scholarly journals Structures of Bragg Scatter Observed with the Polarimetric WSR-88D

2013 ◽  
Vol 30 (7) ◽  
pp. 1253-1258 ◽  
Author(s):  
Valery M. Melnikov ◽  
Richard J. Doviak ◽  
Dusan S. Zrnić ◽  
David J. Stensrud
Keyword(s):  
Boundary Layer ◽  
Signal Processing ◽  
Data Collection ◽  
Convective Boundary Layer ◽  
Dual Polarization ◽  
Detection Capability ◽  
Convective Boundary ◽  
Boundary Layer Turbulence ◽  
Fine Structures

Abstract Enhancements to signal processing and data collection in the dual-polarization Weather Surveillance Radar-1988 Doppler (WSR-88D) to increase its detection capability yield observations of “fine” structures from Bragg scatterers. Several types of the fine structures observed in and above the boundary layer are discussed. These Bragg scatter structures include the top of the convective boundary layer, nonprecipitating clouds, strong convective plumes above the boundary layer, and a layer of weak reflections associated with decaying boundary layer turbulence. A conclusion that data from polarimetric WSR-88Ds can be used to obtain the depth of the convective boundary layer is made.

scholarly journals Convective Boundary Layer Depth Estimation from S-Band Dual-Polarization Radar

2018 ◽  
Vol 35 (8) ◽  
pp. 1723-1733 ◽  
Author(s):  
John R. Banghoff ◽  
David J. Stensrud ◽  
Matthew R. Kumjian
Keyword(s):  
Boundary Layer ◽  
New York ◽  
Convective Boundary Layer ◽  
Depth Estimation ◽  
Dual Polarization ◽  
Layer Depth ◽  
Reasonable Estimate ◽  
Convective Boundary ◽  
Using Data ◽  
Differential Reflectivity

AbstractThis study investigates Bragg scatter signatures in dual-polarization radar observations, which are defined by low differential reflectivity values, as a proxy for convective boundary layer (CBL) depth. Using data from the WSR-88D in Twin Lakes, Oklahoma (KTLX), local minima in quasi-vertical profiles of are found to provide a reasonable estimate of CBL depth when compared with depth estimates from upper-air soundings from Norman, Oklahoma (KOUN), during 2014. The 243 Bragg scatter and upper-air sounding CBL depth estimates have a correlation of 0.90 and an RMSE of 254 m. Using Bragg scatter as a proxy for CBL depth was expanded to other seasons and locations—performing well in Wilmington, Ohio; Fairbanks, Alaska; Tucson, Arizona; Minneapolis, Minnesota; Albany, New York; Portland, Oregon; and Tampa, Florida—showing its potential usefulness in monitoring CBL depth throughout the year in a variety of geographic locations and meteorological conditions.

scholarly journals Conceptual study on nucleation burst evolution in the convective boundary layer – Part I: Modelling approach

2005 ◽  
Vol 5 (6) ◽  
pp. 11413-11487 ◽  
Author(s):  
O. Hellmuth
Keyword(s):  
Boundary Layer ◽  
Convective Boundary Layer ◽  
Ultrafine Particle ◽  
Particle Formation ◽  
Convective Boundary ◽  
Aerosol Dynamics ◽  
Boundary Layer Turbulence ◽  
Model Setup ◽  
Conceptual Study ◽  
Modelling Approach

Abstract. A high-order modelling approach to interprete 'continental-type' particle formation bursts in the anthropogenically influenced convective boundary layer (CBL) is proposed. The model considers third-order closure for planetary boundary layer turbulence, sulfur and ammonia chemistry and aerosol dynamics. In part I of the present paper, previous observations of ultrafine particle evolution are reviewed, model equations are derived, the model setup for a conceptual study on binary and ternary homogeneous nucleation is defined, and shortcomings of process parameterization are discussed. In subsequent parts of the paper simulation results obtained within the framework of a conceptual study on the CBL evolution and new particle formation (NPF) will be presented and compared with observational findings.

scholarly journals Columnar modelling of nucleation burst evolution in the convective boundary layer – first results from a feasibility study Part I: Modelling approach

2006 ◽  
Vol 6 (12) ◽  
pp. 4175-4214 ◽  
Author(s):  
O. Hellmuth
Keyword(s):  
Boundary Layer ◽  
Convective Boundary Layer ◽  
Ultrafine Particle ◽  
Particle Formation ◽  
Convective Boundary ◽  
Aerosol Dynamics ◽  
Boundary Layer Turbulence ◽  
First Results ◽  
Conceptual Study ◽  
Modelling Approach

Abstract. A high-order modelling approach to interpret "continental-type" particle formation bursts in the anthropogenically influenced convective boundary layer (CBL) is proposed. The model considers third-order closure for planetary boundary layer turbulence, sulphur and ammonia chemistry as well as aerosol dynamics. In Paper I of four papers, previous observations of ultrafine particle evolution are reviewed, model equations are derived, the model setup for a conceptual study on binary and ternary homogeneous nucleation is defined and shortcomings of process parameterisation are discussed. In the subsequent Papers II, III and IV simulation results, obtained within the framework of a conceptual study on the CBL evolution and new particle formation (NPF), will be presented and compared with observational findings.

scholarly journals Aspects of Convective Boundary Layer Turbulence Measured by a Dual-Doppler Lidar System

2013 ◽  
Vol 30 (9) ◽  
pp. 2132-2142 ◽  
Author(s):  
Luisa Röhner ◽  
Katja Träumner
Keyword(s):  
Boundary Layer ◽  
Convective Boundary Layer ◽  
Horizontal Wind ◽  
High Temporal Resolution ◽  
Wind Component ◽  
Rain Event ◽  
Convective Boundary ◽  
Light Rain ◽  
Boundary Layer Height ◽  
Boundary Layer Turbulence

Abstract Special designed dual-Doppler setups can be used to retrieve simultaneous measurements of two wind components with high temporal resolution in several heights throughout the atmospheric boundary layer. During a field campaign in summer 2011, different scan strategies were performed to demonstrate the opportunities of obtaining variance profiles of the vertical and horizontal wind components in complex terrain. A simplified error analysis reveals the effects of the error propagation of the uncorrelated noise of the single lidar systems. A comparison shows that the course of the derived horizontal wind component is in accordance to in situ measurements. The dual-Doppler vertical wind velocity reflects the up- and downdrafts in a convective boundary layer and is even able to reflect a light rain event. The normalized profiles of the vertical velocity variances reproduce the well-known decrease from about one-third of the boundary layer height to its top. The horizontal velocity variance did not reveal a systematic behavior on the considered days.

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