气候变化领域集成服务门户(CCPortal): Variation in rain drop size distribution and rain integral parameters during southwest monsoon over a tropical station: An inter-comparison of disdrometer and Micro Rain Radar

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DOI	10.1016/j.atmosres.2018.10.014
	Variation in rain drop size distribution and rain integral parameters during southwest monsoon over a tropical station: An inter-comparison of disdrometer and Micro Rain Radar
	Jash D.; Resmi E.A.; Unnikrishnan C.K.; Sumesh R.K.; Sreekanth T.S.; Sukumar N.; Ramachandran K.K.
发表日期	2019
ISSN	0169-8095
起始页码	24
结束页码	36
卷号	217
英文摘要	The study focuses on the inter-comparison of rain drop size distributions (DSD) and rain integral parameters retrieved using continuous observations from Micro Rain Radar (MRR) and Optical Disdrometer (OD). The variations of the rain parameters during the southwest monsoon period of 2012 over a tropical coastal station are examined. The rain rate and radar reflectivity obtained from both MRR and disdrometer show a correlation of ~0.9. Observations from both the instruments do show that rain intensity of ~2 mm h−1 contributes maximum towards the accumulated rain water. Rain rates are classified into six rain categories to understand the variation with rain intensity. For each rain rate regime, DSDs from MRR and disdrometer compare well for ~1–3 mm diameter range. On the other hand, at larger drop diameters (above D ~ 3 mm) disdrometer overestimates number concentration and at smaller diameters (below D ~ 0.7 mm) disdrometer underestimates number concentration. RD (integrand of rain rate integral) follows a bell-shaped distribution in which the peak position shifts between 1-2 mm drop diameter and widens along with each rain class. Profiles of DSD in Bright Band (BB) and Non-Bright Band (NBB) cases demonstrate that the BB rain events are associated with higher number concentration of larger drops and NBB events are associated with higher concentration of smaller drops. The vertical profile of RD explains that in BB conditions D ~ 1.3 mm significantly contributes total rain water content and for NBB contribution arises from D ~ 1.1 mm at surface level. The profiles also show smaller drops (<1 mm) are found prominent above 2 km towards the rain water content. The Z-R relationships calculated using SIFT method that reduces the scatters in the relation shows good agreement between MRR and disdrometer for the coefficient and exponent values. The relation found for BB(NBB) is Z = 355R1.42(Z = 215R1.46) from disdrometer and those found from MRR is Z = 367R1.37(Z = 211R1.44). The exponent values of Z-R profile (well within 1 ≤ b ≤ 1.63) for BB case represents the DSD spectra are evolved through mixed controlled processes whereas NBB cases are dominated by size-controlled processes. The study reveals that in heavy rainfall conditions there is significant disparity in rain integral parameters between disdrometer and MRR measurements which arises due to the laser inhomogeneity problem of disdrometer, difference in measurement principles and the attenuation of MRR signal at different altitude levels. © 2018
英文关键词	Bright band; Disdrometer; Drop size distribution; Micro rain radar; Monsoon; Z-R relation
语种	英语
scopus关键词	Atmospheric thermodynamics; Drops; Infiltration; Process control; Radar; Size distribution; Tropics; Bright band; Disdrometers; Drop size distribution; Monsoon; Rain radar; Z-R relation; Rain; droplet; monsoon; precipitation intensity; RADARSAT; raindrop; seasonal variation; size distribution
来源期刊	Atmospheric Research
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/162098
作者单位	National Centre for Earth Science Studies (NCESS), ESSO-MoES, Govt. of India, Thiruvananthapuram, India
推荐引用方式 GB/T 7714	Jash D.,Resmi E.A.,Unnikrishnan C.K.,et al. Variation in rain drop size distribution and rain integral parameters during southwest monsoon over a tropical station: An inter-comparison of disdrometer and Micro Rain Radar[J],2019,217.
APA	Jash D..,Resmi E.A..,Unnikrishnan C.K..,Sumesh R.K..,Sreekanth T.S..,...&Ramachandran K.K..(2019).Variation in rain drop size distribution and rain integral parameters during southwest monsoon over a tropical station: An inter-comparison of disdrometer and Micro Rain Radar.Atmospheric Research,217.
MLA	Jash D.,et al."Variation in rain drop size distribution and rain integral parameters during southwest monsoon over a tropical station: An inter-comparison of disdrometer and Micro Rain Radar".Atmospheric Research 217(2019).