Smaller average stratospheric aerosol sizes after volcanic eruptions in 2018 and 2019

Solar Occultation ◽

Temporal And Spatial

We present surprising results of our stratospheric aerosol size retrieval which is using the SAGE III/ISS solar occultation measurements, that started in 2017. Due to the broad wavelength spectrum covered by the instrument a robust retrieval of the median radius, mode width and number density of monomodal lognormal size distributions is possible.In the timeframe of SAGE III&#8217;s operation so far three small to mid intensity volcanic eruptions that reached and perturbed the stratospheric aerosol layer were observed by the instrument: The Ambae eruptions (15.3&#176;S) in spring of 2018 and the Raikoke (48.3&#176;N) and Ulawun (5.05&#176;S) eruptions, both in June 2019. While the Raikoke eruption led to an increase in the median radius of the stratospheric aerosols, which was to be expected and is in line with previous observations, the Ambae and Ulawun eruption had a different effect. After both eruptions the average aerosol size decreased, with lower median radii and narrower size distributions, while the number density increased strongly. The observation, that volcanic eruptions may lead to smaller average stratospheric aerosol sizes is a novel one and should be of great interest to the modeling as well as remote sensing community.We will present the temporal and spatial evolution of the stratospheric perturbations and discuss what may distinguish those three eruptions from each other.

Retrieval of stratospheric aerosol size distribution parameters using satellite solar occultation measurements at three wavelengths

Atmospheric Measurement Techniques ◽

10.5194/amt-14-2345-2021 ◽

2021 ◽

Vol 14 (3) ◽

pp. 2345-2357

Author(s):

Felix Wrana ◽

Christian von Savigny ◽

Jacob Zalach ◽

Larry W. Thomason

Keyword(s):

Size Distribution ◽

Space Station ◽

Volcanic Eruptions ◽

Stratospheric Aerosol ◽

Aerosol Layer ◽

Data Set ◽

Extinction Coefficients ◽

Solar Occultation ◽

Spatial Coverage

Abstract. In this work, a novel approach for the determination of the particle size distribution (PSD) parameters of stratospheric sulfate aerosols is presented. For this, ratios of extinction coefficients obtained from SAGE III/ISS (Stratospheric Aerosol and Gas Experiment III on the International Space Station) solar occultation measurements at 449, 756 and 1544 nm were used to retrieve the mode width and median radius of a size distribution assumed to be monomodal lognormal. The estimated errors at the peak of the stratospheric aerosol layer, on average, lie between 20 % and 25 % for the median radius and 5 % and 7 % for the mode width. The results are consistent in magnitude with other retrieval results from the literature, but a robust comparison is difficult, mainly because of differences in temporal and spatial coverage. Other quantities like number density and effective radius were also calculated. A major advantage of the described method over other retrieval techniques is that both the median radius and the mode width can be retrieved simultaneously, without having to assume one of them. This is possible due to the broad wavelength spectrum covered by the SAGE III/ISS measurements. Also, the presented method – being based on the analysis of three wavelengths – allows unique solutions for the retrieval of PSD parameters for almost all of the observed extinction spectra, which is not the case when using only two spectral channels. In addition, the extinction coefficients from SAGE III/ISS solar occultation measurements, on which the retrieval is based, are calculated without a priori assumptions about the PSD. For those reasons, the data produced with the presented retrieval technique may be a valuable contribution for a better understanding of the variability of stratospheric aerosol size distributions, e.g. after volcanic eruptions. While this study focuses on describing the retrieval method, and a future study will discuss the PSD parameter data set produced in depth, some exemplary results for background conditions in June 2017 are shown.

Retrieval of stratospheric aerosol size distribution parameters using SAGE-III/ISS extinction measurements at three wavelengths

10.5194/amt-2020-277 ◽

2020 ◽

Cited By ~ 1

Author(s):

Felix Wrana ◽

Christian von Savigny ◽

Jacob Zalach ◽

Larry W. Thomason

Keyword(s):

