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Background: Domestic violence is referred as shadow pandemic because it is seen globally. Domestic violence abuse is usually considered a problem that requires involvement of police or social services and not a problem that requires dental interference, but it is important to take under consideration that other services may even not be approached by the victim due to various reasons6. However, they may approach a dentist for facial trauma. Hence it is important to understand awareness, attitude and behaviour of dentists towards domestic violence victim patients. Materials and Methods: in this cross-sectional study, a self-administered, structured questionnaire was sent to dentists practicing in central India. Collected data were subjected to statistical analysis using Chi-square test, and P < 0.05 was considered statistically significant. Result: Mostly dentists were aware about and have heard about domestic violence in practice. As many as 37.6% dentist have encountered domestic violence victims in their practice but only 11.7% participants took any measures to record or report or refer DV victims Conclusion: As dental professionals are usually the first line of contact for patient with head and neck trauma, they would need to undergo special training to identify, support, and treat domestic violence patients. [ABSTRACT FROM AUTHOR]

The Indian summer monsoon trough (MT) is a dynamically active region of the quasi-stationary feature extending from north-western India towards the Bay of Bengal (BoB). The eastern rim of the MT (EMT) is modulated by the embedded synoptic-scale monsoon low-pressure systems (LPSs) in north BoB. We examine the spatiotemporal variability of the convective storm (CS) in the EMT region, which lies along the pathway of LPSs. A Lagrangian-based objective-tracking method, Thunderstorm Identification, Tracking, Analysis, and Nowcasting (TITAN), was injected into Kolkata S-band radar observations of nine wet seasons (June–September, 2009–2017). CSs frequently occur near the onshore areas and is linked to the formation and propagation of LPSs in the BoB. By examining the relationship of CS top heights with reflectivity lapse rate and fractional volume of 40 dBZ or more, three vertical categories of CS have been identified as shallow (SCS) below 5 km, medium depth (MDCS), and deep CS (DCS). The land–ocean contrast in the spatial distribution of MDCS and DCS and the contoured frequency by altitude diagram shows continental convective vigor. Although short-lived smaller CSs account for most storms in EMT, the bulk of the precipitation (75 % ) contributed from the infrequent largest storms. A weak (strong) linkage between the precipitation flux and CS top (area-time integral) gives a clue on the importance of CS voluminous organization rather than the linkage of heaviest rainfall to tallest CS. While most CSs propagate inland following the mass-weighted mean winds, the largest CS propagate offshore steered by the mid-level wind at 700 hPa. [ABSTRACT FROM AUTHOR]

This study focuses on integrating dual‐frequency precipitation radar (DPR) observations on‐board the Global Precipitation Mission with the storm index from INSAT‐3D for the development of reconstructed radar reflectivity. Performance of the derived product was tested against the independent DPR observations. A correlation coefficient of 0.81 is reported between the reconstructed radar reflectivity and the DPR observations. Derived reconstructed reflectivity is shown to be an excellent product for the weather monitoring over the regions without radar coverage. [ABSTRACT FROM AUTHOR]

Potentiality of Synthetic Aperture Radar (SAR) based Radar Forest Degradation Index (RFDI) combined with field observations for monitoring spatio-temporal dynamics of intertidal mudflat vegetation was assessed in this study. Five vegetation zones were delineated in the Junput mudflat of eastern India with very high classification accuracy (Kappa coefficient ≥ 0.79). Fragmentation and coalescence patterns of different vegetation zones under two plantation initiatives were also analysed by different spatial metrics. Results reveal gradual degradation of tree dominated vegetation zones and growth of shrub dominated and herbaceous ones from 2007 to 2019. Plantation of exotic species like Eucalyptus globulus and Casuarina equisetifolia along the shoreline had been found to be less effective against storms and sea surges. Conversely, native mangrove plantations and associated herbs had demonstrated remarkable growth in the intertidal areas. Based on the findings, the study pointed out that a zone-wise cum site-specific plantation strategy is needed towards developing effective bio-shields. [ABSTRACT FROM AUTHOR]

Monsoon convection characteristics over land and sea within 150 km of the west coast of India are studied using coastal Mumbai S-band radar. The intraseasonal and interannual monsoon variabilities in cloud characteristics are investigated for the contrasting monsoon seasons of 2013 and 2014. The cloud characteristics studied are frequency of occurrences, cloud top height (CTH), longitudinal distribution, diurnal variation, and scale-wise distribution of cloud cells. The number of cloud cells is about four times higher over land than over sea. The maximum frequency of CTH is found in the cumulus category (3–4 km). The mean CTH varies from 4.49–5.44 km. No significant difference between the CTH over the land and sea regions is found. The contribution of congestus to total cloud cells is found maximum over both land and sea. The longitudinal variation of cloud frequency shows maximum frequency at a distance of 50–60 km from the location of radar over both sea and land. The maximum over the land region is the new feature revealed in the analysis. The diurnal variation of clouds shows a broad structure with maximum in the local noon and minimum in the morning hours. The mean duration of the clouds is 40–44 min both over land and sea. The contribution by the mesoscale convective system (MCS) is dominant (57–63%). The study of cloud distribution over land and sea over the west coast of India using radar data is the first of its kind and has brought out detailed structure of cloud distribution with time and space. [ABSTRACT FROM AUTHOR]

