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Estimation of Raindrop Size Distribution Parameters Using Lightning Data over West Sumatra Salma, Faridah; Marzuki, Marzuki; Hashiguchi, Hiroyuki; Nauval, Fadli
Jurnal Ilmu Fisika Vol 13, No 2 (2021): Published in September 2021 (COMING ISSUE)
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jif.13.2.92-100.2021

Abstract

In situ observations of raindrop size distributions (DSDs) are still limited, especially in the tropics. Therefore, this study develops an alternative method to calculate DSD parameters by utilizing lightning data from the World-Wide Lightning Location Network (WWLLN) observation. DSD data was obtained from Parsivel's observations in the equatorial regions of Indonesia, i.e., Kototabang (100.32◦E, 0.20◦S, 865 m above mean sea level/ASL), Padang (100.46°E, 0.915°S, 200 m ASL), and Sicincin (100.30°E, 0.546°S, 134 m ASL). A gamma distribution parameterized the DSD. Three analysis domains were examined, with a grid of 0.1° x 0.1°, 0.5° x 0.5°, and 1° x 1°.  We examined the possibility to calculate the near-instantaneous DSD parameter, so three short time intervals, namely, one, five and ten minutes, were used. The results showed that the number of lightning strokes does not adequately correlate with DSD parameters. This is observed in all time intervals and analysis domains. Thus, the use of lightning data to calculate DSD parameters is not possible for short time interval of DSD (near instantaneous DSD). However, lightning data can estimate the average DSD parameters for an average time of more than one hour, as recommended by previous studies.
Differences in Mechanisms of Orographic Rainfall over West Sumatra (Case Study: 10 April and 23 April 2004) Harjupa, Wendi; Shimomai, Toyoshi; Hashiguchi, Hiroyuki; Fujiyoshi, Yasushi; Kawashima, Masayuki
Jurnal Ilmu Fisika Vol 13, No 1 (2021): Published in March 2021
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jif.13.1.8-17.2021

Abstract

Two different mechanisms of orographic rainfall enhancement  in West Sumatra were investigated utilizing observed data during the Coupling Processes in the Equatorial Atmosphere (CPEA)-I campaign. The variation of the atmospheric conditions during the campaign was shown by rainfall, surface wind, humidity, and stability index. An X-band Doppler radar captured the atmospheric conditions related to the enhancement of orographic rainfall mechanisms. The dry and less stable atmospheric conditions resulted in the convective type of rainfall. In contrast, the humid and stable atmospheric conditions brought the large-scale rainfall in the mountainous region where the events took place coincided with the inactive and active MJO phases..
Comparison of Bright Band Radar from GPM and MRR Observation in West Sumatera Ramadhan, Ravidho; Marzuki, Marzuki; Vonnisa, Mutya; Harmadi, Harmadi; Hashiguchi, Hiroyuki; Shimomai, Toyoshi
Jurnal Penelitian Fisika dan Aplikasinya (JPFA) 2021: Articles in Press
Publisher : Universitas Negeri Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26740/jpfa.v11n1.p%p

Abstract

AbstractThe Bright band (BB) measurement from NS scan on Global Precipitation Measurement (GPM) had been compared with Micro Rain Radar (MRR) which is installed in Kototabang, West Sumatera (0.23o S; 100.32oE; 865 m above sea level). The GPM data were collected from December 2014 to June 2018 and compared with MRR observation from January 2012 to August 2016. The BB values from these instruments were also compared with the values recommended by the International Telecommunication Union Recommendation (ITU-R) P.839. The BB from GPM and MRR shown slightly diurnal and seasonal variations. BB observations from GPM and MRR show good agreement with slightly difference in diurnal and seasonal variations. BB observations are more similar when the intensity of solar radiation is lower, ie at night (18.00-24.00 LT) until dawn (00.00-06.00 LT). Furthermore, MRR determined a slight bimodal pattern in the seasonal variation while GPM did not, it cause variation in observation of both instrument quite significant in seasonal variation. The largest different from the seasonal variation was observed in the summer season (Juni-August(JJA)). Moreover the measurement of the mean BB is still below the Freezing Height Level (FHL) value from ITU-R model, the measurement of both instruments obtained a high number than FHL considerably (>36 %). It showed the constant value for FHL in West Sumatera that would cause the attenuation estimation of microwaves to be less accurate.
Seasonal and Diurnal Variations of Lightning Activity Over West Sumatra and Its Correlation with Precipitation Type Saufina, Elfira; Marzuki, Marzuki; Vonnisa, Mutya; Hashiguchi, Hiroyuki; Harmadi, Harmadi
Makara Journal of Science Vol. 22, No. 2
Publisher : UI Scholars Hub

