Schlagwort: aerosols

Yue, Chao; et al. (2021): Insensitivity of mass loss of Icelandic Vatnajökull ice cap to solar geoengineering

Yue, Chao; Schmidt, Louise Steffensen; Zhao, Liyun; Wolovick, Michael; Moore, John C. (2021): Insensitivity of mass loss of Icelandic Vatnajökull ice cap to solar geoengineering. [in review]. In The Cryosphere Discuss. [preprint]. DOI: 10.5194/tc-2021-318.

„Geoengineering by stratospheric aerosol injection (SAI) may reduce the mass loss from Vatnajökull ice cap (VIC), Iceland, by slowing surface temperature rise, despite relative increases in ocean heat flux brought by the Atlantic Meridional Circulation (AMOC). Although surface mass balance (SMB) is affected by the local climate, the sea level contribution is also dependent on ice dynamics. We use the Parallel Ice Sheet Model (PISM) to estimate the VIC mass balance under the CMIP5 (Coupled Model Intercomparison Project Phase 5) RCP4.5, 8.5 and GeoMIP (Geoengineering Model Intercomparison Project) G4 SAI scenarios during the period 1982–2089. The G4 scenario is based on the RCP4.5, but with additional 5 Tg yr−1 of SO2 injection to the lower stratosphere. By 2089, G4 reduces VIC mass loss from 16 % lost under RCP4.5, to 12 %. Ice dynamics are important for ice cap loss rates, increasing mass loss for RCP4.5 and G4 by 1/4 to 1/3 compared with excluding ice dynamics, but making no difference to mass loss difference under the scenarios. We find that VIC dynamics are remarkably insensitive to climate forcing partly because of AMOC compensation to SMB and low rates of iceberg calving making ocean forcing close to negligible. But the exceptionally high geothermal heat flow under parts of the ice cap which produces correspondingly high basal melt rates means that surface forcing changes are relatively less important than for glaciers with lower geothermal heat flow.“

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University of York (2021): Geoengineering: A climate of uncertainty. Youth guide and policy brief on geoengineering

University of York (2021): Geoengineering: A climate of uncertainty. Youth guide and policy brief on geoengineering. Available online at https://www.york.ac.uk/media/educationalstudies/documents/research/uyseg/best/Geoengineering%20-%20a%20climate%20of%20uncertainty.pdf.

„The purpose of this guide is to introduce key ideas and questions about geoengineering in order to spark a conversation about intervention in the Earth’s climate system in the context of the range of possible responses to the climate crisis. It has been written by young people, for young people.“

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Tang, Weiyi; et al. (2021): Widespread phytoplankton blooms triggered by 2019-2020 Australian wildfires

Tang, Weiyi; Llort, Joan; Weis, Jakob; Perron, Morgane M. G.; Basart, Sara; Li, Zuchuan et al. (2021): Widespread phytoplankton blooms triggered by 2019-2020 Australian wildfires. In Nature 597 (7876), pp. 370–375. DOI: 10.1038/s41586-021-03805-8.

„Droughts and climate-change-driven warming are leading to more frequent and intense wildfires1,2,3, arguably contributing to the severe 2019–2020 Australian wildfires4. The environmental and ecological impacts of the fires include loss of habitats and the emission of substantial amounts of atmospheric aerosols5,6,7. Aerosol emissions from wildfires can lead to the atmospheric transport of macronutrients and bio-essential trace metals such as nitrogen and iron, respectively8,9,10. It has been suggested that the oceanic deposition of wildfire aerosols can relieve nutrient limitations and, consequently, enhance marine productivity11,12, but direct observations are lacking. Here we use satellite and autonomous biogeochemical Argo float data to evaluate the effect of 2019–2020 Australian wildfire aerosol deposition on phytoplankton productivity.“

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Bonou, Frederic; et al. (2021): Stratospheric Sulfate Aerosols impacts on West African monsoon precipitation using GeoMIP Models

Bonou, Frederic; Da-Allada, Casimir Yelognisse; Baloïtcha, Ezinvi; Alamou, Eric; Biao, Eliezer Iboukoun; Zandagba, Josué et al. (2021): Stratospheric Sulfate Aerosols impacts on West African monsoon precipitation using GeoMIP Models. In Earth and Space Science Open Archive. DOI: 10.1002/essoar.10507841.1.