Analysis of pre-monsoon convective systems over the southern peninsular India has been performed using C-band radar and numerical simulation. Statistics on the radar polarimetric measurements show that the distribution of differential reflectivity (Zdr) and specific differential phase (Kdp) have much higher spread over convective regions. The distribution of Kdp is almost uniform across the vertical over the stratiform regions. The mean profile of Zdr over stratiform regions shows a distinct local maxima near melting level. A comprehensive analysis has been done on an isolated deep convective system on 13 May 2018. Plan position indicator (PPI) diagrams and satellite measured cloud top temperature demonstrate that pre-monsoon deep convective systems can develop very rapidly within a very short span of time over the region. Heavy precipitation near the surface is reflected in the high value of Kdp (>5° km−1). High values of Zdr (>3 dB) were measured at lower levels indicating the oblate shape of bigger raindrops. A fuzzy logic-based hydrometeor identification algorithm has been applied with five variables (Zh, Zdr, ρhv, Kdp, and T) to understand the bulk microphysical properties at different heights within the storm. The presence of bigger graupel particles near the melting layer indicates strong updrafts within the convective core regions. The vertical ice hydrometeor signifies the existence of a strong electric field causing them to align vertically. Numerical simulation with the spectral bin microphysics (SBM) scheme could produce most of the features of the storm reasonably well. In particular, the simulated reflectivity, graupel mixing ratio and rainfall were in good agreement with the observed values. [ABSTRACT FROM AUTHOR]

A Stratosphere‐Troposphere (ST) Radar operating at 53 MHz is being installed at Ionosphere Field Station (22.94°N, 88.51°E, and 34°N geomagnetic latitude) of University of Calcutta in the eastern part of India adjoining northern Bay of Bengal. This radar is unique, being the only one operational at this frequency in the entire eastern and northeastern part of the country and also in the south‐east Asian longitude sector. Two components of horizontal winds (zonal and meridional) measured by the Pilot version of this radar have been validated with 90 collocated simultaneous balloon‐borne radiosonde observations during July and August 2019. A good correlation of the order of 90%–99% and 75%–95% up to 8 km has been observed between the radar and radiosonde measured zonal winds and meridional winds respectively. This correlation is much stronger between 2 and 6 km altitudes. The correspondence is better for the zonal winds than meridional. However, there have been some data outliers, which may primarily be attributed to different measurement techniques, large beam width of the Pilot array and less antenna aperture. The differences between radar and radiosonde measurements are marginally higher for precipitation events compared to non‐precipitation cases. The zonal and meridional wind patterns exhibit different variations in July and August 2019 while the standard errors in zonal and meridional winds mostly lie within 1 m/s. These results are the first validation of the Pilot version of this radar facility. Plain Language Summary: A 53 MHz radar is being set up by University of Calcutta near Calcutta in the geophysically sensitive transition region from the tropics to the sub‐tropics in the eastern part of India adjoining Bay of Bengal. It is designed to measure atmospheric winds, which could be very severe particularly during tropical cyclones which often affect this region. As an initial step, a Pilot version of the radar has been established and wind measurements compared with simultaneous collocated balloon‐borne radiosondes during July‐August 2019 for precipitation as well as non‐precipitation days up to altitudes of 8 km. Good correspondence have been noted between the two measurements with 90% correlation. Some data outliers have been noted which may be due to large beam width of the Pilot system and less antenna aperture. Key Points: Validation of zonal and meridional wind measurements using a Stratosphere‐Troposphere Radar with radiosondes during July‐August 2019Good correspondence of about 90% is noted between the two measurementsValidation has been classified into precipitation and non‐precipitation cases up to 8 km height [ABSTRACT FROM AUTHOR]

Characteristics of developing convective clouds (Cu) in Karnataka State (India) during the thunderstorm formation are analyzed using weather radar and lightning detection network data. It is noted that radar characteristics of Cu which produced lightning, exceed those where lightning does not form. The study has shown that the number of negative cloud-to-ground strokes exceeds the number of positive ones by an order of magnitude. The radar characteristics of clouds in India and the North Caucasus are compared. Significant differences in lightning flash rates over the mentioned regions are registered. A low correlation is found between the supercooled volume and the flash rate of negative lightning. The paper also presents the results of studying the dynamic characteristics of four Cu seeded with a glaciogenic reagent. The thunderstorm risk is estimated for the clouds. It is shown that the seeding increases a probability of lightning events. [ABSTRACT FROM AUTHOR]

