Sensitivity of modeled arctic mixed-phase stratocumulus to cloud condensation and ice nuclei over regionally varying surface conditions
A two-moment microphysics scheme implemented in the polar version of the mesoscale model MM5 is used to simulate a mixed-phase stratocumulus deck observed during the Fall 2004 Mixed-Phase Arctic Cloud Experiment (MPACE). In situ aircraft instrumentation and remote sensors gathered extensive microphy...
Published in: | Journal of Geophysical Research: Atmospheres |
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Language: | English |
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American Geophysical Union
2008
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Online Access: | http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-084 https://doi.org/10.1029/2007JD008729 |
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ftncar:oai:drupal-site.org:articles_6519 2023-10-01T03:53:27+02:00 Sensitivity of modeled arctic mixed-phase stratocumulus to cloud condensation and ice nuclei over regionally varying surface conditions Morrison, Hugh (author) Pinto, James (author) Curry, Judith (author) McFarquhar, Greg (author) 2008-03-04 application/pdf http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-084 https://doi.org/10.1029/2007JD008729 en eng American Geophysical Union Journal of Geophysical Research-Atmospheres http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-084 doi:10.1029/2007JD008729 ark:/85065/d7319w3x An edited version of this paper was published by AGU. Copyright 2008 American Geophysical Union. Clouds Mixed-phase Arctic Text article 2008 ftncar https://doi.org/10.1029/2007JD008729 2023-09-04T18:27:23Z A two-moment microphysics scheme implemented in the polar version of the mesoscale model MM5 is used to simulate a mixed-phase stratocumulus deck observed during the Fall 2004 Mixed-Phase Arctic Cloud Experiment (MPACE). In situ aircraft instrumentation and remote sensors gathered extensive microphysical and radiative data that serve as a testbed for the model. Model results are reasonably similar to observations in terms of the liquid microphysical properties, while the ice microphysical properties are more significantly biased, especially the ice crystal concentration. Sensitivity tests examine the impact of increased cloud condensation and ice nucleus concentrations. Increasing the concentration of cloud condensation nuclei to values typical for polluted 'Arctic haze' conditions substantially reduces the mean droplet size, but has little impact on the downwelling longwave flux because the cloud already emits as a blackbody (except near the Arctic Ocean pack ice edge). However, the smaller droplet size does lead to a slight increase in liquid water path and more significant decrease (~50%) in the ice water path and snowfall rate due to reduced collision-coalescence and riming of snow by droplets. Increasing the ice nucleus concentration specified from MPACE observations by 1 - 2 orders of magnitude produces a substantial reduction in liquid water path and downwelling longwave flux at the surface over interior northern Alaska, but has less impact over the open ocean and coastal regions. However, a large discrepancy between the observed ice nucleus and ice crystal concentrations, leading to the under-prediction of simulated crystal concentration, also suggests that additional ice initiation mechanisms (not included in current models) may have occurred in the real cloud layer. Article in Journal/Newspaper Arctic Arctic Ocean Alaska OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Arctic Arctic Ocean Journal of Geophysical Research: Atmospheres 113 D5 n/a n/a |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
language |
English |
topic |
Clouds Mixed-phase Arctic |
spellingShingle |
Clouds Mixed-phase Arctic Sensitivity of modeled arctic mixed-phase stratocumulus to cloud condensation and ice nuclei over regionally varying surface conditions |
topic_facet |
Clouds Mixed-phase Arctic |
description |
A two-moment microphysics scheme implemented in the polar version of the mesoscale model MM5 is used to simulate a mixed-phase stratocumulus deck observed during the Fall 2004 Mixed-Phase Arctic Cloud Experiment (MPACE). In situ aircraft instrumentation and remote sensors gathered extensive microphysical and radiative data that serve as a testbed for the model. Model results are reasonably similar to observations in terms of the liquid microphysical properties, while the ice microphysical properties are more significantly biased, especially the ice crystal concentration. Sensitivity tests examine the impact of increased cloud condensation and ice nucleus concentrations. Increasing the concentration of cloud condensation nuclei to values typical for polluted 'Arctic haze' conditions substantially reduces the mean droplet size, but has little impact on the downwelling longwave flux because the cloud already emits as a blackbody (except near the Arctic Ocean pack ice edge). However, the smaller droplet size does lead to a slight increase in liquid water path and more significant decrease (~50%) in the ice water path and snowfall rate due to reduced collision-coalescence and riming of snow by droplets. Increasing the ice nucleus concentration specified from MPACE observations by 1 - 2 orders of magnitude produces a substantial reduction in liquid water path and downwelling longwave flux at the surface over interior northern Alaska, but has less impact over the open ocean and coastal regions. However, a large discrepancy between the observed ice nucleus and ice crystal concentrations, leading to the under-prediction of simulated crystal concentration, also suggests that additional ice initiation mechanisms (not included in current models) may have occurred in the real cloud layer. |
author2 |
Morrison, Hugh (author) Pinto, James (author) Curry, Judith (author) McFarquhar, Greg (author) |
format |
Article in Journal/Newspaper |
title |
Sensitivity of modeled arctic mixed-phase stratocumulus to cloud condensation and ice nuclei over regionally varying surface conditions |
title_short |
Sensitivity of modeled arctic mixed-phase stratocumulus to cloud condensation and ice nuclei over regionally varying surface conditions |
title_full |
Sensitivity of modeled arctic mixed-phase stratocumulus to cloud condensation and ice nuclei over regionally varying surface conditions |
title_fullStr |
Sensitivity of modeled arctic mixed-phase stratocumulus to cloud condensation and ice nuclei over regionally varying surface conditions |
title_full_unstemmed |
Sensitivity of modeled arctic mixed-phase stratocumulus to cloud condensation and ice nuclei over regionally varying surface conditions |
title_sort |
sensitivity of modeled arctic mixed-phase stratocumulus to cloud condensation and ice nuclei over regionally varying surface conditions |
publisher |
American Geophysical Union |
publishDate |
2008 |
url |
http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-084 https://doi.org/10.1029/2007JD008729 |
geographic |
Arctic Arctic Ocean |
geographic_facet |
Arctic Arctic Ocean |
genre |
Arctic Arctic Ocean Alaska |
genre_facet |
Arctic Arctic Ocean Alaska |
op_relation |
Journal of Geophysical Research-Atmospheres http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-084 doi:10.1029/2007JD008729 ark:/85065/d7319w3x |
op_rights |
An edited version of this paper was published by AGU. Copyright 2008 American Geophysical Union. |
op_doi |
https://doi.org/10.1029/2007JD008729 |
container_title |
Journal of Geophysical Research: Atmospheres |
container_volume |
113 |
container_issue |
D5 |
container_start_page |
n/a |
op_container_end_page |
n/a |
_version_ |
1778520057830178816 |