Vertical Structure Characteristics of Precipitation in Mêdog Area of Southeastern Tibet During the Monsoon Period

Wen Jiaqi; Wang Gaili; Zhou Renran; Li Ran

doi:10.11898/1001-7313.20230505

Vol.34, NO.5, 2023

Turn off MathJax

Article Contents

Article Navigation > Journal of Applied Meteorological Science > 2023 > 34(5): 562-573

Wen Jiaqi, Wang Gaili, Zhou Renran, et al. Vertical structure characteristics of precipitation in Mêdog area of southeastern Tibet during the monsoon period. J Appl Meteor Sci, 2023, 34(5): 562-573. DOI: 10.11898/1001-7313.20230505.

Citation:

Wen Jiaqi, Wang Gaili, Zhou Renran, et al. Vertical structure characteristics of precipitation in Mêdog area of southeastern Tibet during the monsoon period. J Appl Meteor Sci, 2023, 34(5): 562-573. DOI: 10.11898/1001-7313.20230505.

Citation:

PDF( 22014 KB)

Vertical Structure Characteristics of Precipitation in Mêdog Area of Southeastern Tibet During the Monsoon Period

DOI: 10.11898/1001-7313.20230505

Wen Jiaqi^{1, 2},
Wang Gaili^{1, 2
,
,},
Zhou Renran^{1, 2},
Li Ran^{1, 2}

1.
State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Science, Beijing 100081
2.
Mêdog National Climate Observatory, Mêdog 860700

Received Date: 2023-04-04
Rev Recd Date: 2023-07-14
Publish Date: 2023-09-30

Abstract

Abstract

Precipitation is particularly important for the earth's climate system. Understanding the structural characteristics, microphysical processes and drop size distribution (DSD) of precipitation is very important for quantitative precipitation estimation with radar and improving microphysical parameter schemes of numerical weather prediction models. With the launch of the Second Tibet Plateau Scientific Expedition and Research(STEPS), Chinese Academy of Meteorological Sciences has deployed Ka-band cloud radar (KaCR), X-band dual polarization phased array radar (X-PAR), disdrometer, micro rain radar (MRR) and other detection equipment in Mêdog, filling the gap of cloud and precipitation observation in this area and provides data basis for studying the physical characteristics of clouds and precipitation. Mêdog is located at Yarlung Zangbo Grand Canyon, the entrance of the water vapor channel in southeastern Tibet. Influenced by the warm and humid airflow brought by the Indian Ocean monsoon, the precipitation of Mêdog during the monsoon period exceeds 60% of the annual precipitation. MRR is a low-cost, miniaturized vertical directional Doppler rain radar that can more accurately analyze the vertical structural changes of precipitation. Based on observation of the rain gauge, MRR and disdrometer set up at Mêdog National Climate Observatory from 1 June to 30 September in 2021, the consistency of different instruments is studied. The observed rainfall is classified into convective, stratiform and shallow precipitation types, and the average vertical distribution characteristics of different precipitation types are studied from the aspects of raindrop size distribution, falling speed, rain rate, liquid water content and radar reflectivity. The results show that the measurement of rain gauge, MRR and distrometer are highly consistent. The correlation coefficient of daily rainfall is above 0.89, and the highest correlation coefficient between MRR and rain gauge is 0.96. However, MRR overestimates weak precipitation and underestimate strong precipitation. There are significant differences in the vertical structure of different precipitation types during the monsoon period of Mêdog. Values of each microphysical quantity of convective precipitation are larger. The collision and growth process of raindrop is significant during the falling process below 3 km height, and the raindrop number concentration increases rapidly. There is significant updraft at a height of 1-2 km. The echo intensity of stratiform cloud precipitation is weak below the height of the melting layer. The radar reflectivity, rain rate and liquid water content increase with altitude decrease, the falling speed of raindrops remains basically stable in the vertical direction. The concentration of medium-sized raindrops remains constant with height, and the evaporation, fragmentation, and coalescence processes are in a relatively balance. Values of each microphysical quantity of shallow precipitation are relatively small but vary significantly with height and show negative slops in the vertical direction. The shallow precipitation is dominated by the collision process of raindrops.
- micro rain radar;
- raindrop size distribution;
- Mêdog;
- vertical structure;
- precipitation classification

FullText(HTML)

References(39)

Figures and Tables

图 1 墨脱国家气候观象台位置(红色实心圆点)及青藏高原地形(填色)

