Differences in the QBO response to stratospheric aerosol modification depending on injection strategy and species

Abstract. A known adverse side effect of stratospheric aerosol modification (SAM) is the modification of the quasi-biennial oscillation (QBO), which is caused by the stratospheric heating associated with an artificial aerosol layer. Multiple studies found the QBO to slow down or even completely vanish for point-like injections of SO2 at the equator. The cause for this was found to be a modification of the thermal wind balance and a stronger tropical upwelling. For other injection strategies, different responses of the QBO have been observed. It has not yet been presented a theory which is able to explain those differences in a comprehensive manner, which is further complicated by the fact that the simulated QBO response is highly sensitive to the used model even under identical boundary conditions. Therefore, within this study we investigate the response of the QBO to SAM for three different injection strategies (point-like injection at the equator, point-like injection at 30° N and 30° S simultaneously, and areal injection into a 60° wide belt along the equator). Our simulations confirm that the QBO response significantly depends on the injection location. Based on the thermal wind balance, we demonstrate that this dependency is explained by differences in the meridional structure of the aerosol-induced stratospheric warming, i.e. the location and meridional extension of the maximum warming. Additionally, we also tested two different injection species (SO2 and H2SO4). The QBO response is qualitatively similar for both investigated injection species. Comparing the results to corresponding results of a second model, we further demonstrate the generality of our theory as well as the importance of an interactive treatment of stratospheric ozone for the simulated QBO response.

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Differences in the quasi-biennial oscillation response to stratospheric aerosol modification depending on injection strategy and species

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-8615-2021 ◽

2021 ◽

Vol 21 (11) ◽

pp. 8615-8635

Author(s):

Henning Franke ◽

Ulrike Niemeier ◽

Daniele Visioni

Keyword(s):

Stratospheric Ozone ◽

Stratospheric Aerosol ◽

Adverse Side Effect ◽

Aerosol Layer ◽

Quasi Biennial Oscillation ◽

Thermal Wind ◽

Highly Sensitive ◽

Maximum Warming ◽

Biennial Oscillation ◽

Injection Strategies

Abstract. A known adverse side effect of stratospheric aerosol modification (SAM) is the alteration of the quasi-biennial oscillation (QBO), which is caused by the stratospheric heating associated with an artificial aerosol layer. Multiple studies found the QBO to slow down or even completely vanish for point-like injections of SO2 at the Equator. The cause for this was found to be a modification of the thermal wind balance and a stronger tropical upwelling. For other injection strategies, different responses of the QBO have been observed. A theory which is able to explain those differences in a comprehensive manner has not yet been presented. This is further complicated by the fact that the simulated QBO response is highly sensitive to the used model even under identical boundary conditions. Therefore, within this study we investigate the response of the QBO to SAM for three different injection strategies (point-like injection at the Equator, point-like injection at 30∘ N and 30∘ S simultaneously, and areal injection into a 60∘ wide belt along the Equator). Our simulations confirm that the QBO response significantly depends on the injection location. Based on the thermal wind balance, we demonstrate that this dependency is explained by differences in the meridional structure of the aerosol-induced stratospheric warming, i.e., the location and meridional extension of the maximum warming. Additionally, we also tested two different injection species (SO2 and H2SO4). The QBO response is qualitatively similar for both investigated injection species. Comparing the results to corresponding results of a second model, we further demonstrate the generality of our theory as well as the importance of an interactive treatment of stratospheric ozone for the simulated QBO response.

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Modifications of the quasi-biennial oscillation by a geoengineering perturbation of the stratospheric aerosol layer

Geophysical Research Letters ◽

10.1002/2013gl058818 ◽

2014 ◽

Vol 41 (5) ◽

pp. 1738-1744 ◽

Cited By ~ 65

Author(s):

V. Aquila ◽

C. I. Garfinkel ◽

P.A. Newman ◽

L.D. Oman ◽

D.W. Waugh

Keyword(s):

Stratospheric Aerosol ◽

Aerosol Layer ◽

Quasi Biennial Oscillation ◽

Biennial Oscillation

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Quasi-biennial oscillation of the tropical stratospheric aerosol layer

Atmospheric Chemistry and Physics ◽

10.5194/acp-15-5557-2015 ◽

2015 ◽

Vol 15 (10) ◽

pp. 5557-5584 ◽

Cited By ~ 14

Author(s):

R. Hommel ◽

C. Timmreck ◽

M. A. Giorgetta ◽

H. F. Graf

Keyword(s):

