Nature of light rain during presence and absence of bright band

Konwar, Mahen; Maheskumar, R. S.; Das, Subrata Kumar; Morwal, Savita B.

doi:10.1007/s12040-012-0202-x

Cited by 23 publications

(34 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Another important aspect observed from both the radars is the increasing trend of mean Z toward the lower altitudes during R low . This possibly indicates the increase of raindrop size by the CC process similar to the observation during the NBB conditions at Pune located on the leeward side of the WG [Konwar et al, 2012a]. Enhanced Z at lower altitudes is reported for orographic rain over the south Wales [Hill et al, 1981].…”

Section: 1002/2014jd021606supporting

confidence: 75%

“…The DSDs characterized by size-controlled processes provide a limiting case for valid range of shape factor μ [Steiner et al, 2004]. From wind profiler measurements and MRR, the CCB processes are found to dominate among the raindrops during the tropical stratiform rain [Kirankumar et al, 2008;Sharma et al, 2009;Konwar et al, 2012a]. Although we do not have simultaneous X band radar observations of the storms under discussion, limited observations of the stratiform precipitating system for another day indicates presence of liquid hydrometeors below the melting layer ( Figure S1).…”

Section: Altitude and Temporal Variability Of Raindrop Size Distributmentioning

confidence: 94%

“…Light rain events occurred in Pune on 11 August 2008 is considered for studying the microphysics of BB and FBB conditions while for NBB, an event on 12 August 2008 is considered. The BB and FBB events are characterized by enhanced Z at the melting layer while the NBB events are characterized by shallow storm heights of 2-3 km [Konwar et al, 2012a]. The Gamma DSD fits are carried out to the PD and MRR observed DSDs.…”

Section: Altitude and Temporal Variability Of Raindrop Size Distributmentioning

confidence: 99%

“…It is therefore critical to understand the underlying cloud and rain microphysical processes of the monsoonal precipitating systems responsible for such rainfall. On the leeward side of WG, CCB mechanisms among the raindrops are dominant during stratiform rain in the presence of bright band (BB) but in case of the shallow convective systems, the collisioncoalescence (CC) process is found to be the dominant mechanism among the raindrops [Konwar et al, 2012a]. In the past, several modeling and observational studies are carried out to understand monsoon rain characteristics over the WG [e.g., Sarkar, 1966;Smith and Lin, 1983, Ogura and Yoshizaki, 1988, Kumar et al, 2013Sijikumar et al, 2013, and references therein].…”

Section: Introductionmentioning

confidence: 99%

“…The NBB conditions were characterized by an absence of prominent hydrometeor fall velocity gradient below 0°C isotherm level which was assigned in the shallow convective cloud category. Their storm tops typically are located below the 0°C isotherm level [Konwar et al, 2012a].…”

mentioning

confidence: 99%

See 4 more Smart Citations

Microphysics of clouds and rain over the Western Ghat

et al. 2014

Self Cite

View full text Add to dashboard Cite

In an attempt to unravel the interactions between cloud microphysics and dynamics that make shallow clouds precipitate heavily in this region, some unique observations of rain and cloud microphysical parameters are presented here from two stations, Pune and Mahabaleshwar, one each on the lee and windward sides, respectively, of the Western Ghat (WG) mountains in peninsular India. To elucidate rain microphysics, we used the raindrop size distribution (DSD) by fitting three parameter Gamma functions to the observed raindrop spectra. Over Pune, during stratiform rain with bright band (BB) at 0°C isotherm; concave upward DSD shapes are observed below the BB which becomes concave downward at lower altitudes. It is due to breakup process of large raindrops which increases drop concentration at midsizes suggesting coalescence, collision, and breakup processes. Both slope and intercept parameters of Gamma DSD decrease during no BB condition as altitudes decrease, signifying collision and coalescence processes. Over Mahabaleshwar, bimodal and monomodal DSD are observed during light and heavy rainfall, respectively. With shallow storm heights, small raindrops mainly contribute to both types of rainfall. The DSDs are parameterized, and their radar reflectivity factor-rainfall intensity relationships are evaluated suggesting the dominance of collision-coalescence processes. Aircraft measurements of orographic clouds over the WG suggest interaction of cloud mass with the ambient updraft speed. The orographically forced updrafts foster rapid condensational growth of cloud droplets triggering coalescence process within few hundred meters of cloud depth. Hence, these clouds are dynamically forced to produce precipitation over the WG.