(叠加2021年季风期平均垂直积分水汽通量(黑色箭头))

Fig. 1 Location of Mêdog National Climate Observatory(the red solid dot) and topography(the shaded) of Tibetan Plateau

(which is superimposed with mean vertical integral of water vapor flux(black arrows) in monsoon period of 2021)

DownLoad: Full-Size Img PowerPoint

图 2 2021年6月1日—9月30日雨滴数浓度随直径和下落速度的分布

(黑色实线为Altas经验曲线，黑色虚线为经验关系±60%的范围)

Fig. 2 Distribution of raindrop number concentration with diameter and fall speed from 1 Jun to 30 Sep in 2021

(the solid black line denotes Altas experience curve, dashed black lines denote ±60% range of the experience relationship)

DownLoad: Full-Size Img PowerPoint

图 3 2021年9月29日微雨雷达、雨量计、降水现象仪观测对比

(a)日降水量, (b)03:00—07:00 6 min降水率随时间变化

Fig. 3 Rainfall Observed by micro rain radar, rain gauge and disdrometer on 29 Sep 2021

(a)daily rainfall, (b)6-minute average rain rate from 0300 BT to 0700 BT

DownLoad: Full-Size Img PowerPoint

Fig. 4 Radar reflectivity(a),falling speed(b) and ground raindrop size distributions(c) from 0300 BT to 0700 BT on 29 Sep 2021

DownLoad: Full-Size Img PowerPoint

图 5 2021年6月1日—9月30日墨脱3种类型降水的雷达反射率因子、下落速度、降水率和液态水含量的归一化高度-频率分布

(黑色实线为不同高度微物理特征量最大值连线，填色为发生频率)

Fig. 5 Normalized height-frequency of radar reflectivity, falling speed, rain rate and liquid water content for 3 rain types at Mêdog from 1 Jun to 30 Sep in 2021

(the solid black line connects points of the maximum at different altitude frequencies, the shaded denotes frequency)

DownLoad: Full-Size Img PowerPoint

图 6 2021年6月1日—9月30日墨脱3种类型降水微物理特征量的平均垂直廓线

(a)雷达反射率因子, (b)下落速度, (c)降水率, (d)液态水含量

Fig. 6 Average vertical profiles of the micro-physics for 3 rain types at Mêdog from 1 Jun to 30 Sep in 2021

(a)radar reflectivity, (b)falling speed, (c)rain rate, (d)liquid water content

DownLoad: Full-Size Img PowerPoint

图 7 2021年6月1日—9月30日墨脱3种类型降水的雨滴谱分布

(a)对流云降水，(b)层状云降水，(c)浅层云降水

Fig. 7 Raindrop spectrum distribution for 3 rain types at Mêdog from 1 Jun to 30 Sep in 2021

(a)convective, (b)stratiform, (c)shallow

DownLoad: Full-Size Img PowerPoint

Table 1 Main performance parameters of micro rain radar

性能参数	取值
发射频率	24.230 GHz
操作模式	FMCW
发射功率	50 mW(+17 dBm)
波束宽度	1.5°
时间分辨率	10 s(最低1 s)
高度分辨率	10~200 m(可调节)
距离库数	128(可调节)

DownLoad: Download CSV

Table 2 Classification of rain types

降水类型	样本		降水量		降水率/(mm·h^-1)
降水类型	数量	占比/%	数值/mm	占比/%	降水率/(mm·h^-1)
对流云降水	1933	6.7	363.32	32.03	11.27
层状云降水	25485	88.4	747.53	65.90	1.74
浅层云降水	1417	4.9	23.55	2.07	0.99

