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Johna E. Rudzin, Lynn K. Shay, and Benjamin Jaimes de la Cruz

forcing, since entrainment cooling is less with deep-ocean mixed layers, and sustain air–sea fluxes into the storm ( Shay et al. 2000 ; Lin et al. 2005 , 2009 , 2013 ; Shay and Uhlhorn 2008 ; Jaimes and Shay 2009 , 2010 ; Jaimes et al . 2015 ). In addition to ocean thermal structure, a few studies have indicated that the upper-ocean salinity stratification within the Amazon–Orinoco River plume plays a role in modulating SST during TC passage by reducing the efficiency of upper-ocean mixing

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Johannes Mohrmann, Christopher S. Bretherton, Isabel L. McCoy, Jeremy McGibbon, Robert Wood, Virendra Ghate, Bruce Albrecht, Mampi Sarkar, Paquita Zuidema, and Rabindra Palikonda

continental boundary layers predominantly driven by surface fluxes). Randall (1980) examined the role of cloud-top entrainment in generating additional instability and Sc breakup. Nicholls (1984) and Nicholls and Leighton (1986) explored in depth the decoupling of the cloud versus subcloud layers in marine stratocumulus, noting the role of cumulus clouds in recoupling the two layers. From a climatological perspective, Klein and Hartmann (1993) found that lower-tropospheric stability (LTS

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Kuan-Ting O, Robert Wood, and Christopher S. Bretherton

). Collision–coalescence increases not only the size of water droplets but also size of the aerosol inside. The advantage of the 2D bin framework is that the resulting aerosol mass can be saved after collision–coalescence takes place, which may be important for the temporal evolution of DSDs. The hybrid bin scheme developed by Chen and Lamb (1994 ; CL scheme) is applied to treat condensation and evaporation processes. The two-dimensional flux method developed by Bott (2000 ; Bott scheme) is used to treat

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Jenny V. Turton, Thomas Mölg, and Dirk Van As

travel between Iceland and the east coast of Greenland, leaving a fingerprint in the climate signal ( Fig. 6a ). Under low pressure conditions to the southeast of Greenland, warm, moist air is advected toward 79N from over the Atlantic. Concurrently, the warmer and moister air creates a low-level cloud or fog level, which additionally warms the surface and air because of an increased downward flux of longwave radiation to the surface ( Bednorz and Fortuniak 2012 ). We hypothesize that a combination

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Mampi Sarkar, Paquita Zuidema, Bruce Albrecht, Virendra Ghate, Jorgen Jensen, Johannes Mohrmann, and Robert Wood

shallow cloud transition is primarily dependent upon the ratio of surface latent heat fluxes to cloud-top longwave radiative cooling ( Krueger et al. 1995 ; Bretherton and Wyant 1997 ). More recent research has focused on articulating the pace of the transition. One comprehensive analysis of Lagrangian trajectories based on reanalyses and satellite observations concluded that changes in the underlying sea surface temperature, more so than in the atmosphere, dominate the speed of the cloud transition

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Bruce Albrecht, Virendra Ghate, Johannes Mohrmann, Robert Wood, Paquita Zuidema, Christopher Bretherton, Christian Schwartz, Edwin Eloranta, Susanne Glienke, Shaunna Donaher, Mampi Sarkar, Jeremy McGibbon, Alison D. Nugent, Raymond A. Shaw, Jacob Fugal, Patrick Minnis, Robindra Paliknoda, Louis Lussier, Jorgen Jensen, J. Vivekanandan, Scott Ellis, Peisang Tsai, Robert Rilling, Julie Haggerty, Teresa Campos, Meghan Stell, Michael Reeves, Stuart Beaton, John Allison, Gregory Stossmeister, Samuel Hall, and Sebastian Schmidt

energy and moisture fluxes associated with these clouds are critical in maintaining the thermodynamic structure of the lower troposphere. Thus, both the turbulent mixing and the radiative impact on the surface associated with marine boundary layer (MBL) clouds need to be adequately parameterized in large-scale models ( Bony and Dufresne 2005 ). The inadequate representation of MBL cloud processes in large-scale models continues to be a major contributor to model uncertainties in cloud feedback

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Robert Wood, Kuan-Ting O, Christopher S. Bretherton, Johannes Mohrmann, Bruce. A. Albrecht, Paquita Zuidema, Virendra Ghate, Chris Schwartz, Ed Eloranta, Susanne Glienke, Raymond A. Shaw, Jacob Fugal, and Patrick Minnis

fluxes increase over warmer waters ( Bretherton and Wyant 1997 ; Wyant et al. 1997 ). As several studies have shown ( Martin et al. 1995 ; Zhou et al. 2015 ), stratocumulus cloud breakup is not an immediate response to MBL decoupling but can be delayed by as much as 1–3 days with cloud cover often remaining above 50% until 500–2000 km downstream of decoupling onset ( Zhou et al. 2015 ). Given the importance of the SCT, it is remarkable that few dedicated aircraft observations have sampled the MBL

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Christopher S. Bretherton, Isabel L. McCoy, Johannes Mohrmann, Robert Wood, Virendra Ghate, Andrew Gettelman, Charles G. Bardeen, Bruce A. Albrecht, and Paquita Zuidema

the boundary layer, based on G-V profiles (crosses) and dropsonde soundings (filled circles) from all CSET flights. Symbols are colored by the GOES-derived low cloud fraction in a 2° × 2° box centered on the profiles. c. Turbulence Approximately half of the CSET low-level sampling consisted of constant-altitude legs, either at 150 m, or within or above the main cloud layer. One could estimate vertical velocity variance or turbulent fluxes from these legs, but very few estimates are obtained for

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M. Christian Schwartz, Virendra P. Ghate, Bruce. A. Albrecht, Paquita Zuidema, Maria P. Cadeddu, Jothiram Vivekanandan, Scott M. Ellis, Pei Tsai, Edwin W. Eloranta, Johannes Mohrmann, Robert Wood, and Christopher S. Bretherton

and deepening of the marine boundary layer, in which turbulence entrains free-tropospheric air through the MBL’s top ( Bretherton and Wyant 1997 ; Sandu and Stevens 2011 ). Other proposed mechanisms that influence the characteristics of the transition, as opposed to the occurrence of the transition itself, include the precipitation flux within the MBL, changes in the large-scale subsidence, diurnal variations in the warming of the MBL clouds, changes in the water vapor above the MBL, and changes

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