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Jianjun Yin, Ronald J. Stouffer, Michael J. Spelman, and Stephen M. Griffies

is the misrepresentation of physical processes in the model formulation. A notable misrepresentation in AOGCMs is the wide use of an unphysical virtual salt flux (VSF) to represent the freshwater flux (FWF) at the ocean surface. The VSF assumption was introduced as a result of the classical rigid-lid approximation, which suppressed fast external gravity waves in the ocean to allow longer time steps but led to a fixed volume of a model ocean ( Bryan 1969 ). Under the rigid-lid approximation, the

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Ronald Dobosy, David Sayres, Claire Healy, Edward Dumas, Mark Heuer, John Kochendorfer, Bruce Baker, and James Anderson

1. Introduction Surface heterogeneity is a prime reason to make flux measurements from aircraft, but it is also a significant source of uncertainty. One approach is to sample above the blending height ( Wieringa 1986 ; Mahrt 2000 ) to obtain a measure of the bulk flux. If the intent is to develop and improve models relating surface flux to remotely sensible parameters, however, it is important to acquire the signal of the surface’s influence on air–surface exchange. Depending on the parameters

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Paola Cessi

, the regions where eddy fluxes are important coincide with areas of strong heat flux exchange with the atmosphere, and it is probable that eddy heat fluxes are crucial in the earth’s heat budget. Despite this, the oceanic component of the global climate models is unable to resolve eddy scales, except in computations about a decade long ( Maltrud and McClean 2005 ) and for one set of climate scenarios. For climate-oriented computations that are integrated for centuries and for several sets of

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Baozhang Chen, Jing M. Chen, Gang Mo, Chiu-Wai Yuen, Hank Margolis, Kaz Higuchi, and Douglas Chan

; Pitman 2003 ; Pleim and Xiu 2003 ). Significant problems related to LSMs, however, have yet to be addressed, including the difficulties in parameterizing hydrological processes, root processes, subgrid-scale heterogeneity, and biogeochemical cycles ( Pitman 2003 ). It has also been recognized that LSMs need to be coupled with atmospheric general circulation models (GCMs) to adequately simulate the surface fluxes of energy, water, and carbon ( Sellers et al. 1996 ; Garratt 1993 ; Saunders et al

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Ronny Engelmann, Ulla Wandinger, Albert Ansmann, Detlef Müller, Egidijus Žeromskis, Dietrich Althausen, and Birgit Wehner

(the transition layer between PBL and the free troposphere) are not well understood and thus are not well parameterized in atmospheric models. Observations of fluxes covering the entire PBL and the entrainment zone are rare. With respect to aerosols, vertical transport is even more complicated because the ascent of particles is often combined with water uptake because of a relative humidity increase with height in the PBL. The particle mass concentration and optical and microphysical properties

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Gerald N. Flerchinger, Michele L. Reba, and Danny Marks

1. Introduction Rangeland ecosystems are often characterized by a patchy mosaic of vegetation types, making measurement and modeling of surface energy fluxes in these environments particularly challenging. Understanding the role of different vegetation communities in modulating energy, water, and carbon fluxes is critical to quantifying the energy flux, carbon storage, and water balances of these ecosystems. Eddy covariance (EC) systems have gained popularity as a means to measure the surface

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R. J. Ronda and F. C. Bosveld

1. Introduction The soil heat flux quantifies transport of heat through planes perpendicular to the soil surface. At the surface it quantifies the energy transport (positive downward) through the interface between the air–vegetation continuum and the soil. The thus-defined surface soil heat flux G 0 is in balance with the net radiation R N and the atmospheric transport (positive upward) of sensible heat H and latent heat LE ( Stull 1988 ). During daytime and for vegetated surfaces, G 0

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Carsten Eden

1. Introduction Eddy buoyancy fluxes tend to show a large diapycnal projection even when only weak (or even no) irreversible mixing is associated with the process leading to the eddying motion. Mathematically, this is related to a large rotational component of the diapycnal eddy flux, with no net effect on the mean buoyancy. To identify the rotational component and to differentiate it from the residual divergent component in an objective manner, McDougall and McIntosh (1996 , 2001) developed

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Thomas Haiden, C. David Whiteman, Sebastian W. Hoch, and Manuela Lehner

conceptual picture suggested by Whiteman et al. (2010) is tested within the framework of a mass flux model, which is solved analytically and numerically. The central questions we would like to answer are (i) whether an intrusion of cold air from the outside can cause the basin atmosphere to become near-isothermal, and (ii) what mechanism causes the isothermalcy. The problem addressed in this study is of interest also in the wider context of basin and valley meteorology. Decoupling of the surface layer

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X. Capet, J. C. McWilliams, M. J. Molemaker, and A. F. Shchepetkin

oceanic general circulation. Our purpose is to understand the origins of submesoscale fluctuations, their flow structure and dynamics, and their time-averaged eddy fluxes both spatially and in wavenumber space as a possible route to energy dissipation at the microscales ( Müller et al. 2005 ). In Part I and Part II a set of computational simulations for an idealized subtropical, eastern-boundary, upwelling current system is analyzed for the emergent submesoscale flows and underlying processes that

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