ORCID Profile
0000-0001-7821-7398
Current Organisations
Christ's College, University of Cambridge
,
University of Cambridge
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Publisher: Copernicus GmbH
Date: 04-03-2021
DOI: 10.5194/EGUSPHERE-EGU21-5684
Abstract: & & During the EPL (Etna Plume Lab) c aigns occurring in 2017 (EPL-RADIO) and 2019 (EPL-REFLECT),& gas& and aerosol measurements were performed& at Mount Etna (Sicily, Italy) to better assess the role of volcanic aerosols on both regional climate system and local health hazard. Gas related to volcanic emissions (such as SO2, H2S and others) were measured with low cost sensors (Alphasense) and HCl/SO2 ratio was validated in comparison to FTIR measurements. Aerosol physical and chemical properties were measured using low-cost Optical Particle Counters (OPCN2 from Alphasense) and filter measurements dedicated to organic acids, inorganic ions, soluble metals and total metals. During the EPL-REFLECT c aign, in-situ measurements were performed during: 1) the hike up, 2) a 2-hours period in the close vicinity of the Bocca Nuova crater, 3) the hike down and 4) in Milo (city on the flank of the Etna). Moreover, few OPCs were left unattended at the Bocca Nuova crater for two full days.& & & & & & & & & & Gas abundances at the crater-rim ranged from a few to 10& #8217 s ppmv SO2, with correlation to PM. The analysis of the 2 days measurements highlights a clear diurnal variation of aerosol size distributions. Indeed, at sunrise the total number and mass concentration is rapidly increasing from 15mg/m3 to 125mg/m3 in less than 2 hours. The variation of PM1/PM10 ratio shows a constant trend throughout the day except during a short period of time associated with high wind speeds. These results suggest that most aerosols are emitted through degassing and conversion of precursor gases to particles.& & & & Moreover, analysis of aerosol s les collected on filters showed a change in metal solubility from the s les collected at the crater and the s les collected after atmospheric transport in Milo. This may indicate that the volcanic plume underwent processing in the aqueous phase during transport.& &
Publisher: Copernicus GmbH
Date: 04-03-2021
DOI: 10.5194/EGUSPHERE-EGU21-12380
Abstract: & & The EPL-RADIO (Etna Plume Lab - Radioactive Aerosols and other source parameters for better atmospheric Dispersion and Impact estimatiOns) and EPL-REFLECT (near-source estimations of Radiative EFfects of voLcanic aErosols for Climate and air quality sTudies) projects, funded by the EC Horizon2020 ENVRIplus and EUROVOLC Transnational Access to European Observatories programmes, aim to advance the understanding of Mount Etna as a persistent source of atmospheric aerosols and its impact on the& radiative budget at proximal to regional spatial scales. Research was tackled by carrying out three c aigns in the summers of 2016, 2017 and 2019 to observe the volcanic plume produced by passive degassing, proximally and distally from the summit craters, using a wide array of remote sensing and in situ instruments. Diverse data are collected to explore the link of inner degassing mechanisms to the characterisation of near-source aerosol physicochemical properties and subsequent impacts on the atmosphere, environment and regional climate system.& & & & The results of the three c aigns have shown that the volcanic plume emitted by Mount Etna often mixes with aerosols of different origins generating a complex layered pattern. Frequent mineral dust transport events were observed by both LiDAR observations located at Serra La Nave (~7 km south-west from summit craters) and at a medium-term radiometric station, equipped with a Multi-Filter Rotating Shadowband Radiometer (MFRSR), and other instruments located at Milo (~10 km eastwards from the craters). LiDAR observations also allowed to study the coexistence of volcanic aerosols and biomass burning particles from local to more distal smoke plumes transports (like for the well-documented large fires from continental southern Italy in July 2017). In situ filter and optical particles counter measurements confirmed the presence of dust at Milo. The interaction/mixing among volcanic, wildfire, and dust aerosols occurs in an overall dynamical regime which appears to be dominated by sea breeze, which is strengthened by the presence of the dark volcanic lava flanks. Photolysis process also possibly play a role in determining the daily evolution of the aerosol plume.& & & & The sources of these different aerosol types are studied in detail using Lagrangian trajectories and meteorological data. Off-line radiative transfer calculations, using EPL-RADIO/REFLECT observations as input data, are used to estimate the relative radiative impact of the different aerosol types with respect to the background passive-degassing aerosols coming from Mount Etna.& &
