Experimental studies of ice particle formation with tropospheric relevance

In their fourth assessment report, the Intergovernmental Panel on Climate Change points out the influence of particles suspended in air, known as an aerosol, as the main uncertainty in the understanding of the climate system. Aerosols affect climate in a number of ways. The so-called direct effect i...

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Main Author: Svensson, Erik
Format: Doctoral or Postdoctoral Thesis
Language:English
Published: 2008
Subjects:
heterogeneous nucleation
water
freezing
cloud droplets
levitation
electrodynamic balance
light scattering
oxalic acid
kaolinite
dinitrogen pentoxide
Arctic
Online Access:http://hdl.handle.net/2077/18317
id ftunivgoeteborg:oai:gupea.ub.gu.se:2077/18317
record_format openpolar
spelling ftunivgoeteborg:oai:gupea.ub.gu.se:2077/18317 2023-10-29T02:33:01+01:00 Experimental studies of ice particle formation with tropospheric relevance Svensson, Erik 2008-11-07T12:58:38Z application/pdf http://hdl.handle.net/2077/18317 eng eng I. Svensson, E.A., Badiei, S., Hallquist, M., Pettersson, J.B.C, “Freezing of evaporating oxalic acid solution droplets”, Submitted to Journal of Physical Chemistry A. II. Svensson, E. A, Pettersson J. B. C., “Evaporation freezing of water droplets: influence of initial oxalic acid concentration”, Manuscript for Geophysical Research Letters. III. Svensson, E. A., Delval, C., von Hessberg, P., Johnson, M. S., Pettersson, J. B. C, “Freezing of water droplets colliding with kaolinite particles”, Submitted to Atmospheric Chemistry and Physics. IV. Olofson, K. G. F., Svensson, E. A., Witt, G., Pettersson, J. B. C., “Arctic aerosol and clouds studied by bistatic lidar technique”, Submitted to Journal of Geophysical Research: Atmospheres. V. Romero Lejonthun, L. S. E., Svensson, E. A., Andersson, P. U. and Pettersson, J. B. C., “Formation of adsorbed layers by deposition of dinitrogen pentoxide, nitric acid and water on graphite”, Submitted to Journal of Physical Chemistry C. ISBN 978-91-628-7644-9 http://hdl.handle.net/2077/18317 heterogeneous nucleation water freezing cloud droplets levitation electrodynamic balance light scattering oxalic acid kaolinite dinitrogen pentoxide Text Doctoral thesis Doctor of Philosophy 2008 ftunivgoeteborg 2023-10-04T21:22:46Z In their fourth assessment report, the Intergovernmental Panel on Climate Change points out the influence of particles suspended in air, known as an aerosol, as the main uncertainty in the understanding of the climate system. Aerosols affect climate in a number of ways. The so-called direct effect is due to scattering and absorption of light passing through the atmosphere. The indirect effects are caused by aerosol-cloud interactions. The formation of clouds requires pre-existing particles for the water vapor to condense onto. The number concentration, size distribution and chemical properties, as well as the atmospheric dynamics, determine the development of a cloud. Clouds reflect incoming solar radiation into space, but also trap heat radiation from the ground. Ice formation in clouds affects their interaction with radiation, their lifetime, and it may induce the formation of precipitation. Cloud droplets can be supercooled to very low temperatures, and droplets of pure water freeze by homogeneous nucleation at temperatures below -33°C. However, droplet freezing can be facilitated by solid particles, a process called heterogeneous freezing. This thesis presents results from laboratory studies of ice formation processes of atmospheric relevance. The overall aim has been to improve the understanding of ice cloud microphysics. An electrodynamic balance was developed and used to study freezing of single levitated droplets in the micrometer size range. Evaporation freezing of oxalic acid solution droplets was investigated at temperatures from 236 to 248 K. Freezing was observed in the whole temperature range, but at the higher temperatures freezing took place after a period of droplet evaporation. The process was explained by the formation of oxalic acid precipitates as the droplets evaporated, which in a subsequent step induced freezing. The potential importance of the process in atmosphere is currently unknown, but it may explain observed freezing in evaporating cloud and further studies should elucidate if the ... Doctoral or Postdoctoral Thesis Arctic University of Gothenburg: GUPEA (Gothenburg University Publications Electronic Archive)
institution Open Polar
collection University of Gothenburg: GUPEA (Gothenburg University Publications Electronic Archive)