The analysis of field observations of thunderclouds in India is provided. The characteristics of the cloud collection obtained from the radar and lightning detection network in the area of the city of Aurangabad (the Maharashtra province, India) are considered. The maximum radar reflectivity of thunderstorm cells, the volume of the supercooled part above the 0°C isotherm, the intensity and precipitation flux, and the frequency of electric discharges are obtained. It is shown that the frequency of electric discharges is linked with some radar parameters of thunderclouds, and this relationship depends on the stage of cloud development. Comparative field data for other regions are given. [ABSTRACT FROM AUTHOR]

A stratosphere–troposphere (ST) wind profiler radar operating at a high VHF range (205 MHz) installed at Cochin (10.03°N, 76.33°E), India, provides high‐resolution winds in time and altitude extending from 315 m to 20 km. We evaluated the horizontal and vertical winds obtained from atmospheric global reanalyses (ERA5, ERA‐Interim, MERRA‐2 and NCEP) data and the high‐resolution regional model (WRF) output winds with the ST radar (STR) wind observations at Cochin. The data for one whole year, from 1 August 2018 to 31 July 2019, for 0600 UTC and 1200 UTC were used. Wind data appraisal has been carried out at 24 levels from 315 m to 18.5 km altitude for the reanalyses datasets and 29 levels for model‐simulated winds in different seasons. Vertical profiles of horizontal winds from reanalysis and model‐simulated data somewhat catch the major changes observed from STR. The zonal winds match very well with the STR, whereas meridional winds show moderate similarity. Higher correlations in zonal winds are found during the summer monsoon, whereas meridional winds show apparent likeness during winter. The ERA5, ERA‐Interim, and model‐simulated winds have better agreement with the STR winds. Observed vertical winds from STR displays large fluctuations, while the estimated vertical winds in reanalysis are highly smoothed. Vertical profiles of vertical winds from the reanalysis datasets are not uniform. The reliability of vertical winds in reanalysis and WRF model output values are dubious compared to that of the directly observed winds from STR. The study indicates that improved quality of vertical and meridional winds in reanalysis data is needed by assimilating directly observed data from the available advanced facilities. [ABSTRACT FROM AUTHOR]

Ten-year climatology of physical properties of convective echoes during pre-monsoon season over south peninsular India and neighborhood are studied using Precipitation Radar dataset onboard Tropical Rainfall Measuring Mission satellite. Attenuation corrected radar reflectivity (Ze) is used to define an intense convective echo (ICE) which is a group of two or more contiguous convective pixels with Ze exceeding 30 dBZ. Height distribution of ICE is right skewed, single modal with mean and median as 7.8 and 7.3 kms. The ICE with area in range of more than 102 to 103 km2 (C) are most frequent (58.5%) followed by smallest scale (D) having area ≤ 102 km2 (37.2%). Large ICE's (B/C scale) are less frequent (4.2%). Mean areas of ICE's in D, C and B/C scales are 72.7, 279 and 1932 km2, respectively. The relation between height and area is linear indicating that taller ICE's are broader. The mean top heights of D, C and B/C scales are 5.5, 8.7 and 14.2 km, respectively. Frequency distributions of the height of 30 and 40 dBZ show single peaks at 5.5 and 4.75 km. Mean heights of 30 dBZ and 40 dBZ are 5.7 and 4.8 km while median heights are 5.5 and 4.7 km. Their cumulative frequency distribution shows that 6 and 3% of ICE cross 10 km height. Reflectivity structures of ICE show that systems over land are intense compared to that over ocean. [ABSTRACT FROM AUTHOR]

Storms are convective cells responsible for the major fraction of convective precipitation. Here, the pre-monsoon and monsoon season characteristics of storms are reported at Lucknow, Patna, Bhopal, and Nagpur in India using equivalent radar reflectivity factor ( Z e ) given at these radar locations. It is observed that the lifetime, speed of propagation, area, volume, echo top height and thickness lie in ranges 0.3–3 h, 5–60 km h - 1 , 4–184 km 2 , 8–1600 km 3 , 2–14 km, and 0.5–16 km respectively. For both seasons, the relationships between radar estimated rain volume (RERV; range 10 4 – 10 7 m 3 ) and area-time integral (ATI; range 1–100 km 2 h) are established which are considered as a representative of total precipitation resulted from an individual storm during its life cycle. The results from statistical analysis of RERV-ATI pairs suggest that storms at Lucknow have similar seasonal characteristics at 87% confidence interval while other locations exhibit dissimilarities. In addition, the vertical profiles of radar reflectivity (VPRRs) of storms are constructed at their life phases, namely cumulus, mature and dissipation. It is concluded that the vertical Z e gradient in mixed-phase region (5–8 km) is lower (2–2.9 dBZ km - 1 ) at cumulus and dissipation phases than at mature phase (3.6–4.4 dBZ km - 1 ) in monsoon season. For pre-monsoon season, this gradient lies between 3.3–5.2 dBZ km - 1 at mature phase. Our results are of great importance for advancing knowledge about storm-scale, which has implications in short-range weather forecasting as well as developing new convective parametrization schemes. [ABSTRACT FROM AUTHOR]

