Stratocumulus to cumulus transition in the presence of elevated smoke layers. Issue 23 (11th December 2015)

• Record Type: Journal Article
• Authors: Yamaguchi, Takanobu; Feingold, Graham; Kazil, Jan; McComiskey, Allison
• Is Part Of: Geophysical research letters. Volume 42:Issue 23(2015:Dec.)
• Page Start: 10, 478
• Page End: 10, 485
• Publication Date: 2015-12-11
• Subjects: stratocumulus to cumulus transition -- light absorbing aerosol -- aerosol‐cloud‐radiation interactions -- entrainment -- cloud physics; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2015GL066544
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: The transition from stratocumulus to cumulus clouds in the presence of elevated light‐absorbing smoke layers is investigated with idealized large‐eddy simulations. A smoke layer is placed 1 km above stratocumulus top and evolves with the cloud fields over the course of a 3 day simulation. The simulations presented vary the smoke‐generated heating and the moisture content of the smoke layer. A control case without smoke is simulated for comparison. On day 2 of the transition, when still above cloud, smoke generates a more broken cloud field than the control case, depending weakly on the strength of the aerosol heating but strongly on the water vapor content in the smoke layer. Following nighttime recovery and contact with the stratocumulus, smoke hinders the transition by strengthening the inversion, limiting boundary layer deepening and reducing precipitation‐related breakup. This modulation delays the transition, which may extend the stratocumulus deck westward, with concomitant implications for climate forcing. Key Points: Smoke interacting with cloud delays the transition via suppression of precipitation An elevated smoke layer with high moisture hastens the stratocumulus to cumulus transition The delayed transition results in larger areal cover and stronger forcing by the stratocumulus deck