op_collection_id ftunivgoeteborg
language English
topic heterogeneous nucleation
water
freezing
cloud droplets
levitation
electrodynamic balance
light scattering
oxalic acid
kaolinite
dinitrogen pentoxide
spellingShingle heterogeneous nucleation
water
freezing
cloud droplets
levitation
electrodynamic balance
light scattering
oxalic acid
kaolinite
dinitrogen pentoxide
Svensson, Erik
Experimental studies of ice particle formation with tropospheric relevance
topic_facet heterogeneous nucleation
water
freezing
cloud droplets
levitation
electrodynamic balance
light scattering
oxalic acid
kaolinite
dinitrogen pentoxide
description In their fourth assessment report, the Intergovernmental Panel on Climate Change points out the influence of particles suspended in air, known as an aerosol, as the main uncertainty in the understanding of the climate system. Aerosols affect climate in a number of ways. The so-called direct effect is due to scattering and absorption of light passing through the atmosphere. The indirect effects are caused by aerosol-cloud interactions. The formation of clouds requires pre-existing particles for the water vapor to condense onto. The number concentration, size distribution and chemical properties, as well as the atmospheric dynamics, determine the development of a cloud. Clouds reflect incoming solar radiation into space, but also trap heat radiation from the ground. Ice formation in clouds affects their interaction with radiation, their lifetime, and it may induce the formation of precipitation. Cloud droplets can be supercooled to very low temperatures, and droplets of pure water freeze by homogeneous nucleation at temperatures below -33°C. However, droplet freezing can be facilitated by solid particles, a process called heterogeneous freezing. This thesis presents results from laboratory studies of ice formation processes of atmospheric relevance. The overall aim has been to improve the understanding of ice cloud microphysics. An electrodynamic balance was developed and used to study freezing of single levitated droplets in the micrometer size range. Evaporation freezing of oxalic acid solution droplets was investigated at temperatures from 236 to 248 K. Freezing was observed in the whole temperature range, but at the higher temperatures freezing took place after a period of droplet evaporation. The process was explained by the formation of oxalic acid precipitates as the droplets evaporated, which in a subsequent step induced freezing. The potential importance of the process in atmosphere is currently unknown, but it may explain observed freezing in evaporating cloud and further studies should elucidate if the ...
format Doctoral or Postdoctoral Thesis
author Svensson, Erik
author_facet Svensson, Erik
author_sort Svensson, Erik
title Experimental studies of ice particle formation with tropospheric relevance
title_short Experimental studies of ice particle formation with tropospheric relevance
title_full Experimental studies of ice particle formation with tropospheric relevance
title_fullStr Experimental studies of ice particle formation with tropospheric relevance
title_full_unstemmed Experimental studies of ice particle formation with tropospheric relevance
title_sort experimental studies of ice particle formation with tropospheric relevance
publishDate 2008
url http://hdl.handle.net/2077/18317
genre Arctic
genre_facet Arctic
op_relation I. Svensson, E.A., Badiei, S., Hallquist, M., Pettersson, J.B.C, “Freezing of evaporating oxalic acid solution droplets”, Submitted to Journal of Physical Chemistry A.
II. Svensson, E. A, Pettersson J. B. C., “Evaporation freezing of water droplets: influence of initial oxalic acid concentration”, Manuscript for Geophysical Research Letters.
III. Svensson, E. A., Delval, C., von Hessberg, P., Johnson, M. S., Pettersson, J. B. C, “Freezing of water droplets colliding with kaolinite particles”, Submitted to Atmospheric Chemistry and Physics.
IV. Olofson, K. G. F., Svensson, E. A., Witt, G., Pettersson, J. B. C., “Arctic aerosol and clouds studied by bistatic lidar technique”, Submitted to Journal of Geophysical Research: Atmospheres.
V. Romero Lejonthun, L. S. E., Svensson, E. A., Andersson, P. U. and Pettersson, J. B. C., “Formation of adsorbed layers by deposition of dinitrogen pentoxide, nitric acid and water on graphite”, Submitted to Journal of Physical Chemistry C.
ISBN 978-91-628-7644-9
http://hdl.handle.net/2077/18317
_version_ 1781054951205634048

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