Size Distribution ◽

A Priori ◽

Volcanic Eruptions ◽

Stratospheric Aerosol ◽

Aerosol Layer ◽

Data Set ◽

Extinction Coefficients ◽

Solar Occultation ◽

Spatial Coverage

Abstract. In this work a novel approach to determine the particle size distribution (PSD) parameters of stratospheric sulfate aerosols is presented. For this, ratios of extinction coefficients obtained from SAGE III/ISS solar occultation measurements at 449 nm, 756 nm and 1544 nm were used to retrieve the mode width and median radius of a size distribution assumed to be monomodal lognormal. The estimated errors at the peak of the stratospheric aerosol layer on average lie between 20 % and 25 % for the median radius and 5 % and 7 % for the mode width. The results are consistent in magnitude with other retrieval results from the literature, but a robust comparison is difficult, mainly because of differences in temporal and spatial coverage. Other quantities like number density and effective radius were also calculated. A major advantage of the described method over other retrieval techniques is that both the median radius and the mode width can be retrieved simultaneously, without having to assume one of them, due to the broad wavelength spectrum covered by the SAGE III/ISS measurements. Also the extinction coefficients from SAGE III/ISS solar occultation measurements, on which the retrieval is based, are calculated without a priori assumptions about the PSD. For those reasons, the data produced with the presented retrieval technique may be a valuable contribution to better understand the variability of stratospheric aerosol size distributions, e.g. after volcanic eruptions. While this study focuses on describing the retrieval method and a future study will discuss the PSD parameter data set produced in depth, some exemplary results for background conditions in June 2017 are shown.

Analysis of the temporal and spatial evolution characteristics and influencing factors of China’s herbivorous animal husbandry industry

PLoS ONE ◽

10.1371/journal.pone.0237827 ◽

2020 ◽

Vol 15 (8) ◽

pp. e0237827

Author(s):

Chengji Han ◽

Guogang Wang ◽

Yongxiang Zhang ◽

Lili Song ◽

Lizhi Zhu

Keyword(s):

Influencing Factors ◽

Animal Husbandry ◽

Spatial Evolution ◽

Evolution Characteristics ◽

Herbivorous Animal ◽

Temporal And Spatial

Monitoring the Variability of the Stratospheric Aerosol Layer over Tomsk in 2016–2018 Based on Lidar Data

Meteorologiya i Gidrologiya ◽

10.52002/0130-2906-2021-1-61-72 ◽

2021 ◽

pp. 61-72

Author(s):

V. N. Marichev ◽

◽

D. A. Bochkovskiia ◽

Keyword(s):

Volcanic Eruptions ◽

Temperature Inversion ◽

Cold Season ◽

Stratospheric Aerosol ◽

Single Frequency ◽

Winter Period ◽

Lidar Data ◽

Aerosol Layer ◽

Time Data ◽

Academy Of Sciences

The results of observations of the features of intraannual variability for the vertical structure of background aerosol in the stratosphere over Western Siberia in 2016–2018 are presented and analyzed. Experimental data were obtained at the lidar complex of Zuev Institute of Atmospheric Optics (Siberian Branch, Russian Academy of Sciences) with a receiving mirror diameter of 1 m. The objective of the study is to investigate the dynamics of background stratospheric aerosol, since during this period there were no volcanic eruptions leading to the transport of eruptive aerosol into the stratosphere. The results of the study confirm a stable intraannual cycle of maximum aerosol filling of the stratosphere in winter, a decrease in spring to the minimum, practical absence in summer, and an increase in autumn. At the same time, the variability of stratification and aerosol filling is observed for different years. It was found that aerosol is concentrated in the layer up to 30 km all year round, except for the winter period. It is shown that the vertical aerosol stratification is largely determined by the thermal regime of the tropo- sphere–stratosphere boundary layer. The absence of a pronounced temperature inversion at the tropopause contributes to an increase in the stratosphere–troposphere exchange and, as a result, to the aerosol transport to the stratosphere. This situation is typical of the cold season. For the first time, data on the quantitative content of stratospheric aerosol (its mass concentration) were obtained from single- frequency lidar data.

The Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP): Experimental design and forcing input data

10.5194/gmd-2016-68 ◽

2016 ◽

Cited By ~ 2

Author(s):

Davide Zanchettin ◽

Myriam Khodri ◽

Claudia Timmreck ◽

Matthew Toohey ◽

Anja Schmidt ◽

...

Keyword(s):

Climate Models ◽

Climate Model ◽

Initial Conditions ◽

Volcanic Eruptions ◽

Stratospheric Aerosol ◽

Aerosol Layer ◽

Model Intercomparison ◽

Climatic Response ◽

Volcanic Forcing ◽

Intercomparison Project

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.

