Search Results

You are looking at 1 - 8 of 8 items for :

  • Water vapor x
  • Terrain-Induced Rotor Experiment (T-Rex) x
  • All content x
Clear All
Ronald B. Smith, Bryan K. Woods, Jorgen Jensen, William A. Cooper, James D. Doyle, Qingfang Jiang, and Vanda Grubišić

1. Introduction The sharp boundary between the troposphere and stratosphere has been largely explained as the result of convective cloud-top entrainment (e.g., Staley 1960 ; Reid and Gage 1981 ; Held 1982 ; Sherwood and Dessler 2003 ). The tropopause is defined not only by the jump in temperature lapse rate but also by strong gradients in water vapor and ozone concentrations. In midlatitudes, the jet stream often has its maximum speed at the tropopause level. It is suspected that these

Full access
Qingfang Jiang and James D. Doyle

and rapid microphysical processes with time scales typically less than 3 h. The 3-hourly radiosonde observations indicate substantial variations of water vapor content in the lower troposphere during the observational periods. b. The four moist IOPs The remainder of this paper focuses on the four very moist cases with the upstream RH max > 90%. They correspond to the afternoon flight on 20 March (i.e., IOP-5), the afternoon flight on 25 March (IOP-6c), the afternoon flight on 31 March (IOP-8

Full access
Yanping Li, Ronald B. Smith, and Vanda Grubišić

1. Introduction Diurnal solar atmospheric tides are excited primarily by the absorption of solar radiation by water vapor in the troposphere and ozone in the stratosphere, as well as by the turbulent heat transfer near the ground ( Forbes and Garrett 1979 ). Tides can be easily detected in surface pressure observations. In a hydrostatic atmosphere, surface pressure variations result from the integral effect in the vertical direction of density and temperature perturbations above the ground. For

Full access
James D. Doyle, Qingfang Jiang, Ronald B. Smith, and Vanda Grubišić

1997 ). The Louis (1979) surface layer parameterization, which makes use of a surface energy budget based on the force-restore method, is used to represent the surface fluxes. Subgrid-scale moist convection is represented using the Kain and Fritsch (1993) parameterization. The grid-scale evolution of the moist processes is predicted explicitly from budget equations for cloud water, cloud ice, raindrops, snowflakes, and water vapor ( Rutledge and Hobbs 1983 ). The short- and longwave radiation

Full access
Thomas Raab and Georg Mayr

is temperature, p 0 is a reference pressure, R d is the gas constant of dry air, ϵ is the ratio of molecular weight of water vapor to the mean molecular weight of dry air, and c pd is the heat capacity of dry air at constant pressure. As θ υ is conserved for frictionless, unsaturated airflow, it is possible to distinguish the origin of the flow (pass or crest) by comparing windstorm virtual potential temperatures computed from surface measurements with the vertical profile on the

Full access
James D. Doyle, Saša Gaberšek, Qingfang Jiang, Ligia Bernardet, John M. Brown, Andreas Dörnbrack, Elmar Filaus, Vanda Grubišić, Daniel J. Kirshbaum, Oswald Knoth, Steven Koch, Juerg Schmidli, Ivana Stiperski, Simon Vosper, and Shiyuan Zhong

Schoeberl 1989 ). Mountain waves can have an important impact on the atmosphere because of their role in downslope windstorms ( Klemp and Lilly 1975 ); clear-air turbulence ( Clark et al. 2000 ); vertical mixing of water vapor, aerosols, and chemical constituents in the stratosphere ( Dörnbrack and Dürbeck 1998 ); potential vorticity generation ( Schär and Durran 1997 ); and orographic drag influence on the general circulation ( Bretherton 1969 ; Ólafsson and Bougeault 1996 ). Although numerical models

Full access
Qingfang Jiang and James D. Doyle

water vapor ( Rutledge and Hobbs 1983 ) and the subgrid-scale moist convective processes are parameterized using an approach following Kain and Fritsch (1993) . The short- and longwave radiation processes are parameterized following Harshvardhan et al. (1987) . The initial fields for the model are created from multivariate optimum interpolation analysis of upper-air sounding, surface, commercial aircraft, and satellite data that are quality controlled and blended with the 12-h COAMPS forecast

Full access
James D. Doyle, Vanda Grubišić, William O. J. Brown, Stephan F. J. De Wekker, Andreas Dörnbrack, Qingfang Jiang, Shane D. Mayor, and Martin Weissmann

trapped lee waves with a wavelength that is about 20% longer than for waves generated by a single ridge. Although a cloud and precipitation shield existed upstream of the Sierra, in general there were very few clouds in the lee during this event. However, a water vapor image from the Moderate Resolution Imaging Spectroradiometer (MODIS) valid at 2015 UTC 16 April 2006 exhibits a pattern of dry and moist lineal features consistent with trapped gravity waves in the lee of the Sierra Nevada (not shown

Full access