Microphysical imprint of entrainment in warm cumulus
Small, Jennifer D.
Chuang, Patrick Y.
Jonsson, Haflidi H.
MetadataShow full item record
We analyse the cloud microphysical response to entrainment mixing in warm cumulus clouds observed from the CIRPAS Twin Otter during the GoMACCS field campaign near Houston, Texas, in summer 2006. Cloud drop size distributions and cloud liquid water contents from the Artium Flight phase-Doppler interferometer in conjunction with meteorological observations are used to investigate the degree to which inhomogeneous versus homogeneous mixing is preferred as a function of height above cloud base, distance from cloud edge and aerosol concentration. Using four complete days of data with 101 cloud penetrations (minimum 300m in length), we find that inhomogeneous mixing primarily explains liquid water variability in these clouds. Furthermore, we show that there is a tendency for mixing to be more homogeneous towards the cloud top, which we attribute to the combination of increased turbulent kinetic energy and cloud drop size with altitude which together cause the Damko¨ hler number to increase by a factor of between 10 and 30 from cloud base to cloud top. We also find that cloud edges appear to be air from cloud centres that have been diluted solely through inhomogeneous mixing. Theory predicts the potential for aerosol to affect mixing type via changes in drop size over the range of aerosol concentrations experienced (moderately polluted rural sites to highly polluted urban sites). However, the observations, while consistent with this hypothesis, do not show a statistically significant effect of aerosol on mixing type.
The article of record as published may be located at http://dx.doi.org/10.3402/tellusb.v65i0.19922
Showing items related by title, author, creator and subject.
Evolution of the stratospheric aerosol in the northern hemisphere following the June 1991 volcanic eruption of Mount Pinatubo: Role of tropospheric-stratospheric exchange and transport Jonsson, H.H.; Wilson, James, C.; Brock, Charles A.; Dye, J.E.; Ferry, G.V.; Chan, K.R. (1996-01);Since the eruption of Mount Pinatubo in June 1991, measurements of particle size and concentration have intermittently been carried out from an ER-2 aircraft at altitudes of up to 21 km at midlatitudes and high latitudes ...
Characterization of ambient aerosol from measurements of cloud condensation nuclei during the 2003 Atmospheric Radiation Measurement Aerosol Intensive Observational Period at the Southern Great Plains site in Oklahoma Rissman, T. A.; VanReken, T. M.; Wang, J.; Gasparini, R.; Collins, D. R.; Jonsson, H.H.; Brechtel, F. J.; Flagan, R. C.; Seinfeld, J. H. (2006);Measurements were made by a new cloud condensation nuclei (CCN) instrument (CCNC3) during the Atmospheric Radiation Measurement (ARM) Program’s Aerosol Intensive Observational Period (IOP) in May 2003 in Lamont, Oklahoma. ...
Aerosol particle chemical characteristics measured from aircraft in the lower troposphere during ACE-2 Schmeling, Martina; Russell, Lynn M.; Erlick, Carynelisa; Collins, Donald R.; Jonsson, Haflidi; Wang, Qing; Kregsamer, Peter; Streli, Christina (2000);During the Aerosol Characterization Experiment (ACE-2), filter samples were collected aboard the Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS) Pelican aircraft near Tenerife in June and July of ...