This study examined a typical case of deep convective storm that formed over southwest India on October 12, 2011, using ground-based X-band radar measurements and Weather Research and Forecasting (WRF) model simulations. The radar observation showed isolated pockets of convective storm, which merged later to form a convective cluster. The observed storms were tall, extending well into the mixed-phase region. Few storms even extended up to the tropopause height. Three different WRF cloud microphysics schemes (WRF Double-Moment 6-Class, Morrison Double-Moment, and Milbrandt–Yau Double-Moment) were used to simulate the observed deep convective storm to examine the vertical structure of hydrometeors. All the cloud microphysics schemes were able to reproduce the convective storm event with a lag time of almost two and a half hours. The WRF Double-Moment 6-Class scheme better simulates the vertical structure of storm compared to the other two microphysics schemes. The WRF model reasonably simulated the observed patterns of convective storm when the WRF cloud microphysics scheme better simulate the graupel and snow. The differences in simulated storm structure obtained by different microphysics schemes compared to observation highlight the deficiency involved in the simulations in capturing the microphysics that is guiding the intensity of convective storms. The present study thus underscores the importance of microphysics in different parameterization schemes of WRF simulation over southwest India, which has an implication in the forecasting of convective storms. [ABSTRACT FROM AUTHOR]

Reflectivity measurements from X‐band ground‐based radar (GR) are assessed using observations from the Ku‐band space‐borne radars (SRs) onboard the Tropical Rainfall Measuring Mission and Global Precipitation Measurement satellites as a reference. The GR is at Mandhardev (18.04°N, 73.86°E) in the Western Ghats region, and the evaluation period is from June to September of 2014 and 2018. At X‐band, the rainfall‐induced attenuation leads to significant signal loss. The rain attenuation correction of GR is performed based on the relationship between specific attenuation and reflectivity. Using T‐matrix scattering simulations, the specific attenuation and reflectivity are derived from the disdrometer data. Further, the systematic differences between reflectivity measured by GR and SR are minimized by performing the frequency scaling using scattering simulation. The comparison between corrected reflectivities of GR and SR is achieved by matching the resolution volumes and viewing geometry of both radars. The evaluation between corrected reflectivities of GR and SR shows reasonable agreement between them, indicating that the attenuation correction performs reasonably for GR. In rain regions, the GR bias lies between −2.6 and −1.8 dB for stratiform cases, while for convective samples, the GR bias varies from −2.4 to −0.7 dB relative to SR observations. The GR shows smaller reflectivity compared to SR at all heights. This study aims to implement the attenuation correction to long‐term X‐band radar data available in the Western Ghats region to study the orographic precipitation and convective system during monsoon. Key Points: For the first time, assessment of reflectivities between IITM's X‐band radar and TRMM‐GPM Ku‐band radars is carried outThe bias in GR attenuated corrected reflectivity is within −2.7 dB relative to SR measurementsThis study provides a framework to have attenuated corrected reflectivity for better quantitative application of reflectivity data [ABSTRACT FROM AUTHOR]

Variations in raindrop size distribution (DSD) during the southwest monsoon (SWM) season over different climatic regions in the Indian subcontinent and adjoining seas are studied in this paper using five years (2014 - 2018) of global precipitation measurement dual-frequency precipitation radar derived DSDs. The rain rate (R) stratified DSD measurements show clearly that land, sea, and orography differ in their mass-weighted mean diameter (Dm) values. Irrespective of R, Dm values of deep rain were found to be larger in continental rain than in maritime and orographic rain. However, for shallow storms, the Dm values were smaller for continental rain than for orographic and maritime rain. Based on the Dm values and their variations with R of the deep systems, the regions could be categorized into four groups, within which the Dm values were nearly equal: (1) the northwest India (NWI) and the southeast peninsular India (SEPI); (2) the foothills of the Himalayas (FHH) and the central India (CI); (3) the northeast India (NEI) and the Bay of Bengal (BOB); and (4) the Arabian Sea (AS), the Western Ghats (WG), and the Myanmar coast (MC). Compared to other geographical regions of the Indian subcontinent, the Dm values of the deep systems were the largest over NWI and SEPI and the smallest over the WG, MC, and AS; while for shallow systems, the Dm values were the largest over the BOB and AS and the smallest over the SEPI and NWI regions. Though the cloud drops were smaller over the continental regions, the raindrops were larger than in the maritime and orographic rain regions. The microphysical and dynamical processes that occur during precipitation play a vital role in altering the DSDs of continental rain. [ABSTRACT FROM AUTHOR]

