Dual-Polarization Radar Data Analysis of the Impact of Ground-Based Glaciogenic Seeding on Winter Orographic Clouds. Part I: Mostly Stratiform Clouds

被引:20
作者
Jing, Xiaoqin [1 ]
Geerts, Bart [1 ]
Friedrich, Katja [2 ]
Pokharel, Binod [1 ]
机构
[1] Univ Wyoming, Dept Atmospher Sci, Laramie, WY 82071 USA
[2] Univ Colorado, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA
基金
美国国家科学基金会;
关键词
Clouds; SILVER-IODIDE PARTICLES; POLARIMETRIC RADAR; SENSITIVITY TESTS; ROCKY-MOUNTAINS; PHASE CLOUDS; GRAND MESA; PRECIPITATION; ICE; SIMULATIONS; SNOWFALL;
D O I
10.1175/JAMC-D-14-0257.1
中图分类号
P4 [大气科学(气象学)];
学科分类号
0706 ; 070601 ;
摘要
The impact of ground-based glaciogenic seeding on wintertime orographic, mostly stratiform clouds is analyzed by means of data from an X-band dual-polarization radar, the Doppler-on-Wheels (DOW) radar, positioned on a mountain pass. This study focuses on six intensive observation periods (IOPs) during the 2012 AgI Seeding Cloud Impact Investigation (ASCII) project in Wyoming. In all six storms, the bulk upstream Froude number below mountaintop exceeded 1 (suggesting unblocked flow), the clouds were relatively shallow (with bases below freezing), some liquid water was present, and orographic flow conditions were mostly steady. To examine the silver iodide (AgI) seeding effect, three study areas are defined (a control area, a target area upwind of the crest, and a lee target area), and comparisons are made between measurements from a treated period and those from an untreated period. Changes in reflectivity and differential reflectivity observed by the DOW at low levels during seeding are consistent with enhanced snow growth, by vapor diffusion and/or aggregation, for a case study and for the composite analysis of all six IOPs, especially at close range upwind of the mountain crest. These low-level changes may have been affected by natural changes aloft, however, as evident from differences in the evolution of the echo-top height in the control and target areas. Even though precipitation in the target region is strongly correlated with that in the control region, the authors cannot definitively attribute the change to seeding because there is a lack of knowledge about natural variability, nor can the outcome be generalized, because the sample size is small.
引用
收藏
页码:1944 / 1969
页数:26
相关论文
共 78 条
  • [71] 2
  • [72] ICE NUCLEATION BY COPRECIPITATED SILVER IODIDE AND SILVER BROMIDE
    VONNEGUT, B
    CHESSIN, H
    [J]. SCIENCE, 1971, 174 (4012) : 945 - &
  • [73] Xue L., 2015, J APPL METEOR CLIMAT
  • [74] The Dispersion of Silver Iodide Particles from Ground-Based Generators over Complex Terrain. Part II: WRF Large-Eddy Simulations versus Observations
    Xue, Lulin
    Chu, Xia
    Rasmussen, Roy
    Breed, Daniel
    Boe, Bruce
    Geerts, Bart
    [J]. JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY, 2014, 53 (06) : 1342 - 1361
  • [75] Implementation of a Silver Iodide Cloud-Seeding Parameterization in WRF. Part I: Model Description and Idealized 2D Sensitivity Tests
    Xue, Lulin
    Hashimoto, Akihiro
    Murakami, Masataka
    Rasmussen, Roy
    Tessendorf, Sarah A.
    Breed, Daniel
    Parkinson, Shaun
    Holbrook, Pat
    Blestrud, Derek
    [J]. JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY, 2013, 52 (06) : 1433 - 1457
  • [76] Implementation of a Silver Iodide Cloud-Seeding Parameterization in WRF. Part II: 3D Simulations of Actual Seeding Events and Sensitivity Tests
    Xue, Lulin
    Tessendorf, Sarah A.
    Nelson, Eric
    Rasmussen, Roy
    Breed, Daniel
    Parkinson, Shaun
    Holbrook, Pat
    Blestrud, Derek
    [J]. JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY, 2013, 52 (06) : 1458 - 1476
  • [77] YUTER SE, 1995, MON WEATHER REV, V123, P1941, DOI 10.1175/1520-0493(1995)123<1941:TDKAME>2.0.CO
  • [78] 2