Publisher: Copernicus GmbH
Date: 15-05-2023
DOI: 10.5194/EGUSPHERE-EGU23-15130
Abstract: Dimethyl sulfide (DMS), which originates from phytoplankton, is the major natural source of sulfur compounds in the atmosphere. The oxidation products of DMS can form aerosols, which contribute to the formation of clouds, making them important for rain and the radiative balance of the planet. Additionally, due to DMS naturally occurring above oceans, an oxidation product of DMS, methanesulfonic acid (MSA), has been used to determine sea ice extent in ice cores up to 300 years in the past. However, due to gaps in the oxidation pathway of DMS, there are large uncertainties in the modelling of MSA formation. The aim of this work is to reduce the uncertainties in the DMS oxidation pathway, improving the modelling of the major products.This project uses the KPP wrapper, BOXMOX, to compare box model outputs to chamber experiments from Albu et al. [1], Arsene et al. [2] and Ye et al. [3]. This comparison allows for an assessment of a near-explicit mechanism used in box models (the Master Chemical Mechanism) and a reduced mechanism useful for global models (CRI-Strat) regarding DMS oxidation in both low and high NOx environments. This work presents the outcomes from this assessment and recommendations for the mechanisms to improve their modelling of DMS oxidation.[1] Albu, M. Barnes, I. Becker, K. H. Patroescu-Klotz, I. Benter, T. Mocanu, R. In Simulation and Assessment of Chemical Processes in a Multiphase Environment, Barnes, I., Kharytonov, M. M., Eds. Springer Science: Dortdrecht, 2008, pp 501& #8211 .& & & [2] Arsene, C. Barnes, I. Becker, K. H. Mocanu, R. Atmos. Environ. 2001, 35, 3769& #8211 .[3] Ye, Q. Goss, M. B. Krechmer, J. E. Majluf, F. Zaytsev, A. Li, Y. Roscioli, J. R. Canagaratna, M. Keutsch, F. N. Heald, C. L. Kroll, J. H. Atmos. Chem. Phys., 2022, 22, 16003& #8211 .
Publisher: American Meteorological Society
Date: 07-2019
Abstract: The Aerosol, Radiation and Clouds in southern Africa (AEROCLO-sA) project investigates the role of aerosols on the regional climate of southern Africa. This is a unique environment where natural and anthropogenic aerosols and a semipermanent and widespread stratocumulus (Sc) cloud deck are found. The project aims to understand the dynamical, chemical, and radiative processes involved in aerosol–cloud–radiation interactions over land and ocean and under various meteorological conditions. The AEROCLO-sA field c aign was conducted in August and September of 2017 over Namibia. An aircraft equipped with active and passive remote sensors and aerosol in situ probes performed a total of 30 research flight hours. In parallel, a ground-based mobile station with state-of-the-art in situ aerosol probes and remote sensing instrumentation was implemented over coastal Namibia, and complemented by ground-based and balloonborne observations of the dynamical, thermodynamical, and physical properties of the lower troposphere. The focus laid on mineral dust emitted from salty pans and ephemeral riverbeds in northern Namibia, the advection of biomass-burning aerosol plumes from Angola subsequently transported over the Atlantic Ocean, and aerosols in the marine boundary layer at the ocean–atmosphere interface. This article presents an overview of the AEROCLO-sA field c aign with results from the airborne and surface measurements. These observations provide new knowledge of the interactions of aerosols and radiation in cloudy and clear skies in connection with the atmospheric dynamics over southern Africa. They will foster new advanced climate simulations and enhance the capability of spaceborne sensors, ultimately allowing a better prediction of future climate and weather in southern Africa.
