Observations of strong wind shear using pulse compression radar

Browning, K. A.; James, P. K.; Parkes, D.M.; Rowley, Clark; Whyman, A. J.

doi:10.1038/271529a0

Cited by 10 publications

(3 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Many observational and numerical studies have examined the effects of vertical wind shear on intensity and organization of convective systems, especially for squall lines [e.g., Coniglio et al , ; Rotunno et al , ; Takemi , ; Weisman and Rotunno , ]. Past observations showed that strong wind shear (SWS) may exist at different vertical levels [ Browning et al , ; Hande et al , ; Jensen et al , ; Sathiyamoorthy et al , ; Stensrud et al , ], and wind shear interacts with convection in a complex way. For example, the convective momentum transport is known to transport momentum downward, reducing the upper level winds [ Hagos et al , ; Moncrieff and Klinker , ].…”

Section: Introductionmentioning

confidence: 99%

Roles of wind shear at different vertical levels: Cloud system organization and properties

Chen,

Fan,

Hagos

et al. 2015

JGR Atmospheres

View full text Add to dashboard Cite

Understanding critical processes that contribute to the organization of mesoscale convective systems (MCSs) is important for accurate weather forecasts and climate predictions. In this study, we investigate the effects of wind shear at different vertical levels on the organization and properties of convective systems using the Weather Research and Forecasting model with spectral bin microphysics. Based on a control run for a MCS with weak wind shear (Ctrl), we find that increasing wind shear at the lower troposphere (L-shear) leads to a more organized quasi-line convective system. Strong wind shear in the middle troposphere (M-shear) tends to produce large vorticity and form a mesocyclone circulation and an isolated strong storm that leans toward supercellular structure. By increasing wind shear at the upper vertical levels only (U-shear), the organization of the convection is not changed much, but the convective intensity is weakened. Increasing wind shear in the middle troposphere for the selected case results in a significant drying, and the drying is more significant when conserving moisture advection at the lateral boundaries, contributing to the suppressed convective strength and precipitation relative to Ctrl. Precipitation in the L-shear and U-shear does not change much from Ctrl. Evident changes of cloud macrophysical and microphysical properties in the strong wind shear cases are mainly due to large changes in convective organization and water vapor. The insights obtained from this study help us better understand the major factors contributing to convective organization and precipitation.

show abstract

Section: Introductionmentioning

confidence: 99%

Roles of wind shear at different vertical levels: Cloud system organization and properties

Chen,

Fan,

Hagos

et al. 2015

JGR Atmospheres

View full text Add to dashboard Cite

show abstract

“…values of wind shear and stable temperature gradients (see, for example,35,36,152,160,161) ; detailed analysis of radiosonde data byDowney et al (90) has given similar results.…”

mentioning

confidence: 75%

Fundamental and Applied Aspects of Astronomical “Seeing”

Coulman¹

1985

Annu. Rev. Astron. Astrophys.

View full text Add to dashboard Cite

“…Since then, more engineering and technical aspects have been investigated by Bucci and Urkowitz (1993), Keeler (1995) and Mudukutore et al (1998), among others. Meteorological research carried out using this technique include studies of clear-air wind shear using high power radar (Browning et al, 1978), cloud observations with millimetric radar (Sekelsky and McIntosh, 1996;Clothiaux et al, 2000;Uttal and Kropfli, 2001) or airborne radar precipitation observations (Girardin-Gondeau et al, 1991;Durden et al, 1994;Tanner et al, 1994). Among other related applications, pulse-compression techniques have also been extensively employed in wind-profilers and mesospherestratosphere-troposphere (MST) radars (Gonzáles and Woodman, 1984;Farley, 1985;Sulzer and Woodman, 1985;Thomas, 1999), space-borne precipitation radars (Meneghini and Kozu, 1990;Amayenc et al, 1993), sealevel satellite altimetry (Chelton et al, 1989) and also in sodar systems (Wilson and Thomson, 1994;Ito, 1998).…”

Section: Introductionmentioning

confidence: 99%

Improving weather radar observations using pulse‐compression techniques

O'Hora

Bech

2007

Meteorological Applications

View full text Add to dashboard Cite

Pulse-compression techniques have been used for many years to increase sensitivity and range resolution in military and air traffic control radar systems. However, their application to ground-based weather radar has, so far, been very limited and restricted to research applications. This article describes the practical implementation of pulse compression using non-linear frequency modulation (NLFM) in a commercial digital processor/receiver and demonstrates its application to operational weather radars.Three case studies are presented, including the first application of pulse compression to ground-based travelling wave tube (TWT) weather radars. TWT radars use coherent transmitters with relatively low peak power compared to traditional magnetron or klystron systems, so in this case the sensitivity gain is crucial. The cases are from two different operational radars and illustrate the improved range resolution and sensitivity gain obtained using NLFM pulses compared to traditional simple pulses. Observations obtained using NLFM 40 µs pulses were nearly 15 dB more sensitive than those recorded with lower resolution using 1 µs simple pulses. A comparison of concurrent precipitation observations obtained with a TWT radar using pulse compression and low peak power (NLFM 40 µs and 8 kW) and a nearby traditional magnetron weather radar (2 µs and 250 kW) is also presented. The higher power system was more sensitive by less than 4 dB, but the improved resolution in the pulse compression allowed for enhanced Doppler filtering of ground clutter.

show abstract

Observations of strong wind shear using pulse compression radar

Cited by 10 publications

References 4 publications

Roles of wind shear at different vertical levels: Cloud system organization and properties

Roles of wind shear at different vertical levels: Cloud system organization and properties

Fundamental and Applied Aspects of Astronomical “Seeing”

Improving weather radar observations using pulse‐compression techniques

Contact Info

Product

Resources

About