The effect of hygroscopic seeding on warm rain clouds was examined using a hybrid cloud microphysical model combining a Lagrangian Cloud Condensation Nuclei (CCN) activation model, a semi-Lagrangian droplet growth model, and an Eulerian spatial model for advection and sedimentation of droplets. This hybrid cloud microphysical model accurately estimated the effects of CCN on cloud microstructure...

We have investigated the formation of cloud droplets under pyro-convective conditions using a cloud parcel model with detailed spectral microphysics and with the κ-Köhler model approach for efficient and realistic description of the cloud condensation nucleus (CCN) activity of aerosol particles. Assuming a typical biomass burning aerosol size distribution (accumulation mode centred at 120 nm), ...

Understanding how dynamical and aerosol inputs affect the temporal variability of hydrometeor formation in climate models will help to explain sources of model diversity in cloud forcing, to provide robust comparisons with data, and, ultimately, to reduce the uncertainty in estimates of the aerosol indirect effect. This variability attribution can be done at various spatial and temporal resolut...

This study investigates the height dependency of aerosol-cloud interaction regimes in terms of the joint dependence of the key cloud microphysical properties (e.g., cloud droplet number concentration and cloud droplet relative dispersion) on aerosol number concentration (Na) and vertical velocity (w). The three distinct regimes with differentmicrophysical features are the aerosol-limited regime...

A modification to the relaxed eddy accumulation (REA) flux measurement technique is proposed which maximizes the scalar mixing ratio difference in updrafts and downdrafts. This technique was developed with the goal of measuring the stable isotope (C/C and O/O) ratios of updraft and downdraft air and thus the net fluxes of CO2 and COO. Current mass spectrometer precision is small relative to mea...

cumulus parameterization in numerical weather prediction models can significantly affect severe weather forecasts, such as hurricanes, flash floods, and winter storms. the role of convection is essential in stabilizing an unstable atmosphere through vertically transferring moisture, energy, chemical species and momentum. cumulus parameterization schemes use simple one-dimensional convective clo...

Large-eddy simulations (LESs) were performed for neutrally-stratified turbulent flows within and above a homogeneous plant canopy. 100 realizations of a three-dimensional turbulence field obtained from each of four LES runs, which di¤er in the driving force of the flow and the size of computational domain, were used in the present study. A conditional sampling technique was used to construct en...

Vertical transects of Doppler vertical velocity data, obtained from an airborne profiling millimeter-wave cloud radar, are composited for a large number of cumulus clouds (Cu) at various stages of their life cycle, to examine typical circulations patterns. The Cu clouds range in depth between ;500 and 6000 m and are generally nonprecipitating. They were sampled on board the University of Wyomin...

[1] This work examines the efficacy of various physically based approaches derived from one-dimensional adiabatic parcel model frameworks (a numerical model and a simplified parameterization) to parameterize the cloud droplet distribution characteristics for computing cloud effective radius and autoconversion rate in regional/global atmospheric models. Evaluations are carried out for integratio...