An Evaluation of Two NEXRAD Wind Retrieval Methodologies and Their Use in Atmospheric Dispersion Models

Journal Article · Mon Sep 01 04:00:00 EDT 2008 · Journal of Applied Meteorology and Climatology, 47(9):2351-2371

DOI:https://doi.org/10.1175/2008JAMC1853.1· OSTI ID:939339

Fast, Jerome D; Newsom, Rob K; Allwine, K Jerry; Xu, Qin; Zhang, Pengfei; Copeland, Jeffrey H; Sun, Jenny

Two entirely different methods for retrieving 3-D fields of horizontal winds from NEXRAD radial velocities have been evaluated using radar wind profiler measurements to determine whether routine wind retrievals would be useful for atmospheric dispersion model applications. The first method uses a physical algorithm based on four-dimensional variational data assimilation and the second simpler method uses a statistical technique based on an analytic formulation of the background error covariance. Both methods can be run in near real time, but the simpler method executed about 2.5 times faster than the four-dimensional variational method. The observed multi-day and diurnal variations in wind speed and direction were reproduced by both methods within about 1.5 km of the ground in the vicinity of Oklahoma City during July 2003. However, wind retrievals overestimated the strength of the nighttime low-level jet by as much as 65%. The wind speeds and directions obtained from both methods were usually similar when compared to profiler measurements, and neither method out-performed the other statistically. Within a dispersion model framework, the 3-D wind fields and transport patterns were often better represented when the wind retrievals were included along with operational data. Despite uncertainties in the wind speed and direction obtained from the wind retrievals that is higher than from remote sensing radar wind profilers, the inclusion of the wind retrievals are likely to produce more realistic temporal variations in the winds aloft than would be obtained by interpolation using the available radiosondes, especially during rapidly changing synoptic and mesoscale conditions.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 939339
• Report Number(s): PNNL-SA-56373; 400904120
• Journal Information: Journal of Applied Meteorology and Climatology, 47(9):2351-2371, Journal Name: Journal of Applied Meteorology and Climatology, 47(9):2351-2371 Journal Issue: 9 Vol. 47
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ALGORITHMS
DAILY VARIATIONS
DATA ANALYSIS
ENVIRONMENTAL TRANSPORT
RADAR
REMOTE SENSING
VARIATIONAL METHODS
WIND