Skillful quantitative precipitation forecast using the numerical weather prediction model relies on an accurate estimate of the atmospheric state as an initial condition. Variational assimilation methods (VAR) have the potential to provide improved initial state estimation to the numerical weather prediction model using observations, prior data (background), and their respective error covariance. The quality of variational assimilation hinges on the background error statistics (BES) as it weights the error in prior state and determines the spread of assimilated observations in model space. Traditional approaches used to model stationary BES in a three‐dimensional variational assimilation system often fail to represent the model error in BES. In this study, we have proposed an ensemble method using Stochastically Perturbed Parameterization Tendency to represent the model error in BES. The characteristics of the proposed BES are compared with the traditional approaches using the National Meteorological Centre method for different control variables choices. We have further tested the performance of the proposed method in improving the skill of precipitation forecast for an extreme rainfall event, which caused devastating flood over Chennai city, India, on December 2015. Results demonstrate that the use of the proposed method results in better forecast skill of convective precipitation in terms of both position and intensity than traditional National Meteorological Centre‐based BES. Best results are obtained when zonal and meridional momentum control variables are used for modeling ensemble‐based BES. Key Points: New method is proposed to represent model error of background error statisticsPerformance of proposed method improves forecast skill for an extreme eventBest results are obtained when using zonal and meridional momentum control variables [ABSTRACT FROM AUTHOR]

Periodic crop condition monitoring is of prime importance in cotton belt of western India for water stress management. In this article, vegetation water content (VWC) is assessed using Radar Vegetation Index (RVI) derived from the RISAT-1 data during July to September, vegetative to first picking phase, for utilizing its potential for large area cotton condition assessment. The RVI estimation from dual-polarized data has been demonstrated for regional applications. Prediction models of VWC for cotton crop using RVI and in situ ground measurements depicts significant relationship, with R2 varying from 0.5 to 0.6 and RMSE of 0.3–0.7 kg m−2. High correlation exists between RVI with crop age and crop biomass with R2 varying from 0.55 to 0.7, this proves useful for sowing date prediction. The results showed good validation (R2 = 0.8) for operational applications. The estimated VWC was found with 30–35% error above 4 kg m−2 biomasses as compared to 20–25% in lower ranges. [ABSTRACT FROM AUTHOR]

Microphysical evolution of tropical clouds in the core monsoon region of India is examined for the first time using ground-based cloud radar measurements. Combining high-resolution radar reflectivity (Z) profiles with empirical relations, cloud microphysical profiles in terms of cloud ice/liquid water content (IWC/LWC) during Indian summer monsoon (ISM) season are retrieved. Though the study is carried out using a point observation, it is shown that it represents the large-scale monsoon flow over the radar site. Cloud radar measurements during ISM period are classified into active and break ISM days. Radar-derived IWC profiles are validated against CloudSat, whereas LWC profiles are validated using the collocated microwave radiometer and microphysical observations from in situ aircraft measurements. The validated IWC and LWC profiles show significant differences between active and break ISM phases including their diurnal evolution. Larger (smaller) IWC values observed during active (break) days reveal the microphysical activity associated with the contrasting cloud vertical structure in the respective ISM phases. Observed discontinuity in the cloud vertical structure during break ISM days is attributed to the lack of moist convection. The significance of the present study lies in reporting the first ground-based radar measurements of cloud microphysical properties during active and break ISM period and discussing their distinctiveness. [ABSTRACT FROM AUTHOR]

C-band radars were installed at Baramati and Shegaon as a part of operational cloud seeding program of Maharashtra State in the monsoon season (June-September) 2004. These provided first time a unique opportunity to study (1) characteristics of precipitating monsoon clouds (2) convection and (3) number of seedable clouds over Indian meteorological subdivisions of Madhya Maharashtra (rain-shadow) and Vidarbha (drought-hit). The monsoon season is divided into active and break periods. The cloud characteristics studied are: diurnal variation, cloud top heights and durations. Diurnal variation of cloud frequency shows maximum in the afternoon hours (10-11 UTC) and minimum in the early morning hours (3-4 UTC) in both the periods. Cloud tops show trimodal distributions with modes at 2-3, 8-9 and above 9 km. Mean cloud duration is 55 min. Congestus has been found prominent cloud type (65%) with mean top height of 6.76 km. Frequency of cumulonimbus clouds is found higher in the break periods. Cloud scale is taken as a metric for characterization of convection. Maximum frequency of cloud scale is found at C scale (mesoscale: area 100-1000 km2). Mesoscale Convective System has been found dominating convection type. The convection over the area has been shown to be hybrid type, consisting of basic oceanic type modulated by land convection. Convective clouds having maximum reflectivities between 25 and 35 dBZ, suitable for hygroscopic and glaciogenic seeding, are found in a large number. Understanding of characteristics of clouds and convection is useful for the diagnostic and precipitation enhancement studies over the rain-shadow/drought-hit regions. [ABSTRACT FROM AUTHOR]

Disaster due to inundation is one of the major threats of coal mines. Sudden heavy inrush of high volume of water from the unapproachable and unknown waterlogged workings in underground mines is defined as inundation. There have been several instances of inrush of water due to old galleries getting connected by new development headings, resulting in disasters involving heavy fatalities and loss of machines. This type of disaster has occurred in many coal producing countries and may occur in future until a suitable tool to investigate barriers thickness is in regular use. Directorate General of Mines Safety (DGMS) has stipulated that a safety barrier thickness of not less than 60 m must be maintained between abandoned workings and contemporary mine developments. It has been estimated that a large number of underground coal mines in India are under threat of adjacent unknown waterlogged mine workings. Therefore, evaluation of barrier thickness up to 60 m is essential to prevent mine disasters due to inundations. Considering the above facts, a new GPR system named MineVue radar is developed having depth of penetration of 60 m subject to geo-mining conditions of Indian coal mines first time in the world. Final trial of the developed MineVue radar system was done at the Kachhi Balihari colliery of Bharat Cocking Coal Limited (BCCL), Dhanbad. The validation of GPR data in the known mine sites were done with accurate existing mine-plans to establish the reliability and confidence of mine operators, policy makers and safety personnel. [ABSTRACT FROM AUTHOR]

