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Title: Distinct Impacts of Aerosols on an Evolving Continental Cloud Complex during the RACORO Field Campaign

In this study, a continental cloud complex, consisting of shallow cumuli, a deep convective cloud (DCC), and stratus, is simulated by a cloud-resolving Weather Research and Forecasting Model to investigate the aerosol microphysical effect (AME) and aerosol radiative effect (ARE) on the various cloud regimes and their transitions during the Department of Energy Routine Atmospheric Radiation Measurement Aerial Facility Clouds with Low Optical Water Depths Optical Radiative Observations (RACORO) campaign. Under an elevated aerosol loading with AME only, a reduced cloudiness for the shallow cumuli and stratus resulted from more droplet evaporation competing with suppressed precipitation, but an enhanced cloudiness for the DCC is attributed to more condensation. With the inclusion of ARE, the shallow cumuli are suppressed owing to the thermodynamic effects of light-absorbing aerosols. The responses of DCC and stratus to aerosols are monotonic with AME only but nonmonotonic with both AME and ARE. The DCC is invigorated because of favorable convection and moisture conditions at night induced by daytime ARE, via the so-called aerosol-enhanced conditional instability mechanism. Finally, the results reveal that the overall aerosol effects on the cloud complex are distinct from the individual cloud types, highlighting that the aerosol–cloud interactions for diverse cloud regimes andmore » their transitions need to be evaluated to assess the regional and global climatic impacts.« less
 [1] ;  [2] ;  [1] ;  [1] ;  [3] ;  [1]
  1. Texas A & M Univ., College Station, TX (United States)
  2. California Inst. of Technology (CalTech), Pasadena, CA (United States)
  3. Brookhaven National Lab. (BNL), Upton, NY (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 0022-4928; R&D Project: 2016-BNL-EE631EECA-Budg; KP1703020
Grant/Contract Number:
SC0012704; AC02-98CH10886
Accepted Manuscript
Journal Name:
Journal of the Atmospheric Sciences
Additional Journal Information:
Journal Volume: 73; Journal Issue: 9; Journal ID: ISSN 0022-4928
American Meteorological Society
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
54 ENVIRONMENTAL SCIENCES; Atm/Ocean Structure/ Phenomena; Precipitation; Physical Meteorology and Climatology; Aerosols; Cloud microphysics; Clouds
OSTI Identifier: