Marine Boundary Layer Clouds Associated with Coastally Trapped Disturbances: Observations and Model Simulations
Author
Juliano, Timothy W.Coggon, Matthew M.
Thompson, Gregory

Rahn, David A.
Seinfeld, John H.
Sorooshian, Armin
Lebo, Zachary J.
Affiliation
Univ Arizona, Dept Chem & Environm EngnUniv Arizona, Dept Hydrol & Atmospher Sci
Issue Date
2019-09-11Keywords
North Pacific OceanMarine boundary layer
Stratiform clouds
Cloud parameterizations
Numerical analysis
modeling
Marine chemistry
Metadata
Show full item recordPublisher
AMER METEOROLOGICAL SOCCitation
Juliano, T. W., Coggon, M. M., Thompson, G., Rahn, D. A., Seinfeld, J. H., Sorooshian, A., & Lebo, Z. J. (2019). Marine Boundary Layer Clouds Associated with Coastally Trapped Disturbances: Observations and Model Simulations. Journal of the Atmospheric Sciences, (2019).Rights
Copyright © 2019 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
Modeling marine low clouds and fog in coastal environments remains an outstanding challenge due to the inherently complex ocean–land–atmosphere system. This is especially important in the context of global circulation models due to the profound radiative impact of these clouds. This study utilizes aircraft and satellite measurements, in addition to numerical simulations using the Weather Research and Forecasting (WRF) Model, to examine three well-observed coastally trapped disturbance (CTD) events from June 2006, July 2011, and July 2015. Cloud water-soluble ionic and elemental composition analyses conducted for two of the CTD cases indicate that anthropogenic aerosol sources may impact CTD cloud decks due to synoptic-scale patterns associated with CTD initiation. In general, the dynamics and thermodynamics of the CTD systems are well represented and are relatively insensitive to the choice of physics parameterizations; however, a set of WRF simulations suggests that the treatment of model physics strongly influences CTD cloud field evolution. Specifically, cloud liquid water path (LWP) is highly sensitive to the choice of the planetary boundary layer (PBL) scheme; in many instances, the PBL scheme affects cloud extent and LWP values as much as or more than the microphysics scheme. Results suggest that differences in the treatment of entrainment and vertical mixing in the Yonsei University (nonlocal) and Mellor–Yamada–Janjić (local) PBL schemes may play a significant role. The impact of using different driving models—namely, the North American Mesoscale Forecast System (NAM) 12-km analysis and the NCEP North American Regional Reanalysis (NARR) 32-km products—is also investigated.Note
6 month embargo; published online: 11 September 2019ISSN
0022-4928Version
Final published versionSponsors
State of Wyoming; Carlton R. Barkhurst Fellowship; NCAR through the National Science Foundation; National Science FoundationNational Science Foundation (NSF) [AGS-1439515]; Office of Naval ResearchOffice of Naval Research [N00014-17-1-2719, N00014-10-1-0811, N00014-16-1-2567]; Department of EnergyUnited States Department of Energy (DOE) [DE-SC0016354]ae974a485f413a2113503eed53cd6c53
10.1175/jas-d-18-0317.1