scholarly journals Aso volcano eruption on October 8, 2016, observed by weather radars

2018 ◽  
Vol 70 (1) ◽  
Author(s):  
Eiichi Sato ◽  
Keiichi Fukui ◽  
Toshiki Shimbori
Keyword(s):  
Aso Volcano ◽  
Volcano Eruption ◽  
Weather Radars

scholarly journals Inside Volcanic Clouds: Remote Sensing of Ash Plumes Using Microwave Weather Radars

2013 ◽  
Vol 94 (10) ◽  
pp. 1567-1586 ◽  
Author(s):  
Frank S. Marzano ◽  
Errico Picciotti ◽  
Mario Montopoli ◽  
Gianfranco Vulpiani
Keyword(s):  
Remote Sensing ◽  
Case Studies ◽  
Volcanic Eruptions ◽  
Explosive Volcanism ◽  
Mount Etna ◽  
Retrieval Algorithm ◽  
Volume Data ◽  
Volcano Eruption ◽  
Weather Radars ◽  
X Band

Microphysical and dynamical features of volcanic tephra due to Plinian and sub-Plinian eruptions can be quantitatively monitored by using ground-based microwave weather radars. The methodological rationale and unique potential of this remote-sensing technique are illustrated and discussed. Volume data, acquired by ground-based weather radars, are processed to automatically classify and estimate ash particle concentration and fallout. The physical– statistical retrieval algorithm is based on a backscattering microphysical model of fine, coarse, and lapilli ash particles, used within a Bayesian classification and optimal estimation methodology. The experimental evidence of the usefulness and limitations of radar acquisitions for volcanic ash monitoring is supported by describing several case studies of volcanic eruptions all over the world. The radar sensitivity due to the distance and the system noise, as well as the various radar bands and configurations (i.e., Doppler and dual polarized), are taken into account. The discussed examples of radar-derived ash concentrations refer to the case studies of the Augustine volcano eruption in 2002, observed in Alaska by an S-band radar; the Grímsvötn volcano eruptions in 2004 and 2011, observed in Iceland by C- and X-band weather radars and compared with in situ samples; and the Mount Etna volcano eruption in 2011, observed by an X-band polarimetric radar. These applications demonstrate the variety of radar-based products that can be derived and exploited for the study of explosive volcanism.

Modern Weather Surveillance Radars: Hygienic Aspects of Monitoring Electromagnetic Fields at Operators’ Workplaces and in the Environment

2020 ◽  
pp. 34-40
Author(s):  
VN Nikitina ◽  
GG Lyashko ◽  
NI Kalinina ◽  
EN Dubrovskaya ◽  
VP Plekhanov
Keyword(s):  
Electromagnetic Fields ◽  
Weather Radar ◽  
Measuring Instruments ◽  
Residential Areas ◽  
Emf Measurements ◽  
Operating Modes ◽  
Weather Radars ◽  
Radio Transmitters ◽  
Permissible Levels ◽  
Radar Antennas

Summary. Introduction: Location of weather surveillance radars near settlements, in residential areas and on airport premises makes it important to ensure safe levels of electromagnetic fields (EMF) when operating these radio transmitters. EMF maximum permissible levels for weather radars developed in the 1980s are outdated. Our objective was to analyze modern weather surveillance radars to develop proposals for improvement of radar-generated radiofrequency field monitoring. Materials and methods: We studied trends in meteorological radiolocation and technical characteristics of modern weather radars for atmospheric sensing and weather alerts, analyzed regulations for EMF measurements and hygienic assessment, and measured radiofrequency fields produced by weather radar antennas in open areas and at workplaces of operators. Results: We established that modern types of weather radars used in upper-air sensing systems and storm warning networks differ significantly in terms of technical characteristics and operating modes from previous generations. Developed in the 1980s, current hygienic standards for human exposures to radiofrequency fields from weather radar antennas are obsolete. Conclusions: It is essential to develop an up-to-date regulatory and method document specifying estimation and instrumental monitoring of EMF levels generated by weather radars and measuring instruments for monitoring of pulse-modulated electromagnetic radiation.

scholarly journals Kusatsu-Shirane volcano eruption on January 23, 2018, observed using JMA operational weather radars

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Eiichi Sato
Keyword(s):  
Field Survey ◽  
Estimation Method ◽  
Volcanic Tremor ◽  
Lower Troposphere ◽  
Eruption Style ◽  
Weather Radars ◽  
Ash Fall ◽  
Self Defense ◽  
Erupted Mass ◽  
Eruption Plume

AbstractA phreatic eruption suddenly occurred at Motoshirane (Kusatsu-Shirane volcano, Japan) at 10:02 JST on January 23, 2018. A member of the Japan Self-Defense Force was killed by volcanic blocks during training in Motoshirane, and 11 people were injured by volcanic blocks or fragments of broken glass. According to a field survey, ash fall was confirmed in Minakami, about 40 km east-northeast from Motoshirane. Although the eruption was not captured by a distant camera, the eruption plume/cloud was captured by three of the Japan Meteorological Agency’s operational weather radars. These radars observed the echo propagated to the northeast in the lower troposphere, and to the east in the middle troposphere. This is generally consistent with the observed ash fall distribution. Using the modified probabilistic estimation method, the maximum plume height was estimated to be about 5580 ± 506 m (1σ) above sea level. Estimates of the erupted mass based on the range of plume heights from radar observations and the duration of volcanic tremor during the eruption (about 8 min) do not match that obtained from a field survey (3.0–5.0 × 107 kg). This discrepancy confirms that estimates of erupted mass based on plume heights must account for eruption style parametrically, which can only be constrained by case studies of varied eruption styles.

scholarly journals Investigation of Ionospheric Response to June 2009 Sarychev Peak Volcano Eruption

2021 ◽  
Vol 13 (4) ◽  
pp. 638
Author(s):  
Nikolay Shestakov ◽  
Alexander Orlyakovskiy ◽  
Natalia Perevalova ◽  
Nikolay Titkov ◽  
Danila Chebrov ◽  
...  
Keyword(s):  
Acoustic Mode ◽  
Global Navigation Satellite Systems ◽  
Electron Content ◽  
Field Zone ◽  
Ionospheric Response ◽  
Satellite Systems ◽  
Volcano Eruption ◽  
Close Proximity ◽  
Global Navigation Satellite ◽  
Sarychev Peak

Global Navigation Satellite Systems have been extensively used to investigate the ionosphere response to various natural and man-made phenomena for the last three decades. However, ionospheric reaction to volcano eruptions is still insufficiently studied and understood. In this work we analyzed the ionospheric response to the 11–16 June 2009 VEI class 4 Sarychev Peak volcano eruption by using surrounding Russian and Japanese GPS networks. Prominent covolcanictotal electron content (TEC)ionospheric disturbances (CVIDs) with amplitudes and periods ranged between 0.03–0.15 TECU and 2.5–4.5 min were discovered for the three eruptive events occurred at 18:51 UT, 14 June; at 01:15 and 09:18 UT, 15 June 2009. The estimates of apparent CVIDs velocities vary within 700–1000 m/s in the far-field zone (300–900 km to the southwest from the volcano) and 1300–1800 m/s in close proximity toSarychev Peak. The characteristics of the observed TEC variations allow us to attribute them to acoustic mode. The south-southwestward direction is preferred for CVIDs propagation. We concluded that the ionospheric response to a volcano eruption is mainly determined by a ratio between explosion strength and background ionization level. Some evidence of secondary (F2-layer) CVIDs’ source eccentric location were obtained.

Sign in / Sign up

Export Citation Format

Share Document