scholarly journals PENGAMATAN KEJADIAN HUJAN DENGAN DISDROMETER DAN MICRO RAIN RADAR DI SERPONG

2017 ◽  
Vol 18 (1) ◽  
pp. 1
Author(s):  
Findy Renggono
Keyword(s):  
Size Distribution ◽  
Rainy Season ◽  
Drop Size ◽  
Drop Size Distribution ◽  
Rain Event ◽  
Stratiform Rain ◽  
Convective Rain ◽  
Rain Events ◽  
Rain Radar

IntisariPengamatan hujan dengan menggunakan beberapa peralatan yang mempunyai metode berbeda telah dilakukan di wilayah Serpong. Peralatan yang digunakan adalah Disdrometer dan Micro Rain Radar (MRR). Kedua peralatan tersebut dipasang pada satu lokasi yang sama agar dapat mengukur kejadian hujan yang sama. Pengamatan dilakukan pada akhir tahun 2016 selama 5 bulan, disesuaikan dengan kondisi dimana musim hujan sudah mulai masuk untuk wilayah ini. Perbandingan pengukuran yang telah dilakukan menunjukkan kesesuaian hasil antara kedua peralatan tersebut.  Pengamatan distribusi ukuran butir air pada empat kejadian hujan antara bulan Agustus-Desember 2016 menunjukkan bahwa hujan konvektif mempunyai distribusi ukuran yang lebih besar dibandingkan hujan stratiform.  AbstractRain observation by using several instruments having different method has been done in Serpong area. The instrument used is Disdrometer and Micro Rain Radar (MRR). Both instruments are installed in the same location in order to measure the same rain events. Observations were made at the end of 2016 for 5 months, adjusted to the conditions in which the rainy season has begun to enter for the region. Comparison of measurements that have been done indicate the suitability of the results between the two instrument. Drop size distribution of four rain event during August - December 2016 shows that the drop size distribution on convective rain broaden than on stratiform rain. 

scholarly journals CPOL Radar-Derived Drop Size Distribution Statistics of Stratiform and Convective Rain for Two Regimes in Darwin, Australia

2010 ◽  
Vol 27 (5) ◽  
pp. 932-942 ◽  
Author(s):  
M. Thurai ◽  
V. N. Bringi ◽  
P. T. May
Keyword(s):  
Size Distribution ◽  
Drop Size ◽  
Drop Size Distribution ◽  
Stratiform Rain ◽  
Convective Rain ◽  
Radar Measurements ◽  
Indexing Technique ◽  
Technique Development ◽  
Range Of Values

Abstract This note builds on prior technique development related to the classification of rain types utilizing C-band polarimetric (CPOL) radar measurements. While the prior work was preliminary and limited in scope, the authors elaborate here on the basis of the drop size distribution (DSD)-based indexing technique for rain-type classification (convective/stratiform/mixed), and place it on firmer footing by testing the methodology against texture- and disdrometer-based methods as applied to Darwin datasets. A microphysical-based methodology is attractive as it links more directly to the underlying rainfall physical processes. Statistics of the DSD parameters, namely, histograms of log10(Nw) and D0, for convective and stratiform rain types across the premonsoon buildup and monsoon regimes were derived and further separated for over land and over ocean regions. The maximum value for mean D0 (1.64 mm) and the largest histogram standard deviation (0.32 mm) occurred for convective rain over land during the buildup regime. The largest differences in D0 and NW histograms were found to be for convective rain between the buildup and monsoon regimes (independent of land or ocean areas). Stratiform rain histograms were found to be very similar during the buildup regime with little land–ocean differences. However, somewhat larger land–ocean differences were found for the monsoon stratiform rain. The main histogram characteristics of the “mixed” or “uncertain” rain type were closer to the convective rain type than to stratiform, across both regimes and land–ocean areas. Additionally, the Nw versus D0 cluster of points (mean ±1σ) for convective rain agrees very well with the previously published range of values for maritime convective (equilibrium-like) DSDs.

scholarly journals Precipitation classification at mid-latitudes in terms of drop size distribution parameters

2008 ◽  
Vol 16 ◽  
pp. 11-17 ◽  
Author(s):  
C. Caracciolo ◽  
F. Porcù ◽  
F. Prodi
Keyword(s):  
Size Distribution ◽  
Drop Size ◽  
Fundamental Property ◽  
Drop Size Distribution ◽  
Light Rain ◽  
Real Distribution ◽  
Distribution Parameters ◽  
Rain Events ◽  
Near Future ◽  
Rain Formation

