Modelling of aerosol and cloud processes in the summertime high Arctic

Warming in the Arctic region is significantly faster than the global average rate, and drives further climate changes. Clouds play a major role in the energy budget of the Arctic and are a key uncertainty in projections of Arctic climate change. The behaviour of aerosol particles and their interacti...

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Main Author: Price, Ruth Sarah
Format: Thesis
Language:English
Published: 2022
Subjects:
Online Access:https://etheses.whiterose.ac.uk/32308/
https://etheses.whiterose.ac.uk/32308/1/Price_RS_EarthAndEnvironment_PhD_2022.pdf
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spelling ftwhiterose:oai:etheses.whiterose.ac.uk:32308 2023-06-06T11:48:16+02:00 Modelling of aerosol and cloud processes in the summertime high Arctic Price, Ruth Sarah 2022-09 text https://etheses.whiterose.ac.uk/32308/ https://etheses.whiterose.ac.uk/32308/1/Price_RS_EarthAndEnvironment_PhD_2022.pdf en eng https://etheses.whiterose.ac.uk/32308/1/Price_RS_EarthAndEnvironment_PhD_2022.pdf Price, Ruth Sarah orcid:0000-0003-1981-9860 (2022) Modelling of aerosol and cloud processes in the summertime high Arctic. PhD thesis, University of Leeds. cc_by_nc_sa_4 Thesis NonPeerReviewed 2022 ftwhiterose 2023-04-13T22:32:33Z Warming in the Arctic region is significantly faster than the global average rate, and drives further climate changes. Clouds play a major role in the energy budget of the Arctic and are a key uncertainty in projections of Arctic climate change. The behaviour of aerosol particles and their interactions with clouds is particularly uncertain. Measurements of Arctic clouds have revealed a high sensitivity to perturbations in aerosol concentrations, but climate models show large differences in projections of the Arctic aerosol budget depending on parameterisations used for key processes, such as sea spray aerosol emissions, new particle formation, and wet removal. In this thesis, we use novel measurements of aerosol size distributions from the Arctic Ocean to evaluate Arctic aerosol and cloud processes in regional and global models. We examine primary marine organic carbon, biomass burning, wet removal and new particle formation. Our results show that there is a seasonal transition at the end of summer in the high Arctic from a free-tropospheric source of particles to a boundary layer source of particles. The transition is driven by declining photochemical rates at the end of summer, and coincides with the onset of iodic acid emissions which drive new particle formation in the high Arctic boundary layer during the sea ice freeze period. We show that simulating this transition improves model-observation agreement in the concentration of particles smaller than 100 nm diameter, something that could not be achieved by modifying the primary carbon emissions or wet removal in the model. However, we also reveal biases in the simulation of Arctic clouds in the regional model. Our results show that aerosol processes cannot be considered in isolation, but rather that to model the impact of the changing Arctic aerosol budget on the regional climate system, accurate simulations of cloud behaviour are required. Thesis Arctic Arctic Arctic Ocean Climate change Sea ice White Rose eTheses Online (Universities Leeds, Sheffield, York) Arctic Arctic Ocean
institution Open Polar
collection White Rose eTheses Online (Universities Leeds, Sheffield, York)
op_collection_id ftwhiterose
language English
description Warming in the Arctic region is significantly faster than the global average rate, and drives further climate changes. Clouds play a major role in the energy budget of the Arctic and are a key uncertainty in projections of Arctic climate change. The behaviour of aerosol particles and their interactions with clouds is particularly uncertain. Measurements of Arctic clouds have revealed a high sensitivity to perturbations in aerosol concentrations, but climate models show large differences in projections of the Arctic aerosol budget depending on parameterisations used for key processes, such as sea spray aerosol emissions, new particle formation, and wet removal. In this thesis, we use novel measurements of aerosol size distributions from the Arctic Ocean to evaluate Arctic aerosol and cloud processes in regional and global models. We examine primary marine organic carbon, biomass burning, wet removal and new particle formation. Our results show that there is a seasonal transition at the end of summer in the high Arctic from a free-tropospheric source of particles to a boundary layer source of particles. The transition is driven by declining photochemical rates at the end of summer, and coincides with the onset of iodic acid emissions which drive new particle formation in the high Arctic boundary layer during the sea ice freeze period. We show that simulating this transition improves model-observation agreement in the concentration of particles smaller than 100 nm diameter, something that could not be achieved by modifying the primary carbon emissions or wet removal in the model. However, we also reveal biases in the simulation of Arctic clouds in the regional model. Our results show that aerosol processes cannot be considered in isolation, but rather that to model the impact of the changing Arctic aerosol budget on the regional climate system, accurate simulations of cloud behaviour are required.
format Thesis
author Price, Ruth Sarah
spellingShingle Price, Ruth Sarah
Modelling of aerosol and cloud processes in the summertime high Arctic
author_facet Price, Ruth Sarah
author_sort Price, Ruth Sarah
title Modelling of aerosol and cloud processes in the summertime high Arctic
title_short Modelling of aerosol and cloud processes in the summertime high Arctic
title_full Modelling of aerosol and cloud processes in the summertime high Arctic
title_fullStr Modelling of aerosol and cloud processes in the summertime high Arctic
title_full_unstemmed Modelling of aerosol and cloud processes in the summertime high Arctic
title_sort modelling of aerosol and cloud processes in the summertime high arctic
publishDate 2022
url https://etheses.whiterose.ac.uk/32308/
https://etheses.whiterose.ac.uk/32308/1/Price_RS_EarthAndEnvironment_PhD_2022.pdf
geographic Arctic
Arctic Ocean
geographic_facet Arctic
Arctic Ocean
genre Arctic
Arctic
Arctic Ocean
Climate change
Sea ice
genre_facet Arctic
Arctic
Arctic Ocean
Climate change
Sea ice
op_relation https://etheses.whiterose.ac.uk/32308/1/Price_RS_EarthAndEnvironment_PhD_2022.pdf
Price, Ruth Sarah orcid:0000-0003-1981-9860 (2022) Modelling of aerosol and cloud processes in the summertime high Arctic. PhD thesis, University of Leeds.
op_rights cc_by_nc_sa_4
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