Volcanological Applications of Doppler Radars: A Review and Examples from a Transportable Pulse Radar in L-Band

Donnadieu, Franck

doi:10.5772/35940

Cited by 29 publications

(33 citation statements)

References 59 publications

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“…For instance, fog monitoring feasibility at airports using BASTA radar is currently underway. We are also experimenting with the possibility of using a BASTA radar for studying volcanic ash (Donnadieu et al 2011;Donnadieu 2012). Some recent experiments have been carried with the objective of analyzing whether the refractivity variability measured with W-band radar can lead to information at hectometer scales on turbulent behavior of the atmosphere.…”

Section: Discussionmentioning

confidence: 99%

BASTA: A 95-GHz FMCW Doppler Radar for Cloud and Fog Studies

Delanoë

Protat

Vinson

et al. 2016

Journal of Atmospheric and Oceanic Technology

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Doppler cloud radars are amazing tools to characterize cloud and fog properties and to improve their representation in models. However, commercially available cloud radars (35 and 95 GHz) are still very expensive, which hinders their widespread deployment. This study presents the development of a lower-cost semioperational 95-GHz Doppler cloud radar called the Bistatic Radar System for Atmospheric Studies (BASTA). To drastically reduce the cost of the instrument, a different approach is used compared to traditional pulsed radars: instead of transmitting a large amount of energy for a very short time period (as a pulse), a lower amount of energy is transmitted continuously. By using a specific signal processing technique, the radar can challenge expensive radars and provide high-quality measurements of cloud and fog. The latest version of the instrument has a sensitivity of about −50 dBZ at 1 km for 3-s integration and a vertical resolution of 25 m. The BASTA radar currently uses four successive modes for specific applications: the 12.5-m vertical resolution mode is dedicated to fog and low clouds, the 25-m mode is for liquid and ice midtropospheric clouds, and the 100- and 200-m modes are ideal for optically thin high-level ice clouds. The advantages of such a radar for calibration procedures and field operations are also highlighted. The radar comes with a set of products dedicated to cloud and fog studies. For instance, cloud mask, corrected Doppler velocity, and multimode products combining the high-sensitivity mode and high-resolution modes are provided.

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Section: Discussionmentioning

confidence: 99%

BASTA: A 95-GHz FMCW Doppler Radar for Cloud and Fog Studies

Delanoë

Protat

Vinson

et al. 2016

Journal of Atmospheric and Oceanic Technology

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“…In the morning of 23 November 2013 an explosive lava fountain erupted from the New Southeast Crater (NSEC), lasting for about 1 hour. The lava fountain was clearly observed from two ground-based radars, an X-band polarimetric microwave weather radar (Marzano et al, 2013) and an Lband Doppler radar named Voldorad (Donnadieu, 2012) as well as from a video thermal-infrared camera.…”

Section: Geostatistical Approach To Rainfall Mapping From Commercial mentioning

confidence: 99%

10th European Conference on Radar in Meteorology and Hydrology (ERAD 2018) : 1-6 July 2018, Ede-Wageningen, The Netherlands

Vos¹,

Leijnse²,

Uijlenhoet³

2018

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“…Atmospheric impairments mainly related to refractive index variations, wind, and temperature close to the vent might modify the propagating medium, affecting the acoustic Doppler retrievals. The L-band Doppler radar named VOLDORAD, used for volcano monitoring, detects time variations in fixed resolution volumes above the vent, measuring in each volume the backscattered power and radial velocities of ejected ballistics and falling particles at a rate up to 24 s À1 [e.g., Donnadieu et al, 2005;Donnadieu, 2012]. Geometrical assumptions are then needed to convert the measured radial velocities into updraft or downdraft velocity components [e.g., Dubosclard et al, 2004].…”

Section: Introductionmentioning

confidence: 99%

Velocity profiles inside volcanic clouds from three‐dimensional scanning microwave dual‐polarization Doppler radars

Montopoli

2016

JGR Atmospheres

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In this work, velocity profiles within a volcanic tephra cloud obtained by dual‐polarization Doppler radar acquisitions with three‐dimensional (3‐D) mechanical scanning capability are analyzed. A method for segmenting the radar volumes into three velocity regimes: vertical updraft, vertical fallout, and horizontal wind advection within a volcanic tephra cloud using dual‐polarization Doppler radar moments is proposed. The horizontal and vertical velocity components within the regimes are retrieved using a novel procedure that makes assumptions concerning the characteristics of the winds inside these regimes. The vertical velocities retrieved are combined with 1‐D simulations to derive additional parameters including particle fallout, mass flux, and particle sizes. The explosive event occurred on 23 November 2013 at the Mount Etna volcano (Sicily, Italy), is considered a demonstrative case in which to analyze the radar Doppler signal inside the tephra column. The X‐band radar (3 cm wavelength) in the Catania, Italy, airport observed the 3‐D scenes of the Etna tephra cloud ~32 km from the volcano vent every 10 min. From the radar‐derived vertical velocity profiles of updraft, particle fallout, and horizontal transportation, an exit velocity of 150 m/s, mass flux rate of 1.37 • 107 kg/s, particle fallout velocity of 18 m/s, and diameters of precipitating tephra particles equal to 0.8 cm are estimated on average. These numbers are shown to be consistent with theoretical 1‐D simulations of plume dynamics and local reports at the ground, respectively. A thickness of 3 ± 0.36 km for the downwind ash cloud is also inferred by differentiating the radar‐derived cloud top and the height of transition between the convective and buoyancy regions, the latter being inferred by the estimated vertical updraft velocity profile. The unique nature of the case study as well as the novelty of the segmentation and retrieval methods presented potentially give new insights into the analysis of volcanic cloud dynamics.

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Volcanological Applications of Doppler Radars: A Review and Examples from a Transportable Pulse Radar in L-Band

Cited by 29 publications

References 59 publications

BASTA: A 95-GHz FMCW Doppler Radar for Cloud and Fog Studies

BASTA: A 95-GHz FMCW Doppler Radar for Cloud and Fog Studies

10th European Conference on Radar in Meteorology and Hydrology (ERAD 2018) : 1-6 July 2018, Ede-Wageningen, The Netherlands

Velocity profiles inside volcanic clouds from three‐dimensional scanning microwave dual‐polarization Doppler radars

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