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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

) showed that satellite estimates of decoupling and boundary layer depth are well correlated. The free-tropospheric relative humidity (FT RH) affects low cloud cover by altering both the net longwave radiative cooling and the entrainment at cloud top ( Mauger and Norris 2010 ; Kawai et al. 2017 ; Adebiyi and Zuidema 2018 ), and the magnitude of the effect of FT RH anomalies on cloud cover is sensitive to the vertical distribution of moisture ( Eastman and Wood 2018 ). Large-eddy simulation (LES

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

Lagrangian trajectories. The HYSPLIT model trajectories are assessed in section 4 using carbon monoxide (CO) mixing ratio profiles, and corresponding thermodynamic and moisture profiles are discussed. Section 5 examines in situ precipitation characteristics at the beginning and endpoints of the trajectories. The cloud fraction changes along the transition are quantified using hourly GOES-15 data in section 6 , with a “transition time” determined. The low-level precipitation changes are related to

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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

the Atlantic Stratocumulus Transition Experiment (ASTEX) in 1992 provide one of the most widely used datasets for understanding the SCT and are perhaps the first measurements of cloud microphysical properties in the SCT. The two Lagrangian transition experiments carried out in ASTEX showed that drizzle occurred with sufficient frequency and rate to be important in MBL energy and moisture budgets ( Bretherton and Pincus 1995 ; Bretherton et al. 1995 ). Surface-based radar measurements in ASTEX

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Vasubandhu Misra and Amit Bhardwaj

) attempted to provide a universal index for onset of monsoons by suggesting that, at onset, the wind should exceed 3 m s −1 and the wind direction should shift by at least 120° and persist for at least 40% of the time in the month of its onset. A few of the definitions of onset/demise are complicated. For example, Fasullo and Webster (2003) defined the onset of the SISM based on when the normalized vertically integrated moisture transport over the Arabian Sea exceeds zero. This method, although is

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

be visualized in Figs. 4a – 7a . These results, along with previous analyses, indicate increased plausibility that reduced SST cooling and sustained enthalpy transfer over the PLUME regime helped to increase to a point that is similar to the WCE regime and that has been shown in literature to induce TC intensification. Using these parameters, we speculate that reduced SST cooling and sustained enthalpy flux in the PLUME may have resulted in increased boundary layer moisture, which may have

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Patrik Benáček and Máté Mile

. Meteor. Soc. , 131 , 3323 – 3343 , . 10.1256/qj.05.137 Dee , D. P. , and R. Todling , 2000 : Data assimilation in the presence of forecast bias: The GEOS moisture analysis . Mon. Wea. Rev. , 128 , 3268 – 3282 ,<3268:DAITPO>2.0.CO;2 . 10.1175/1520-0493(2000)128<3268:DAITPO>2.0.CO;2 Evensen , G. , 1994 : Sequential data assimilation with a nonlinear quasi-geostrophic model using Monte Carlo methods to forecast

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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

: Moisture transport, lower tropospheric stability, and decoupling of cloud-topped boundary layers . J. Atmos. Sci. , 54 , 148 – 167 ,<0148:MTLTSA>2.0.CO;2 . 10.1175/1520-0469(1997)054<0148:MTLTSA>2.0.CO;2 Bretherton , C. S. , P. Austin , and S. T. Siems , 1995 : Cloudiness and marine boundary layer dynamics in the ASTEX Lagrangian experiments. Part II: Cloudiness, drizzle, surface fluxes, and entrainment . J. Atmos. Sci. , 52 , 2724 – 2735

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Bradley W. Klotz and David S. Nolan

). The initial vortex has its maximum tangential wind of 15 m s −1 at radius 162 km, again using a modified Rankine vortex with a = 1/3, but with the wind maximized at a height of 1.5 km using the vertical structure formula of Stern and Nolan [2011 ; see their Eq. (4.2)]. As the Ideal5 and Ideal3 simulations evolve, the wind, temperature, and moisture fields on the outer domain are relaxed back to their initial values with a 24-h relaxation time scale. This relaxation does not apply on the nested

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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

023851 . 10.1029/2005GL023851 Borque , P. , E. Luke , and P. Kollias , 2016 : On the unified estimation of turbulence eddy dissipation rate using Doppler cloud radars and lidars . J. Geophys. Res. Atmos. , 121 , 5972 – 5989 , . 10.1002/2015JD024543 Bretherton , C. S. , and M. C. Wyant , 1997 : Moisture transport, lower-tropospheric stability, and decoupling of cloud-topped boundary layers . J. Atmos. Sci. , 54 , 148 – 167 , https

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