Search Results

You are looking at 141 - 150 of 520 items for :

  • Lidar observations x
  • Monthly Weather Review x
  • Refine by Access: All Content x
Clear All
Juanzhen Sun and Ying Zhang

( Weckwerth et al. 2004 ). The IHOP_2002 field campaign took advantage of existing observing systems in the Southern Great Plains of the United States, including the well-distributed WSR-88D units in the region. There were also a large array of specially deployed instrumentation, including, but not limited to, aircraft, mobile radars, mobile soundings, dropsondes, lidar, and radiometers. Several studies have explored the role of assimilating some of the nonconventional observations obtained during IHOP on

Full access
Haldun Karan and Kevin Knupp

Crook (2003) observed similar structures in the form of radar finelines in seven out of 10 cases involving collisions between outflows and the sea breeze front over Florida. Their study suggested a clear relationship between virtual potential temperature deficits within the two density currents and the after-collision characteristics. Lidar observations of small-scale interactions of colliding outflows ( Intrieri et al. 1990 ) revealed that the warmer of the two outflows was deflected upward to

Full access
V. S. Komarov, A. V. Lavrinenko, N. Ya. Lomakina, and S. N. Il’in

application of the prognostic data and/or the Terminal Aerodrome Forecast Product allows for the safety of aircraft taking off and landing to be improved. Numerous investigations devoted to short-term forecasting of the ABL have been performed recently using one-dimensional (1D) models, surface observations, and an ensemble Kalman filter (EnKF) algorithm (e.g., see Hacker and Rostkier-Edelstein 2007 ; Rostkier-Edelstein and Hacker 2010 ). This class of models provides implementation of short

Full access
Chunxi Zhang, Yuqing Wang, and Ming Xue

lidar in Fig. 13 . The EEPS simulation well captures the features of the diurnal variations of TKE. In particular, the height of large TKE is very close to that in observations ( Figs. 13a,b ). For example, both the observed and the EEPS simulated TKEs reach 2.2 km height on 28 October. Note that Fig. 12 shows underprediction of TKE within the atmospheric boundary layer (ABL) during most nighttime conditions, while Fig. 13 shows overprediction of TKE within the ABL during most nighttime

Free access
Gerrit Burgers, Peter Jan van Leeuwen, and Geir Evensen

and applied with success in a twin experiment in Evensen (1994a) and in a realistic application for the Agulhas Current using Geosat altimeter data in Evensen and van Leeuwen (1996) . A serious point that will be discussed here and was not known during the previous applications of the EnKF is that for the analysis scheme to be consistent one must treat the observations as random variables. This assumption was applied implicitly in the derivation of the analysis scheme in Evensen (1994b

Full access
Brian C. Ancell, Erin Kashawlic, and John L. Schroeder

wind forecasts associated with a number of modeling systems and various assimilated observation types. Here we present results regarding one aspect of the WFIP project that focused on the accuracy of forecast initial conditions, which subsequently depends on both the data assimilation technique used to ingest observations as well as the extent and quality of the observations themselves. Two leading atmospheric data assimilation techniques that aim to achieve the most likely analysis with the

Full access
Thomas R. Parish, David A. Rahn, and Dave Leon

observations made by the University of Wyoming King Air research aircraft (UWKA) of a Catalina eddy circulation are presented. Data were collected as part of the Precision Atmospheric Marine Boundary Layer Experiment (PreAMBLE) and observations discussed here are taken from the eddy circulation observed on 9 June 2012. The purpose of the paper is to present evidence as to the dynamics that force the eddy circulation in the California Bight region. Stimulus for the study was the acknowledged lack of

Full access
Bachir Annane, Brian McNoldy, S. Mark Leidner, Ross Hoffman, Robert Atlas, and Sharanya J. Majumdar

1. Introduction Ocean surface wind observations from satellites have been shown to improve the accuracy of numerical weather analyses and forecasts ( Atlas et al. 2001 ; Atlas 1997 ; Candy et al. 2009 ; Leidner et al. 2003 ; Schulz et al. 2007 ). Accurate surface wind analyses and forecasts are key to estimating the potential damage from storm surge (the deadliest tropical storm hazard; Rappaport et al. 2009 ; Powell and Reinhold 2007 ) and wind. However, most current satellite observing

Full access
Sophie Bastin, Philippe Drobinski, Vincent Guénard, Jean-Luc Caccia, Bernard Campistron, Alain M. Dabas, Patricia Delville, Oliver Reitebuch, and Christian Werner

examines the mechanisms driving the unsteady and inhomogeneous aspects of the flow structure at the Rhône Valley exit. Section 6 concludes the study. 2. Measurements and model a. Observations During the ESCOMPTE experiment, a wide range of instruments was deployed around Marseille, leading to a dense network of observations available from Doppler and ozone lidars, wind profilers, sodars, radiosoundings, and meteorological surface stations (see the details in Cros et al. 2004 ). The aim of this

Full access
Roger M. Wakimoto, Hanne V. Murphey, Edward V. Browell, and Syed Ismail

dryline appears to flow up and over the moist air in Fig. 6 similar to the lidar observations presented by Parsons et al. (1991) . There also appears to be descent of the flow 3–4 km east of the dryline. Such descent has been proposed by Hane et al. (1993) to be the downward branch of the dryline solenoidally driven circulation owing to a gradient in θ V across the dryline (the existence of the θ V gradient will be shown in section 5 ). The mean kinematic structure of the dryline was

Full access