Cloud characteristics over the rain-shadow region of the north central peninsular India has been studied using C-band radar data for the period 21 September-30 October 2011. The period covers withdrawal and post-withdrawal periods of monsoon 2011. Though the study has been carried out for one season, it has been shown that it is representative of climatic feature over the region. The cloud characteristics have been discussed in the context of large scale dynamical and thermodynamical conditions over the region using NCEP wind data and radiosonde data, respectively. The large scale dynamic and thermodynamical conditions were found favorable for occurrence of widespread and deep convection. The cloud top heights show tri-modal distribution with peaks at 2-3, 4-6 and 8-12 km which are associated with cumulus, congestus and cumulonimbus clouds, respectively. The tops of these three types of the clouds are found to be associated with the stable layers in the atmosphere. The frequency of congestus clouds was the highest. The cloud characteristics over the region differ from other tropical land and oceanic regions in respect of maximum height, mean duration and cumulative frequency distribution. Distribution of cloud top height and duration show deviation from lognormality in the lower ends. It indicates that the cloud growth mechanism is different than that observed over other tropical land and oceanic regions and also due to the large wind shear prevailed over the region. During the period, a large number of suitable clouds were found available for hygroscopic and glaciogenic cloud seeding. [ABSTRACT FROM AUTHOR]

During the first week of September 2014, the Jammu and Kashmir region witnessed devastating floods across the majority of its districts, caused by multi-day heavy rainfall events. According to data provided by the Home Ministry of India, several thousand villages across the state were hit and 390 villages completely submerged. The preliminary assessment of property damage was estimated between INR 50,000 million to INR 60,000 million. Approximately 277 people died. In this study, an effort was made to analyze the heavy rainfall events over Jammu and Kashmir using hourly data at the fine spatial scale from satellite remote sensing. Data over Jammu and Kashmir reveal strong diurnal variation in rainfall over the severely affected districts. Most of these districts experienced continuous frequent heavy rainfall rates in the range of 15-22 mm/h during the first week of September 2014. The results show that the cumulative rainfall during 2-6 September 2014 may have contributed to the flood events. [ABSTRACT FROM AUTHOR]

Extreme weather events such as cloudburst and thunderstorms are great threat to life and property. It is a great challenge for the forecasters to nowcast such hazardous extreme weather events. Mesoscale model (ARPS) with real-time assimilation of DWR data has been operationally implemented in India Meteorological Department (IMD) for real-time nowcast of weather over Indian region. Three-dimensional variational (ARPS3DVAR) technique and cloud analysis procedure are utilized for real-time data assimilation in the model. The assimilation is performed as a sequence of intermittent cycles and complete process (starting from reception, processing and assimilation of DWR data, running of ARPS model and Web site updation) takes less than 20 minutes. Thus, real-time nowcast for next 3 h from ARPS model is available within 20 minutes of corresponding hour. Cloudburst event of September 15, 2011, and thunderstorm event of October 22, 2010, are considered to demonstrate the capability of ARPS model to nowcast the extreme weather events in real time over Indian region. Results show that in both the cases, ARPS3DVAR and cloud analysis technique are able to extract hydrometeors from radar data which are transported to upper levels by the strong upward motion resulting in the distribution of hydrometeors at various isobaric levels. Dynamic and thermodynamic structures of cloudburst and thunderstorm are also well simulated. Thus, significant improvement in the initial condition is noticed. In the case of cloudburst event, the model is able to capture the sudden collisions of two or more clouds during 09-10 UTC. Rainfall predicted by the model during cloudburst event is over 100 mm which is very close to the observed rainfall (117 mm). The model is able to predict the cloudburst with slight errors in time and space. Real-time nowcast of thunderstorm shows that movement, horizontal extension, and north-south orientation of thunderstorm are well captured during first hour and deteriorate thereafter. The amount of rainfall predicted by the model during thunderstorm closely matches with observation with slight errors in the location of rainfall area. The temporal and spatial information predicted by ARPS model about the sudden collision/merger and broken up of convective cells, intensification, weakening, and maintaining intensity of convective cells has added value to a human forecast. [ABSTRACT FROM AUTHOR]