DownLoad: Download CSV

References

[1]	Milbrandt J A, Yau M K.A multimoment bulk microphysics parameterization.Part Ⅰ:Analysis of the role of the spectral shape parameter.J Atmos Sci, 2005, 62(9):3051-3064. doi: 10.1175/JAS3534.1
[2]	Zhang G F, Sun J Z, Brandes E A. Improving parameterization of rain microphysics with disdrometer and radar observations. J Atmos Sci, 2019, 63(4): 1273-1290.
[3]	Shang B, Zhou Y Q, Liu J Z, et al. Comparing vertical structure of precipitation cloud and non-precipitation cloud using Cloudsat. J Appl Meteor Sci, 2012, 23(1): 1-9. doi: 10.3969/j.issn.1001-7313.2012.01.001
[4]	Ulbrich C W, Atlas D. Microphysics of raindrop size spectra: Tropical continental and maritime storms. J Appl Meteor Climatol, 2007, 46(11): 1777-1791. doi: 10.1175/2007JAMC1649.1
[5]	Chen B J, Yang J, Pu J P. Statistical characteristics of raindrop size distribution in the Meiyu season observed in Eastern China. J Meteor Soc Japan Ser Ⅱ, 2013, 91(2): 215-227. doi: 10.2151/jmsj.2013-208
[6]	Liu C Z, Zhou Y J, Gu J, et al. Characteristics of raindrop size distribution in Chengdu. J Appl Meteor Sci, 2015, 26(1): 112-121. doi: 10.11898/1001-7313.20150112
[7]	Mei H X, Liang X Z, Zeng M J, et al. Raindrop size distribution characteristics of Nanjing in summer of 2015-2017. J Appl Meteor Sci, 2020, 31(1): 117-128. doi: 10.11898/1001-7313.20200111
[8]	Huang Z W, Peng S Y, Zhang H R, et al. Characteristics of raindrop size distribution at Anxi of Fujian. J Appl Meteor Sci, 2022, 33(2): 205-217. doi: 10.11898/1001-7313.20220207
[9]	Cheng P, Luo H, Chang Y, et al. Aircraft measurement of microphysical characteristics of a topographic cloud precipitation in Qilian Mountains. J Appl Meteor Sci, 2021, 32(6): 691-705. doi: 10.11898/1001-7313.20210605
[10]	Liu C W, Guo X L, Duan W, et al. Observation and analysis of microphysical characteristics of stratiform clouds with embedded convections in Yunnan. J Appl Meteor Sci, 2022, 33(2): 142-154. doi: 10.11898/1001-7313.20220202
[11]	Feng Q J, Li P R, Ding J F, et al. Observation and analysis of microphysical characteristics of stratiform cloud precipitation in Shanxi Province. Trans Atmos Sci, 2013, 36(5): 537-545. doi: 10.3969/j.issn.1674-7097.2013.05.003
[12]	Chen S J, Zheng J F, Yang J, et al. Retrieval of air vertical velocity and droplet size distribution in squall line precipitation using C-FMCW radar. J Appl Meteor Sci, 2022, 33(4): 429-441. doi: 10.11898/1001-7313.20220404
[13]	Das S, Maitra A. Vertical profile of rain: Ka band radar observations at tropical locations. J Hydrol, 2016, 534: 31-41. doi: 10.1016/j.jhydrol.2015.12.053
[14]	Song C, Zhou Y Q, Wu Z H. Vertical profile of raindrop size distribution observed by micro rain radar. J Appl Meteor Sci, 2019, 30(4): 479-490. doi: 10.11898/1001-7313.20190408
[15]	Wen L, Zhao K, Wang M Y, Zhang G F. Seasonal variations of observed raindrop size distribution in East China. Adv Atmos Sci, 2019, 36(4): 346-362.
[16]	Chang Y, Guo X L, Tang J, et al. Microphysical characteristics and precipitation formation mechanisms of convective clouds over the Tibetan Plateau. J Appl Meteor Sci, 2021, 32(6): 720-734. doi: 10.11898/1001-7313.20210607
[17]	Zhao Y F, Wang D H, Yin J F. A study on cloud microphysical characteristics over the tibetan plateau using CloudSat data. J Trop Meteor, 2014, 30(2): 239-248. https://www.cnki.com.cn/Article/CJFDTOTAL-RDQX201402005.htm
[18]	Liu L P, Zheng J F, Ruan Z, et al. The preliminary analyses of the cloud properties over Tibetan Plateau from the field experiments in clouds precipitation with the vavious radars. Acta Meteor Sinica, 2015, 73(4): 635-647. https://www.cnki.com.cn/Article/CJFDTOTAL-QXXB201504003.htm
[19]	Chang Y, Guo X L. Characteristics of convective cloud and precipitation during summer time at Naqu over Tibetan Plateau. Chinese Sci Bull, 2016, 61(15): 1706-1720. https://www.cnki.com.cn/Article/CJFDTOTAL-KXTB201615011.htm
