Comparing remotely sensed observations of clouds and aerosols in the Southern Ocean with climate model simulations.
Southern Ocean (SO) shortwave (SW) radiation biases are a common problem in contemporary general circulation models (GCMs), with most models exhibiting a tendency to absorb too much incoming SW radiation. These biases have been attributed to deficiencies in the representation of clouds during the au...
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ftunivcanter:oai:ir.canterbury.ac.nz:10092/101337 2023-05-15T18:25:17+02:00 Comparing remotely sensed observations of clouds and aerosols in the Southern Ocean with climate model simulations. Kuma, Peter 2020 application/pdf https://hdl.handle.net/10092/101337 https://doi.org/10.26021/10400 English en eng University of Canterbury https://hdl.handle.net/10092/101337 http://dx.doi.org/10.26021/10400 All Rights Reserved https://canterbury.libguides.com/rights/theses Theses / Dissertations 2020 ftunivcanter https://doi.org/10.26021/10400 2022-09-08T13:29:52Z Southern Ocean (SO) shortwave (SW) radiation biases are a common problem in contemporary general circulation models (GCMs), with most models exhibiting a tendency to absorb too much incoming SW radiation. These biases have been attributed to deficiencies in the representation of clouds during the austral summer months, either due to cloud cover or cloud albedo being too low. They affect simulation of New Zealand (NZ) and global climate in GCMs due to excessive heating of the sea surface and the effect on large-scale circulation. Therefore, improvement of GCMs is necessary for accurate prediction of future NZ and global climate. We performed ship-based lidar, radar, radiosonde and weather observations on two SO voyages and processed data from multiple past SO voyages. We used the observations and satellite measurements for evaluation of the Hadley Centre Global Environmental Model version 3 (HadGEM3) and contrasting with the Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2) to better understand the source of the problem. Due to the nature of lidar observations (the laser signal is quickly attenuated by clouds) they cannot be used for 1:1 comparison with a model without using a lidar simulator, which performs atmospheric radiative transfer calculations of the laser signal. We modify an existing satellite lidar simulator present in the Cloud Feedback Model Intercomparison Project (CFMIP) Observational Simulator Package (COSP) for use with the ground-based lidars used in our observations by modifying the geometry of the radiative transfer calculations, Mie and Rayleigh scattering of the laser signal. We document and make the modified lidar simulator available to the scientific community as part of a newly-developed lidar processing tool called the Automatic Lidar and Ceilometer Framework (ALCF), which enables unbiased comparison between lidar observations and models by performing calibration of lidar backscatter, noise removal and consistent cloud detection. We apply the lidar ... Other/Unknown Material Southern Ocean University of Canterbury, Christchurch: UC Research Repository Austral Merra ENVELOPE(12.615,12.615,65.816,65.816) New Zealand Southern Ocean |
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Open Polar |
collection |
University of Canterbury, Christchurch: UC Research Repository |
op_collection_id |
ftunivcanter |
language |
English |
description |
Southern Ocean (SO) shortwave (SW) radiation biases are a common problem in contemporary general circulation models (GCMs), with most models exhibiting a tendency to absorb too much incoming SW radiation. These biases have been attributed to deficiencies in the representation of clouds during the austral summer months, either due to cloud cover or cloud albedo being too low. They affect simulation of New Zealand (NZ) and global climate in GCMs due to excessive heating of the sea surface and the effect on large-scale circulation. Therefore, improvement of GCMs is necessary for accurate prediction of future NZ and global climate. We performed ship-based lidar, radar, radiosonde and weather observations on two SO voyages and processed data from multiple past SO voyages. We used the observations and satellite measurements for evaluation of the Hadley Centre Global Environmental Model version 3 (HadGEM3) and contrasting with the Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2) to better understand the source of the problem. Due to the nature of lidar observations (the laser signal is quickly attenuated by clouds) they cannot be used for 1:1 comparison with a model without using a lidar simulator, which performs atmospheric radiative transfer calculations of the laser signal. We modify an existing satellite lidar simulator present in the Cloud Feedback Model Intercomparison Project (CFMIP) Observational Simulator Package (COSP) for use with the ground-based lidars used in our observations by modifying the geometry of the radiative transfer calculations, Mie and Rayleigh scattering of the laser signal. We document and make the modified lidar simulator available to the scientific community as part of a newly-developed lidar processing tool called the Automatic Lidar and Ceilometer Framework (ALCF), which enables unbiased comparison between lidar observations and models by performing calibration of lidar backscatter, noise removal and consistent cloud detection. We apply the lidar ... |
format |
Other/Unknown Material |
author |
Kuma, Peter |
spellingShingle |
Kuma, Peter Comparing remotely sensed observations of clouds and aerosols in the Southern Ocean with climate model simulations. |
author_facet |
Kuma, Peter |
author_sort |
Kuma, Peter |
title |
Comparing remotely sensed observations of clouds and aerosols in the Southern Ocean with climate model simulations. |
title_short |
Comparing remotely sensed observations of clouds and aerosols in the Southern Ocean with climate model simulations. |
title_full |
Comparing remotely sensed observations of clouds and aerosols in the Southern Ocean with climate model simulations. |
title_fullStr |
Comparing remotely sensed observations of clouds and aerosols in the Southern Ocean with climate model simulations. |
title_full_unstemmed |
Comparing remotely sensed observations of clouds and aerosols in the Southern Ocean with climate model simulations. |
title_sort |
comparing remotely sensed observations of clouds and aerosols in the southern ocean with climate model simulations. |
publisher |
University of Canterbury |
publishDate |
2020 |
url |
https://hdl.handle.net/10092/101337 https://doi.org/10.26021/10400 |
long_lat |
ENVELOPE(12.615,12.615,65.816,65.816) |
geographic |
Austral Merra New Zealand Southern Ocean |
geographic_facet |
Austral Merra New Zealand Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
https://hdl.handle.net/10092/101337 http://dx.doi.org/10.26021/10400 |
op_rights |
All Rights Reserved https://canterbury.libguides.com/rights/theses |
op_doi |
https://doi.org/10.26021/10400 |
_version_ |
1766206613383806976 |