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Yang Yang, James C. McWilliams, X. San Liang, Hong Zhang, Robert H. Weisberg, Yonggang Liu, and Dimitris Menemenlis

1. Introduction Submesoscale currents with a horizontal scale of O (0.1–50) km and a time scale of O (1) days are ubiquitous in the ocean. They occur preferentially near the surface of the ocean in the form of fronts, filaments and small-scale eddies, characterized by large variances of vertical velocity and vorticity ( Thomas et al. 2013 ; McWilliams 2016 ). Submesoscale processes can be generated through various mechanisms such as mixed layer instabilities (e.g., Boccaletti et al. 2007

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Ali Tokay and Paul G. Bashor

which its center diameter is around 5.1 mm. Like other types of disdrometers, it requires power and a shelter for its processor, which is linked to a personal computer. This limits site location choices when designing a study for the small-scale variability of DSDs. It is possible, however, to utilize a cable as long as 100 m between the sensor and processor, to provide some flexibility for the site selection. Considering the data processing, a registering raindrop is recorded on one of the 127

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Rita Seiffert and Jin-Song von Storch

representation of processes related to thermodynamical feedbacks, for example, cloud feedbacks, water vapor feedback, and surface albedo feedbacks ( Colman 2003 ; Soden and Held 2006 ; Webb et al. 2006 ; Bony et al. 2006 ). However, other factors also affect the modeled climate sensitivity. In a previous study ( Seiffert and von Storch 2008 , hereafter SS08 ), we showed that the presence of enhanced small-scale fluctuations can affect the model’s sensitivity to a doubling of CO 2 concentration. Using

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Holger Siebert, Kai-Erik Szodry, Ulrike Egerer, Birgit Wehner, Silvia Henning, Karine Chevalier, Janine Lückerath, Oliver Welz, Kay Weinhold, Felix Lauermann, Matthias Gottschalk, André Ehrlich, Manfred Wendisch, Paulo Fialho, Greg Roberts, Nithin Allwayin, Simeon Schum, Raymond A. Shaw, Claudio Mazzoleni, Lynn Mazzoleni, Jakub L. Nowak, Szymon P. Malinowski, Katarzyna Karpinska, Wojciech Kumala, Dominika Czyzewska, Edward P. Luke, Pavlos Kollias, Robert Wood, and Juan Pedro Mellado

observations, continuously performed at two measurement stations to sample the MBL and FT during the 1-month period of the ACORES campaign, were combined with high-resolution helicopter-borne measurements of aerosol, cloud, turbulence, and radiation properties collected during 16 flights around Graciosa/Azores. This multilevel and multiscale approach has been exploited to investigate small-scale entrainment processes under cloudy and cloudless conditions with respect to the boundary layer and aerosol

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P. J. Hosegood, M. C. Gregg, and M. H. Alford

1. Introduction Lateral processes have frequently been invoked as potentially responsible for the excess restratification in the surface mixed layer (SML) that cannot be explained by solar insolation and vertical turbulent fluxes ( Brainerd and Gregg 1993a , 1997 ; Caldwell et al. 1997 ). Typically only 60% ± 15% of observed restratification in the SML can be attributed to the vertical divergence of penetrative solar radiation, with a much smaller proportion due to vertical divergence of

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Lena M. Schulze Chretien and Kevin Speer

measurements include physical parameters, such as temperature and salinity, as well as biological and chemical measurements. Moored instruments have made a general understanding of the frequency spectrum of currents throughout the water column; unfortunately, these sampling strategies are often unable to provide the sampling needed to assess large variability in both space and time. While models often neglect detailed bottom topography and associated small-scale flow that is forced by topography, they

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Peter Sheridan, Simon Vosper, and Samantha Smith

implies an assumption about the scale selectivity of cold-pool formation. In fact, cold pools may form in very small terrain concavities or equally in broad mountain basins. Of course, a 4-km scale coincides with the driving NWP-model grid length, and valley features on a larger scale than this should start to become resolved, with cold-pooling processes beginning to be represented explicitly in the driving model. However, it is unclear at what point valleys and cold-pooling processes are effectively

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Jean-Claude Gascard and R. Allyn Clarke

OCTOI~ER 1983 JEAN-CLAUDE GASCARD AND R. ALLYN CLARKE 1779The Formation of Labrador Sea Water. Part II: Mesoscale and Smaller-Scale Processes JEAN-CLAUDE GASCARDLaboratoire d'Oc~anographie Physique du Museum National d'Histoire Naturelle, 75231, Paris, France R. ALLYN CLARKEAtlantic Oceanographic Laboratory, Bedford Institute of Oceanography, Dartmouth, N.S., Canada B2Y 4A

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Eleanor Frajka-Williams, Peter B. Rhines, and Charles C. Eriksen

in plumes with narrow horizontal scales (100 m) and fast vertical speeds (up to 10 cm s −1 ), mixing waters down to 1000 m or more ( Lilly et al. 1999 ; Steffen and D’Asaro 2002 ). During periods of deep convection, density differences between the surface and the base of the mixed layer are small by definition (less than 0.01 kg m −3 ) ( Lazier et al. 2002 ). When surface buoyancy losses no longer exceed the lateral input of buoyant waters from surrounding regions, the area again becomes

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Clifford L. Trump and George O. Marmorino

along-front variation is generally negligible over the length scales being averaged over. 5. Summary and discussion A new approach has been proposed for the processing of acoustic Doppler current profiler (ADCP) data that can better resolve the velocity and acoustic backscatter structure of small-scale dynamical features such as strongly convergent current fronts. Standard processing—the averaging of ping data over time intervals—will tend to smear out small-scale structure. The essence of the new

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