Seasonal Variations ◽

Stratospheric Aerosol ◽

Static Balance ◽

Aerosol Layer ◽

Mixing Ratio ◽

Quasi Biennial Oscillation ◽

Mixing Ratios ◽

Vertical Extent ◽

Biennial Oscillation ◽

Stratospheric Aerosols

Abstract. This study describes how aerosol in an aerosol-coupled climate model of the middle atmosphere is influenced by the quasi-biennial oscillation (QBO) during times when the stratosphere is largely unperturbed by volcanic material. In accordance with satellite observations, the vertical extent of the stratospheric aerosol layer in the tropics is modulated by the QBO by up to 6 km, or ~ 35% of its mean vertical extent between 100–7 hPa (about 16–33 km). Its largest vertical extent lags behind the occurrence of strongest QBO westerlies. The largest reduction lags behind maximum QBO easterlies. Strongest QBO signals in the aerosol surface area (30 %) and number densities (up to 100% e.g. in the Aitken mode) are found in regions where aerosol evaporates, that is above the 10 hPa pressure level (~ 31 km). Positive modulations are found in the QBO easterly shear, negative modulations in the westerly shear. Below 10 hPa, in regions where the aerosol mixing ratio is largest (50–20 hPa, or ~ 20–26 km), in most of the analysed parameters only moderate statistically significant QBO signatures (< 10%) have been found. QBO signatures in the model prognostic aerosol mixing ratio are significant at the 95% confidence level throughout the tropical stratosphere where modelled mixing ratios exceed 0.1 ppbm. In some regions of the tropical lower stratosphere the QBO signatures in other analysed parameters are partly not statistically significant. Peak-to-peak amplitudes of the QBO signature in the prognostic mixing ratios are up to twice as large as seasonal variations in the region where aerosols evaporate and between 70–30 hPa. Between the tropical tropopause and 70 hPa the QBO signature is relatively weak and seasonal variations dominate the variability of the simulated Junge layer. QBO effects on the upper lid of the tropical aerosol layer turn the quasi-static balance between processes maintaining the layer's vertical extent into a cyclic balance when considering this dominant mode of atmospheric variability. Global aerosol-interactive models without a QBO are only able to simulate the quasi-static balance state. To assess the global impact of stratospheric aerosols on climate processes, those partly nonlinear relationships between the QBO and stratospheric aerosols have to be taken into account.

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Trend and variability in ozone in the tropical lower stratosphere over 2.5 solar cycles observed by SAGE II and OSIRIS

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-16661-2013 ◽

2013 ◽

Vol 13 (6) ◽

pp. 16661-16697 ◽

Cited By ~ 3

Author(s):

C. E. Sioris ◽

C. A. McLinden ◽

V. E. Fioletov ◽

C. Adams ◽

J. M. Zawodny ◽

...

Keyword(s):

Lower Stratosphere ◽

Southern Oscillation ◽

Stratospheric Ozone ◽

Stratospheric Aerosol ◽

Tropopause Height ◽

Solar Cycles ◽

Quasi Biennial Oscillation ◽

Infrared Imager ◽

Biennial Oscillation ◽

Temporal Overlap

Abstract. We are able to replicate previously reported decadal trends in the tropical lower stratospheric ozone anomaly based on Stratospheric Aerosol and Gas Experiment II observations. We have extended the satellite-based ozone anomaly time series to the present (December 2012) by merging SAGE II with OSIRIS (Optical Spectrograph and Infrared Imager System) and correcting for the small bias (~0.5%) between them, determined using their temporal overlap of 4 yr. Analysis of the merged dataset (1984–2012) shows a statistically significant negative trend at all altitudes in the 18–25 km range reaching (−6.5 ± 1.8)% decade−1 at 18.5 km, with underlying strong variations due to El Niño–Southern Oscillation, the Quasi–Biennial Oscillation, and tropopause height.

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Trends in stratospheric ozone derived from merged SAGE II and Odin-OSIRIS satellite observations

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-14-7113-2014 ◽

2014 ◽

Vol 14 (6) ◽

pp. 7113-7140 ◽

Cited By ~ 4

Author(s):

A. E. Bourassa ◽

D. A. Degenstein ◽

W. J. Randel ◽

J. M. Zawodny ◽

E. Kyrölä ◽

...

