Building a comprehensive library of observed Lagrangian trajectories for testing modeled cloud evolution, aerosol–cloud interactions, and marine cloud brightening

<p>As the evolution of marine low clouds is sensitive to the current state of the atmosphere and varying meteorological forcing, it is crucial to ascertain how cloud responses differ across a spectrum of those conditions. In this study, we introduce an innovative approach to encompass a wide a...

Full description

Saved in:
Bibliographic Details
Main Authors: E. Erfani, R. Wood, P. Blossey, S. J. Doherty, R. Eastman
Format: Article
Language:English
Published: Copernicus Publications 2025-08-01
Series:Atmospheric Chemistry and Physics
Online Access:https://acp.copernicus.org/articles/25/8743/2025/acp-25-8743-2025.pdf
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849235912735588352
author E. Erfani
R. Wood
P. Blossey
S. J. Doherty
R. Eastman
author_facet E. Erfani
R. Wood
P. Blossey
S. J. Doherty
R. Eastman
author_sort E. Erfani
collection DOAJ
description <p>As the evolution of marine low clouds is sensitive to the current state of the atmosphere and varying meteorological forcing, it is crucial to ascertain how cloud responses differ across a spectrum of those conditions. In this study, we introduce an innovative approach to encompass a wide array of conditions prevalent in low marine cloud regions by creating a comprehensive library of observed environmental conditions. Using reanalysis and satellite data, over 2200 Lagrangian trajectories are generated within the stratocumulus deck region of the Northeast Pacific during summer 2018–2021. By using eight important cloud-controlling factors (CCFs), we employ principal component analysis (PCA) to reduce the dimensionality of data. This technique demonstrates that two principal components capture 43 % of the variability among CCFs. Notably, PCA facilitates the selection of a reduced number of trajectories (e.g., 54) that represent a diverse array of the observed CCF, aerosol, and cloud variability and co-variability. These trajectories can then be used for process model studies, e.g., with large-eddy simulations (LES), to evaluate the efficacy of marine cloud brightening. Two distinct cases are selected to initiate 2 d long, high-resolution, large-domain LES experiments. The results highlight the ability of our LES to simulate observed conditions. Although perturbed aerosols delay cloud breakup and enhance the cloud radiative effect, the strength of such effects is sensitive to “precipitation-aerosol feedback”. The first case is precipitating and shows the potential for “precipitation-driven” cloud breakup due to positive precipitation-aerosol feedback. The second case is non-precipitating with classic cloud breakup of the “deepening-warming” type, highlighting the impact of entrainment.</p>
format Article
id doaj-art-3a412606bb5c4702b70dcbeab6f9ddf6
institution Kabale University
issn 1680-7316
1680-7324
language English
publishDate 2025-08-01
publisher Copernicus Publications
record_format Article
series Atmospheric Chemistry and Physics
spelling doaj-art-3a412606bb5c4702b70dcbeab6f9ddf62025-08-20T04:02:32ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242025-08-01258743876810.5194/acp-25-8743-2025Building a comprehensive library of observed Lagrangian trajectories for testing modeled cloud evolution, aerosol–cloud interactions, and marine cloud brighteningE. Erfani0R. Wood1P. Blossey2S. J. Doherty3R. Eastman4Division of Atmospheric Sciences, Desert Research Institute, Reno, NV, USADepartment of Atmospheric and Climate Science, University of Washington, Seattle, WA, USADepartment of Atmospheric and Climate Science, University of Washington, Seattle, WA, USADepartment of Atmospheric and Climate Science, University of Washington, Seattle, WA, USADepartment of Atmospheric and Climate Science, University of Washington, Seattle, WA, USA<p>As the evolution of marine low clouds is sensitive to the current state of the atmosphere and varying meteorological forcing, it is crucial to ascertain how cloud responses differ across a spectrum of those conditions. In this study, we introduce an innovative approach to encompass a wide array of conditions prevalent in low marine cloud regions by creating a comprehensive library of observed environmental conditions. Using reanalysis and satellite data, over 2200 Lagrangian trajectories are generated within the stratocumulus deck region of the Northeast Pacific during summer 2018–2021. By using eight important cloud-controlling factors (CCFs), we employ principal component analysis (PCA) to reduce the dimensionality of data. This technique demonstrates that two principal components capture 43 % of the variability among CCFs. Notably, PCA facilitates the selection of a reduced number of trajectories (e.g., 54) that represent a diverse array of the observed CCF, aerosol, and cloud variability and co-variability. These trajectories can then be used for process model studies, e.g., with large-eddy simulations (LES), to evaluate the efficacy of marine cloud brightening. Two distinct cases are selected to initiate 2 d long, high-resolution, large-domain LES experiments. The results highlight the ability of our LES to simulate observed conditions. Although perturbed aerosols delay cloud breakup and enhance the cloud radiative effect, the strength of such effects is sensitive to “precipitation-aerosol feedback”. The first case is precipitating and shows the potential for “precipitation-driven” cloud breakup due to positive precipitation-aerosol feedback. The second case is non-precipitating with classic cloud breakup of the “deepening-warming” type, highlighting the impact of entrainment.</p>https://acp.copernicus.org/articles/25/8743/2025/acp-25-8743-2025.pdf
spellingShingle E. Erfani
R. Wood
P. Blossey
S. J. Doherty
R. Eastman
Building a comprehensive library of observed Lagrangian trajectories for testing modeled cloud evolution, aerosol–cloud interactions, and marine cloud brightening
Atmospheric Chemistry and Physics
title Building a comprehensive library of observed Lagrangian trajectories for testing modeled cloud evolution, aerosol–cloud interactions, and marine cloud brightening
title_full Building a comprehensive library of observed Lagrangian trajectories for testing modeled cloud evolution, aerosol–cloud interactions, and marine cloud brightening
title_fullStr Building a comprehensive library of observed Lagrangian trajectories for testing modeled cloud evolution, aerosol–cloud interactions, and marine cloud brightening
title_full_unstemmed Building a comprehensive library of observed Lagrangian trajectories for testing modeled cloud evolution, aerosol–cloud interactions, and marine cloud brightening
title_short Building a comprehensive library of observed Lagrangian trajectories for testing modeled cloud evolution, aerosol–cloud interactions, and marine cloud brightening
title_sort building a comprehensive library of observed lagrangian trajectories for testing modeled cloud evolution aerosol cloud interactions and marine cloud brightening
url https://acp.copernicus.org/articles/25/8743/2025/acp-25-8743-2025.pdf
work_keys_str_mv AT eerfani buildingacomprehensivelibraryofobservedlagrangiantrajectoriesfortestingmodeledcloudevolutionaerosolcloudinteractionsandmarinecloudbrightening
AT rwood buildingacomprehensivelibraryofobservedlagrangiantrajectoriesfortestingmodeledcloudevolutionaerosolcloudinteractionsandmarinecloudbrightening
AT pblossey buildingacomprehensivelibraryofobservedlagrangiantrajectoriesfortestingmodeledcloudevolutionaerosolcloudinteractionsandmarinecloudbrightening
AT sjdoherty buildingacomprehensivelibraryofobservedlagrangiantrajectoriesfortestingmodeledcloudevolutionaerosolcloudinteractionsandmarinecloudbrightening
AT reastman buildingacomprehensivelibraryofobservedlagrangiantrajectoriesfortestingmodeledcloudevolutionaerosolcloudinteractionsandmarinecloudbrightening