Fluctuations and Luck in Droplet Growth by Coalescence
نویسنده
چکیده
How can such “enormous variations” arise from seemingly identical mean-field thermodynamic conditions? For example, why does one such stratocumulus cloud drizzle while another one does not? Part of the answer, we think, is in pronounced fluctuations (deviations from the mean), and methods of statistical physics may be helpful. In particular, the initiation of drizzle or rain is reminiscent of colliding gas molecules insofar as to form a 1-mm raindrop in a warm (no ice) cloud requires that a million 10-mm droplets coalesce. The case for fluctuations in cloud physics is, of course, not new. In fact, the notion of statistically fortunate droplets (ones that grow much faster than average) is an important part of the current understanding as indicated by many texts in cloud physics (e.g., Houghton 1985, 272–277; Mason 1971, 145–155; Pruppacher and Klett 1997, section 15.3; Rogers and Yau 1989, 134–136; Wallace and Hobbs 1977, 172–181; Young 1993, 180–185). Yet, a quantitative theory of warm rain initiation remains elusive. For example, Blyth et al. (2003) write
منابع مشابه
Electro-Coalescence of an Aqueous Droplet at an Oil–Water Interface with an Investigation of Secondary Droplets Formation
متن کامل
Growth of Cloud Droplets in a Turbulent Environment
Motivated by the need to resolve the condensation-coalescence bottleneck in warm rain formation, a significant number of studies have emerged in the past 15 years concerning the growth of cloud droplets by water-vapor diffusion and by collision-coalescence in a turbulent environment.With regard to condensation, recent studies suggest that small-scale turbulence alone does not produce a signific...
متن کاملFermentation broth components influence droplet coalescence and hinder advanced biofuel recovery during fermentation.
Developments in synthetic biology enabled the microbial production of long chain hydrocarbons, which can be used as advanced biofuels in aviation or transportation. Currently, these fuels are not economically competitive due to their production costs. The current process offers room for improvement: by utilizing lignocellulosic feedstock, increasing microbial yields, and using cheaper process t...
متن کاملExperiments on Droplet Collisions, Bounce, Coalescence and Disruption
-There has been a significant effort to understand the events that occur when two or more droplets collide. The majority of the early work, which dates from the 1960s, focused on droplet growth relating to precipitation and was thus limited to water droplet collision phenomena. Recently, studies have sought information on the collision behavior of fuel droplets for application to combustion spr...
متن کاملThe validity of the kinetic collection equation revisited
The kinetic collection equation (KCE) describes the evolution of the average droplet spectrum due to successive events of collision and coalescence. Fluctuations and non-zero correlations present in the stochastic coalescence process would imply that the size distributions may not be correctly modeled by the KCE. In this study we expand the known analytical studies of the coalescence equation w...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2005