Abstract

AbstractIn this paper, the timescale of the convective mass‐flux response to step‐function changes in external forcing conditions is measured directly using idealized cloud‐resolving model simulations of unorganized convection in radiative–convective equilibrium. Many parametrization schemes require an estimate of this response time in the form of a fixed adjustment timescale, but the physical mechanism which sets its value is currently unknown. These experiments confirm the existence of a unique timescale, for given initial forcing conditions, of the order of one hour. The hypothesized role of gravity waves in effecting the convective adjustment is tested by changing the mean cloud spacing of the initial state. This reveals a linear dependence of the response time on the cloud spacing, in agreement with the theory. Meanwhile, similar experiments to investigate the sensitivity of the timescale to changes in gravity‐wave speed reveal a remarkable robustness of the average wave speed over a range of stratifications and tropospheric depths. Copyright © 2004 Royal Meteorological Society.

Full Text
Paper version not known

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 call

Disclaimer: 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.