Keyword(s):

Southern Oscillation ◽

Stratospheric Ozone ◽

Stratospheric Aerosol ◽

Basis Functions ◽

Quasi Biennial Oscillation ◽

Tropical Tropopause ◽

Infrared Imager ◽

Ozone Profile ◽

Biennial Oscillation

Abstract. Stratospheric ozone profile measurements from the Stratospheric Aerosol and Gas Experiment (SAGE) II satellite instrument (1984–2005) are combined with those from the Optical Spectrograph and InfraRed Imager System (OSIRIS) instrument on the Odin satellite (2001–Present) to quantify interannual variability and decadal trends in stratospheric ozone between 60° S and 60° N. These data are merged into a multi-instrument, long-term stratospheric ozone record (1984–present) by analyzing the measurements during the overlap period of 2002–2005 when both satellite instruments were operational. The variability in the deseasonalized time series is fit using multiple linear regression with predictor basis functions including the quasi-biennial oscillation, El Niño-Southern Oscillation index, solar activity proxy, and the pressure at the tropical tropopause, in addition to two linear trends (one before and one after 1997), from which the decadal trends in ozone are derived. From 1984–1997, there are statistically significant negative trends of 5–10% per decade throughout the stratosphere between approximately 30–50 km. From 1997–present, a statistically significant recovery of 3–8% per decade has taken place throughout most of the stratosphere with the notable exception between 40° S–40° N below approximately 22 km where the negative trend continues. The recovery is not significant between 25–35 km altitude when accounting for a conservative estimate of instrument drift.

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Trends in stratospheric ozone derived from merged SAGE II and Odin-OSIRIS satellite observations

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-6983-2014 ◽

2014 ◽

Vol 14 (13) ◽

pp. 6983-6994 ◽

Cited By ~ 44

Author(s):

A. E. Bourassa ◽

D. A. Degenstein ◽

W. J. Randel ◽

J. M. Zawodny ◽

E. Kyrölä ◽

...

Keyword(s):

Southern Oscillation ◽

Stratospheric Ozone ◽

Stratospheric Aerosol ◽

Basis Functions ◽

Quasi Biennial Oscillation ◽

Tropical Tropopause ◽

Infrared Imager ◽

Ozone Profile ◽

Biennial Oscillation

Abstract. Stratospheric ozone profile measurements from the Stratospheric Aerosol and Gas Experiment~(SAGE) II satellite instrument (1984–2005) are combined with those from the Optical Spectrograph and InfraRed Imager System (OSIRIS) instrument on the Odin satellite (2001–Present) to quantify interannual variability and decadal trends in stratospheric ozone between 60° S and 60° N. These data are merged into a multi-instrument, long-term stratospheric ozone record (1984–present) by analyzing the measurements during the overlap period of 2002–2005 when both satellite instruments were operational. The variability in the deseasonalized time series is fit using multiple linear regression with predictor basis functions including the quasi-biennial oscillation, El Niño–Southern Oscillation index, solar activity proxy, and the pressure at the tropical tropopause, in addition to two linear trends (one before and one after 1997), from which the decadal trends in ozone are derived. From 1984 to 1997, there are statistically significant negative trends of 5–10% per decade throughout the stratosphere between approximately 30 and 50 km. From 1997 to present, a statistically significant recovery of 3–8% per decade has taken place throughout most of the stratosphere with the notable exception between 40° S and 40° N below approximately 22 km where the negative trend continues. The recovery is not significant between 25 and 35 km altitudes when accounting for a conservative estimate of instrument drift.

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Quasi-biennial oscillation of the tropical stratospheric aerosol layer

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-14-16243-2014 ◽

2014 ◽

Vol 14 (11) ◽

pp. 16243-16290 ◽

Cited By ~ 3

Author(s):

R. Hommel ◽

C. Timmreck ◽

M. A. Giorgetta ◽

H. F. Graf

Keyword(s):

Climate Model ◽

Middle Atmosphere ◽

Stratospheric Aerosol ◽

Dominant Mode ◽

Static Balance ◽

Aerosol Layer ◽

Quasi Biennial Oscillation ◽

Volcanic Material ◽

Biennial Oscillation ◽

Stratospheric Aerosols

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Stratospheric ozone interannual variability (1995–2011) as observed by Lidar and Satellite at Mauna Loa Observatory, HI and Table Mountain Facility, CA

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-12-30825-2012 ◽

2012 ◽

Vol 12 (11) ◽

pp. 30825-30867

Author(s):

G. Kirgis ◽

T. Leblanc ◽

I. S. McDermid ◽

T. D. Walsh

Keyword(s):

