed about one year after the eruption, by April 2016. The volcanic aerosol plume is advected eastward in the Southern Hemisphere and its latitudinal extent is clearly bounded by the subtropical barrier and the polar vortex. The transient behavior of the aerosol layers observed above Reunion Island between May and July 2015 reflects an inhomogeneous geographical distribution of the plume which is controlled by the latitudinal motion of these dynamical barriers.

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Impact of the Ambae, Raikoke and Ulawun eruptions in 2018-2019 on the global stratospheric aerosol layer and climate

10.5194/egusphere-egu2020-2406 ◽

2020 ◽

Author(s):

Corinna Kloss ◽

Pasquale Sellitto ◽

Bernard Legras ◽

Jean-Paul Vernier ◽

Fabrice Jégou ◽

...

Keyword(s):

Radiative Transfer ◽

Radiative Forcing ◽

Volcanic Eruptions ◽

Stratospheric Aerosol ◽

Orthogonal Polarization ◽

Transfer Model ◽

Aerosol Layer ◽

The Impact ◽

Aerosol Plume

Using a combination of satellite, ground-based and in-situ observations, and radiative transfer modelling, we quantify the impact of the most recent moderate volcanic eruptions (Ambae, Vanuatu in July 2018; Raikoke, Russia and Ulawun, New Guinea in June 2019) on the global stratospheric aerosol layer and climate.For the Ambae volcano (15&#176;S and 167&#176;E), we use the Stratospheric Aerosol and Gas Experiment III (SAGE III), the Ozone Mapping Profiler Suite (OMPS), the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) and Himawari geostationary satellite observations of the aerosol plume evolution following the Ambae eruption of July 2018. It is shown that the aerosol plume of the main eruption at Ambae in July 2018 was distributed throughout the global stratosphere within the global large-scale circulation (Brewer-Dobson circulation, BDC), to both hemispheres. Ground-based LiDAR observations in Gadanki, India, as well as in-situ Printed Optical Particle Spectrometer (POPS) measurements acquired during the BATAL campaign confirm a widespread perturbation of the stratospheric aerosol layer due to this eruption. Using the UVSPEC radiative transfer model, we also estimate the radiative forcing of this global stratospheric aerosol perturbation. The climate impact is shown to be comparable to that of the well-known and studied recent moderate stratospheric eruptions from Kasatochi (USA, 2008), Sarychev (Russia, 2009) and Nabro (Eritrea, 2011). Top of the atmosphere radiative forcing values between -0.45 and -0.60 W/m2, for the Ambae eruption of July 2018, are found.In a similar manner the dispersion of the aerosol plume of the Raikoke (48&#176;N and 153&#176;E) and Ulawun (5&#176;S and 151&#176;E) eruptions of June 2019 is analyzed. As both of those eruptions had a stratospheric impact and happened almost simultaneously, it is challenging to completely distinguish both events. Even though the eruptions occurred very recently, first results show that the aerosol plume of the Raikoke eruption resulted in an increase in aerosol extinction values, double as high as compared to that of the Ambae eruption. However, as the eruption occurred on higher latitudes, the main bulk of Raikoke aerosols was transported towards the northern higher latitude&#8217;s in the stratosphere within the BDC, as revealed by OMPS, SAGE III and a new detection algorithm for SO2 and sulfate aerosol using IASI (Infrared Atmospheric Sounder Interferometer). Even though the Raikoke eruption had a larger impact on the stratospheric aerosol layer, both events (the eruptions at Raikoke and Ambae) have to be considered in stratospheric aerosol budget and climate studies.

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Evaluation of WRF-DART (ARW v3.9.1.1 and DART Manhattan release) multiphase cloud water path assimilation for short-term solar irradiance forecasting in a tropical environment

Geoscientific Model Development ◽

10.5194/gmd-12-3939-2019 ◽

2019 ◽

Vol 12 (9) ◽

pp. 3939-3954

Author(s):

Frederik Kurzrock ◽

Hannah Nguyen ◽

Jerome Sauer ◽

Fabrice Chane Ming ◽

Sylvain Cros ◽

...