„Stratospheric Aerosol Geoengineering (SAG) is proposed to offset global warming; the use of this approach can impact the hydrological cycle. We use simulations from Coupled Model Intercomparison Project (CMIP5) and Geoengineering Model Intercomparison Project (G3 simulation) to analyze the impacts of SAG on precipitation (P) and to determine its responsible causes in West Africa and Sahel region.“

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Visioni, Daniele; et al. (2021): Reduced poleward transport due to stratospheric heating under geoengineering

Visioni, Daniele; Simpson, Isla Ruth; MacMartin, Douglas G.; Richter, Jadwiga H.; Kravitz, Ben; Lee, Walker (2021): Reduced poleward transport due to stratospheric heating under geoengineering. DOI: 10.1002/essoar.10503509.1.

„Simulating the complex aerosol microphysical processes in a comprehensive Earth System Model can be very computationally intensive and therefore many models utilize a modal approach, where aerosol size distributions are represented by observations-derived lognormal functions. This approach has been shown to yield satisfactory results in a large array of applications, but there may be cases where the simplification in this approach may produce some shortcomings. In this work we show specific conditions under which the current approximations used in modal approaches might yield some incorrect answers. Using results from the Community Earth System Model v1 (CESM1) Geoengineering Large Ensemble (GLENS) project, we analyze the effects in the troposphere of a continuous increasing load of sulfate aerosols in the stratosphere, with the aim of counteracting the surface warming produced by non-mitigated increasing greenhouse gases concentration between 2020–2100.“

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Yue, Chao; et al. (2021): Vatnajökull mass loss under solar geoengineering due to the North Atlantic meridional overturning circulation

Yue, Chao; Schmidt, Louise Steffensen; Zhao, Liyun; Wolovick, Michael; Moore, John C. (2021): Vatnajökull mass loss under solar geoengineering due to the North Atlantic meridional overturning circulation. In Earth’s Future. DOI: 10.1029/2021EF002052.

„The objective of solar geoengineering by stratospheric aerosol injection (SAI) is to lower global temperatures, but it may also have adverse side-effects. Iceland is situated close to the overturning regions of the Atlantic Meridional Overturning Circulation (AMOC) that warms the North Atlantic area. Hence this may be one region where reduced irradiance by SAI may not be successful in reducing impacts from greenhouse gas warming. We examine this proposition by estimating how the Icelandic Vatnajökull ice cap (VIC) surface mass balance (SMB) and surface runoff changes in response to greenhouse gas and solar geoengineering scenarios over the period 1982-2089.“

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Huynh, Han N.; McNeill, V. Faye (2021): Heterogeneous Reactivity of HCl on CaCO 3 Aerosols at Stratospheric Temperature

Huynh, Han N.; McNeill, V. Faye (2021): Heterogeneous Reactivity of HCl on CaCO 3 Aerosols at Stratospheric Temperature. In ACS Earth Space Chem. DOI: 10.1021/acsearthspacechem.1c00151.

„We studied the kinetics of HCl uptake on airborne CaCO3 aerosols at stratospheric temperature, 207 ± 3 K, by performing experiments under dry conditions using an aerosol flow tube coupled with a custom-built quadrupole chemical ionization mass spectrometer (CIMS) for HCl detection.“

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Laakso, Anton; et al. (2021): Dependency of the impacts of geoengineering on the stratospheric sulfur injection strategy part 1: Intercomparison of modal and sectional aerosol module

Laakso, Anton; Niemeier, Ulrike; Visioni, Daniele; Tilmes, Simone; Kokkola, Harri (2021): Dependency of the impacts of geoengineering on the stratospheric sulfur injection strategy part 1: Intercomparison of modal and sectional aerosol module. In Atmospheric Chemistry and Physics Discussions, pp. 1–36. DOI: 10.5194/acp-2021-526.

„Here, we have studied different spatio-temporal injections strategies with different injection magnitudes by using the aerosol-climate model ECHAM-HAMMOZ with two aerosol microphysical modules: the sectional module SALSA and the modal module M7.“

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Neukermans, Armand; et al. (2021): Methods for Dispersal of Precipitated Calcium Carbonate for Stratospheric Aerosol Injection

Neukermans, Armand; Cooper, Gary; Foster, Jack; Galbraith, Lee; Jain, Sudhanshu (2021): Methods for Dispersal of Precipitated Calcium Carbonate for Stratospheric Aerosol Injection. In Journal of Atmospheric and Oceanic Technology. DOI: 10.1175/JTECH-D-20-0205.1.

„Two methods for the laboratory-scale formation of aerosols of nanosized particles of precipitated calcium carbonate (PCC), for potential use in Stratospheric Aerosol Injection (SAI), a Solar Radiation Management (SRM) technique, are described“

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