Harm of Hail to Crops and Countermeasures of Artificial Hail Suppression in Ulanqab City

Hail is one of meteorological disasters affecting crop growth in Ulanqab City.It happens frequently from May to September,and this period is also the main growing season of crops.In this period,hail will cause damage to crops,make farmland soil harden,and bring varying degrees of harm to agricultural production.Artificial hail suppression is an important scientific and technological means for disaster prevention and mitigation.It is necessary to strengthen the monitoring,analysis and forecast of severe convection weather,intensify the release of early warning information of hail weather,provide accurate and reliable real-time information for the implementation of artificial hail suppression operations,strengthen the implementation of artificial weather modification,effectively carry out artificial hail suppression operations,and avoid and reduce the impact of hail disaster.

Analysis of Characteristics of Hail Disaster and a Typical Hail Suppression Process in Qujing City

Based on the data of hail disaster in Qujing City and the detection data of the new generation of Doppler weather radar, the spatial and temporal distribution characteristics of hail disaster and hail suppression operations in Qujing City were analyzed statistically, and the hail suppression operations of a typical cell case was analyzed. The results showed that the number of hail days and hail frequency showed an increasing trend in Qujing City from 2017 to 2022, and the number of artificial hail suppression operations increased accordingly. Hail disaster occurred most frequently in Xuanwei City. Through the analysis of hail suppression operations of a typical cell case, it is found that the operations were timely, and the location was reasonable. The ammunition used was sufficient, and the overall effect of the hail suppression operations was good.

Analysis on Features of Hail and Hail Suppression in Hohhot in Recent 30 Years

Some characters of hail,such as its frequency,duration,diameter,disaster degree,were analyzed,based on the 1 375 pieces data of hails in Huhhot from1969 to 2000.Besides,3 000 pieces information about hail prevention from 1985 to 2000 was elaborated.The results showed that normally,the hail disaster lasts less than 5minutes,and its diameter is between 1 to 5 mm.Hail is more likely to happen from 16:00 pm to 17:00 pm.The practice of hail prevention effectively decreased hail disasters,and thus resulted in less damage.

Objective Evaluations of the Manner and Effect for Artificial Hail Suppression Operation in the Middle Region of Inner Mongolia

[ Objective] The research aimed to conduct objective evaluation on manner and effect of the artificial hail suppression operation in central Inner Mongolia. [ Method] Depending on analyses of the radar observation data, hail shooting data and artificial hail suppression operation data in the middle region of Inner Mongolia （ represented by Huhhot） from 1990 to 2007, and combining capability of the artificial hail suppression operation tool （＂ 37＂ anti-aircraft gun）, nucleation rate of the catalyst and suitable catalyst volume in hail cloud per unit volume, objective evaluation of the manner and effect for artificial hail suppression operation in the area was obtained. [ Result] It was exacter to distinguish shape and intensity of the hail cloud, but it was uncertain to distinguish height of the hail cloud, when selecting operation target cloud. Operation height was still lower, and perfect seeding height couldn＇t be attained. Operation occasion was controlled well, but there still were phenomena of the late operation. Shell amounts of the operation were few obviously, needing to increase shell amount or to improve nucleation rate of the catalyst. [ Conclsion] Syntheti- cally, manner of the artificial hail suppression operation in central Inner Mongolia was suitable, and total efficiency was about 85%.

Reanalysis on Hail Suppression Weather Prewarning of the "8.21" Rare Hail in Shenyang

[Objective]The research aimed to analyze hail weather during 18：30-19：30 on August 21,2011.[Method]Based on NCEP 6 h reanalysis data,Micaps data and FY-2 satellite cloud image,weather situation field,meteorological element field and satellite cloud image of the hail during 18：30-19：30 on August 21,2011 were reanalyzed.Weather causes of the hail and characteristics of the satellite cloud image were discussed.We summed up how to conduct prewarning analysis of the hail suppression weather from live weather data and numerical forecast products.[Result]In occurrence and development process of the hail weather,cold vortex at 500 hPa was background weather system.850 hPa warm tongue and ground wind shear were essential conditions for forming strong convective hail cloud.Early weather chart was analyzed.It could analyze occurrence reason of the weather from mechanism aspect of the weather system,and issue weather prewarning as early as possible.Numerical forecast products were used to analyze meteorological element field.It could further analyze and accurately predict probability,time and range of the hail occurrence.Infrared satellite cloud image was more accurate for monitoring strong convective hail cloud,which could intuitively predict occurrence of the hail weather.[Conclusion]The research offered some hail suppression prewarning experiences for the future similar hail weather.

Hail Detector and Forecaster ArtAr-HDF

This article describes a new and low-cost microwave passive sensor for hail prediction (forecasting) and detection developed in Armenia, which can be used to implement fully autonomous and automatically functioning hail protection of locally limited or large agricultural and urban areas in order to prevent, suppress or catch hail in traps. The article also presents the results of measurements of the intrinsic emission characteristics of water and ice, rain and hail clouds, carried out in laboratory and field conditions in the Ku-band of radio frequencies. The results obtained showed that the intrinsic emission of a hail cloud in the Ku-band of radio frequencies differs significantly from the intrinsic emission of a rain cloud. The presented results show that indeed the radar is not very suitable for the timely detection and determination of hail with a high probability, which is very important for the timely starting up of anti-hail protection means. On the contrary, radiometers (passive microwave sensors) can become an effective sensing tool for timely detection and recognition of hail with a high probability of long-range approaches up to ~12 - 15 km.