A new technique has been developed to estimate rainfall at very fine scale (hourly rain rate at 0.05^\circ \times 0.05^\circ spatial resolution) over India and associated oceanic regions (20^\circ\ \S–40 ^\circ\ \N, 40^ \circ\ \E–130^\circ\ \E). By using infrared (IR) and 6.7-\mu\m water vapor (WV) channel observations from Meteosat-7, a new rain index (RI) is computed. The index computation is composed of two steps. First, the IR and WV brightness temperatures are divided by their respective nonrainy thresholds to get the IR and WV rain coefficients. The product of these coefficients is defined as the RI. These RIs are collocated against rainfall from the Precipitation Radar (PR) on board the Tropical Rainfall Measuring Mission to develop a relationship between the index and the rain rate. This relationship was utilized to monitor rainfall by applying it to numerous cases of monsoon and tropical cyclones over India and associated oceanic regions. Detailed validation with rain gauges and independent PR observations and comparisons with Global Satellite Mapping of Precipitation (GSMaP) and a regional rainfall algorithm based on IR observations are performed in this study. The present technique shows a correlation coefficient (CC) of 0.74, a bias of 0.086 mm, and a root-mean-square error (rmse) of 4.78 mm when compared with rain gauge. On the other hand, the regional rainfall technique and GSMaP show CCs of 0.72 and 0.59, bias values of 1.59 and 0.338 mm, and rmses of 5.49 and 7.20 mm, respectively, compared with rain gauge. It is observed that the present technique is able to monitor the rainfall with good accuracy at very fine scale over India. [ABSTRACT FROM AUTHOR]

Infrastructures are constructed with reinforced and prestressed concrete. For quality assurance and quality control, non-destructive techniques are adopted. In India, rebound hammer and ultrasonic pulse velocity test are widely used. Most of the time, it becomes necessary to find the reinforcements and ducts present in the concrete structure. Ground Penetrating Radar (GPR), shortly called radar, is one of the advanced non-destructive techniques, used for inspection of concrete structures, pavements and to detect reinforcements and ducts in concrete. It is also used for quality assessment and to locate flaws inside the concrete. It is based on the propagation of short electromagnetic waves of frequency 1.0 GHz to 2.5 GHz. This paper focuses on the detection of reinforcements and ducts which are present inside the concrete and simulated specimens. The effect of grid spacing during the collection of data is an important parameter in locating the reinforcements and ducts. The effect of grid spacing that is effective in identifying the reinforcements and ducts was studied and reported. [ABSTRACT FROM AUTHOR]

An L-band radar wind profiler was established at National Atmospheric Research Laboratory, Gadanki, India (13.5°N, 79.2°E), to provide continuous high-resolution wind measurements in the lower atmosphere. This system utilizes a fully active array and passive beam-forming network. It operates at 1280 MHz with peak output power of 1.2 kW. The active array comprises a 16 × 16 array of microstrip patch antenna elements fed by dedicated solid-state transceiver modules. A 2D modified Butler beam-forming network is employed to feed the active array. The combination of active array and passive beam-forming network results in enhanced signal-to-noise ratio and simple beam steering. This system also comprises a direct intermediate frequency (IF) digital receiver and pulse compression scheme, which result in more flexibility and enhanced height coverage. The scientific objectives of this profiler are to study the atmospheric boundary layer dynamics and precipitation. Observations made by this profiler have been validated using a collocated GPS sonde. This paper presents the detailed system description, including sample observations for clear-air and precipitation cases. [ABSTRACT FROM AUTHOR]

In the present study, we have used the Weather Research and Forecasting (WRF) model to simulate the features associated with a severe thunderstorm observed over Gadanki (13.5° N, 79.2° E), over southeast India, on 21 May 2008 and examined its sensitivity to four different microphysical (MP) schemes (Thompson, Lin, WSM6 and Morrison). We have used the WRF model with three nested domains with the innermost domain of 2 km grid spacing with explicit convection. The model was integrated for 36 h with the GFS initial conditions of 00:00 UTC, 21 May 2008. For validating simulated features of the thunderstorm, we have considered the vertical wind measurements made by the Indian MST radar installed at Gadanki, reflectivity profiles by the Doppler Weather Radar at Chennai, and automatic weather station data at Gadanki. There are major differences in the simulations of the thunderstorm among the MP schemes, in spite of using the same initial and boundary conditions and model configuration. First of all, all the four schemes simulated severe convection over Gadanki almost an hour before the observed storm. The DWR data suggested passage of two convective cores over Gadanki on 21 May, which was simulated by the model in all the four MP schemes. Comparatively, the Thompson scheme simulated the observed features of the updraft/downdraft cores reasonably well. However, all the four schemes underestimated strength and vertical extend of the updraft cores. The MP schemes also showed problems in simulating the downdrafts associated with the storm. While the Thompson scheme simulated surface rainfall distribution closer to observations, the other three schemes overestimated observed rainfall. However, all the four MP schemes simulated the surface wind variations associated with the thunderstorm reasonably well. The model simulated reflectivity profiles were consistent with the observed reflectivity profile, showing two convective cores. These features are consistent with the simulated condensate profiles, which peaked around 5-6 km. As the results are dependent on initial conditions, in simulations with different initial conditions, different schemes may become closer to observations. The present study suggests not only large sensitivity but also variability of the microphysical schemes in the simulations of the thunderstorm. The study also emphasizes the need for a comprehensive observational campaign using multi-observational platforms to improve the parameterization of the cloud microphysics and land surface processes over the Indian region. [ABSTRACT FROM AUTHOR]