show abstract

Section: 1002/2014jd021606supporting

confidence: 75%

Section: Altitude and Temporal Variability Of Raindrop Size Distributmentioning

confidence: 94%

Section: Altitude and Temporal Variability Of Raindrop Size Distributmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Microphysics of clouds and rain over the Western Ghat

et al. 2014

Self Cite

View full text Add to dashboard Cite

show abstract

Investigation of orographic features influencing spatial distribution of rainfall over the Western Ghats of India using satellite data

Tawde

Singh

2014

Int. J. Climatol

View full text Add to dashboard Cite

Using remotely sensed Tropical Rainfall Measuring Mission (TRMM) 3B42 rainfall and topographic data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Digital Elevation Model (DEM), the impact of oroghraphical aspects such as topography, spatial variability of elevation and altitude of apexes are examined to investigate capacious summer monsoon rainfall over the Western Ghats (WG) of India. TRMM 3B42 v7 rainfall data is validated with Indian Meteorological Department (IMD) gridded rainfall data at 0.5 ∘ resolution over the WG. The analysis of spatial pattern of monsoon rainfall with orography of the WG ascertains that the grade of orographic precipitation depends mainly on topography of the mountain barrier followed by steepness of windward side slope and altitude of the mountain. Longer and broader, i.e. cascaded topography, elevated summits and gradually increasing slopes impel the enhancement in precipitation. Comparing topography of various states of the WG, it has been observed that windward side of Karnataka receives intense rainfall in the WG during summer monsoon. It has been observed that the rainfall is enhanced before the peak of the mountain and confined up to the height about 800 m over the WG. In addition to this, the spatial distribution of heavy and very heavy rainfall events in the last 14 years has also been explored. Heavy and very heavy rain events on this hilly terrain are categorized with a threshold of precipitation (R) in the range 150 > R > 120 mm day −1 and exceeding 150 mm day −1 using probability distribution of TRMM 3B42 v7 rainfall. The areas which are prone to heavy precipitation are identified. The study would help policy makers to manage the hazard scenario and, to improve weather predictions on mountainous terrain of the WG.

show abstract

A study of raindrop size distribution during stratiform rain and development of its parameterization scheme in the framework of multi‐parameter observations

Sarma¹,

Deshamukhya

Rao

et al. 2016

Meteorological Applications

View full text Add to dashboard Cite

ABSTRACT:A study was carried out to investigate the rain drop size distribution (DSD) characteristics during strong bright band (SBB), weak bright band (WBB) and no bright band (NBB) regimes of stratiform rain by using an L-band wind profiler and Joss-Waldvogel disdrometer at Gadanki (13.5 ∘ N, 79.20 ∘ E), a tropical station in India. The stratiform events with SBB (bright band width >0.49 km) are associated with larger mean drops (D m ) at ground level compared with WBB and NBB situations. Different shapes of raindrop DSDs during these three situations suggest different microphysical processes involved in the evolution of rain DSDs. During SBB regimes, the raindrop spectrum, which is found to be governed predominantly by an aggregation process, is size controlled. On the other hand, during WBB regimes, the raindrop spectrum, which is found to be governed predominantly by a riming process, is number controlled. A new rain DSD parameterization scheme, P (Z, N 0 * ), is proposed in the framework of multi-parameter radar observation. The considered parameters are radar reflectivity factor (Z) and normalized scale parameter (N 0 * ). These two parameters are found to be mutually independent. Reasonable improvement in the estimation of rain intensity is observed by the developed P(Z, N 0 * ) scheme compared with P(Z) and P(Z, D m ). The rain DSDs simulated by the developed P(Z, N 0 * ) scheme are in good agreement with the observed spectrum.

show abstract

Nature of light rain during presence and absence of bright band

Cited by 23 publications

References 42 publications

Microphysics of clouds and rain over the Western Ghat

Microphysics of clouds and rain over the Western Ghat

Investigation of orographic features influencing spatial distribution of rainfall over the Western Ghats of India using satellite data

A study of raindrop size distribution during stratiform rain and development of its parameterization scheme in the framework of multi‐parameter observations

Contact Info

Product

Resources

About