Publisher: Copernicus GmbH
Date: 10-10-2023
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.TALANTA.2018.10.042
Abstract: The majority of atmospheric compounds measured in ice cores are inorganic, while analysis of their organic counterparts is a less well developed field. In recent years, understanding of formation, transport pathways and preservation of these compounds in ice and snow has improved, showing great potential for their use as biomarkers in ice cores. This study presents an optimised analytical technique for quantification of terrestrial and marine biosphere emissions of secondary organic aerosol (SOA) components and fatty acids in ice using HPLC-MS analysis. Concentrations of organic compounds in snow and ice are extremely low (typically ppb or ppt levels) and thus pre-concentration is required prior to analysis. Stir bar sorptive extraction (SBSE) showed potential for fatty acid compounds, but failed to recover SOA compounds. Solid phase extraction (SPE) recovered compounds across both organic groups but methods improving some recoveries came at the expense of others, and background contamination of fatty acids was high. Rotary evaporation was by far the best performing method across both SOA and fatty acid compounds, with average recoveries of 80%. The optimised preconcentration - HPLC-MS method achieved repeatability of 9% averaged for all compounds. In environmental s les, both concentrations and seasonal trends were observed to be reproducible when analysed in two different laboratories using the same method.
Publisher: American Geophysical Union (AGU)
Date: 20-05-2022
DOI: 10.1029/2022GL098770
Abstract: Marine ecosystems are important drivers of the global climate system. They emit volatile species into the atmosphere, involved in complex reaction cycles that influence the lifetime of greenhouse gases. Sea spray and marine biogenic aerosols affect Earth's climate by scattering solar radiation and controlling cloud microphysical properties. Here we show larger than expected marine biogenic emissions of butenes, three orders of magnitude higher than dimethyl sulfide, produced by the coastal part of the Benguela upwelling system, one of the most productive marine ecosystems in the world. We show that these emissions may contribute to new particle formation in the atmosphere within the marine boundary layer through production of Criegee intermediates that oxidize SO 2 to H 2 SO 4 . Butene emissions from the marine biota may affect air quality and climate through ozone, secondary organic aerosol, and cloud condensation nuclei formation even in pristine regions of the world. Our results indicate a potentially important role of butene emissions in marine particle formation that requires investigation in other regions.
Publisher: Elsevier BV
Date: 11-2023
Publisher: Copernicus GmbH
Date: 10-10-2023
Publisher: Copernicus GmbH
Date: 23-03-2020
DOI: 10.5194/EGUSPHERE-EGU2020-8337
Abstract: & & The aerosol properties of Mount Etna& #8217 s passive degassing plume and its short-term processes and radiative impact were studied in detail during the EPL-RADIO/REFLECT c aigns (summer 2016, 17 and 19), using a synergistic combination of remote-sensing and in situ observations, and radiative transfer modelling. Summit observations show extremely high particulate matter concentrations, with no evidence of secondary sulphate aerosols (SA) formation. Marked indications of secondary SA formation, i.e. by the conversion of volcanic SO2 emissions, are found at larger spatial scales (& km downwind craters). Using portable photometers, the first mapping of small-scale spatial variability of the average size and burden of volcanic aerosols is obtained, as well as different longitudinal, perpendicular and vertical sections. A substantial variability of the plume properties is found at these spatial scales, revealing that processes (e.g. new particle formation and coarse aerosols sedimentation) are at play, which are not represented with current regional scale modelling and satellite observations. Vertical structures of typical passive degassing plumes are also obtained using observations from a fixed LiDAR station constrained with quasi-simultaneous photometric observations. These observations are used as input to radiative transfer calculations, to obtain the shortwave top of the atmosphere (TOA) and surface radiative effects of the plume. Moreover, the radiative impact of Mount Etna& #8217 s emissions is studied using a medium-term time series (a few months during summer 2019) of coupled aerosol optical properties and surface radiative flux at a fixed station on Etna& #8217 s eastern flank. These are the first available estimations in the literature of the radiative impact of a passive degassing volcanic plume and are here critically discussed. Cases of co-existent volcanic aerosol layers and aerosols from other sources (Saharan dust transport events, wildfire from South Italy and marine aerosols) are also presented and discussed.& &
Publisher: Elsevier BV
Date: 03-2018
Publisher: American Chemical Society (ACS)
Date: 20-03-2019
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Chiara Giorio.