Keyword(s):

Data Assimilation ◽

Weather Prediction ◽

Cloud Water ◽

Specific Humidity ◽

Reunion Island ◽

Short Term ◽

Water Path ◽

Réunion Island ◽

Cloud Water Path ◽

The Impact

Abstract. Numerical weather prediction models tend to underestimate cloud presence and therefore often overestimate global horizontal irradiance (GHI). The assimilation of cloud water path (CWP) retrievals from geostationary satellites using an ensemble Kalman filter (EnKF) led to improved short-term GHI forecasts of the Weather Research and Forecasting (WRF) model in midlatitudes in case studies. An evaluation of the method under tropical conditions and a quantification of this improvement for study periods of more than a few days are still missing. This paper focuses on the assimilation of CWP retrievals in three phases (ice, supercooled, and liquid) in a 6-hourly cycling procedure and on the impact of this method on short-term forecasts of GHI for Réunion Island, a tropical island in the southwest Indian Ocean. The multilayer gridded cloud properties of NASA Langley's Satellite ClOud and Radiation Property retrieval System (SatCORPS) are assimilated using the EnKF of the Data Assimilation Research Testbed (DART) Manhattan release (revision 12002) and the advanced research WRF (ARW) v3.9.1.1. The ability of the method to improve cloud analyses and GHI forecasts is demonstrated, and a comparison using independent radiosoundings shows a reduction of specific humidity bias in the WRF analyses, especially in the low and middle troposphere. Ground-based GHI observations at 12 sites on Réunion Island are used to quantify the impact of CWP DA. Over a total of 44 d during austral summertime, when averaged over all sites, CWP data assimilation has a positive impact on GHI forecasts for all lead times between 5 and 14 h. Root mean square error and mean absolute error are reduced by 4 % and 3 %, respectively.

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Lidar Observations of the Stratospheric Aerosol Layer over Kingston, Jamaica

Journal of the Atmospheric Sciences ◽

10.1175/1520-0469(1985)042<0967:lootsa>2.0.co;2 ◽

1985 ◽

Vol 42 (9) ◽

pp. 967-976 ◽

Cited By ~ 2

Author(s):

M. T. Philip ◽

G. S. Kent ◽

M. T. Ottway

Keyword(s):

Stratospheric Aerosol ◽

Aerosol Layer ◽

Lidar Observations

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Lidar observations of volcanic aerosol over the UK since June 2019

10.5194/egusphere-egu2020-5653 ◽

2020 ◽

Author(s):

Geraint Vaughan ◽

David Wareing ◽

Hugo Ricketts

Keyword(s):

Volcanic Ash ◽

Stratospheric Aerosol ◽

Aerosol Layer ◽

Raman Lidar ◽

Lidar System ◽

Elastic Channel ◽

Enhanced Sensitivity ◽

Volcanic Cloud ◽

The Uk ◽

Lidar Observations

On 22 June 2019, the Raikoke volcano in the Kuril Islands erupted, sending a plume of ask and sulphur dioxide into the stratosphere. A Raman lidar system at Capel Dewi, UK (52.4&#176;N, 4.1&#176;W) has been used to measure the extent and optical depth of the stratospheric aerosol layer following the eruption. The lidar was modified to give it much enhanced sensitivity in the elastic channel, allowing measurements up to 25 km, but the Raman channel is only sensitive to the troposphere. Therefore, backscatter ratio profiles were derived by comparison with aerosol-free profiles derived from nearby radiosondes, corrected for aerosol extinction. Small amounts of stratospheric aerosol were measured prior to the arrival of the volcanic cloud, probably from pyroconvection over Canada. Volcanic ash began to arrive as a thin layer at 14 km late on 3 July, extending over the following month to fill the stratosphere below around 19 km. Aerosol optical depths reached around 0.03 by mid-August and continued at this level for the remainder of the year. The location of peak backscatter varied considerably but was generally around 15 km. However, on one notable occasion on August 25, a layer around 300 m thick with peak lidar backscatter ratio around 1.5 was observed as high as 21 km.

