Gaoyuan qixiang (Oct 2022)

Study on the Vertical Structures and Characteristics of Different Cloud-Precipitation Types during a Qinghai-Xizang Plateau Vortex Transit

  • Yuanyuan ZUO,
  • Jiafeng ZHENG,
  • Jingshu HE,
  • Xiaoyan YIN,
  • Boyong LI,
  • Zhiqun HU,
  • Zhiyu LEI

DOI
https://doi.org/10.7522/j.issn.1000-0534.2021.00059
Journal volume & issue
Vol. 41, no. 5
pp. 1251 – 1265

Abstract

Read online

Using measurements from a Ka-band cloud radar（Ka-MMCR）， a K-band micro rain radar（K-MRR）， and a ground disdrometer of the Third Qinghai-Xizang Plateau Atmospheric Science Experiment， combined with data from a Doppler weather radar， ERA-Interim reanalysis， and FY-2E satellite images， the vertical structures and characteristics of different cloud-precipitation types triggered by a Qinghai-Xizang Plateau vortex process that happened over Nagqu on August 13-14， 2015 were studied and compared in detail.Results indicate that there exist three stages of cloud-precipitation including the deep and strong convection （DSP）， the deep and weak convection （DWP）， and the shallow convection （SP） appeared successively over the Nagqu with different macro and micro characteristics.Specifically， the DSP has the shortest time scale， the strongest convection， and the highest echo top.The inner strong updraft makes ice crystals effectively collide with supercooled water and facilitate forming large graupels， which then quickly settle and melt into heavy raindrops.The average profile of radar reflectivity factor Ze （mean particle terminal velocity VT ） exhibit gradually increased （decreased） as height decrease.The DWP has the longest time scale， relatively weaker convection intensity， and lower echo top.The growth of ice crystals is mainly dominated by the accretion or coalescence process.From 8 km to the melting layer， the Ze increment of the DWP is larger than that of the DSP， but the VT decrement is smaller.The SP has the weakest convection intensity and the lowest echo height and is composed of small-scale cumulus.The variation trends of radar variables of SP are similar to the DWP.Comparisons also suggest that the DWP shows a clearest radar bright band， followed by the SP， the bright band in the DSP is weakest， and the radar spectrum skewness can also be a good indicator of the bright band.The ground rain spectra of the three stages are also different， the spectral width and the number concentration magnitude both exhibit as DSP>DWP>SP.

Keywords