A Sensitivity Study of Arctic Air‐Mass Transformation Using Large Eddy Simulation

Arctic air mass transformation is a process in which an air mass originating over the open ocean enters the high Arctic and cools. Low‐altitude clouds form and are often very persistent. They can exist for several days and warm the surface by emitting infrared radiation towards the surface. In this...

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Bibliographic Details
Published in:Journal of Geophysical Research: Atmospheres
Main Authors: Dimitrelos, Antonios, Ekman, Annika M L, Caballero, Rodrigo, Savre, Julien
Format: Article in Journal/Newspaper
Language:unknown
Published: 2020
Subjects:
Online Access:https://zenodo.org/record/4554607
https://doi.org/10.1029/2019JD031738
Description
Summary:Arctic air mass transformation is a process in which an air mass originating over the open ocean enters the high Arctic and cools. Low‐altitude clouds form and are often very persistent. They can exist for several days and warm the surface by emitting infrared radiation towards the surface. In this study, we have investigated the effect of the cloud on the surface energy budget by conducting large eddy simulations. In the model code we have incorporated a module that considers the thermodynamics of the sea ice surface. Knowing the sensitivity of these clouds to different parameters and physical processes will make us capable of predicting the cloud lifetime and radiative properties, and thus the induced warming effect on the sea ice surface. We have found that an increased ice crystal number concentration leads to a tenuous form of the cloud that only weakly warms the surface. An imposed large‐scale ascent or descent affects the cloud lifetime by more than a day. Increasing the number of cloud condensation nuclei enhances the warming effect of the cloud.