Analysis of Arctic ice cloud properties using in-situ and remote sensing measurements
Cirrus clouds play an important role in the radiation balance of the atmosphere as theycan have a warming and cooling effect. The resulting net radiation effect depends ontheir micro- and macrophysical properties such as particle size, shape, and numberconcentration. The net warming or cooling effec...
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Luleå tekniska universitet, Rymdteknik
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ftluleatu:oai:DiVA.org:ltu-73710 2023-05-15T14:53:05+02:00 Analysis of Arctic ice cloud properties using in-situ and remote sensing measurements Analys av egenskaper av arktiska ismoln med hjälp av in situ och fjärrananlysmätningar Wolf, Veronika 2019 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-73710 eng eng Luleå tekniska universitet, Rymdteknik Luleå Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, 1402-1544 http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-73710 urn:isbn:978-91-7790-368-0 urn:isbn:978-91-7790-369-7 info:eu-repo/semantics/openAccess Arctic cirrus clouds ice particle properties in-situ measurements in-situ and lidar comparison Meteorology and Atmospheric Sciences Meteorologi och atmosfärforskning Doctoral thesis, comprehensive summary info:eu-repo/semantics/doctoralThesis text 2019 ftluleatu 2022-10-25T20:55:28Z Cirrus clouds play an important role in the radiation balance of the atmosphere as theycan have a warming and cooling effect. The resulting net radiation effect depends ontheir micro- and macrophysical properties such as particle size, shape, and numberconcentration. The net warming or cooling effect of clouds is still one of the biggest uncertainties, for example in climate models. For weather and climate models and remotesensing retrievals, precise knowledge of micro- and macrophysical cloud propertiesis therefore necessary. This is true in particular for Arctic cirrus clouds, where we still lack data and need better understanding. Yet, climate change affects high latitudes stronger than other regions. Thus, more knowledge about micro- and macrophysicalproperties of Arctic cirrus clouds is needed urgently. The focus of this thesis is on the retrieval of physical particle properties of Arcticice clouds. Balloon-borne in-situ measurements with concurrent lidar measurementshave been performedinKiruna in winter. The Balloon-borne IceCloud Particle Imager(B-ICI) takes images of ice particles directly inside the cloud. After recovery, the imagesare analysed to gain information about particle shape, size, area, and number concentrationand to determine the extinction coefficient. Whenever possible, concurrent lidar measurements have supplemented the balloonbornemeasurements. Due to balloon drift, there is a spatial and temporal distance betweenB-ICI and lidar. Hence, both instruments do not sample a cloud at the same timeand place. Taking into account the wind speed, it is possible to determine the time of lidarobservation at which the cloud segment probed by balloon was closest to the lidar. However, cloud homogeneity has to be assumed. The results from B-ICI are comparedto extinction coefficients and depolarization ratios obtained fromlidar measurements. Measurement results from B-ICI and lidar measurements are, despite the spatial andtemporal distance, very similar and thus comparable. Clouds consisting of small ... Doctoral or Postdoctoral Thesis Arctic Arktis* Climate change Luleå University of Technology Publications (DiVA) Arctic |
institution |
Open Polar |
collection |
Luleå University of Technology Publications (DiVA) |
op_collection_id |
ftluleatu |
language |
English |
topic |
Arctic cirrus clouds ice particle properties in-situ measurements in-situ and lidar comparison Meteorology and Atmospheric Sciences Meteorologi och atmosfärforskning |
spellingShingle |
Arctic cirrus clouds ice particle properties in-situ measurements in-situ and lidar comparison Meteorology and Atmospheric Sciences Meteorologi och atmosfärforskning Wolf, Veronika Analysis of Arctic ice cloud properties using in-situ and remote sensing measurements |
topic_facet |
Arctic cirrus clouds ice particle properties in-situ measurements in-situ and lidar comparison Meteorology and Atmospheric Sciences Meteorologi och atmosfärforskning |
description |
Cirrus clouds play an important role in the radiation balance of the atmosphere as theycan have a warming and cooling effect. The resulting net radiation effect depends ontheir micro- and macrophysical properties such as particle size, shape, and numberconcentration. The net warming or cooling effect of clouds is still one of the biggest uncertainties, for example in climate models. For weather and climate models and remotesensing retrievals, precise knowledge of micro- and macrophysical cloud propertiesis therefore necessary. This is true in particular for Arctic cirrus clouds, where we still lack data and need better understanding. Yet, climate change affects high latitudes stronger than other regions. Thus, more knowledge about micro- and macrophysicalproperties of Arctic cirrus clouds is needed urgently. The focus of this thesis is on the retrieval of physical particle properties of Arcticice clouds. Balloon-borne in-situ measurements with concurrent lidar measurementshave been performedinKiruna in winter. The Balloon-borne IceCloud Particle Imager(B-ICI) takes images of ice particles directly inside the cloud. After recovery, the imagesare analysed to gain information about particle shape, size, area, and number concentrationand to determine the extinction coefficient. Whenever possible, concurrent lidar measurements have supplemented the balloonbornemeasurements. Due to balloon drift, there is a spatial and temporal distance betweenB-ICI and lidar. Hence, both instruments do not sample a cloud at the same timeand place. Taking into account the wind speed, it is possible to determine the time of lidarobservation at which the cloud segment probed by balloon was closest to the lidar. However, cloud homogeneity has to be assumed. The results from B-ICI are comparedto extinction coefficients and depolarization ratios obtained fromlidar measurements. Measurement results from B-ICI and lidar measurements are, despite the spatial andtemporal distance, very similar and thus comparable. Clouds consisting of small ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Wolf, Veronika |
author_facet |
Wolf, Veronika |
author_sort |
Wolf, Veronika |
title |
Analysis of Arctic ice cloud properties using in-situ and remote sensing measurements |
title_short |
Analysis of Arctic ice cloud properties using in-situ and remote sensing measurements |
title_full |
Analysis of Arctic ice cloud properties using in-situ and remote sensing measurements |
title_fullStr |
Analysis of Arctic ice cloud properties using in-situ and remote sensing measurements |
title_full_unstemmed |
Analysis of Arctic ice cloud properties using in-situ and remote sensing measurements |
title_sort |
analysis of arctic ice cloud properties using in-situ and remote sensing measurements |
publisher |
Luleå tekniska universitet, Rymdteknik |
publishDate |
2019 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-73710 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Arktis* Climate change |
genre_facet |
Arctic Arktis* Climate change |
op_relation |
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, 1402-1544 http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-73710 urn:isbn:978-91-7790-368-0 urn:isbn:978-91-7790-369-7 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766324502393782272 |