Tag: particle injection

Lee, H.; et al. (2019): The response of permafrost and high latitude ecosystems under large scale stratospheric aerosol injection and its termination

Lee, H.; Ekici, A.; Tjiputra, J.; Muri, H.; Chadburn, S.; Lawrence, D.; Schwinger, J. (2019): The response of permafrost and high latitude ecosystems under large scale stratospheric aerosol injection and its termination. In: Earth’s Future. DOI: 10.1029/2018EF001146.

“Climate engineering arises as one of the potential methods that could contribute to meeting the 1.5oC global warming target agreed under the Paris Agreement. We examine how permafrost and high latitude vegetation respond to large scale implementation of climate engineering. Specifically, we explore the impacts of applying the solar radiation management method of stratospheric aerosol injections (SAI) on permafrost temperature and the global extent of near‐surface permafrost area.”

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Niemeier, Ulrike; Schmidt, Hauke (2017): Changing transport processes in the stratosphere by radiative heating of sulfate aerosols

Niemeier, Ulrike; Schmidt, Hauke (2017): Changing transport processes in the stratosphere by radiative heating of sulfate aerosols. In Atmos. Chem. Phys 17 (24), pp.[nbsp]14871–14886. DOI: 10.5194/acp-17-14871-2017.

The injection of sulfur dioxide (SO2) into the stratosphere to form an artificial stratospheric aerosol layer is discussed as an option for solar radiation management. Sulfate aerosol scatters solar radiation and absorbs infrared radiation, which warms the stratospheric sulfur layer. Simulations with the general circulation model ECHAM5-HAM, including aerosol microphysics, show consequences of this warming, including changes of the quasi-biennial oscillation (QBO) in the tropics. The QBO slows down after an injection of 4 Tg(S) yr−1 and completely shuts down after an injection of 8 Tg(S) yr−1.

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Visioni, Daniele; et al. (2017): Quantification of sulfur deposition changes under sulfate geoengineering conditions

Visioni, Daniele; Pitari, Giovanni; Tuccella, Paolo; Curci, Gabriele (2017): Quantification of sulfur deposition changes under sulfate geoengineering conditions. In Atmos. Chem. Phys. Discuss., pp.[nbsp]1–42. DOI: 10.5194/acp-2017-987.

In this study we present results from a composition-climate coupled model (ULAQ-CCM) and a chemistry-transport model (GEOS-Chem), assuming a sustained lower stratospheric equatorial injection of 8 Tg-SO2/yr. Total S-deposition is found to globally increase by 5.2 % when sulfate geoengineering is deployed, with a clear interhemispheric asymmetry (3.8 % and 10.3 % in NH and SH, respectively). The latter is mostly due to the combination of a quasi-homogeneous tropospheric influx of sulfate from the stratosphere, and the highly inhomogeneous amount of anthropogenic sulfur emissions in the boundary layer (mostly located in the Northern Hemisphere).

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Cao, Long; et al. (2017): Simultaneous stabilization of global temperature and precipitation through cocktail geoengineering

Cao, Long; Duan, Lei; Bala, Govindasamy; Caldeira, Ken (2017): Simultaneous stabilization of global temperature and precipitation through cocktail geoengineering. In Geophys. Res. Lett. 37 (D6), p.[nbsp]117. DOI: 10.1002/2017GL074281.

“Here we investigate the possibility of stabilizing both global mean temperature and precipitation simultaneously by combining two geoengineering approaches: stratospheric sulfate aerosol increase (SAI) that deflects sunlight to space and cirrus cloud thinning (CCT) that enables more longwave radiation to escape to space.”

