Search Results

You are looking at 1 - 10 of 10 items for :

  • Radiative fluxes x
  • Mountain Terrain Atmospheric Modeling and Observations (MATERHORN) x
  • All content x
Clear All
Jeffrey D. Massey, W. James Steenburgh, Sebastian W. Hoch, and Jason C. Knievel

et al. 2003 ; Cheng and Steenburgh 2005 ). In this paper, we concentrate on the initialization and parameterization of land surface characteristics and processes, which control the surface energy budget and contribute to NST errors through the inaccurate partitioning of sensible, latent, and ground heat fluxes (e.g., Huang et al. 1996 ; Davis et al. 1999 ; Marshall et al. 2003 ; Reeves et al. 2011 ). In most land surface models (LSMs), land surface parameters (e.g., albedo, roughness length

Full access
Feimin Zhang and Zhaoxia Pu

al. 2007 , 2016 ). Surface radiative cooling is closely related to the surface energy balance, which is composed of incoming and outgoing radiation and heat fluxes in the atmosphere, canopy, and soil. The complexities involved in the calculation of fluxes are substantial, especially in the case of radiation fog or ice fog. In numerical models, the parameterization of the surface energy balance is strongly related to the parameterizations of both the land surface and boundary layer. Specifically

Open access
Robert S. Arthur, Katherine A. Lundquist, Jeffrey D. Mirocha, and Fotini K. Chow

1. Introduction In mountainous terrain, the diurnal variations of the surface sensible heat flux can lead to thermally driven upvalley or upslope flow during the daytime and downvalley or downslope flow during the nighttime ( Zardi and Whiteman 2013 ). Topographic effects on radiation can strongly influence these flows by creating large spatiotemporal inhomogeneities in the net radiation, and thus in the surface energy budget. These effects include topographic shading, where direct solar

Open access
Manuela Lehner, C. David Whiteman, Sebastian W. Hoch, Derek Jensen, Eric R. Pardyjak, Laura S. Leo, Silvana Di Sabatino, and Harindra J. S. Fernando

respective wind components; and υ s is the wind component in the cross-slope direction y . The terms on the left-hand side are heat storage or potential temperature tendency, horizontal advection in the along-slope and cross-slope directions, and slope-normal advection. The two terms on the right-hand side are radiative-flux divergence and heat-flux divergence, where ρ 0 is density, c p is the heat capacity of air at constant pressure, and R is the radiative flux. Potential temperature storage

Full access
Jeffrey D. Massey, W. James Steenburgh, Sebastian W. Hoch, and Derek D. Jensen

-DS and EFS-Playa. During MATERHORN-Spring, data are available continuously at both sites. Fig . 2. Photographs of (a) EFS-DS and (b) EFS-Playa, illustrating the difference in land surface and vegetation cover. The photographs show the sawhorse-type structure supporting the pyranometers and pyrgeometers deployed to measure the incoming and outgoing SW and LW radiative fluxes. Table 1. MATERHORN-Fall EFS site availability. The X indicates that data are available for that day and site. Given the large

Full access
H. J. S. Fernando, E. R. Pardyjak, S. Di Sabatino, F. K. Chow, S. F. J. De Wekker, S. W. Hoch, J. Hacker, J. C. Pace, T. Pratt, Z. Pu, W. J. Steenburgh, C. D. Whiteman, Y. Wang, D. Zajic, B. Balsley, R. Dimitrova, G. D. Emmitt, C. W. Higgins, J. C. R. Hunt, J. C. Knievel, D. Lawrence, Y. Liu, D. F. Nadeau, E. Kit, B. W. Blomquist, P. Conry, R. S. Coppersmith, E. Creegan, M. Felton, A. Grachev, N. Gunawardena, C. Hang, C. M. Hocut, G. Huynh, M. E. Jeglum, D. Jensen, V. Kulandaivelu, M. Lehner, L. S. Leo, D. Liberzon, J. D. Massey, K. McEnerney, S. Pal, T. Price, M. Sghiatti, Z. Silver, M. Thompson, H. Zhang, and T. Zsedrovits

could be traced to errors in the initialization of soil moisture and parameterization of soil thermal conductivity. WRF forecasts of nocturnal surface temperature as well as the predicted ground heat flux, soil thermal conductivity, and near-surface radiative fluxes could be improved by initializing with measured soil moisture and replacing the Johansen (1975) parameterization for soil thermal conductivity in the Noah land surface model with that proposed by McCumber and Pielke (1981) for silt

Full access
Sean M. Wile, Joshua P. Hacker, and Kenneth H. Chilcoat

radiative cooling at KSLC; precipitation falling into a weakened inversion and shallow cold pool case, where precipitation increased low-level moisture supporting fog formation; and shallow cold pool advecting from the GSL case, where radiative cooling over the lake enabled fog to form and later move over KSLC. b. Dense fog event At 2243 UTC 23 January 2009, dense fog developed over KSLC, forcing the closure of one runway and prompting the National Weather Service to issue a dense fog warning

Full access
Hailing Zhang, Zhaoxia Pu, and Xuebo Zhang

studied ( Hanna and Yang 2001 ; Zhang and Zheng 2004 ). To accurately simulate near-surface atmospheric conditions, several factors must be represented properly in numerical models. These include land use, topography, surface heat flux transport, and various characteristics of the lower atmosphere ( Lee et al. 1989 ; Wolyn and McKee 1989 ; Shafran et al. 2000 ; Cheng and Steenburgh 2005 ). Thus, the accurate simulation of near-surface atmospheric diurnal variation is one of the most important and

Full access
Jeffrey D. Massey, W. James Steenburgh, Jason C. Knievel, and William Y. Y. Cheng

modeling systems, resolutions, and configurations (e.g., Cheng and Steenburgh 2005 ; Hart et al. 2005 ; Zhang et al. 2013 ; Massey et al. 2014 ). Hypothesized contributors to the DTR underprediction include inadequate vertical or horizontal resolution, near-surface turbulence flux errors, or inaccurate land surface characteristics and processes (e.g., Hanna and Yang 2001 ; Mass et al. 2002 ; Marshall et al. 2003 ; Cheng and Steenburgh 2005 ; Massey et al. 2014 ). Recently, Massey et al. (2014

Full access
Matthew E. Jeglum, Sebastian W. Hoch, Derek D. Jensen, Reneta Dimitrova, and Zachariah Silver

zone 12T) of the study area at DPG with the southern part of Granite Mountain detailed in the inset. The color-coded circles indicate the daily frequency of LTFs at various sites at DPG. Elevation contours are 80 m in the main plot and 30 m in the inset, with the 1315-m contour annotated in both. The transect in the inset marked L1–L4 is the primary slope transect in this study. The location of the flux tower ES2 and the Granite Ridge and West slope sites are annotated in the inset. An extensive

Full access