The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Default user image.

Vaughan Phillips

Research in the Area of Clouds, Aerosols and Climate

Default user image.

Effects from Time Dependence of Ice Nucleus Activity for Contrasting Cloud Types

Author

  • Deepak Waman
  • Vaughan Phillips
  • Arti Jadav
  • Sachin Patade
  • Jonas Jakobsson
  • Aaron Bansemer

Other contributions

  • Akash Deshmukh

Summary, in English

The role of time-dependent freezing of ice nucleating particles (INPs) is evaluated with the “Aerosol–Cloud” (AC) model in 1) deep convection observed over Oklahoma during the Midlatitude Continental Convective Cloud Experiment (MC3E), 2) orographic clouds observed over North California during the Atmospheric Radiation Measurement (ARM) Cloud Aerosol Precipitation Experiment (ACAPEX), and 3) supercooled, stratiform clouds over the United Kingdom, observed during the Aerosol Properties, Processes And Influences on the Earth’s climate (APPRAISE) campaign. AC uses the dynamical core of the WRF Model and has hybrid bin–bulk microphysics and a 3D mesoscale domain. AC is validated against coincident aircraft, ground-based, and satellite observations for all three cases. Filtered concentrations of ice (.0.1–0.2 mm) agree with those observed at all sampled levels. AC predicts the INP activity of various types of aerosol particles with an empirical parameterization (EP), which follows a singular approach (no time dependence). Here, the EP is modified to represent time-dependent INP activity by a purely empirical approach, using our published laboratory observations of time-dependent INP activity. In all simulated clouds, the inclusion of time dependence increases the predicted INP activity of mineral dust particles by 0.5–1 order of magnitude. However, there is little impact on the cloud glaciation because the total ice is mostly (80%–90%) from secondary ice production (SIP) at levels warmer than about 2368C. The Hallett–Mossop process and fragmentation in ice–ice collisions together initiate about 70% of the total ice, whereas fragmentation during both raindrop freezing and sublimation contributes ,10%. Overall, total ice concentrations and SIP are unaffected by time-dependent INP activity. In the simulated APPRAISE case, the main causes of persistence of long-lived clouds and precipitation are predicted to be SIP in weak embedded convection and reactivation following recirculation of dust particles in supercooled layer cloud.

Department/s

  • Dept of Physical Geography and Ecosystem Science
  • MERGE: ModElling the Regional and Global Earth system
  • BECC: Biodiversity and Ecosystem services in a Changing Climate
  • eSSENCE: The e-Science Collaboration
  • LTH Profile Area: Aerosols

Publishing year

2023-08-15

Language

English

Pages

2013-2039

Publication/Series

Journal of Atmospheric Sciences

Volume

80

Document type

Journal article

Publisher

Amer Meteorological Soc

Topic

  • Meteorology and Atmospheric Sciences

Keywords

  • Ice crystals
  • Clouds
  • Time dependence
  • primary ice
  • secondary ice
  • layer clouds
  • orographic clouds
  • thunderstorm
  • numerical cloud model

Status

Published

Project

  • Mechanisms for the Ice Nucleus Aerosols and their Indirect Effects: Cloud Modelling
  • Secondary ice production: An empirical formulation and organization of mechanisms among simulated cloud-types
  • Mechanisms for the Influence from Ice Nucleus Aerosols on Clouds and their Indirect Effects: Cloud Modelling

ISBN/ISSN/Other

  • ISSN: 1520-0469