Related Experiment Video
Updated: Aug 9, 2026
13:27
Exploring the Effects of Atmospheric Forcings on Evaporation: Experimental Integration of the Atmospheric Boundary Layer and Shallow Subsurface
Published on: June 8, 2015
Kinetic potential and barrier crossing: a model for warm cloud drizzle formation
1Environmental Sciences Department, Atmospheric Sciences Division, Brookhaven National Laboratory, Upton, New York 11973, USA.
Physical Review Letters
|February 7, 2003
Summary
Nucleation theory explains cloud droplet growth into drizzle. Drizzle formation is more likely in transient cloud conditions, and aerosols can suppress drizzle by increasing droplet concentration.
Area of Science:
- Cloud microphysics
- Atmospheric science
- Climate modeling
Background:
- Cloud droplets grow into drizzle through various microphysical processes.
- Understanding drizzle formation is crucial for accurate climate predictions.
- Aerosols significantly influence cloud properties and precipitation.
Purpose of the Study:
- To model cloud droplet growth into drizzle using nucleation theory.
- To investigate the factors influencing drizzle formation rates.
- To quantify the indirect effect of aerosols on drizzle suppression.
Main Methods:
- Applied kinetic potential of nucleation theory to droplet growth.
- Modeled drizzle formation as a barrier-crossing phenomenon.
- Calculated steady-state and transient drizzle rates under various conditions.
Main Results:
- Drizzle formation is identified as a statistical barrier-crossing process.
- Drizzle rates depend on turbulent diffusion, droplet collection, and size distribution.
- Transient conditions were found to favor drizzle formation.
- Higher droplet concentrations, influenced by aerosols, suppress drizzle.
Conclusions:
- The study provides a theoretical framework for understanding drizzle formation.
- Transient cloud conditions enhance the likelihood of drizzle.
- Aerosols exert an indirect but significant influence on cloud precipitation through drizzle suppression.
Related Concept Videos
02:39Phase Transitions: Vaporization and Condensation
The physical form of a substance changes on changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize (convert into vapor). The process is called vaporization—a surface phenomenon. Vaporization occurs when the thermal motion of the molecules overcome the intermolecular forces, and the molecules (at the surface) escape into the gaseous state. When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase molecules...
01:12Kinetic Theory of an Ideal Gas
A mole is defined as the amount of any substance that contains as many molecules as there are atoms in exactly 12 grams of carbon-12. An Italian scientist Amedeo Avogadro (1776–1856) formed the hypothesis that equal volumes of gas at equal pressure and temperature contain equal numbers of molecules, independent of the type of gas. Later, the hypothesis was developed to form the SI unit for measuring the amount of any substance.
The number of molecules in one mole is called Avogadro's number...
The number of molecules in one mole is called Avogadro's number...
01:12Precipitation Processes
The experimental conditions in a gravimetric analysis should be optimized to maximize the particle size and purity of the obtained precipitate. Ideally, the concentration of the precipitating reagent should be low with effective stirring to maintain low relative supersaturation for the growth of large crystals. In homogeneous precipitation, the precipitant is slowly generated by a chemical reaction in the solution to avoid local reagent excesses. For example, urea decomposes gradually to...
01:24The Kinetic Model of Gases
The kinetic model of gases explains the properties of a perfect gas using three main assumptions: molecules move in ceaseless random motion, their size is negligible compared to the distances between them, and they do not interact except during perfectly elastic collisions. The total energy of a gas is the sum of the kinetic energies of all its constituent molecules. The pressure exerted by the gas arises from the continual bombardment of the container walls by billions of colliding molecules.
01:09Theories of Dissolution: The Danckwerts' Model and Interfacial Barrier Model
Various dissolution theories provide insight into the factors that influence the dissolution rate. Danckwerts' Model suggests that turbulence, rather than a stagnant layer, characterizes the dissolution medium at the solid-liquid interface. In this model, the agitated solvent contains macroscopic packets that move to the interface via eddy currents, facilitating the absorption and delivery of the drug to the bulk solution. The regular replenishment of solvent packets maintains the concentration...
01:18Boundary Layer Characteristics
When a fluid encounters a solid surface, a boundary layer forms due to the interaction between the fluid's motion and the stationary surface. This phenomenon is characterized by a thin region adjacent to the surface where viscous forces dominate, influencing the fluid's velocity profile. The development of the boundary layer begins at the leading edge of the surface and evolves as the fluid moves downstream.As the fluid flows over the surface, friction between the fluid and the wall slows down...