Abstract. The drop size distribution (DSD) is a fundamental property of rainfall because the shape of the distribution reflects the physics of rain formation processes. Given the lack of studies on the DSD at mid-latitudes, the present work focuses on the microphysical characterization of precipitation events occurring in Italy, using two different types of disdrometer. A large number of different rain events was collected: they underwent microphysical analysis by computing the Z-R relationships, observing the average DSDs and DSD parameters, fitting the real distribution for different rainfall rate categories and applying convective (C) – stratiform (S) discrimination algorithms. A general agreement with past works at mid-latitudes is found both in the Z-R relationship and in DSD parameters. The rain distribution is well described by a gamma DSD and only in some cases (especially the light rain events) by an exponential DSD. Marked differences are observed in DSD parameters and Z-R relationships between C and S episodes. The use of disdrometers for areas covered by multiparametric radar is suggested and will be performed in the near future.

Estimation of Spatial Correlation of Drop Size Distribution Parameters and Rain Rate Using NASA’s S-Band Polarimetric Radar and 2D Video Disdrometer Network: Two Case Studies from MC3E

2015 ◽  
Vol 16 (3) ◽  
pp. 1207-1221 ◽  
Author(s):  
V. N. Bringi ◽  
L. Tolstoy ◽  
M. Thurai ◽  
W. A. Petersen
Keyword(s):  
Size Distribution ◽  
Spatial Correlation ◽  
Drop Size ◽  
Rain Rate ◽  
Pearson Correlation ◽  
Drop Size Distribution ◽  
Distinct Advantage ◽  
Rain Event ◽  
Polarimetric Radar ◽  
Spatial Correlation Function

Abstract Polarimetric radar data obtained at high spatial and temporal resolutions offer a distinct advantage in estimating the spatial correlation function of drop size distribution (DSD) parameters and rain rate compared with a fixed gauge–disdrometer network. On two days during the 2011 Midlatitude Continental Convective Clouds Experiment (MC3E) campaign in Oklahoma, NASA’s S-band polarimetric radar (NPOL) performed repeated PPI scans every 40 s over six 2D video disdrometer (2DVD) sites, located 20–30 km from the radar. The two cases were 1) a rapidly evolving multicell rain event (with large drops) and 2) a long-duration stratiform rain event. From the time series at each polar pixel, the Pearson correlation coefficient is computed as a function of distance along each radial in the PPI scan. Azimuthal dependence is found, especially for the highly convective event. A pseudo-1D spatial correlation is computed that is fitted to a modified-exponential function with two parameters (decorrelation distance R0 and shape F). The first event showed significantly higher spatial variability in rain rate (shorter decorrelation distance R0 = 3.4 km) compared with the second event with R0 = 10.2 km. Further, for the second event, the spatial correlation of the DSD parameters and rain rate from radar showed good agreement with 2DVD-based spatial correlations over distances ranging from 1.5 to 7 km. The NPOL also performed repeated RHI scans every 40 s along one azimuth centered over the 2DVD network. Vertical correlations of the DSD parameters as well as the rainwater content were determined below the melting level, with the first event showing more variability compared with the second event.

Effects of Radar Beam Shielding on Rainfall Estimation for the Polarimetric C-Band Radar

2007 ◽  
Vol 24 (11) ◽  
pp. 1839-1859 ◽  
Author(s):  
Katja Friedrich ◽  
Urs Germann ◽  
Jonathan J. Gourley ◽  
Pierre Tabary
Keyword(s):  
Size Distribution ◽  
Drop Size ◽  
Radar Data ◽  
Drop Size Distribution ◽  
Rainfall Estimation ◽  
Axis Ratio ◽  
Radar Beam ◽  
Average Rainfall ◽  
Rain Events ◽  
Rainfall Estimates

