PROBING FINESCALE DYNAMICS AND MICROPHYSICS OF CLOUDS WITH HELICOPTER-BORNE MEASUREMENTS

Helicopter-based measurements provide an opportunity for probing the finescale dynamics and microphysics of clouds simultaneously in space and time. Due to the low true air speed compared with research aircraft, a helicopter allows for measurements with much higher spatial resolution. To circumvent...

Full description

Saved in:
Bibliographic Details
Published in:Bulletin of the American Meteorological Society 2006-12, Vol.87 (12), p.1727-1738
Main Authors: Siebert, Holger, Franke, Harald, Lehmann, Katrin, Maser, Rolf, Saw, Ewe Wei, Schell, Dieter, Shaw, Raymond A., Wendisch, Manfred
Format: Article
Language:English
Subjects:
Aircraft
Aviation regulation
Clouds
Coalescence
Cumulus clouds
Data collection
Downwash
Flight conditions
Helicopters
Measurement techniques
Meteorology
Problems
Remote sensing
Satellites
Sensors
Size distribution
Systems design
Turbulence
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Helicopter-based measurements provide an opportunity for probing the finescale dynamics and microphysics of clouds simultaneously in space and time. Due to the low true air speed compared with research aircraft, a helicopter allows for measurements with much higher spatial resolution. To circumvent the influence of the helicopter downwash the autonomous measurement pay-load Airborne Cloud Turbulence Observation System (ACTOS) is carried as an external cargo 140 m below the helicopter. ACTOS allows for collocated measurements of the dynamical and cloud microphysical parameters with a spatial resolution of better than 10 cm. The interaction between turbulence and cloud microphysical processes is demonstrated using the following two cloud cases from recent helicopter measurements: i) a cumulus cloud with a low degree of turbulence and without strong vertical dynamics, and, in contrast, ii) an actively growing cloud with increased turbulence and stronger updrafts. The turbulence and microphysical measurements suggest that entrainment at the tops of these two clouds occurs by inhomogeneous and homogeneous mixing, respectively.
ISSN:0003-0007
1520-0477
DOI:10.1175/BAMS-87-12-1727