Understanding the drivers of marine liquid-water cloud occurrence and properties with global observations using neural networks


Date

2017

Publication Type

Journal Article

ETH Bibliography

yes

Citations

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Data

Abstract

The role of aerosols, clouds and their interactions with radiation remain among the largest unknowns in the climate system. Even though the processes involved are complex, aerosol–cloud interactions are often analyzed by means of bivariate relationships. In this study, 15 years (2001–2015) of monthly satellite-retrieved near-global aerosol products are combined with reanalysis data of various meteorological parameters to predict satellite-derived marine liquid-water cloud occurrence and properties by means of region-specific artificial neural networks. The statistical models used are shown to be capable of predicting clouds, especially in regions of high cloud variability. On this monthly scale, lower-tropospheric stability is shown to be the main determinant of cloud fraction and droplet size, especially in stratocumulus regions, while boundary layer height controls the liquid-water amount and thus the optical thickness of clouds. While aerosols show the expected impact on clouds, at this scale they are less relevant than some meteorological factors. Global patterns of the derived sensitivities point to regional characteristics of aerosol and cloud processes.

Publication status

published

Editor

Book title

Volume

17 (15)

Pages / Article No.

9535 - 9546

Publisher

European Geophysical Society

Event

Edition / version

Methods

Software

Geographic location

Date collected

Date created

Subject

Organisational unit

03690 - Lohmann, Ulrike / Lohmann, Ulrike check_circle

Notes

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