Search Results

You are looking at 151 - 160 of 215 items for :

  • Acoustic measurements/effects x
  • Monthly Weather Review x
  • Refine by Access: All Content x
Clear All
Tzvi Gal-Chen

. They foundthat the estimates of ~ from two Doppler radars werenot far apart and were also consistent with the towermeasurements. D(z) is a positive empirical function(~1, away from the surface) designed to partiallycorrect for the various inadequacies of the parameterization. As is discussed later in this section, itsexplicit form can be determined from observations. Overall, we see that the parameterization outlinedhere uniquely determines the subgrid-scale effects interms of measured

Full access
S. Bielli, P. Barbour, R. Samelson, E. Skyllingstad, and J. Wilczak

resolved by the Eta sea surface temperature analysis ( Samelson et al. 2002 ). A 915-MHz Radio Acoustic Sounding System (RASS) profiler was in place at Newport during this period, supported by the Oregon NOPP project. Hourly consensus-averaged winds available from the National Oceanic and Atmospheric Administration/Environmental Technology Laboratory (NOAA/ETL) ( were used to produce the wind composites. Details on wind profiler processing and accuracy can be

Full access
R. K. Smith, R. N. Ridley, M. A. Page, J. T. Steiner, and A. P. Sturman

Island are discussed byMcGann (1983), McKendry ( 1983 ), McKendry et al.(1986), and Ryan (1987), who examine the spatial,annual, and diurnal variability of the wind field. Similarorographic and heating effects are known to occur onthe east coast of the North Island, but they have notbeen subject to systematic studies. When a northwest flow is established and there is asubsequent southerly or southwesterly change, there isoften a very rapid fall in temperature. Crawford (1977)and Revellet al. (1987

Full access
Ying-Hwa Kuo and Yong-Run Guo

rawinsondes, theyfound that profiler wind observations, because of higheraccuracy, are likely to have a positive impact on shortrange prediction utilizing a static initialization. Thisimpact, however, is only moderate and it decreases withc 1989 American Meteorological Society1976 MONTHLY WEATHER REVIEW VOLUME 117time. In light of the time-continuous nature of the profiler measurements, it is clear that static

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

the meso- β scale (~100 km; e.g., Atkins et al. 1999 ; Richardson 1999 ; Rasmussen et al. 2000 ; Richardson et al. 2007 ); however, investigations of the effects of meso- γ -scale (~10 km) heterogeneity on deep moist convection have been limited to very few studies, such as a numerical study of a cumulus congestus cloud in a CBL with no ambient shear ( Carpenter et al. 1998 ) and a numerical study of a supercell in a poorly resolved CBL ( Crook and Weisman 1998 ). Crook and Weisman discovered

Full access
Nathaniel S. Winstead and Pierre D. Mourad

data, the supplemental sounding sites also provided wind profiler data from the Remote Acoustic Sounding System (RASS). The first of these soundings, at 1200 UTC 14 January, 1998, was launched from Sheboygan (ISS2) while the second, at 1205 UTC on the same day, was launched from Montague (ISS1). The sounding sites are labeled in Fig. 1a . Of interest to this study, RASS data were available from both sites for several hours surrounding 1200 UTC. The WSR-88D base reflectivity data presented here

Full access
Ming Hu, Ming Xue, Jidong Gao, and Keith Brewster

tornadogenesis. The possible reason for the smaller impact of radial velocity data is that the initial thermal, moisture, and cloud field disturbances introduced by the reflectivity can sustain during forecast and induce corresponding changes in wind field but initial wind disturbances from radial velocity disperse quickly in the form of acoustic waves in the absence of proper balances with other fields and among the three wind components themselves. d. Comparison of assimilation results To understand the

Full access
Robert M. Banta

). Theseimpacts include effects on fire weather, air pollution,aviation and military operations, agriculture, recreation, urban development, shipping, and transportation.The sea breeze also influences coastal ocean currents,which affect coastal erosion and beach development,coastal marine ecosystems, and activities such as fishing and shellfishing. We recently used analyses of Doppler lidar scan datataken at Monterey Bay to reveal the structure of theshallow (<300 m deep) sea-breeze layer as it formedin

Full access
Stanley G. Benjamin, Dezsö Dévényi, Stephen S. Weygandt, Kevin J. Brundage, John M. Brown, Georg A. Grell, Dongsoo Kim, Barry E. Schwartz, Tatiana G. Smirnova, Tracy Lorraine Smith, and Geoffrey S. Manikin

. Using the optimal digital filter, a weighted mean of the dynamic variables over the forward/backward integrations is then introduced as the actual initial condition for those variables. There is no filtering of moisture fields at this time. To monitor the effects of the DFI on the RUC model, the mean absolute surface pressure tendency ( N 1 in Huang and Lynch 1993 ) is calculated as Figure 2 shows the N 1 parameter for a set of 6-h RUC model forecasts initialized with and without the DFI. At

Full access
Margaret A. LeMone, Mukul Tewari, Fei Chen, and Jimy Dudhia

velocity , where g is the acceleration of gravity, is the friction velocity, and and are the vertical fluxes of the horizontal wind components u and υ at the surface, respectively. The TKE profiles in the figure closely resemble those based on aircraft measurements in a similar environment by Stull (1988 , his Fig. 2.9). The profiles represent data averaged over time and space for LES or observations; with statistical uniformity and a sufficient sample, they approach the ideal “ensemble

Full access