Search Results

You are looking at 161 - 170 of 215 items for :

  • Acoustic measurements/effects x
  • Monthly Weather Review x
  • Refine by Access: All Content x
Clear All
Paul J. Neiman, Natalie Gaggini, Christopher W. Fairall, Joshua Aikins, J. Ryan Spackman, L. Ruby Leung, Jiwen Fan, Joseph Hardin, Nicholas R. Nalli, and Allen B. White

. 2003 , 2006 , 2011 ; Dettinger et al. 2011 ; Lavers et al. 2011 ; Neiman et al. 2011 ) and an increase in high-elevation mountain snowpack (e.g., Neiman et al. 2008b ; Guan et al. 2012 , 2013 ). Aerosols, which originate from both local sources and via long-range transport, can modulate the intensity and distribution of precipitation during AR landfalls (e.g., Ault et al. 2011 ; Creamean et al. 2013 , 2015 ). Collecting and analyzing extensive CalWater measurements in the AR environment

Full access
F. M. Ralph, C. Mazaudier, M. Crochet, and S. V. Venkateswaran

, the detailed vertical structure of the gravity current itselfis well resolved from the data. Moreover, the vertical velocity measurements provided by the sodars and theradar wind profiler at high time resolution have given unique information about the height structure of gravitywaves excited by the gravity current. Although only wave periods, and not phase speeds or wavelengths, aredirectly measured, it is possible to make reasonable inferences about wave excitation mechanisms and aboutthe

Full access
Qingnong Xiao, Xiaolei Zou, and Bin Wang

forecast model into the initial conditions ( Kurihara and Ross 1993 ; Kurihara et al. 1995 ; Peng et al. 1993 ; Liu et al. 1997 ); and (iii) improve the initial conditions by making use of satellite–rain gauge based measurements of rainfall through a physical initialization procedure ( Krishnamurti and Ross 1993 , 1995 , 1997 , 1998 ). Although bogusing schemes are employed by many NWP centers, they do not always work well for a large range of tropical cyclones ( Wang 1998 ). In order to minimize

Full access
Raul A. Valenzuela and David E. Kingsmill

gap flows that includes both pressure-gradient forces and frictional effects: Here, u (0) and u ( x ) represent the airflow at the entrance and at some distance x downstream from the gap entrance (respectively), PGF is the along-gap pressure gradient force ( ), and K = 2.8 C D / H is a parameter representing friction through a drag coefficient ( C D ) and the average depth of the boundary layer within the gap ( H) . After exiting the mountain barrier, gap flows are able to turn to the right

Full access
Eugene W. McCaul Jr., Charles Cohen, and Cody Kirkpatrick

on storm behavior. In CAPE-starved environments, storms were generally weak, except when the parcel buoyancy profile was shaped to provide a maximum close to cloud base, while in shear-starved environments, storms could become stronger if buoyancy reached a maximum at higher altitudes, so that storm cold pools did not become too strong. Subsequently, McCaul and Cohen (2002 , hereafter MC02 ) extended the MW01 methodology to experiments using a cloud model that included the effects of ice

Full access
G. R. Halliwell Jr., L. K. Shay, J. K. Brewster, and W. J. Teague

from moored acoustic Doppler current profiler (ADCP) measurements. Unfortunately, targeted aircraft observations that could have provided simultaneous subsurface profiles of temperature, salinity, and currents before, during, and after Ivan were not available, thus limiting the extent of the evaluation that could be performed. Section 2 describes the ocean model, forcing fields, and observations. Section 3 summarizes the model experiments and analysis procedures. The evaluation and

Full access
Christopher J. Nowotarski, Paul M. Markowski, and Yvette P. Richardson

effects of low-level static stability on the characteristics of supercell thunderstorms. The supercells are simulated within horizontally homogeneous environments having varying degrees of surface-based CIN. The supercells simulated over a stable boundary layer are compared to a supercell in a control experiment initialized in an environment with negligible low-level static stability. Though the updraft and downdraft structures of surface-based supercell thunderstorms have been well documented by

Full access
Changan Zhang, David A. Randall, Chin-Hoh Moeng, Mark Branson, Kerry A. Moyer, and Qing Wang

computed using data taken from thepaper of Lenschow et al. (1988), as listed in Table1. The data was collected in May 1979 in centralOklahoma, in support of a subprogram of the SevereEnvironmental Storms and Mesoscale Experiment(SESAME). Most of the data are based on aircraftobservations made using the NCAR Queen Air. Tethered balloon and acoustic sounder systems were alsoused. The observations were filtered, with high- andlow-frequency cutoffs of 10 Hz and 0.01 Hz, respectively. We have estimated

Full access
Martin Charron, P. L. Houtekamer, and Peter Bartello

member of ensemble α ; β equals one (two) when α is two (one), and N is the number of ensemble members ( N = 50 throughout the paper). Details on the numerical solver can be found in Houtekamer and Mitchell (1998 , 2001 ). 3. Model description and experiment settings At the meso- β scale (20–200 km) and in the context of the present study, acoustic and Rossby waves are neglected in the development and evolution of the relevant dynamics. This dynamics is mainly nongeostrophic and can give

Full access
Gerald G. Mace and Thomas P. Ackerman

Office, 1991 ) and the Atmospheric Radiation Measurement (ARM) Program (Stokes and Schwartz1994). ARM has augmented the WPDN inner profilerswith five radiosonde sites (Fig. 1 ) that collect soundings at high temporal resolution during frequent campaigns. Integrating major field efforts as closely as possiblewith a dense spatial network of wind profilers seems Corresponding author address: Dr. Gerald G. Mace, Departmentof Meteorology, The Pennsylvania State University, 503 WalkerBuilding

Full access