[20]	Zhang W X, Zhang L X, Zhou T J. Interannual variability and the underlying mechanism of summer precipitation over the Yarlung Zangbo River Basin. Chinese J Atmos Sci, 2016, 40(5): 965-980. https://www.cnki.com.cn/Article/CJFDTOTAL-DQXK201605007.htm
[21]	Wang G L, Zhou R R, Zhaxi S L, et al. Comprehensive observations and preliminary statistical analysis of clouds and precipitation characteristics in Motuo of Tibet Plateau. Acta Meteor Sinica, 2021, 79(5): 841-852. https://www.cnki.com.cn/Article/CJFDTOTAL-QXXB202105010.htm
[22]	Zhou R R. Comprehensive Observation and Cloud Characteristics Analysis of Cloud Precipitation in Southeastern Qinghai Tibet Plateau. Beijing: Chinese Academy of Meteorological Sciences, 2021.
[23]	Zhang J Y, Wang G L, Zheng J F, et al. Study of the microphysical characteristics of weak precipitation in Mêdog southeastern Tibetan Plateau using Ka-band cloud radar. Chinese J Atmos Sci, 2022, 46(5): 1239-1252. https://www.cnki.com.cn/Article/CJFDTOTAL-DQXK202205010.htm
[24]	Li R, Wang G L, Zhou R R, et al. Seasonal variation in microphysical characteristics of precipitation at the entrance of water vapor channel in Yarlung Zangbo Grand Canyon. Remote Sens, 2022, 14(13). DOI: 10.3390/rs14133149.
[25]	Gunn R, Kinzer G D. The terminal velocity of fall for water droplets in stagnant air. J Atmos Sci, 1949, 6(4): 243-248.
[26]	Foote G B, Toit P. Terminal velocities of raindrops aloft. J Appl Meteor, 1969, 8: 249-253.
[27]	Peters G, Fischer B, Clemens M. Rain attenuation of radar echoes considering finite-range resolution and using drop size distributions. J Atmos Oceanic Technol, 2010, 27(5): 829-842.
[28]	Peters G, Fischer B, Andersson T. Rain observations with a vertically looking micro rain radar(MRR). Boreal Env Res, 2002, 7(4): 353-362.
[29]	Huo Z, Ruan Z, Wei M, et al. Statistical characteristics of raindrop size distribution in south China summer based on the vertical structure derived from VPR-CFMCW. Atmos Res, 2019, 222: 47-61. http://www.xueshufan.com/publication/2912765457
[30]	Atlas D, Srivastava R C, et al. Doppler radar characteristics of precipitation at vertical incidence. Rev Geophys, 1973, 11(1): 1-35.
[31]	Bringi V N, Chandrasekar V, Hubbert J, et al. Raindrop size distribution in different climatic regimes from disdrometer and dual-polarized radar analysis. J Atmos Sci, 2003, 60(2): 354-365.
[32]	Tokay A, Bashor P G. An experimental study of small-scale variability of raindrop size distribution. J Appl Meteor Climatol, 2010, 49(11): 2348-2365.
[33]	Wen L, Zhao K, Zhang G F, et al. Statistical characteristics of raindrop size distributions observed in East China during the Asian summer monsoon season using 2-D video disdrometer and micro rain radar data. J Geophys Res Atmos, 2016, 121(5): 2265-2282.
[34]	Fabry F, Zawadzki I. Long-term radar observations of the melting layer of precipitation and their interpretation. J Atmos Sci, 1995, 52(7): 838-851.
[35]	Habib E, Krajewski W F, Kruger A. Sampling errors of tipping-bucket rain gauge measurements. J Hydrol Eng, 2001, 6(2): 159-166.
[36]	Peters G, Fischer B, Munster H, et al. Profiles of raindrop size distributions as retrieved by micro rain radars. J Appl Meteor Climatol, 2005, 44(12): 1930-1949.
[37]	Barros A P, Joshi M, Putkonen J, et al. A study of the 1999 monsoon rainfall in a mountainous region in central Nepal using TRMM products and rain gauge observations. Geophys Res Lett, 2000, 27(22): 3683-3686.
[38]	Cha J W, Chang K H, Yum S S, et al. Comparison of the bright band characteristics measured by micro rain radar(MRR) at a mountain and a coastal site in South Korea. Adv Atmos Sci, 2009, 26: 211-221.
[39]	Morrison H, Tessendorf S A, Ikeda K, et al. Sensitivity of a simulated midlatitude squall line to parameterization of raindrop breakup. Mon Wea Rev, 2012, 140(8): 2437-2460.