Search Results

You are looking at 51 - 60 of 1,662 items for :

  • Model performance/evaluation x
  • Journal of the Atmospheric Sciences x
  • Refine by Access: All Content x
Clear All
Stuart Marlatt, Scott Waggy, and Sedat Biringen

assumption in our paper was intended as a simplification consistent with the formulation of the turbulence closure models being evaluated and was not to be construed as necessarily descriptive of turbulence in the Ekman boundary layer. We do appreciate Bergmann’s comment noting that the eddy diffusivity K m used for these model assessments [in Eq. (6) of MWB12 ] was not clearly defined in the text. This quantity was defined in terms of dimensionless variables; consequently, K m is also a

Full access
Domingo Muñoz-Esparza, Jeremy A. Sauer, Rodman R. Linn, and Branko Kosović

larger-scale flows and to examine the interaction of an upstream boundary layer modified by surface heat fluxes on downslope winds, respectively. Recently, Sauer et al. (2016) have used an LES technique to further understand the mechanisms behind the interactions of the atmospheric boundary layer with large-scale stably stratified flow over hilly terrain. Herein, we leverage the research of Sauer et al. (2016) by using their LES results in order to systematically evaluate mesoscale model

Full access
Andrew C. Bushell, Neal Butchart, Stephen H. Derbyshire, David R. Jackson, Glenn J. Shutts, Simon B. Vosper, and Stuart Webster

of observational constraints and the many current uncertainties over the schemes’ performance and impact, this approach also seems somewhat complex, [e.g., the Choi and Chun (2011) scheme requires four model fields and eight variables, five from the convective scheme]. In contrast, the stochastic, multiwave scheme of Lott and Guez (2013) identifies total precipitation as a useful proxy for column-integrated latent heat release that avoids any explicit dependence on vertical structure or

Full access
Manuela Lehner, Richard Rotunno, and C. David Whiteman

scheme (e.g., Zhong and Whiteman 2008 ; Axelsen and van Dop 2009a , b ), including early simulations of downslope flows (see Denby 1999 ). Smith and Porté-Agel (2014) compared the performance of different subgrid models for large-eddy simulations of downslope flows, a Smagorinsky model, and two dynamic models. Different turbulence parameterization schemes were also compared with results from a large-eddy simulation for stable conditions, although not katabatic flows, by Cuxart et al. (2006

Full access
Tobias Selz, Lucas Fischer, and George C. Craig

atmosphere’s scale-dependence behavior appropriately, shortcomings in the numerics or parameterizations are likely. In the case of kinetic energy, the evaluation of scaling exponents has provided valuable insights into model performance ( Skamarock 2004 ; Hamilton et al. 2008 ; Bierdel et al. 2012 ; Fang and Kuo 2015 ). For water vapor, Schemann et al. (2013) investigated the scaling behaviors of a GCM, an NWP model, and a large-eddy simulation (LES) and the implication for cloud parameterizations

Full access
Andrew R. Jongeward, Zhanqing Li, Hao He, and Xiaoxiong Xiong

, organic carbon, and SO 2 from 1980 to 2010 for hindcast model experiments . Atmos. Chem. Phys. Discuss. , 12 , 24 895 – 24 954 , doi: 10.5194/acpd-12-24895-2012 . Engel-Cox , J. A. , C. H. Hollman , B. W. Coutant , and R. M. Hoff , 2004 : Qualitative and quantitative evaluation of MODIS satellite sensor data for regional and urban scale air quality . Atmos. Environ. , 38 , 2495 – 2509 , doi: 10.1016/j.atmosenv.2004.01.039 . Fischer-Bruns , I. , J. Feichter , S. Kloster , and

Full access
Christopher G. Kruse, Ronald B. Smith, and Stephen D. Eckermann

and high-resolution modeling. Acknowledgments This work was supported by the National Science Foundation (NSF-AGS-1338655) and the Chief of Naval Research (PE-61153N). High-performance computing was performed on the Yellowstone supercomputer (ark:/85065/d7wd3xhc) with support provided by NCAR’s Computational and Information Systems Laboratory, sponsored by the National Science Foundation. We would like to acknowledge Andreas Dörnbrack for providing the ECMWF analyses, Johannes Wagner for

Full access
George H. Bryan and Richard Rotunno

interest to us because they can be used to evaluate the maximum cold pool depth predicted by analytic theory (e.g., Benjamin 1968 , p. 219). Because the cold pool depths in BAMEX cases were not negligible compared to the density-scale height, the incompressible equations cannot be justified for these flows. Therefore, these observations raise questions about the applicability of results based on the incompressible equations to atmospheric gravity currents. The purpose of this new study is to derive

Full access
Hai Lin, Gilbert Brunet, and Jacques Derome

indications of extratropical forcing, it is still unclear how the MJO is excited and maintained. Using a linear two-level model with a realistic three-dimensional basic-state flow and a cumulus convection parameterization, Frederiksen and Frederiksen (1997 , hereafter FF ) found that one of the unstable modes couples the extratropics with a tropical 40–60-day disturbance, which is similar to the MJO. The connection of the MJO to the extratropical instability was also suggested by Straus and Lindzen

Full access
Philip Cunningham

with the interaction remain poorly understood, and in this regard, numerical simulations may be able to provide insight. Herein, the dynamics of the interaction between buoyant plumes and density currents are investigated from an idealized modeling perspective, and a series of numerical simulations are described that examine the interactions between a buoyant plume that is representative of a fire plume and a density current that could be representative of a thunderstorm outflow, a sea-breeze front

Full access