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Tropical stratospheric aerosol layer from CALIPSO lidar observations

Journal of Geophysical Research Atmospheres ◽

10.1029/2009jd011946 ◽

2009 ◽

Vol 114 ◽

Cited By ~ 91

Author(s):

J. P. Vernier ◽

J. P. Pommereau ◽

A. Garnier ◽

J. Pelon ◽

N. Larsen ◽

...

Keyword(s):

Stratospheric Aerosol ◽

Aerosol Layer ◽

Lidar Observations

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Evaluation of WRF-DART (ARW v.3.9.1.1 and DART manhattan release) multi-phase cloud water path assimilation for short-term solar irradiance forecasting in a tropical environment

10.5194/gmd-2019-29 ◽

2019 ◽

Author(s):

Frederik Kurzrock ◽

Hannah Nguyen ◽

Jerome Sauer ◽

Fabrice Chane Ming ◽

Sylvain Cros ◽

...

Keyword(s):

Data Assimilation ◽

Weather Prediction ◽

Cloud Water ◽

Specific Humidity ◽

Reunion Island ◽

Short Term ◽

Water Path ◽

Réunion Island ◽

Cloud Water Path ◽

The Impact

Abstract. Numerical weather prediction models tend to underestimate cloud presence and therefore often overestimate global horizontal irradiance (GHI). The assimilation of cloud water path (CWP) retrievals from geostationary satellites using an ensemble Kalman filter (EnKF) led to improved short-term GHI forecasts of the Weather Research and Forecasting (WRF) model in mid-latitudes in case studies. An evaluation of the method under tropical conditions and a quantification of this improvement for study periods of more than a few days is still missing. This paper focuses on the assimilation of CWP retrievals in three phases (ice, supercooled, and liquid) in a 6-hourly cycling procedure, and on the impact of this method on short-term forecasts of GHI for Reunion Island, a tropical island in the South-West Indian Ocean. The multi-layer gridded cloud properties of NASA Langley's Satellite ClOud and Radiation Property retrieval System (SatCORPS) are assimilated using the EnKF of the Data Assimilation Research Testbed (DART) manhattan release (revision 12002) and the advanced research WRF (ARW) v3.9.1.1. The ability of the method to improve cloud analyses and GHI forecasts is demonstrated and a comparison using independent radiosoundings shows a reduction of specific humidity bias in the WRF analyses, especially in the low and mid troposphere. Ground-based GHI observations at 12 sites on Reunion Island are used to quantify the impact of CWP DA. Over a total of 44 days during austral summer time, when averaged over all sites, CWP data assimilation has a positive impact on GHI forecasts for all lead times between 5 and 14 hours. Root Mean Squared Error and Mean Absolute Error are reduced by 4 % and 3 % respectively.

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Interactive Stratospheric Aerosol models response to different sulfur injection amount and altitude distribution during volcanic eruption

10.5194/egusphere-egu21-13387 ◽

2021 ◽

Author(s):

Ilaria Quaglia ◽

Christoph Brühl ◽

Sandip Dhomse ◽

Henning Franke ◽

Anton Laakso ◽

...

Keyword(s):

