Satellite-based estimate of global aerosol–cloud radiative forcing by marine warm clouds
Chen, Y.-C.; Christensen, M.W.; Stephens, G.L.; Seinfeld, J.H. (2014). Satellite-based estimate of global aerosol–cloud radiative forcing by marine warm clouds. Nature Geoscience 7(9): 643–646. http://dx.doi.org/10.1038/ngeo2214
In: Nature Geoscience. Nature Publishing Group: London. ISSN 1752-0894; e-ISSN 1752-0908, more
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| Authors | | Top |
- Chen, Y.-C.
- Christensen, M.W.
- Stephens, G.L.
- Seinfeld, J.H.
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| Abstract |
Changes in aerosol concentrations affect cloud albedo and Earth's radiative balance(1). Aerosol radiative forcing from pre-industrial time to the present due to the effect of atmospheric aerosol levels on the micro- and macrophysics of clouds bears the largest uncertainty among external influences on climate change(1). Of all cloud forms, low-level marine clouds exert the largest impact on the planet's albedo(2). For example, a 6% increase in the albedo of global marine stratiform clouds could offset the warming that would result from a doubling of atmospheric CO2 concentrations(3). Marine warm cloud properties are thought to depend on aerosol levels and large-scale dynamic or thermodynamic states(4-6). Here we present a comprehensive analysis of multiple measurements from the A-Train constellation of Earth-observing satellites, to quantify the radiative forcing exerted by aerosols interacting with marine clouds. Specifically, we analyse observations of co-located aerosols and clouds over the world's oceans for the period August 2006-April 2011, comprising over 7.3 million CloudSat single-layer marine warm cloud pixels. We find that thermodynamic conditions-that is, tropospheric stability and humidity in the free troposphere-and the state of precipitation act together to govern the cloud liquid water responses to the presence of aerosols and the strength of aerosol-cloud radiative forcing. |
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