Time Series ◽

Solar Cycle ◽

Interannual Variability ◽

Southern Oscillation ◽

Stratospheric Ozone ◽

Montreal Protocol ◽

Quasi Biennial Oscillation ◽

Mauna Loa ◽

Table Mountain ◽

Biennial Oscillation

Abstract. The Jet Propulsion Laboratory (JPL) lidars, at the Mauna Loa Observatory, Hawaii (MLO, 19.5° N, 155.6° W) and the JPL Table Mountain Facility (TMF, California, 34.5° N, 117.7° W), have been measuring vertical profiles of stratospheric ozone routinely since the early 1990's and late-1980s respectively. Interannual variability of ozone above these two sites was investigated using a multi-linear regression analysis on the deseasonalized monthly mean lidar and satellite time-series at 1 km intervals between 20 and 45 km from January 1995 to April 2011, a period of low volcanic aerosol loading. Explanatory variables representing the 11-yr solar cycle, the El Niño Southern Oscillation, the Quasi-Biennial Oscillation, the Eliassen–Palm flux, and horizontal and vertical transport were used. A new proxy, the mid-latitude ozone depleting gas index, which shows a decrease with time as an outcome of the Montreal Protocol, was introduced and compared to the more commonly used linear trend method. The analysis also compares the lidar time-series and a merged time-series obtained from the space-borne stratospheric aerosol and gas experiment II, halogen occultation experiment, and Aura-microwave limb sounder instruments. The results from both lidar and satellite measurements are consistent with recent model simulations which propose changes in tropical upwelling. Additionally, at TMF the ozone depleting gas index explains as much variance as the Quasi-Biennial Oscillation in the upper stratosphere. Over the past 17 yr a diminishing downward trend in ozone was observed before 2000 and a net increase, and sign of ozone recovery, is observed after 2005. Our results which include dynamical proxies suggest possible coupling between horizontal transport and the 11-yr solar cycle response, although a dataset spanning a period longer than one solar cycle is needed to confirm this result.

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Quasi-biennial oscillation in variations of vertical distribution of midlatitude stratospheric ozone and aerosol

10.1117/12.723236 ◽

2006 ◽

Author(s):

Vladimir Burlakov ◽

Oleg Bazhenov ◽

Sergey Dolgii ◽

Andrey Elnikov ◽

Vladimir Zuev ◽

...

Keyword(s):

Vertical Distribution ◽

Stratospheric Ozone ◽

Quasi Biennial Oscillation ◽

Biennial Oscillation

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Stratospheric aerosol evolution after Pinatubo simulated with a coupled size-resolved aerosol–chemistry–climate model, SOCOL-AERv1.0

Geoscientific Model Development ◽

10.5194/gmd-11-2633-2018 ◽

2018 ◽

Vol 11 (7) ◽

pp. 2633-2647 ◽

Cited By ~ 3

Author(s):

Timofei Sukhodolov ◽

Jian-Xiong Sheng ◽

Aryeh Feinberg ◽

Bei-Ping Luo ◽

Thomas Peter ◽

...

Keyword(s):

Climate Model ◽

Reference Model ◽

Volcanic Eruptions ◽

Global Scale ◽

Stratospheric Aerosol ◽

Atmospheric Effects ◽

Aerosol Layer ◽

Aerosol Chemistry ◽

Quasi Biennial Oscillation ◽

Aerosol Parameters

Abstract. We evaluate how the coupled aerosol–chemistry–climate model SOCOL-AERv1.0 represents the influence of the 1991 eruption of Mt. Pinatubo on stratospheric aerosol properties and atmospheric state. The aerosol module is coupled to the radiative and chemical modules and includes comprehensive sulfur chemistry and microphysics, in which the particle size distribution is represented by 40 size bins with radii spanning from 0.39 nm to 3.2 µm. SOCOL-AER simulations are compared with satellite and in situ measurements of aerosol parameters, temperature reanalyses, and ozone observations. In addition to the reference model configuration, we performed series of sensitivity experiments looking at different processes affecting the aerosol layer. An accurate sedimentation scheme is found to be essential to prevent particles from diffusing too rapidly to high and low altitudes. The aerosol radiative feedback and the use of a nudged quasi-biennial oscillation help to keep aerosol in the tropics and significantly affect the evolution of the stratospheric aerosol burden, which improves the agreement with observed aerosol mass distributions. The inclusion of van der Waals forces in the particle coagulation scheme suggests improvements in particle effective radius, although other parameters (such as aerosol longevity) deteriorate. Modification of the Pinatubo sulfur emission rate also improves some aerosol parameters, while it worsens others compared to observations. Observations themselves are highly uncertain and render it difficult to conclusively judge the necessity of further model reconfiguration. The model revealed problems in reproducing aerosol sizes above 25 km and also in capturing certain features of the ozone response. Besides this, our results show that SOCOL-AER is capable of predicting the most important global-scale atmospheric effects following volcanic eruptions, which is also a prerequisite for an improved understanding of solar geoengineering effects from sulfur injections to the stratosphere.

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