Temporal and spatial evolution of dynamic support from river profiles: A framework for Madagascar

Geochemistry Geophysics Geosystems ◽

10.1029/2012gc004040 ◽

2012 ◽

Vol 13 (4) ◽

pp. n/a-n/a ◽

Cited By ~ 41

Author(s):

Gareth G. Roberts ◽

Jonathan D. Paul ◽

Nicky White ◽

Jeffrey Winterbourne

Keyword(s):

Spatial Evolution ◽

Dynamic Support ◽

Temporal And Spatial ◽

River Profiles

Optical Diagnostics of Temporal and Spatial Evolution of a Reacting Diesel Fuel Jet

Combustion Science and Technology ◽

10.1080/00102209908935769 ◽

1999 ◽

Vol 148 (1-6) ◽

pp. 1-16 ◽

Cited By ~ 19

Author(s):

MASSIMO ASTARITA ◽

FELICE E. CORCIONE ◽

BIANCA MARIA VAGLIECO ◽

GERARDO VALENTINO

Keyword(s):

Diesel Fuel ◽

Optical Diagnostics ◽

Spatial Evolution ◽

Fuel Jet ◽

Temporal And Spatial

Evidence for the predictability of changes in the stratospheric aerosol size following volcanic eruptions of diverse magnitudes using space-based instruments

10.5194/acp-2020-480 ◽

2020 ◽

Author(s):

Larry W. Thomason ◽

Mahesh Kovilakam ◽

Anja Schmidt ◽

Christian von Savigny ◽

Travis Knepp ◽

...

Keyword(s):

Size Distribution ◽

Extinction Coefficient ◽

Volcanic Eruptions ◽

Stratospheric Aerosol ◽

Global Climate Models ◽

Aerosol Layer ◽

Aerosol Extinction ◽

Volcanic Event ◽

Aerosol Extinction Coefficient

Abstract. An analysis of multiwavelength stratospheric aerosol extinction coefficient data from the Stratospheric Aerosol and Gas Experiment II and III/ISS instruments is used to demonstrate a coherent relationship between the perturbation in extinction coefficient in an eruption's main aerosol layer and an apparent change in aerosol size distribution that spans multiple orders of magnitude in the stratospheric impact of a volcanic event. The relationship is measurement-based and does not rely on assumptions about the aerosol size distribution. We note limitations on this analysis including that the presence of significant amounts of ash in the main aerosol layer may significantly modulate these results. Despite this limitation, these findings represent a unique opportunity to verify the performance of interactive aerosol models used in Global Climate Models and Earth System Model and may suggest an avenue for improving aerosol extinction coefficient measurements from single channel observations such the Optical Spectrograph and Infrared Imager System as they rely on a priori assumptions about particle size.

Evidence for the predictability of changes in the stratospheric aerosol size following volcanic eruptions of diverse magnitudes using space-based instruments

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-1143-2021 ◽

2021 ◽

Vol 21 (2) ◽

pp. 1143-1158 ◽

Cited By ~ 1

Author(s):

Larry W. Thomason ◽

Mahesh Kovilakam ◽

Anja Schmidt ◽

Christian von Savigny ◽

Travis Knepp ◽

...

Keyword(s):

Extinction Coefficient ◽

Climate Models ◽

Single Channel ◽

Volcanic Eruptions ◽

Stratospheric Aerosol ◽

Global Climate Models ◽

Aerosol Layer ◽

Aerosol Extinction ◽

Aerosol Extinction Coefficient

Abstract. An analysis of multiwavelength stratospheric aerosol extinction coefficient data from the Stratospheric Aerosol and Gas Experiment II and III/ISS instruments is used to demonstrate a coherent relationship between the perturbation in extinction coefficient in an eruption's main aerosol layer and the wavelength dependence of that perturbation. This relationship spans multiple orders of magnitude in the aerosol extinction coefficient of stratospheric impact of volcanic events. The relationship is measurement-based and does not rely on assumptions about the aerosol size distribution. We note limitations on this analysis including that the presence of significant amounts of ash in the main sulfuric acid aerosol layer and other factors may significantly modulate these results. Despite these limitations, the findings suggest an avenue for improving aerosol extinction coefficient measurements from single-channel observations such as the Optical Spectrograph and Infrared Imager System as they rely on a prior assumptions about particle size. They may also represent a distinct avenue for the comparison of observations with interactive aerosol models used in global climate models and Earth system models.