Aerosol-driven droplet concentrations dominate coverage and water of oceanic low-level clouds

  title={Aerosol-driven droplet concentrations dominate coverage and water of oceanic low-level clouds},
  author={Daniel Rosenfeld and Yannian Zhu and Minghuai Wang and Youtong Zheng and Tom Goren and Shaocai Yu},
Reflections on cloud effects How much impact does the abundance of cloud condensation nuclei (CCN) aerosols above the oceans have on global temperatures? Rosenfeld et al. analyzed how CCN affect the properties of marine stratocumulus clouds, which reflect much of the solar radiation received by Earth back to space (see the Perspective by Sato and Suzuki). The CCN abundance explained most of the variability in the radiative cooling. Thus, the magnitude of radiative forcing provided by these… 

Aerosols enhance cloud lifetime and brightness along the stratus-to-cumulus transition

It is shown that aerosols can enhance cloud fraction and extend the lifetime of overcast cloud fields primarily under stable atmospheric conditions as typically found off the west coasts of subtropical stratocumulus-dominated regions.

Aerosol-cloud-climate cooling overestimated by ship-track data

It is shown that ship-track studies cannot be generalized to estimate the climatological forcing of anthropogenic aerosol, and the ship track–derived sensitivity of the radiative effect of nonprecipitating stratocumulus to aerosol overestimates their cooling effect.

Weak average liquid-cloud-water response to anthropogenic aerosols

The cooling of the Earth’s climate through the effects of anthropogenic aerosols on clouds offsets an unknown fraction of greenhouse gas warming. An increase in the amount of water inside

Phytoplankton Impact on Marine Cloud Microphysical Properties Over the Northeast Atlantic Ocean

The current understanding of the impact of natural cloud condensation nuclei (CCN) variability on cloud properties in marine air is low, thus contributing to climate prediction uncertainty. By

Ship-track-based assessments overestimate the cooling effect of anthropogenic aerosol

The effect of anthropogenic aerosol on the reflectivity of stratocumulus cloud decks through changes in cloud amount is a major uncertainty in climate projections. The focus of this study is the

Snow-induced buffering in aerosol–cloud interactions

Abstract. Complex aerosol–cloud–precipitation interactions lead to large differences in estimates of aerosol impacts on climate among general circulation models (GCMs) and satellite retrievals.

How do aerosols affect cloudiness?

The Rosenfeld et al. (2) report that the cloud response to the interaction is much larger than previously estimated (see the figure).

Environmental Effects on Aerosol-Cloud Interaction in non-precipitating MBL Clouds over the Eastern North Atlantic

Abstract. Over the eastern north Atlantic (ENA) ocean, a total of 20 non-precipitating single-layer marine boundary layer (MBL) stratus and stratocumulus cloud cases are selected in order to

Measurement report: Cloud processes and the transport of biological emissions affect southern ocean particle and cloud condensation nuclei concentrations

Abstract. Long-range transport of biogenic emissions from the coast of Antarctica, precipitation scavenging, and cloud processing are the main processes that influence the observed variability in

Large‐Scale Industrial Cloud Perturbations Confirm Bidirectional Cloud Water Responses to Anthropogenic Aerosols

Aerosols offset a poorly quantified fraction of anthropogenic greenhouse gas warming, and the aerosol impact on clouds is the most uncertain mechanism of anthropogenic climate forcing. Here



From aerosol-limited to invigoration of warm convective clouds

It is proposed that convective-cloud invigoration by aerosols can be viewed as an extension of the concept of aerosol-limited clouds, where cloud development is limited by the availability of cloud-condensation nuclei.

Hemispheric Aerosol Vertical Profiles: Anthropogenic Impacts on Optical Depth and Cloud Nuclei

This work examines more than 1000 vertical profiles from 11 major airborne campaigns in the Pacific hemisphere and confirms that regional enhancements in aerosol light scattering, mass, and number are associated with carbon monoxide from combustion and can exceed values in unperturbed regions by more than one order of magnitude.

Global observations of aerosol‐cloud‐precipitation‐climate interactions

Cloud drop condensation nuclei (CCN) and ice nuclei (IN) particles determine to a large extent cloud microstructure and, consequently, cloud albedo and the dynamic response of clouds to

Satellite-based estimate of global aerosol-cloud radiative forcing by marine warm clouds

Changes in aerosol concentrations affect cloud albedo and Earth’s radiative balance. Aerosol radiative forcing from pre-industrial time to the present due to the effect of atmospheric aerosol levels

Aerosol effects on cloud water amounts were successfully simulated by a global cloud-system resolving model

The authors show that using explicit representation of cloud microphysics, in global scale modelling, rather than parameterisations, reduces the overestimation of aerosol effect on cloud properties.

On the determination of a cloud condensation nuclei from satellite: Challenges and possibilities

[1] We use aerosol size distributions measured in the size range from 0.01 to 10+ μm during Transport and Chemical Evolution over the Pacific (TRACE-P) and Aerosol Characterization Experiment–Asia

Further evidence for CCN aerosol concentrations determining the height of warm rain and ice initiation in convective clouds over the Amazon basin

Abstract. We have investigated how aerosols affect the height above cloud base of rain and ice hydrometeor initiation and the subsequent vertical evolution of cloud droplet size and number

Cancellation of Aerosol Indirect Effects in Marine Stratocumulus through Cloud Thinning

  • R. Wood
  • Environmental Science, Physics
  • 2007
Applying perturbation theory within a mixed layer framework, the response of the marine boundary layer (MBL) cloud thickness h to imposed increases of the cloud droplet concentration Nd as a

Extensive closed cell marine stratocumulus downwind of Europe—A large aerosol cloud mediated radiative effect or forcing?

Marine stratocumulus clouds (MSC) cover large areas over the oceans and possess super sensitivity of their cloud radiative effect to changes in aerosol concentrations. Aerosols can cause transitions

Constraining the aerosol influence on cloud fraction

Aerosol‐cloud interactions have the potential to modify many different cloud properties. There is significant uncertainty in the strength of these aerosol‐cloud interactions in analyses of