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Title: Do Ultrafine Cloud Condensation Nuclei Invigorate Deep Convection?

Journal Article · · Journal of the Atmospheric Sciences
 [1];  [1]
  1. National Center for Atmospheric Research, Boulder, CO (United States)
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Numerical simulations of the impact of ultrafine cloud condensation nuclei (CCN) on deep convection are analyzed herein to investigate the idea proposed by Fan et al. that addition of ultrafine CCN to an otherwise pristine environment leads to convective invigoration. The piggybacking methodology is applied, allowing rigorous separation of the impact of aerosols from different flow realizations that typically occur when even a small element of the model physics or modeling setup is changed. The setup follows the case of daytime convective development over land based on observations during the Large-Scale Biosphere–Atmosphere (LBA) experiment in Amazonia. Overall, the simulated impacts of ultrafine CCN are similar to the previous study by the authors on the impact of pollution on deep convection. There is no convective invigoration above the freezing level, but there is a small invigoration (increase in vertical velocities) below due to the supersaturation and buoyancy differences in conditions with additional ultrafine CCN compared to unperturbed pristine conditions. As in the previous study, the most significant impact is on the upper-tropospheric convective anvils that feature higher cloud fractions in conditions with ultrafine CCN. The increase comes from purely microphysical considerations as the increased cloud droplet concentrations from ultrafine CCN lead to increased ice crystal concentrations and, consequently, smaller sizes and fall velocities, and longer residence times. Mesoscale organization due to low-level shear has a small effect on the simulated ultrafine CCN impacts. Finally, an alternative explanation of increased lightning above oceanic shipping lines seen in satellite observations and argued to result from convective invigoration is provided.

Research Organization:
University Corporation for Atmospheric Research, Boulder, CO (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Biological and Environmental Research (BER); National Science Foundation (NSF)
Grant/Contract Number:
SC0016476; SC0020104; SC0020118
OSTI ID:
1657808
Journal Information:
Journal of the Atmospheric Sciences, Vol. 77, Issue 7; ISSN 0022-4928
Publisher:
American Meteorological SocietyCopyright Statement
Country of Publication:
United States
Language:
English

References (36)

The Supercooling of Water journal August 1953
Locally Enhanced Aerosols Over a Shipping Lane Produce Convective Invigoration but Weak Overall Indirect Effects in Cloud-Resolving Simulations journal September 2018
Influence of the Subcloud Layer on the Development of a Deep Convective Ensemble journal September 2012
Thunderstorm Structure and Circulation journal June 1948
How do changes in warm-phase microphysics affect deep convective clouds? journal January 2017
Dominant role by vertical wind shear in regulating aerosol effects on deep convective clouds journal January 2009
Microphysical effects determine macrophysical response for aerosol impacts on deep convective clouds journal November 2013
Substantial convection and precipitation enhancements by ultrafine aerosol particles journal January 2018
Factors Responsible for Precipitation Efficiencies in Midlatitude and Tropical Squall Simulations journal October 1996
Can the Impact of Aerosols on Deep Convection be Isolated from Meteorological Effects in Atmospheric Observations? journal October 2018
Separating physical impacts from natural variability using piggybacking technique journal January 2019
Growth of Cloud Droplets in a Turbulent Environment journal January 2013
Separating Dynamic and Thermodynamic Impacts of Climate Change on Daytime Convective Development over Land journal August 2019
Daytime convective development over land: A model intercomparison based on LBA observations journal January 2006
Macroscopic impacts of cloud and precipitation processes on maritime shallow convection as simulated by a large eddy simulation model with bin microphysics journal January 2015
Make It a Double? Sobering Results from Simulations Using Single-Moment Microphysics Schemes journal February 2015
Simulation of Effects of Atmospheric Aerosols on Deep Turbulent Convective Clouds Using a Spectral Microphysics Mixed-Phase Cumulus Cloud Model. Part II: Sensitivity Study journal December 2004
Aerosol impact on the dynamics and microphysics of deep convective clouds journal October 2005
Aerosol-induced changes of convective cloud anvils produce strong climate warming journal January 2010
The invigoration of deep convective clouds over the Atlantic: aerosol effect, meteorology or retrieval artifact? journal January 2010
A Numerical Study of the Effects of Ambient Flow and Shear On Density Currents journal October 1996
Impacts of Updraft Size and Dimensionality on the Perturbation Pressure and Vertical Velocity in Cumulus Convection. Part I: Simple, Generalized Analytic Solutions journal April 2016
Impacts of Updraft Size and Dimensionality on the Perturbation Pressure and Vertical Velocity in Cumulus Convection. Part II: Comparison of Theoretical and Numerical Solutions and Fully Dynamical Simulations journal April 2016
Mesoscale Modeling of Springtime Arctic Mixed-Phase Stratiform Clouds Using a New Two-Moment Bulk Microphysics Scheme journal October 2005
Comparison of Bulk and Bin Warm-Rain Microphysics Models Using a Kinematic Framework journal August 2007
Modeling Supersaturation and Subgrid-Scale Mixing with Two-Moment Bulk Warm Microphysics journal March 2008
A Novel Approach for Representing Ice Microphysics in Models: Description and Tests Using a Kinematic Framework journal May 2008
Cloud-system resolving model simulations of aerosol indirect effects on tropical deep convection and its thermodynamic environment journal January 2011
Response of Tropical Deep Convection to Localized Heating Perturbations: Implications for Aerosol-Induced Convective Invigoration journal November 2013
The Radiative Forcing of Aerosol–Cloud Interactions in Liquid Clouds: Wrestling and Embracing Uncertainty journal February 2018
A cloud-resolving model study of aerosol-cloud correlation in a pristine maritime environment: A CRM Study of Aerosol-Cloud Correlation journal June 2017
Flood or Drought: How Do Aerosols Affect Precipitation? journal September 2008
Influence of local circulations on wind, moisture, and precipitation close to Manaus City, Amazon Region, Brazil journal December 2014
Aerosol-cloud-precipitation effects over Germany as simulated by a convective-scale numerical weather prediction model journal January 2012
The effects of aerosols on precipitation and dimensions of subtropical clouds: a sensitivity study using a numerical cloud model journal January 2006
What Controls the Transition from Shallow to Deep Convection? journal June 2009

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Related Subjects

54 ENVIRONMENTAL SCIENCES
Cloud microphysics
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