Subjects: Geosciences >> Geography submitted time 2024-04-29 Cooperative journals: 《干旱区研究》
Abstract： Based on data obtained from the Micro Rain Radar (MRR), OTT-PARSIVEL laser raindrop spectrometer, and Rain Gauge (RG) at Zeku Station, the applicability of the MRR in the plateau region was compared and examined for a precipitation weather process on September 17, 2021. The vertical variation characteristics of the MRR observation parameters and raindrop spectrum were investigated at different rain rates. Results show that the observed cumulative rainfall results of the MRR were consistent with those of the raindrop spectrometer and RG, and the MRR 200 m rain rate was highly associated with the raindrop spectrometer inversion value. At various levels of rainfall intensity, differences were found in the vertical distribution of precipitation parameters. Reflectivity, rain rate and liquid water content were affected by evaporation, and they fluctuated from high to low levels in the Ⅰ stage of rain. The evaporation effect was weakened, and the peak height of each microphysical quantity was lower in the II stage of rain. The increase in particle diameter was due to the intensification of collision and coalescence, and the microphysical quantities increased with the decrease in height in the III stage of rain. Precipitation was dominated by small particles, and the raindrop number concentration contribution of small particles at each height layer was the largest. The contribution rate of 1000-4000 m small particles to the rain rate exceeded 90%, and the contribution rate of medium particles below 1000 m to the rain rate increased with the decrease of height. The contribution rate of large particles to the rain rate in the upper layer was greater than that in the lower layer.
Subjects: Geosciences >> Geography submitted time 2024-03-01 Cooperative journals: 《干旱区研究》
Abstract： The northeast of Qinghai province is the main area of crop production, and also the high-risk area of hail. Hail Forecast, early warning and artificial anti-hail operation are the important means to reduce hail disaster, to master the characteristics of hail monitoring data is the precondition to improve the ability of hail forecast and to carry out hail suppression as early as possible. The hailstorm process on 29 June 2021 at northeast of Qinghai is analyzed by using doppler radar data, raindrop spectrum data, high and ground data. The results show that there is cold advection transportation of upper-level while temperature increases obviously on ground in the northeast of Qinghai, formation of the extreme unstable atmosphere stratification, which is the weather background of this hailstorm process. During the period of hailstorm, the average raindrop spectrum and velocity spectrum are multi-peak distribution at Pingan station. The difference between the maximum diameter of Pingan hailstorm observed artificial and raindrop spectrometer is not large, which indicates that raindrop spectrometer can observe hail particles well and determine the time of maximum hail appears. The development of this hail cloud has roughly gone through the stages of occurrence, jump, hail and extinction. There is an obvious “V” shaped inflow gap in the low-level radar reflectivity factor before hail. In the mature stage, the hail cloud has obvious bounded weak echo area, and there is obvious southerly inflow in the middle and lower layers, at this time, the hail cloud on the radial velocity map has an obvious“0 line”, “0 line” vertical upward, through the overhanging echo and bounded weak echo region, pointing to the hail cloud top. The research results have important guiding significance for hail forecast at northeast of Qinghai, and the characteristics of various elements before hail occurrence are the important criteria for scientific guiding hail suppression operation sites to carry out artificial hail suppression operation timely and appropriately in the later stage.
Hits
Hits
Downloads
Comment