设为首页
加入收藏
Bright Band Analysis in Yangtze-Huaihe Region of Anhui Using Data Detection from C-FMCW Radar
-
摘要: 不同于体扫雷达探测降水系统，垂直指向雷达可探测降水云中粒子垂直演变的微物理过程。C波段调频连续波垂直指向雷达 (C-FMCW) 采用收发分置天线，数据垂直分辨率达15~30 m，时间分辨率达2~3 s，利用其2013年6—8月在安徽定远探测数据对降水云垂直结构特征及亮带中融化微物理过程进行研究。6次降水过程共计46 h中的39.1%数据具有清晰的亮带结构特征，期间降水占地面总降水量的15%；江淮雨季层状云、对流云和混合性降水系统中均出现零度层亮带，层状云中亮带长时间维持，对流降水系统移出后减弱阶段的亮带结构稳定，混合降水系统中的对流扰动加强冲破了亮带结构。以融化层中最大回波强度Zp所在高度进行融化层的粒子碰并增长和破碎减弱分层分析，上半层融化过程主要表现为碰并增长，下半层则是粒子破碎减弱。剔除了介电常数、下降速度引起的粒子浓度改变影响后，层状云和对流降水后期的回波强度加强表明融化增长程度接近，后者略强，混合降水云的融化增长最强。Abstract: Being different from the scanning radar, the vertical detection radar is used to analyze the micro-physics process in the precipitation cloud and the fusion layer from the vertical structural feature and the evolution process of the precipitation cloud. The C-FMCW vertical pointing radar adopts the solid-state system, bistatic antenna technology, and the demodulated signal processing adopts two-dimensional FFT signal processing technology to extract the distance information and the spectrum distribution information in the range bin. The vertical resolution of data is from 15 m to 30 m and the time resolution is from 1 s to 3 s, and the minimum reflectivity at 15 km height is-20 dBZ. Compared with the neighboring CINRAD/SA radars at Bengbu and Hefei, the reflectivity calibration difference is less than 1 dB, and root mean square error is less than 2.02 dB. Using C-FMCW radar detective data from June to August in 2013 at Dingyuan of Anhui, the bright band of the precipitation cloud detection data in 46 h are identified. The cumulative rainfall reaches 340.3 mm, during which 55620 precipitation cloud vertical profiles are obtained. 39.1% of precipitation clouds show clear bright band structural feature and during the occurrence of the bright band the precipitation makes up 15% of the total amount. During the Yangtze-Huaihe rainy season, the bright bands appear in stratiform cloud, convective cloud and the mixed precipitation system. In the stratiform cloud, the bright band is most stable and maintains longer. The bright band appears in the decay stage of the convective precipitation and the melting increase is obviously slower. The aggregation increase is of the strongest in the mixed precipitation system, after which the continuous bight band structure is broken by the strengthened convection distribution. The micro-physics process in the fusion layer is complicated. Excluding effects of phase changes and particle number concentration changes, the vapor change in the melting process is given. The maximum reflectivity in the melting process is used to analyze the layering process. It shows the melting process in the upper layer is mainly absorption growth, while in the lower layer is breakup process.
