Classification of tropical precipitating systems and associated <i>Z</i>‐<i>R</i> relationships

Rao, T. Narayana; Rao, D. Narayana; Mohan, K. Rama; Raghavan, S.

doi:10.1029/2000jd900836

Cited by 102 publications

(61 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is noticed that the JWD is consistently overestimating the rain intensity. At Gadanki, similar results are also reported by Rao et al (2001). The intercomparison of the L-band profiler and JWD-measured mean diameter (D mean ) and reflectivity (dBZ) are also carried out for all the selected events.…”

supporting

confidence: 59%

“…Later on many researchers reported the existence of a transition region between the convective and stratiform regimes (Williams et al 1995;Maki et al 2001;Steiner et al 1995). Recently, Atlas et al (1999), Rao et al (2001), and Ulbrich and Atlas (2007) studied the DSDs during the three regimes and found the Z-R relations for each regime. It is pointed out that there is a systematic variation of the Z-R relations for these three types of rain (Atlas and Ulbrich 2006;Ulbrich and Atlas 2007).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Characteristics of Rain Integral Parameters during Tropical Convective, Transition, and Stratiform Rain at Gadanki and Its Application in Rain Retrieval

Sharma¹,

Konwar²,

Sarma³

et al. 2009

Journal of Applied Meteorology and Climatology

View full text Add to dashboard Cite

In the present study the characteristics of rain integral parameters during tropical convective (C), transition (T), and stratiform (S) types of rain are studied with the help of Joss-Waldvogel disdrometer (JWD), L-band, and very-high-frequency wind profilers at Gadanki (13.58N, 79.208E). The classifications of three regimes are made with the help of an L-band wind profiler. For rain rate R , 10 mm h 21 larger drops are found in S type of rain relative to C and T rain, and for R $ 10 mm h 21 larger drops are found in convective rain. Empirical relations are developed for D m -R, D m -Z, N 0 * -R, Z-R, and Z/D m -R by fitting the power-law equations. Event to event, no systematic variation of the coefficients and exponents could be found for Z-R and Z/D m -R relations during the three types of rain. Overall, the C and S events are found to be number controlled, and T events are size controlled. During C type of rain, bigger mean raindrops are found during the presence of strong updrafts. During S type of rain, bigger mean raindrops are found to be associated with the higher mean thickness of the bright band and strong velocity gradient. For each of the developed empirical relations, the correlation coefficients are found in the order of T . C . S rain. During the three types of rain, correlations are found in the order of Z/D m -R . Z-R . D m -Z . D m -R. Significant improvement is observed in rain retrieval by using the Z/D m -R relation relative to the conventional Z-R relation. By utilizing the Z/D m -R relations, the root-mean-square error was reduced by 19%-46%.

show abstract

supporting

confidence: 59%

Section: Introductionmentioning

confidence: 99%

Characteristics of Rain Integral Parameters during Tropical Convective, Transition, and Stratiform Rain at Gadanki and Its Application in Rain Retrieval

Sharma¹,

Konwar²,

Sarma³

et al. 2009

Journal of Applied Meteorology and Climatology

View full text Add to dashboard Cite

show abstract

“…Three years (October 2011 to September 2014) of impact-type disdrometer data collected at NARL, Gadanki have been used as it provides 1 min rain rates (Rao et al, 2001). The distributions for event duration and rain rate have been generated by employing three different temporal intervals for separating rain events, 25, 60 and 120 min.…”

Section: Regional Variability In Rain Rate and Rain Durationmentioning

confidence: 99%

Assessment of small-scale variability of rainfall and multi-satellite precipitation estimates using measurements from a dense rain gauge network in Southeast India