Abstract Radar reflectivity (Zh), differential reflectivity (Zdr), and specific differential phase (Kdp) measured from the operational, polarimetric weather radar located in Trappes, France, were used to examine the effects of radar beam shielding on rainfall estimation. The objective of this study is to investigate the degree of immunity of Kdp-based rainfall estimates to beam shielding for C-band radar data during four typical rain events encountered in Europe. The rain events include two cold frontal rainbands with average rainfall rates of 7 and 17 mm h−1, respectively, and two summertime convective rain events with average rainfall rates of 11 and 22 mm h−1. The large effects of beam shielding on rainfall accumulation were observed for algorithms using Zh and Zdr with differences of up to ∼2 dB (40%) compared to a Kdp-based algorithm over a power loss range of 0–8 dB. This analysis reveals that Zdr and Kdp are not affected by partial beam shielding. Standard reflectivity corrections based on the degree of beam shielding would have overestimated rainfall rates by up to 1.5 dB for less than 40% beam shielding and up to 3 dB for beam shielding less than 75%. The investigation also examined the sensitivity of beam shielding effects on rainfall rate estimation to (i) axis–ratio parameterization and drop size distribution, (ii) methods used to smooth profiles of differential propagation phase (ϕdp) and estimate Kdp, and (iii) event-to-event variability. Although rainfall estimates were sensitive to drop size distribution and axis–ratio parameterization, differences between Zh- and Kdp-based rainfall rates increased independently from those parameters with amount of shielding. Different approaches to smoothing ϕdp profiles and estimating Kdp were examined and showed little impact on results.

scholarly journals VARIASI HARIAN DAN TAHUNAN HUJAN DI SERPONG BERDASARKAN PENGAMATAN DENGAN MICRO RAIN RADAR

2017 ◽  
Vol 18 (2) ◽  
pp. 75
Author(s):  
Findy Renggono
Keyword(s):  
Rainy Season ◽  
Dry Season ◽  
Stratiform Rain ◽  
Daily Variations ◽  
Convective Rain ◽  
Rain Radar

IntisariKemampuan MRR untuk mengamati profil hujan sampai ketinggian di atas 7500m dapat digunakan untuk mengamati kemunculan jenis hujan. Dari parameter yang diperoleh dapat dibedakan menjadi dua jenis hujan, konvektif dan stratiform berdasarkan keberadaan brightband. Pengamatan kemunculan jenis hujan dengan MRR di Serpong menunjukkan bahwa hujan konvektif relatif muncul lebih banyak dibandingkan stratiform pada puncak musim kering, sedangkan pada musim hujan sebaliknya. Untuk variasi hariannya, puncak hujan konvektif muncul sekitar pukul 15.00-16.00 WIB sedangkan stratiform sekitar pukul 18.00 WIB.  AbstractThe ability of micorain radar to observe precipitation profiles up to 7500m height can be used to observe the precipitation types. Precipitation can be classified into two types of rain, convective and stratiform based on the existence of brightband. MRR observation in Serpong shows that convective rain relatively appears more than stratiform rain during the peak of the dry season, while in the rainy season vice versa. For daily variations, the peak of the convective rain appears at about 15.00-16.00 LT while the stratiform is around 18.00 LT. 

Effect of Boundary Layer Dynamics on the Profiles of Rain Drop Size Distribution During Convective Rain

2019 ◽  
Vol 16 (7) ◽  
pp. 1007-1011 ◽  
Author(s):  
Animesh Maitra ◽  
Gargi Rakshit ◽  
Soumyajyoti Jana ◽  
Rohit Chakraborty
Keyword(s):  
Boundary Layer ◽  
Size Distribution ◽  
Drop Size ◽  
Drop Size Distribution ◽  
Convective Rain ◽  
Rain Drop ◽  
Boundary Layer Dynamics

scholarly journals Rain Drop Size Distribution Analysis at a Tropical Location Near Land-sea Boundary

2021 ◽  
Author(s):  
Pallabi Saha ◽  
Souvik Majumder ◽  
Animesh Maitra
Keyword(s):  
Size Distribution ◽  
Land Surface ◽  
Drop Size ◽  
Drop Size Distribution ◽  
Distribution Analysis ◽  
Gamma Model ◽  
Rain Drop ◽  
Rain Events ◽  
Size Interval

Abstract Rain events can be characterized by rain drop size distribution (DSD) that denotes the number of drops as a function of diameter per unit size interval and per unit volume of space. DSD describes the microstructure of precipitation during different phases of rain varying both spatially and temporally. DSD can be influenced by the nature and origin of rain. The present study investigates the role of continental and maritime airflow in influencing the precipitation features near the land-sea boundary. Rain DSD data used in the present analysis are collected from a ground based disdrometer located at Kolkata, India during the year of 2011-2017. The dataset is divided into two categories namely, maritime and continental rainfall, based on the airflow trajectories associated with rainfall, respectively, from Bay of Bengal and from land surface in the west of Kolkata, as derived from TRAJSTAT software. Variations of the DSD parameters using Gamma model is presented showing the abundance of smaller drops during maritime rain events whereas dominance of larger raindrops in the case of the continental rain events. The Z-R relations are also found to be significantly different for these two types of rain. The present study reveals the microstructures of rain at a location where the influences of both land and sea climatic features prevail.

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