-
图 1 2013年6月22日20:30—21:30 C-FMCW雷达探测层状降水云演变时序图
Fig. 1 C-FMCW radar detect stratiform cloud revolution sequence diagram from 2030 UTC to 2130 UTC on 22 Jun 2013
图 2 2013年8月24日C-FMCW雷达探测对流降水云演变时序图
Fig. 2 Convective cloud revolution sequence detected by C-FMCW radar on 24 Aug 2013
图 3 2013年7月4日20:30—21:30 C-FMCW雷达探测对流降水云演变时序图
Fig. 3 Convective cloud revolution sequence detected C-FMCW radarfrom 2030 UTC to 2130 UTC on 4 Jul 2013
图 4 2013年7月4日21:38—21:54零度层亮带识别结果及融化过程参数
(a) 回波强度，(b) 径向速度, (c)G1和G2，(d)G, (c)Zp
Fig. 4 Bright band identification results and melting process parameters from 2138 UTC to 2154 UTC on 4 Jul 2013
(a) reflectivity, (b) velocity, (c)G1 and G2, (d)G, (e) Zp
图 5 3类降水云的亮带整层及分层参数
(a) 亮带Ⅰ区，(b) 亮带Ⅱ区, (c) 整层
Fig. 5 Melting parameters in the different areas of bright band
(a)Ⅰ area, (b)Ⅱ area, (c) all areas
表 1 3类降水云的亮带与地面降水
Table 1 Bright-band and rain count in 3 precipitation types
降水云
类型降水
过程降水时
长/h亮带时间
比例/%过程降水
量/mm亮带
比例/%过程降水强度
/(mm·h-1)亮带期间降水强度
/(mm·h-1)SC 06-22 10.17 30 4.7 38 0.46 0.59 CCD 07-21 2.38 11 37.1 0.5 14.18 0.64 CCD 08-24 9.05 78 115.6 4 12.77 0.66 MC 06-24 13.13 42 89.0 16 6.78 2.58 MC 07-04 6.36 58 49.3 50 7.43 6.68 MC 07-21 13.33 15 43.4 13 3.23 2.83 
下载: 导出CSV
表 2 亮带结构参数统计特征
Table 2 The statistical characteristic of them bright bind structure
降水过程 降水类型 ΔH/m Ⅰ区/m Ⅱ区/m Zp/dBZ ΔV/(m·s-1) 平均 δ 平均 δ 平均 δ 06-22 SC 640 85 310 50 330 65 26.90 3.45 07-21 CCD 630 80 260 55 370 50 24.45 4.72 08-24 CCD 720 95 320 65 400 60 29.56 4.70 06-24 MC 770 140 360 100 410 80 36.61 4.95 07-04 MC 720 120 340 110 380 110 32.31 4.65 07-22 MC 740 130 350 115 390 105 31.00 4.75
下载: 导出CSV
表 3 3类降水云G1, G2和G的平均值
Table 3 The average and the distribution proportion of G1, G2and G of three kind precipitation cloud
日期 降水云类型 G1/dB G2/dB G/dB ΔZ/dB 06-22 SC 6.05 -5.88 0.17 1.77 07-21 CCD 5.75 -4.99 0.76 1.3 08-24 CCD 6.16 -5.15 1.01 2.01 06-24 MC 7.87 -4.28 3.59 4.87 07-04 MC 7.86 -5.56 2.29 3.72 07-22 MC 6.35 -4.39 1.96 3.21
下载: 导出CSV
-
[1] Neiman P J, Wick G A, Ralph F M, et al.Wintertime nonbrightband rain in California and Oregon during CALJET and PACJET:Geographic, interannual, and synoptic variability.Mon Wea Rev, 2005, 133:1199-1223. doi: 10.1175/MWR2919.1 [2] 阮征, 葛润生, 吴志根.风廓线仪探测降水云体结构方法的研究.应用气象学报, 2002, 13(3):330-338. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20020343&flag=1 [3] Kim D K, Knupp K R, Williams C R.Airflow and precipitation properties within the stratiform region of tropical storm Gabrielle during landfall.Mon Wea Rev, 2009, 137(6):1954-1971. doi: 10.1175/2008MWR2754.1 [4] Schafer R, Avery S, May P, et al.Williams estimation of drop size distributions from dual frequency wind profiler spectra using deconvolution and a nonlinear least squares fitting technique.J Atmos Oceanic Technol, 2002, 19:864-874. doi: 10.1175/1520-0426(2002)019<0864:EORDSD>2.0.CO;2 [5] 陈明轩, 高峰.利用一种自动识别算法移除天气雷达反射率因子中的亮带.