Sunilkumar

Rao

Satheeshkumar

2016

Hydrol. Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract. This paper describes the establishment of a dense rain gauge network and small-scale variability in rain events (both in space and time) over a complex hilly terrain in Southeast India. Three years of high-resolution gauge measurements are used to validate 3-hourly rainfall and subdaily variations of four widely used multi-satellite precipitation estimates (MPEs). The network, established as part of the Megha-Tropiques validation program, consists of 36 rain gauges arranged in a near-square grid area of 50 km × 50 km with an intergauge distance of 6-12 km. Morphological features of rainfall in two principal rainy seasons (southwest monsoon, SWM, and northeast monsoon, NEM) show marked differences. The NEM rainfall exhibits significant spatial variability and most of the rainfall is associated with large-scale/long-lived systems (during wet spells), whereas the contribution from small-scale/short-lived systems is considerable during the SWM. Rain events with longer duration and copious rainfall are seen mostly in the western quadrants (a quadrant is 1/4 of the study region) in the SWM and northern quadrants in the NEM, indicating complex spatial variability within the study region. The diurnal cycle also exhibits large spatial and seasonal variability with larger diurnal amplitudes at all the gauge locations (except for 1) during the SWM and smaller and insignificant diurnal amplitudes at many gauge locations during the NEM. On average, the diurnal amplitudes are a factor of 2 larger in the SWM than in the NEM. The 24 h harmonic explains about 70 % of total variance in the SWM and only ∼ 30 % in the NEM. During the SWM, the rainfall peak is observed between 20:00 and 02:00 IST (Indian Standard Time) and is attributed to the propagating systems from the west coast during active monsoon spells. Correlograms with different temporal integrations of rainfall data (1, 3, 12, 24 h) show an increase in the spatial correlation with temporal integration, but the correlation remains nearly the same after 12 h of integration in both monsoon seasons. The 1 h resolution data show the steepest reduction in correlation with intergauge distance and the correlation becomes insignificant after ∼ 30 km in both monsoon seasons.Validation of high-resolution rainfall estimates from various MPEs against the gauge rainfall data indicates that all MPEs underestimate the light and heavy rain. The MPEs exhibit good detection skills of rain at both 3 and 24 h resolutions; however, considerable improvement is observed at 24 h resolution. Among the different MPEs investigated, the Climate Prediction Centre morphing technique (CMORPH) performs better at 3-hourly resolution in both monsoons. The performance of Tropical Rainfall Measuring Mission (TRMM) multi-satellite precipitation analysis (TMPA) is much better at daily resolution than at 3-hourly, as evidenced by better statistical metrics than the other MPEs. All MPEs captured the basic shape of the diurnal cycle and the amplitude quite well, but failed to reproduce the weak/insign...

show abstract

“…Rao et al (2001), first noticed the differences in rain DSD in these monsoon seasons. They obtained different reflectivity-rainfall rate (Z -R) relations in SW and NE monsoon seasons.…”

Section: Introductionmentioning

confidence: 99%

Differences in raindrop size distribution from southwest monsoon to northeast monsoon at Gadanki

Rao

Radhakrishna

Nakamura

et al. 2009

Quart J Royal Meteoro Soc

View full text Add to dashboard Cite

Characteristics of raindrop size distribution (DSD) are studied during the southwest (SW) and northeast (NE) monsoon seasons using 4 1/2 years of DSD measurements made at Gadanki (13.5 • N, 79.2 • E) by an impact-type disdrometer. The observed DSD is found to be distinctly different in the NE monsoon from that of the SW monsoon. The stratified DSD (based on rain rate) shows more small drops and fewer bigger drops in the NE monsoon than in the SW monsoon, particularly in the low rain rate regime. This feature is not an anomalous one, rather observed consistently in all the years. The diurnal variation of DSD (in terms of mass-weighted mean diameter, D m ) plots in both monsoons show large values of D m in the evening hours. Several possible reasons, from instrumental problems to geophysical mechanisms, for the observed DSD differences are examined. The wind field and the range of D m values indicate that the DSDs in the SW and NE monsoons are continental and oceanic in nature, respectively. Further, high temperature and intense convective activity (vigorous updraughts) in the SW monsoon modify the DSD through evaporation, drop sorting, and collision-coalescence processes.

show abstract

Classification of tropical precipitating systems and associated Z‐R relationships

Abstract: Abstract. Simultaneous observations of Indian

Cited by 102 publications

References 23 publications

Characteristics of Rain Integral Parameters during Tropical Convective, Transition, and Stratiform Rain at Gadanki and Its Application in Rain Retrieval

Characteristics of Rain Integral Parameters during Tropical Convective, Transition, and Stratiform Rain at Gadanki and Its Application in Rain Retrieval

Assessment of small-scale variability of rainfall and multi-satellite precipitation estimates using measurements from a dense rain gauge network in Southeast India

Differences in raindrop size distribution from southwest monsoon to northeast monsoon at Gadanki

Contact Info

Product

Resources

About