Automated radar identification, measurement of parameters, and classification of convective cells for hail protection and storm warning

Abshaev, Magomet T.; Abshaev, A. M.; Malkarova, A. M.; Zharashuev, M. V.

doi:10.3103/s1068373910030040

Cited by 9 publications

(3 citation statements)

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“…We used isotherm heights such as 0 °C (H0), -10 °C (H-10), and -20 °C (H-20). These can be considered key isotherms used for a medium-term hail forecasting or to detect convective storm cells with hail probability (Abshaev et al, 2010;Potapov and Garaba, 2016). The altitude of these isotherms was determined by calculating a local, thermal gradient.…”

Section: Methodsmentioning

confidence: 99%

Sounding-derived parameters associated with severe hail events in Romania

Vasilică¹,

Dobri²,

Florentina³

et al. 2021

Időjárás

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The present paper analyzes 549 severe weather events reported to the ESWD (European Severe Weather Database) that caused large hail in the territory of Romania. Values of atmospheric instability indices have been analyzed for these episodes using data from Bucharest and Budapest sounding stations. For a period of 140 days with episodes of large hail, 24 instability indices were analyzed to describe the atmospheric conditions of the main daily convective activity. The mean values for most indices characterize an unstable atmospheric environment. Of the indices that measure potential instability, VT (vertical totals index) and TT (totals index) had values that described a conductive atmospheric environment for the development of hailstorms. In addition, the interquartile values of LIV (lifted index using virtual temperature) had values lower than zero. For SWEAT (severe weather threat index) and CAPEV (convective available potential energy index using virtual temperature), only the values in the 75th percentile describe a very unstable environment (according to the literature). Strong linear correlations were registered between several pairs of indices such as CAPEV-LIV and SWEAT-SI that can be used for the operational forecast of hail.

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Section: Methodsmentioning

confidence: 99%

Sounding-derived parameters associated with severe hail events in Romania

Vasilică¹,

Dobri²,

Florentina³

et al. 2021

Időjárás

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“… The wind in the surface layer of the atmosphere leads to the jet deformation in the vertical and horizontal plane tilts and blows the updraft top to the leeward side for hundreds of meters. In the horizontal section, the jet takes the form of an arc covering the region of maximum updrafts, which lags behind the ambient air flow by analogy with the lagging behind the leading flow of the updrafts region and the powerful radar echo of convective storms 29 . The presence of even shallow wind ( U = 1 + 0.005 H ) almost halves the jet height, which greatly limits the possibility of creating artificial clouds.…”

Section: Discussionmentioning

confidence: 99%

CFD simulation of updrafts initiated by a vertically directed jet fed by the heat of water vapor condensation

Abshaev¹,

Abshaev²,

Aksenov

et al. 2022

Sci Rep

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This paper presents the results of the development of a mathematical model and numerical simulation of the ascent in the atmosphere of a vertically directed jet fed by the heat of condensation of water vapor on a hygroscopic aerosol introduced into the jet at the start. The possibility of creating artificial convective clouds depending on jet parameters, condensation heat value and vertical profiles of wind speed, air temperature and humidity has been evaluated. Numerical experiments showed that the motion of a high-speed and high-temperature jet in the atmosphere has a complex turbulent nature. As the jet ascends, it expands, losing superheat and velocity. The temperature of the jet decreases faster than the velocity, so the jet rises slightly above the level at which its superheat disappears. The jet's ascent height increases as the humidity of the air and the vertical temperature gradient increase. Wind causes the jet to deform, bend, and decrease the height of ascent. Feed the jet with condensation heat results in a significant increase in jet lift height. This is particularly effective in the case of introducing into the jet two-layer NaCl/TiO2 nanoaerosol, which is capable of absorbing water vapor in an amount significantly greater than its mass. The simulation results are encouraging in the possibility of creating artificial updrafts that can lead to the formation of convective clouds and precipitation on days with favorable atmospheric conditions, when wind speed in the sub-cloud layer is < 6 m/s, air humidity is > 65%, and the temperature lapse rate is > 7.5 °C/km.

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“…The moist (cloud) convection triggers severe storms that lead to showery rains, thunderstorms, hail, squalls, tornadoes, flash floods, and inundations [17]. Convective storms are usually local [18], hence, forecasting the locations, timings, and causes of their development are the most difficult challenges in weather forecasting [19]. Current operational numerical models are still generally unable to forecast the location and onset time of cloud convection initiated by the sub-cloud layer processes due to the poor representation of these processes in the model physics.…”

Section: Introductionmentioning

confidence: 99%

Influence of Atmosphere Near-Surface Layer Properties on Development of Cloud Convection

Abshaev¹,

Zakinyan

Abshaev³

et al. 2019

Atmosphere

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A two-dimensional mathematical model of moist air convection in the sub-cloud and cloud layers is proposed. A theoretical analysis of the influence of near ground atmospheric parameters on the development of sub-cloud and cloud convection is provided, and the criteria of convection development are considered. As a rule, this relationship is parameterized in general circulation, regional or mesoscale models of the atmosphere. Therefore, achieving a more complete and correct understanding of this relationship can lead to an improvement in the accuracy of weather forecasts. The mathematical model describes the system of the equations of motion, heat conductivity and the continuity equations for a two-dimensional vertical plane. The approximate analytical solution of the system of equations is obtained. Expressions for the estimation of the convection height and height of maximum velocity are derived for vertical and horizontal components of updraft wind and for vertical distribution of temperature. From the expressions obtained, the criterion of sub-cloud convection development is derived. The expressions for the convection parameters at a condensation level have also been formulated, from which the criterion of cloud development through convection is derived. It is established that the development of cloud convection depends on absolute values of the dew point deficit in a near-surface layer and, in a greater degree, on vertical gradients of water vapor mass fraction. It is shown that at certain critical values of a vertical gradient of water vapor mass fraction “explosive convective growth” is observed. The application of the obtained results to artificial stimulation of convection by means of air heating in the near-ground atmosphere has shown that the success of such an application and the required air heating-up depend on: (i) the vertical temperature gradient; (ii) the vertical dew-point gradient; and (iii) the value of the dew point deficit in the near-ground layer. The analysis performed has shown the possibility of successful stimulation of artificial convection under specific favorable atmospheric conditions.

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Automated radar identification, measurement of parameters, and classification of convective cells for hail protection and storm warning

Cited by 9 publications

References 0 publications

Sounding-derived parameters associated with severe hail events in Romania

Sounding-derived parameters associated with severe hail events in Romania

CFD simulation of updrafts initiated by a vertically directed jet fed by the heat of water vapor condensation

Influence of Atmosphere Near-Surface Layer Properties on Development of Cloud Convection

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