The Indian mesosphere–stratosphere–troposphere (MST) radar observations during the passage of 37 convective systems are utilized to investigate the characteristics of vertical air velocity w in different convection categories (shallow, deep, and decaying) and also the differences in draft core statistics from the wet to dry spell. The radar and optical rain gauge measurements show pronounced differences in core statistics (in terms of their vertical structure, draft strength, size, number, and the elevation angle) and surface rainfall characteristics from the dry to wet spell. The shallow convective cores are preponderant in the dry spell. Composite w profiles, retrieved from all deep cases and also from individual convection cases, depict an upper-tropospheric peak in the wet spell and a bimodal distribution (peaks at 5 and 11–13 km) in the dry spell, illustrating that they are characteristic features of wet and dry spells. The average vertical extents of the cores are nearly equal (about 8 km) in both spells of the monsoon; however, the core-base (and top) altitudes are different. In both wet and dry spells, the composite w profile for all cores show similar vertical variation to that of for updraft cores, while the composite w for downdraft cores do not show much variation with altitude, indicating that the updraft cores dictate the vertical structure of composite w. The core size varies considerably (a factor of 2) with altitude in both spells of the monsoon. Although nearly equal in the lower troposphere in both phases of the monsoon, the core size is larger by 1–2 km in the dry spell in the middle and upper troposphere. Consistent with the longer lifetime (bigger core size) of cores in the dry spell, the cores are more inclined (with a mean elevation angle of 30°) in the dry spell. The surface rainfall distribution is wider and has large number of intense rainfall rates in the wet spell. The mean rainfall rate for the wet spell is also larger by a factor of 2, consistent with earlier studies. [ABSTRACT FROM AUTHOR]

The present paper gives an account of potential of Environment Satellite-Advanced Synthetic Aperture Radar (ENVISAT-ASAR) C-band data in forest parameter retrieval and forest type classification over deciduous forests of Tadoba Andhari Tiger Reserve (TATR), central India. Ground data on phyto-sociology and Leaf Area Index (LAI) over the study area was collected in 23 sampling points (20m×20m) over the study area. Phyto-sociological data collected over the study area was used to compute plot-wise biometric parameters like basal area, volume, stem density and dominant height. ENVISAT ASAR data covering the study area, pertaining to 24 November 2005, has been geo-referenced and digital number (DN) values were converted to radar backscatter values. Regression analysis between backscatter and the retrieved biometric variables has been done to explain the relationships between SAR backscatter and forest parameters. Analysis showed a significant correlation between backscatter and biometric parameters and backscatter values typically increased with increase in basal area, volume, stem density and dominant height. The scatter observed between ASAR backscatter and stem density, basal area and dominant height suggested limitation of C-band data in estimating biometric variables in heterogeneous forest systems. Further, ASAR data was used in conjunction with Indian Remote sensing Satellite (IRS-P6) - Linear Imaging Self Scanner (LISS) III data of 16 October 2004 to classify the study area into different land use/land cover (LU/LC) classes. Various texture and adaptive filters were applied on ASAR image to reduce speckle noise and enhance image features. An attempt is made to merge ASAR image with LISS-III to enhance feature discrimination. Training sets corresponding to the ground data have been used to derive confusion matrices for the ASAR and LISS-III images. Results suggested better discrimination of vegetation types in the merged data suggesting the possible use of ASAR data in forest type discrimination. [ABSTRACT FROM AUTHOR]

A study has been carried out to analyse the high temporal Ku-band scatterometer data from QuikSCAT with 4.45 km resolution for regional assessment of rice crop phenology. Four-day composite data were used covering the two predominant rice-growing states in India during the monsoon season of 2004. These data were registered with reference to a rice map derived from RADARSAT SAR data of the same season in order to select predominant rice sites. Analysis shows the dual peak backscatter profile of rice crop (at tillering stage and another at maturity). Minima of the backscatter profile were found to coincide with the heading. The derived heading stage using a lognormal curve fitting matched well with the observed dates. The slope of the second peak varied with crop variety, and shows the potential of correlation with the panicle characteristic. [ABSTRACT FROM AUTHOR]

A comparison of thundercloud characteristics in different regions of the world was conducted. The clouds studied developed in India, China and in two regions of Russia. Several field projects were discussed. Cloud characteristics were measured by weather radars, the SEVERI instrument installed on board of the Meteosat satellite, and lightning detection systems. The statistical characteristics of the clouds were tabulated from radar scans and correlated with lightning observations. Thunderclouds in India differ significantly from those observed in other regions. The relationships among lightning strike frequency, supercooled cloud volume, and precipitation intensity were analyzed. In most cases, high correlation was observed between lightning strike frequency and supercooled volume. [ABSTRACT FROM AUTHOR]