A Large‐Scale Analysis of Pockets of Open Cells and Their Radiative Impact
Abstract Pockets of open cells sometimes form within closed‐cell stratocumulus cloud decks but little is known about their statistical properties or prevalence. A convolutional neural network was used to detect occurrences of pockets of open cells (POCs). Trained on a small hand‐logged data set and...
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| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2021-03-01
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| Series: | Geophysical Research Letters |
| Online Access: | https://doi.org/10.1029/2020GL092213 |
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| author | D. Watson‐Parris S. A. Sutherland M. W. Christensen R. Eastman P. Stier |
| author_facet | D. Watson‐Parris S. A. Sutherland M. W. Christensen R. Eastman P. Stier |
| author_sort | D. Watson‐Parris |
| collection | DOAJ |
| description | Abstract Pockets of open cells sometimes form within closed‐cell stratocumulus cloud decks but little is known about their statistical properties or prevalence. A convolutional neural network was used to detect occurrences of pockets of open cells (POCs). Trained on a small hand‐logged data set and applied to 13 years of satellite imagery the neural network is able to classify 8,491 POCs. This extensive database allows the first robust analysis of the spatial and temporal prevalence of these phenomena, as well as a detailed analysis of their micro‐physical properties. We find a large (30%) increase in cloud effective radius inside POCs as compared to their surroundings and similarly large (20%) decrease in cloud fraction. This also allows their global radiative effect to be determined. Using simple radiative approximations we find that the instantaneous global annual mean top‐of‐atmosphere perturbation by all POCs is only 0.01 W/m2. |
| format | Article |
| id | doaj-art-9fdaebf885704e8a820d26be0c4663d8 |
| institution | DOAJ |
| issn | 0094-8276 1944-8007 |
| language | English |
| publishDate | 2021-03-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geophysical Research Letters |
| spelling | doaj-art-9fdaebf885704e8a820d26be0c4663d82025-08-20T03:11:04ZengWileyGeophysical Research Letters0094-82761944-80072021-03-01486n/an/a10.1029/2020GL092213A Large‐Scale Analysis of Pockets of Open Cells and Their Radiative ImpactD. Watson‐Parris0S. A. Sutherland1M. W. Christensen2R. Eastman3P. Stier4Atmospheric, Oceanic and Planetary Physics, Department of Physics University of Oxford Oxford UKAtmospheric, Oceanic and Planetary Physics, Department of Physics University of Oxford Oxford UKAtmospheric, Oceanic and Planetary Physics, Department of Physics University of Oxford Oxford UKDepartment of Atmospheric Sciences University of Washington Seattle WA USAAtmospheric, Oceanic and Planetary Physics, Department of Physics University of Oxford Oxford UKAbstract Pockets of open cells sometimes form within closed‐cell stratocumulus cloud decks but little is known about their statistical properties or prevalence. A convolutional neural network was used to detect occurrences of pockets of open cells (POCs). Trained on a small hand‐logged data set and applied to 13 years of satellite imagery the neural network is able to classify 8,491 POCs. This extensive database allows the first robust analysis of the spatial and temporal prevalence of these phenomena, as well as a detailed analysis of their micro‐physical properties. We find a large (30%) increase in cloud effective radius inside POCs as compared to their surroundings and similarly large (20%) decrease in cloud fraction. This also allows their global radiative effect to be determined. Using simple radiative approximations we find that the instantaneous global annual mean top‐of‐atmosphere perturbation by all POCs is only 0.01 W/m2.https://doi.org/10.1029/2020GL092213 |
| spellingShingle | D. Watson‐Parris S. A. Sutherland M. W. Christensen R. Eastman P. Stier A Large‐Scale Analysis of Pockets of Open Cells and Their Radiative Impact Geophysical Research Letters |
| title | A Large‐Scale Analysis of Pockets of Open Cells and Their Radiative Impact |
| title_full | A Large‐Scale Analysis of Pockets of Open Cells and Their Radiative Impact |
| title_fullStr | A Large‐Scale Analysis of Pockets of Open Cells and Their Radiative Impact |
| title_full_unstemmed | A Large‐Scale Analysis of Pockets of Open Cells and Their Radiative Impact |
| title_short | A Large‐Scale Analysis of Pockets of Open Cells and Their Radiative Impact |
| title_sort | large scale analysis of pockets of open cells and their radiative impact |
| url | https://doi.org/10.1029/2020GL092213 |
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