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Zhao, Liyun; et al. (2017): Glacier evolution in high-mountain Asia under stratospheric sulfate aerosol injection geoengineering

Zhao, Liyun; Yang, Yi; Cheng, Wei; Ji, Duoying; Moore, John C. (2017): Glacier evolution in high-mountain Asia under stratospheric sulfate aerosol injection geoengineering. In: Atmos. Chem. Phys. 17 (11), S. 6547–6564. DOI: 10.5194/acp-17-6547-2017[nbsp]

We examine this hypothesis for the glaciers in high-mountain Asia using a glacier mass balance model driven by climate simulations from the Geoengineering Model Intercomparison Project[nbsp](GeoMIP). The G3[nbsp]and G4[nbsp]schemes specify use of stratospheric sulfate aerosols to reduce the radiative forcing under the Representative Concentration Pathway (RCP)[nbsp]4.5 scenario for the 50 years between[nbsp]2020 and[nbsp]2069, and for a further 20[nbsp]years after termination of geoengineering. We estimate and compare glacier volume loss for every glacier in the region using a glacier model based on surface mass balance parameterization under climate projections from three Earth system models under[nbsp]G3, five models under[nbsp]G4, and six models under RCP4.5 and RCP8.5.

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Xia, Lili; et al. (2017): Impacts of Stratospheric Sulfate Geoengineering on Tropospheric Ozone

Xia, Lili; Nowack, Peer J.; Tilmes, Simone; Robock, Alan (2017): Impacts of Stratospheric Sulfate Geoengineering on Tropospheric Ozone. In: Atmos. Chem. Phys. Discuss., S. 1–38. DOI: 10.5194/acp-2017-434

Using a version of the Community Earth System Model from the National Center for Atmospheric Research that includes comprehensive tropospheric and stratospheric chemistry, we model both stratospheric sulfur injection and solar irradiance reduction schemes, with the aim of achieving equal levels of surface cooling relative to the Representative Concentration Pathway 6.0 scenario. This allows us to compare the impacts of sulfate aerosol and solar dimming on atmospheric ozone concentrations.

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Visioni, Daniele; et al. (2017): Sulfate geoengineering. A review of the factors controlling the needed injection of sulfur dioxide

Visioni, Daniele; Pitari, Giovanni; Aquila, Valentina (2017): Sulfate geoengineering. A review of the factors controlling the needed injection of sulfur dioxide. In Atmos. Chem. Phys 17 (6), pp.[nbsp]3879–3889. DOI: 10.5194/acp-17-3879-2017.

A review of previous studies on these effects is presented here, with an outline of the important factors that control the amount of sulfur dioxide to be injected in an eventual realization of the experiment. However, we need to take into account that atmospheric models used for these studies have shown a wide range of climate sensitivity and differences in the response to stratospheric volcanic aerosols. In addition, large uncertainties exist in the estimate of some of these aerosol effects.

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Smith, C. J.; et al. (2017): Impacts of stratospheric sulfate geoengineering on global solar photovoltaic and concentrating solar power resource. (in press)

Smith, C. J.; Crook, J. A.; Crook, R. (2017): Impacts of stratospheric sulfate geoengineering on global solar photovoltaic and concentrating solar power resource. (in press). In Journal of Applied Meteorology and Climatology.

“We analyze results from the HadGEM2-CCS climate model with stratospheric emissions of 10 Tg yr-1 of SO2, designed to offset global temperature rise by around 1°C. A reduction in concentrating solar power (CSP) output of 5.9% on average over land is shown under SSI compared to a baseline future climate change scenario (RCP4.5) due to a decrease in direct radiation.”

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Laakso, Anton; et al. (2017): Radiative and climate effects of stratospheric sulfur geoengineering using seasonally varying injection areas

Laakso, Anton; Korhonen, Hannele; Romakkaniemi, Sami; Kokkola, Harri (2017): Radiative and climate effects of stratospheric sulfur geoengineering using seasonally varying injection areas. In: Atmos. Chem. Phys. Discuss., S. 1–25. DOI: 10.5194/acp-2017-107.

In this study we employ alternative aerosol injection scenarios to investigate if the resulting radiative forcing can be optimized to be zonally more uniform without decreasing the global efficacy. We used a global aerosol-climate model together with an Earth system model to study the radiative and climate effects of stratospheric sulfur injection scenarios with different injection areas. According to our simulations, varying the SO2 injection area seasonally would result in a similar global mean cooling effect as injecting SO2 to the equator, but with a more uniform zonal distribution of shortwave radiative forcing.

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