Abstract
Abstract. In this paper, aircraft measurements are presented of liquid phase (ice-free) wave clouds made at temperatures greater than −5°C that formed over Scotland, UK. The horizontal variations of the vertical velocity across wave clouds display a distinct pattern. The maximum updraughts occur at the upshear flanks of the clouds and the strong downdraughts at the downshear flanks. The cloud droplet concentrations were a couple of hundreds per cubic centimetres, and the drops generally had a mean diameter between 15–45 μm. A small proportion of the drops were drizzle. The measurements presented here and in previous recent studies suggest a different interaction of dynamics and microphysics in wave clouds from the accepted model. The results in this paper provide a case for future numerical simulation of wave cloud and the interaction between wave and cloud.
Highlights
Wave clouds are produced when air passes over obstacles such as mountains or islands in specific environmental conditions
The ranges of temperature, humidity, and vertical velocity of wave clouds are similar to laboratorylike settings, especially for ice formation and development (e.g. Baker and Lawson, 2006)
In Run 2 (Fig. 7), the vertical velocity with respect to cloud varied in a similar way in clouds C9, C10, and C11 as in clouds C2–C7 in Run 1: the maximum of the updraughts were on the upshear side of the clouds and maximum of the downdraughts were on the downshear side, with a gradual change from one to the other
Summary
Wave clouds are produced when air passes over obstacles such as mountains or islands in specific environmental conditions. Clark et al (1986) found that gravity waves play an important role in the vertical velocity of air surrounding the cloud Their simulated clouds have clear air updraughts occurring both in front and overhead on the upshear side and clear downdraughts both in the rear and overhead on the downshear side. Heymsfield and Miloshevich (1995) studied the influence of relative humidity and temperature on wave cloud formation and evolution using aircraft measurements. They showed that cloud occurred between the maximum updraught and maximum downdraught. The results of the study will provide an opportunity for numerical study of the impact of moist processes on mountain waves and wave-cloud interaction with models
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
