Global modelling of ice-nucleating particles and impacts on mixed-phase clouds
The process of cloud glaciation strongly alters the properties of mixed-phase clouds. Between 0C to about -37C, cloud liquid droplets can either exist in the liquid phase in metastable state known as supercooling, or they can be composed of solid ice crystals. For a liquid droplet to freeze at these...
Main Author: | |
---|---|
Format: | Thesis |
Language: | English |
Published: |
University of Leeds
2017
|
Subjects: | |
Online Access: | https://etheses.whiterose.ac.uk/19602/ https://etheses.whiterose.ac.uk/19602/1/Vergara-Temprado_PhD_Thesis.pdf |
id |
ftwhiterose:oai:etheses.whiterose.ac.uk:19602 |
---|---|
record_format |
openpolar |
spelling |
ftwhiterose:oai:etheses.whiterose.ac.uk:19602 2023-05-15T18:25:16+02:00 Global modelling of ice-nucleating particles and impacts on mixed-phase clouds Vergara Temprado, Jesus 2017-12 text https://etheses.whiterose.ac.uk/19602/ https://etheses.whiterose.ac.uk/19602/1/Vergara-Temprado_PhD_Thesis.pdf en eng University of Leeds https://etheses.whiterose.ac.uk/19602/1/Vergara-Temprado_PhD_Thesis.pdf Vergara Temprado, Jesus (2017) Global modelling of ice-nucleating particles and impacts on mixed-phase clouds. PhD thesis, University of Leeds. cc_by_nc_sa CC-BY-NC-SA Thesis NonPeerReviewed 2017 ftwhiterose 2023-01-30T21:24:53Z The process of cloud glaciation strongly alters the properties of mixed-phase clouds. Between 0C to about -37C, cloud liquid droplets can either exist in the liquid phase in metastable state known as supercooling, or they can be composed of solid ice crystals. For a liquid droplet to freeze at these temperatures, the action of an external agent, known as ice-nucleating particle (INP) is needed. The atmospheric distribution of ice-nucleating particles was simulated in past studies as a function of the aerosol concentration, however, new experimental information about the ice- nucleating ability of different aerosol species and several new atmospheric measurements of INP are now available to be used in models. In this thesis, I use this new information to develop a global atmospheric model of the distribution of ice-nucleating particles to assess the relative importance of mineral dust, marine organic aerosols and black carbon for contributing to atmospheric concentrations of INPs. The model is evaluated against several datasets of INP concentrations measured in the atmosphere to test its realism and locate regions of the world where additional currently missing sources of INP could be important. The results show that feldspar aerosols dominate the atmospheric INP concentration for most parts of the globe, whereas marine organic aerosols are more relevant in the remote Southern Ocean. Black carbon particles, in contrast, seem not to play a substantial role when new estimates of its ice-nucleating ability are used. With the information obtained by this model, I explore whether the representation of ice-nucleating particles in climate models plays a role in the Southern Ocean radiative bias. This bias is related to modelled clouds reflecting too-little solar radiation, causing large errors in sea-surface temperatures and atmospheric circulations. I combine cloud-resolving simulations over regions of 1000 km with the new estimates of the INP concentration in remote regions to show that the simulated clouds reflect ... Thesis Southern Ocean White Rose eTheses Online (Universities Leeds, Sheffield, York) Southern Ocean |
institution |
Open Polar |
collection |
White Rose eTheses Online (Universities Leeds, Sheffield, York) |
op_collection_id |
ftwhiterose |
language |
English |
description |
The process of cloud glaciation strongly alters the properties of mixed-phase clouds. Between 0C to about -37C, cloud liquid droplets can either exist in the liquid phase in metastable state known as supercooling, or they can be composed of solid ice crystals. For a liquid droplet to freeze at these temperatures, the action of an external agent, known as ice-nucleating particle (INP) is needed. The atmospheric distribution of ice-nucleating particles was simulated in past studies as a function of the aerosol concentration, however, new experimental information about the ice- nucleating ability of different aerosol species and several new atmospheric measurements of INP are now available to be used in models. In this thesis, I use this new information to develop a global atmospheric model of the distribution of ice-nucleating particles to assess the relative importance of mineral dust, marine organic aerosols and black carbon for contributing to atmospheric concentrations of INPs. The model is evaluated against several datasets of INP concentrations measured in the atmosphere to test its realism and locate regions of the world where additional currently missing sources of INP could be important. The results show that feldspar aerosols dominate the atmospheric INP concentration for most parts of the globe, whereas marine organic aerosols are more relevant in the remote Southern Ocean. Black carbon particles, in contrast, seem not to play a substantial role when new estimates of its ice-nucleating ability are used. With the information obtained by this model, I explore whether the representation of ice-nucleating particles in climate models plays a role in the Southern Ocean radiative bias. This bias is related to modelled clouds reflecting too-little solar radiation, causing large errors in sea-surface temperatures and atmospheric circulations. I combine cloud-resolving simulations over regions of 1000 km with the new estimates of the INP concentration in remote regions to show that the simulated clouds reflect ... |
format |
Thesis |
author |
Vergara Temprado, Jesus |
spellingShingle |
Vergara Temprado, Jesus Global modelling of ice-nucleating particles and impacts on mixed-phase clouds |
author_facet |
Vergara Temprado, Jesus |
author_sort |
Vergara Temprado, Jesus |
title |
Global modelling of ice-nucleating particles and impacts on mixed-phase clouds |
title_short |
Global modelling of ice-nucleating particles and impacts on mixed-phase clouds |
title_full |
Global modelling of ice-nucleating particles and impacts on mixed-phase clouds |
title_fullStr |
Global modelling of ice-nucleating particles and impacts on mixed-phase clouds |
title_full_unstemmed |
Global modelling of ice-nucleating particles and impacts on mixed-phase clouds |
title_sort |
global modelling of ice-nucleating particles and impacts on mixed-phase clouds |
publisher |
University of Leeds |
publishDate |
2017 |
url |
https://etheses.whiterose.ac.uk/19602/ https://etheses.whiterose.ac.uk/19602/1/Vergara-Temprado_PhD_Thesis.pdf |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
https://etheses.whiterose.ac.uk/19602/1/Vergara-Temprado_PhD_Thesis.pdf Vergara Temprado, Jesus (2017) Global modelling of ice-nucleating particles and impacts on mixed-phase clouds. PhD thesis, University of Leeds. |
op_rights |
cc_by_nc_sa |
op_rightsnorm |
CC-BY-NC-SA |
_version_ |
1766206582637461504 |