The interaction between boundary layer and convection schemes in a WRF simulation of post-cold-frontal clouds over the ARM East North Atlantic site
The correct representation of low-level midlatitude clouds found in the wake of cold fronts strongly relies on the representation of planetary boundary layer (PBL) and convection processes, which are typically parameterized separately in numerical models. Using the Weather Research and Forecasting M...
Published in: | Journal of Geophysical Research: Atmospheres |
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Online Access: | http://www.osti.gov/servlets/purl/1594072 https://www.osti.gov/biblio/1594072 https://doi.org/10.1029/2018JD029370 |
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ftosti:oai:osti.gov:1594072 2023-07-30T04:05:20+02:00 The interaction between boundary layer and convection schemes in a WRF simulation of post-cold-frontal clouds over the ARM East North Atlantic site Lamraoui, Fayçal Booth, James F. Naud, Catherine M. Jensen, Michael P. Johnson, Karen L. 2022-01-03 application/pdf http://www.osti.gov/servlets/purl/1594072 https://www.osti.gov/biblio/1594072 https://doi.org/10.1029/2018JD029370 unknown http://www.osti.gov/servlets/purl/1594072 https://www.osti.gov/biblio/1594072 https://doi.org/10.1029/2018JD029370 doi:10.1029/2018JD029370 58 GEOSCIENCES 2022 ftosti https://doi.org/10.1029/2018JD029370 2023-07-11T09:39:14Z The correct representation of low-level midlatitude clouds found in the wake of cold fronts strongly relies on the representation of planetary boundary layer (PBL) and convection processes, which are typically parameterized separately in numerical models. Using the Weather Research and Forecasting Model (WRF), this study investigates how distinct pairs of PBL and convection parameterization schemes represent cloud fraction in the post-cold-frontal region. The simulations focus on the region of the DOE-ARM Eastern North Atlantic observation site in the Azores Islands in the wake of a cold front that passed on December 25, 2015. Different PBL and convection schemes are combined to create 12 distinct configurations. The main differences between the selected physical parameterizations are the strength of vertical mixing and the entrainment. The simulations produce a wide range of cloud fractions, where some configurations significantly underestimate while others clearly overestimate satellite and surface-based estimates of cloud fraction. A skill score is used to quantitatively assess the performance of each configuration with respect to ground-based radar data. The key processes that are found to significantly impact the cloud fraction distribution are the strength of the PBL decoupling, the vertical wind shear, entrainment and detrainment rates in shallow convection and the occurrence of drizzle. This indicates that to successfully simulate post-cold-frontal clouds, modeled physics must balance strong internal vertical mixing and weak exchange with the free troposphere. For this case study, cloud fraction was more sensitive to the choice of convection scheme than PBL scheme. Other/Unknown Material North Atlantic SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Journal of Geophysical Research: Atmospheres 124 8 4699 4721 |
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SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
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58 GEOSCIENCES Lamraoui, Fayçal Booth, James F. Naud, Catherine M. Jensen, Michael P. Johnson, Karen L. The interaction between boundary layer and convection schemes in a WRF simulation of post-cold-frontal clouds over the ARM East North Atlantic site |
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58 GEOSCIENCES |
description |
The correct representation of low-level midlatitude clouds found in the wake of cold fronts strongly relies on the representation of planetary boundary layer (PBL) and convection processes, which are typically parameterized separately in numerical models. Using the Weather Research and Forecasting Model (WRF), this study investigates how distinct pairs of PBL and convection parameterization schemes represent cloud fraction in the post-cold-frontal region. The simulations focus on the region of the DOE-ARM Eastern North Atlantic observation site in the Azores Islands in the wake of a cold front that passed on December 25, 2015. Different PBL and convection schemes are combined to create 12 distinct configurations. The main differences between the selected physical parameterizations are the strength of vertical mixing and the entrainment. The simulations produce a wide range of cloud fractions, where some configurations significantly underestimate while others clearly overestimate satellite and surface-based estimates of cloud fraction. A skill score is used to quantitatively assess the performance of each configuration with respect to ground-based radar data. The key processes that are found to significantly impact the cloud fraction distribution are the strength of the PBL decoupling, the vertical wind shear, entrainment and detrainment rates in shallow convection and the occurrence of drizzle. This indicates that to successfully simulate post-cold-frontal clouds, modeled physics must balance strong internal vertical mixing and weak exchange with the free troposphere. For this case study, cloud fraction was more sensitive to the choice of convection scheme than PBL scheme. |
author |
Lamraoui, Fayçal Booth, James F. Naud, Catherine M. Jensen, Michael P. Johnson, Karen L. |
author_facet |
Lamraoui, Fayçal Booth, James F. Naud, Catherine M. Jensen, Michael P. Johnson, Karen L. |
author_sort |
Lamraoui, Fayçal |
title |
The interaction between boundary layer and convection schemes in a WRF simulation of post-cold-frontal clouds over the ARM East North Atlantic site |
title_short |
The interaction between boundary layer and convection schemes in a WRF simulation of post-cold-frontal clouds over the ARM East North Atlantic site |
title_full |
The interaction between boundary layer and convection schemes in a WRF simulation of post-cold-frontal clouds over the ARM East North Atlantic site |
title_fullStr |
The interaction between boundary layer and convection schemes in a WRF simulation of post-cold-frontal clouds over the ARM East North Atlantic site |
title_full_unstemmed |
The interaction between boundary layer and convection schemes in a WRF simulation of post-cold-frontal clouds over the ARM East North Atlantic site |
title_sort |
interaction between boundary layer and convection schemes in a wrf simulation of post-cold-frontal clouds over the arm east north atlantic site |
publishDate |
2022 |
url |
http://www.osti.gov/servlets/purl/1594072 https://www.osti.gov/biblio/1594072 https://doi.org/10.1029/2018JD029370 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
http://www.osti.gov/servlets/purl/1594072 https://www.osti.gov/biblio/1594072 https://doi.org/10.1029/2018JD029370 doi:10.1029/2018JD029370 |
op_doi |
https://doi.org/10.1029/2018JD029370 |
container_title |
Journal of Geophysical Research: Atmospheres |
container_volume |
124 |
container_issue |
8 |
container_start_page |
4699 |
op_container_end_page |
4721 |
_version_ |
1772817174497329152 |