应用气象学报, 2006, 17(2):207-214. doi: 10.11898/1001-7313.20060212 [6] 吴翠红, 万玉发, 吴涛, 等.雷达回波垂直廓线及其生成方法.应用气象学报, 2006, 17(2):233-239. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20060239&flag=1 [7] 肖艳娇, 刘黎平, 李中华.任意基线雷达反射率因子垂直剖面生成算法.应用气象学报, 2008, 19(4):428-434. doi: 10.11898/1001-7313.20080406 [8] 张乐坚, 程明虎, 陶岚.CINRAD-SA/SB零度层亮带识别方法.应用气象学报, 2010, 21(2):172-179. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20100206&flag=1 [9] Williams C R, Ecklund W L, Gage K S.Classification of precipitating clouds in the tropics using 915-MHz wind profilers.J Atmos Oceanic Technol, 1995, 12:996-1012. doi: 10.1175/1520-0426(1995)012<0996:COPCIT>2.0.CO;2 [10] White D J, Gottas E T, Strem F M, et al.An automated brightband height detection algorithm for use with Doppler radar spectral moments.J Atmos Oceanic Technol, 2002, 19:687-697. doi: 10.1175/1520-0426(2002)019<0687:AABHDA>2.0.CO;2 [11] Rico R M A, Cluckie I D.Bright-band detection from radar vertical reflectivity profiles.Int J Remote Sensing, 2007, 28(18):4013-4025. doi: 10.1080/01431160601047797 [12] Fabry F, Zawadzki I.Long-term radar observations of the melting layer of precipitation and their interpretation.J Atmos Sci, 1995, 52:838-851. doi: 10.1175/1520-0469(1995)052<0838:LTROOT>2.0.CO;2 [13] Stewart R E, Marwitz J D, Pace L C, et al.Characteristics through the melting layer of stratiform c1ouds.J Atmos Sci, 1984, 41:3227-3237. doi: 10.1175/1520-0469(1984)041<3227:CTTMLO>2.0.CO;2 [14] Drummond F J, Rogers R R, Cohn S A, et al.A new look at the melting layer.J Atmos Sci, 1996, 53(5):759-769. doi: 10.1175/1520-0469(1996)053<0759:ANLATM>2.0.CO;2 [15] 黄钰, 阮征, 葛润生, 等.风廓线雷达探测零度层亮带的试验研究.高原气象, 2011, 30(5):1376-1383. http://cdmd.cnki.com.cn/Article/CDMD-10300-1011155644.htm [16] Williams A B W, Gage K S, Ralph F M.Vertical structure of precipitation and related microphysics observed by NOAA profilers and TRMM during NAME 2004.Climate, 2007, 20:1693-1712. doi: 10.1175/JCLI4102.1 [17] Hooper J E N, Kippax A A.Interim Report on Measurements of Radar Echo Intensities from Rain and Snow.TRE Report T-2082, 1947. [18] 陈万奎, 游来光.融化层附近降水粒子微物理特征的个例分析.应用气象学报, 1987, 2(2):143-150. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=19870219&flag=1 [19] Austin P M, Bemis A C.A quantitative study of the "bright band" in radar precipitation echoes.J Atmos Sci, 1950, 7:145-151. https://www.researchgate.net/publication/234246543_a_Quantitative_Study_of_the_BRIGHT_Band%27_in_Radar_Precipitation_Echoes [20] Löffler-Mang M, Joss J.An optical disdrometer for measuring size and velocity of hydrometeors.J Atmos Oceanic Technol, 2000, 17(2):130-139. doi: 10.1175/1520-0426(2000)017<0130:AODFMS>2.0.CO;2 [21] Friedrich K E A K, Masters F J, Lopez C R.Drop-size distributions in thunderstorms measured by optical disdrometers during VORTEX2.Mon Wea Rev, 2013, 141(4):1182-1203. doi: 10.1175/MWR-D-12-00116.1 -
点击查看大图
计量
- 摘要浏览量: 4242
- HTML全文浏览量: 1118
- PDF下载量: 633
- 被引次数: 0
