Harvard Univ., Cambridge, MA (United States). Dept. of Earth and Planetary Sciences; Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts
Harvard Univ., Cambridge, MA (United States). John A. Paulson School of Engineering and Applied Sciences and Dept. of Earth and Planetary Sciences
Here, the dependence of entrainment rate on environmental conditions and cloud characteristics is investigated using large eddy simulations (LES) of the response of shallow cumulus convection to a small-amplitude temperature perturbation that is horizontally uniform and localized in height. The simulated cumulus fields are analyzed in the framework of an ensemble of entraining plumes by tracking a large number of Lagrangian parcels embedded in the LES and grouping them into different plumes based on their detrainment heights. The results show that fractional entrainment rate per unit height of a plume is inversely proportional to the plume’s vertical velocity and its distance to the cloud edge, while changes in environmental stratification and relative humidity, the plume’s buoyancy, or the vertical gradient of its buoyancy due to the temperature perturbation have little effect on the plume’s entrainment rate.
Tian, Yang and Kuang, Zhiming. "Dependence of entrainment in shallow cumulus convection on vertical velocity and distance to cloud edge." Geophysical Research Letters, vol. 43, no. 8, Apr. 2016. https://doi.org/10.1002/2016GL069005
Tian, Yang, & Kuang, Zhiming (2016). Dependence of entrainment in shallow cumulus convection on vertical velocity and distance to cloud edge. Geophysical Research Letters, 43(8). https://doi.org/10.1002/2016GL069005
Tian, Yang, and Kuang, Zhiming, "Dependence of entrainment in shallow cumulus convection on vertical velocity and distance to cloud edge," Geophysical Research Letters 43, no. 8 (2016), https://doi.org/10.1002/2016GL069005
@article{osti_1469308,
author = {Tian, Yang and Kuang, Zhiming},
title = {Dependence of entrainment in shallow cumulus convection on vertical velocity and distance to cloud edge},
annote = {Here, the dependence of entrainment rate on environmental conditions and cloud characteristics is investigated using large eddy simulations (LES) of the response of shallow cumulus convection to a small-amplitude temperature perturbation that is horizontally uniform and localized in height. The simulated cumulus fields are analyzed in the framework of an ensemble of entraining plumes by tracking a large number of Lagrangian parcels embedded in the LES and grouping them into different plumes based on their detrainment heights. The results show that fractional entrainment rate per unit height of a plume is inversely proportional to the plume’s vertical velocity and its distance to the cloud edge, while changes in environmental stratification and relative humidity, the plume’s buoyancy, or the vertical gradient of its buoyancy due to the temperature perturbation have little effect on the plume’s entrainment rate.},
doi = {10.1002/2016GL069005},
url = {https://www.osti.gov/biblio/1469308},
journal = {Geophysical Research Letters},
issn = {ISSN 0094-8276},
number = {8},
volume = {43},
place = {United States},
publisher = {American Geophysical Union},
year = {2016},
month = {04}}
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); National Oceanic and Atmospheric Administration (NOAA), Boulder, CO (United States); National Science Foundation (NSF)
Grant/Contract Number:
SC0008679
OSTI ID:
1469308
Journal Information:
Geophysical Research Letters, Journal Name: Geophysical Research Letters Journal Issue: 8 Vol. 43; ISSN 0094-8276
Morton, B. R.; Taylor, Geoffrey Ingram; Turner, John Stewart
Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, Vol. 234, Issue 1196, p. 1-23https://doi.org/10.1098/rspa.1956.0011