Volcanic Eruptions ◽

Stratospheric Aerosol ◽

Climate Modelling ◽

Aerosol Layer ◽

Volcanic Aerosol ◽

Surface Cooling ◽

Altitude Distribution ◽

Aerosol Cloud ◽

Modelling Studies ◽

Intercomparison Project

Large magnitude tropical volcanic eruptions emit sulphur dioxide and other gases directly into the stratosphere, creating a long-lived volcanic aerosol cloud which scatter incoming solar radiation, absorbs outgoing terrestrial radiation, and can strongly affect the composition of the stratosphere.Such major volcanic enhancements of the stratospheric aerosol layer have strong &#8220;direct effects&#8221; on climate via these influences on radiative transfer, primarily surface cooling via the reduced insolation, but also have a range of indirect effects, due to the volcanic aerosol cloud&#8217;s effects on stratospheric circulation, dynamics and chemistry.In this study, we investigate the 3 largest volcanic enhancements to the stratospheric aerosol layer in the last 100 years (Mt Agung 1963; Mt El Chich&#243;n 1982; Mt Pinatubo 1991), comparing co-ordinated simulations within the so-called HErSEA experiments (Historical Eruptions SO2 Emission Assessment) several national climate modelling centres carried out for the model intercomparison project ISA-MIP.The HErSEA experiment saw participating models performing interactive stratospheric aerosol simulations of each of the volcanic aerosol clouds with common upper-, mid- and lower-estimate amounts and injection heights of sulfur dioxide, in order to better understand known differences among modelling studies for which initial emission gives best agreement with observations.&#160;First, we compare results of several models HErSEA simulations with a range of observations, with the aim to find where there is agreement between the models and where there are differences, at the different initial sulfur injection amount and altitude distribution.In this way, we could understand the differences and limitations in the mechanisms that controls the dynamical, microphysical and chemical processes of stratospheric aerosol layer.

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Volcanic aerosol heating in the tropical tropopause region and associated water vapour changes

10.5194/egusphere-egu21-12318 ◽

2021 ◽

Author(s):

Clarissa Kroll ◽

Hauke Schmidt ◽

Claudia Timmreck

Keyword(s):

Water Vapour ◽

Volcanic Eruptions ◽

Aerosol Layer ◽

Volcanic Aerosol ◽

Surface Warming ◽

Tropical Tropopause ◽

Tropopause Region ◽

Cold Point ◽

The Impact

Large volcanic eruptions affect the distribution of atmospheric water vapour, for instance through cooling of the surface, warming of the lowermost stratosphere, and increasing the upwelling in the tropical tropopause region.To better understand the volcanic impact on the tropical tropopause region and associated changes in the water vapour distribution in the stratosphere we employ a combination of short term convection-resolving global simulations with ICON and long term low resolution ensemble simulations with the MPI-ESM1.2-LR EVAens, both with prescribed volcanic forcing. With the EVAens a long term statistical analysis of the water vapour trends during the build-up and decay of a volcanic aerosol layer is made possible. The impact of the heating in the cold point regions is studied for five different eruption magnitudes. Stratospheric water vapour changes are analyzed in simulations with synthetic and observation based aerosol profiles showing that the distance of the aerosol profile from the cold point region can be more important for the water vapour entry into the stratosphere than the emitted amount of sulfur.Whereas the EVAens is ideal to investigate the slow ascent of water vapour into the stratosphere the 10 km high resolution simulations with ICON allow insights into the convective changes after volcanic eruptions going beyond the limitations parameterizations usually impose on the model data.

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Stratospheric residence time and the lifetime of volcanic aerosol

10.5194/egusphere-egu21-12131 ◽

2021 ◽

Author(s):

Matthew Toohey ◽

Yue Jia ◽

Susann Tegetmeier

Keyword(s):

Residence Time ◽

Volcanic Eruptions ◽

Stratospheric Aerosol ◽

Volcanic Aerosol ◽

Aerosol Forcing ◽

Radiative Impact ◽

The Common ◽

The Impact ◽

The Relationship ◽

Common Era

The cumulative radiative impact of major volcanic eruptions depends strongly on the length of time volcanic sulfate aerosol remains in the stratosphere. Observations of aerosol from recent eruptions have been used to suggest that residence time depends on the latitude of the volcanic eruption, with tropical eruptions producing aerosol loading that persists longer than that from extratropical eruptions. However, the limited number of eruptions observed make it difficult to disentangle the roles of latitude and injection height in controlling aerosol lifetime. Here we use satellite observations and model experiments to explore the relationship between eruption latitude, injection height and resulting residence time of stratospheric aerosol. We find that contrary to earlier interpretations of observations, the residence time of aerosol from major tropical eruptions like Pinatubo (1991) is on the order of 24 months. Model results suggest that the residence time is greatly sensitive to the height of the sulfur injection, especially within the lowest few kilometers of the stratosphere. As injection heights and latitudes are unknown for the majority of eruptions over the common era, we estimate the impact of this uncertainty on volcanic aerosol forcing reconstructions.&#160;

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