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LAACI ¿ Light Absorbing Aerosol-Cloud Interactions Experiment

Active Dates 9/1/2020-8/31/2024
Program Area Atmospheric System Research
Project Description
Atmospheric light-absorbing aerosols, especially black carbon-containing particles, significantly impact the Earth’s radiation budget through direct radiative forcing (i.e., light absorption and scattering), indirect effects by interactions with clouds, and semi-direct effects by altering atmospheric dynamics.  Morphological changes of black carbon and encapsulation within other aerosol material affect the particles' scattering and absorption cross-sections, a process that has been the subject of several studies led by the Department of Energy to reduce direct radiative forcing uncertainties. However, significantly less work has focused on the interactions of black carbon-containing particles with clouds, and thus many important questions remain open. With this project, we aim to fill key gaps in our understanding of the interactions of black carbon-containing particles with clouds, including how these interactions drive direct and indirect radiative forcing, modify cloud microphysical properties, and govern the particles’ wet removal. To achieve these objectives, we plan to examine the optical, physical, and chemical properties of black carbon-containing particles in clouds under controlled laboratory conditions. We plan to participate in planned experiments at Brookhaven National Laboratory, and to lead a series of experiments in a turbulent cloud chamber at Michigan Technological University to examine the cloud processing of two extreme types of black carbon-containing particles: nascent (i.e., recently emitted) and thickly-coated (i.e., atmospherically aged).

In particular, we plan to tackle questions on how black carbon-containing particles participate in aqueous-phase/cloud-chemistry, how that affects the particles' physical, and chemical properties, how that affects their ability to act as cloud condensation nuclei, and how that affects their lifetime in the atmosphere. We will also focus on the effects that black carbon-containing particle properties have on the cloud properties and the role of turbulence in cloud-aerosol as well as aerosol-cloud interactions. The overarching goal of this project is to provide climate models with data to drive a new generation of parameterizations specifically developed to address and improve the fidelity of numerical simulations of the interactions between black carbon-containing particles and clouds, and accounting for the effects of aerosol atmospheric aging and turbulence. To achieve this goal, as an integral part of the project, we plan to work in close collaboration with modeling experts running cloud-parcel and particle-resolved models.
Award Recipient(s)
  • Michigan Technological University (PI: Mazzoleni, Claudio)