Stratocumulus cloud response to climate change

How will stratocumulus clouds respond dynamically to increased concentrations of atmospheric CO2?

  • Stratocumulus clouds are sustained through cloud-top longwave cooling that drives their unique upside-down convection.
  • They are prevelent only in certain regions (e.g. off the coast of California) because they exist through a delicate balance of cool ocean temperatures below and a strong temperature inversion at the top of the boundary layer created from subsiding free-tropospheric air.
  • Increasing CO2 concentrations will lead to weaker cloud-top cooling, increased surface temperatures and latent heat fluxes, and changing large-scale circulation and subsidence. All of these impact the dynamics of stratocumlus clouds.
  • We are developing a theoretical model to explain the dissipation of stratocumulus clouds to increased CO2 seen in Schneider et al. 2019.
In collaboration with: Tapio Schneider

Aerosol-cloud interactions

What is the importance of aerosol hygroscopicity in cloud dynamics?

  • I am quantifying the impact of aerosol hygroscopicity using large-eddy simulations (LES) with Lagrangian particle-based microphysics (superdroplets).
  • This research is being done using the University of Warsaw Lagrangian Cloud Model.

In collaboration with: Anna Jaruga and John Seinfeld

3D cloud radiative effects

How large is the albedo bias in climate models resulting from 1D radiative transfer assumptions?

Read the paper here:

Fig 1. Top-of-atmosphere flux (a) and albedo (b) bias as a function of solar zenith angle for various cloud types: shallow cumulus (BOMEX and RICO), stratocumulus (DYCOMS-II RF01), deep convection (TRMM-LBA and TRMM-LBA agg.).

Fig 2. Zonal-mean and map of annual-mean flux bias inferred from ISCCP cloud water path. Bias is smallest over stratocumulus regions and largest over the ITCZ and storm tracks, areas with deep clouds and persistent cloudiness.

In collaboration with: Ignacio Lopez-Gomez, Sally Zhang, and Tapio Schneider