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Seasonal and diurnal variations of lightning activity over West Sumatra have been investigated using observations of Tropical Rainfall Measuring Mission–Lightning Imaging Sensor (TRMM–LIS) over a 16-year period. This study also used TRMM 3B43 and 2A25 data to observe the correlation between lightning activity with rainfall and precipitation type. Results show that lightning occurs more frequently over land than over ocean and coastal areas, in contrast to total rainfall, which is higher over ocean and coastalareas. The lightning pattern is similar to the convective rainfall (particularly deep convective) pattern, which indicates that the majority of lightning in West Sumatra is associated with deep convective rain. The lightning intensity in Indonesia during the convection period, namely, December–January–February and September–October–November, is higher than that during other periods. The diurnal cycle of lightning coincides with the diurnal cycle of cloud migration from the ocean to in land Sumatra, as reported in previous research. Lightning and deep convective precipitation are dominant during the day and evening (16.00–20.00 Local Standard Time [LST]), particularly over land. Stratiform precipitation occursmore frequentlyfrom afternoon to early morning (16.00–04.00 LST) over landand at 00.00–12.00 LST over the ocean.
PERBANDINGAN KARAKTERISTIK DISTRIBUSI UKURAN BUTIRAN HUJAN DI PADANG DAN DI KOTOTABANG Chandra, Rio; -, Marzuki; Hashiguchi, Hiroyuki
Jurnal Fisika Unand Vol 4 No 3: Juli 2015
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jfu.4.3.%p.2015

Abstract

ABSTRAKDistribusi ukuran butiran hujan atau raindrop size distribution (RDSD) di Padangdan di Kototabang, Sumatera Barat,  telah dibandingkan.  Perbandingan dilakukan melalui pengamatan particle size velocity (Parsivel) selama Maret 2014 – Mei 2015 untuk Padang dan Januari 2014 – Januari 2015 untuk Kototabang.  RDSD dimodelkan dengan distribusi gamma dan parameternya didapatkan menggunakan metode momen.  Terlihat bahwa intensitas curah hujan yang tinggi lebih banyak di Padang daripada di Kototabang.  Selain itu, butiran hujan yang berukuran besar di Padang lebih banyak daripada di Kototabang.  Banyaknya butiran hujan yang berukuran besar ini berdampak pada nilai radar reflectivity (Z) di Padang yang sedikit lebih besar dari Kototabang untuk intensitas curah hujan yang sama.  Karena itu nilai koefisien A yang ada dalam persamaan Z-R di Padang juga sedikit lebih besar dari Kototabang.  Sedikitnya perbedaan karakteristik RDSD antara Padang dan Kototabang, disebabkan oleh hujan yang terjadi  di Padang dan di Kototabang kemungkinan berasal dari awan konvektif yang sama, yaitu awan dari Samudra Hindia.  Awan tersebut mengalami proses yang berbeda di Kototabangdisebabkan oleh adanya pegunungan di sekitar daerah ini sehingga menimbulkan hujan dengan RDSD yang agak berbeda dengan di Padang. Kata kunci: raindrop size distribution, metode momen, Parsivel, Padang, KototabangAbstractCharacteristics of raindrop size distribution (RDSD) in Padang and Kototabang have been compared through particle size distribution (Parsivel) observation during March 2014 – May 2015 for Padang and January 2014 – January 2015 for Kototabang.  The RDSD was parameterized by the modified gamma distribution and its parameter was calculated by the moment method.  It was found that the occurrence frequency of heavy rain in Padang is higher than Kototabang.  Moreover, rains in Padang have more large-sized drop than Kototabang.  As consequence, the radar reflectivity factor (Z) in Padang was slightly larger than Kotabang for the same rainfall rate.  A small difference in the RDSD between Padang and Kototabang may indicate that the precipitating cloud of the two regions is the same, i.e., same origin (Indian Ocean).  However, the cloud will undergo different process when it reaches Sumatera.  At Kototabang, it will be influenced by the mountain around this region which can cause orographic precipitation.  The orographic precipitation is characterized by the large concentration of small size drops as found at Kototabang in this study.Keywords: raindrop size distribution, moment method, Parsivel, Padang, Kototabang
Struktur Vertikal Distribusi Butiran Hujan di Kototabang Berdasarkan Pengamatan Micro Rain Radar (MRR) Rahayu, Indah; Marzuki, Marzuki; Hashiguchi, Hiroyuki; Shimomai, Toyoshi
Jurnal Fisika Unand Vol 5 No 4 (2016)
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jfu.5.4.287-296.2016

Abstract

Distribusi ukuran butiran hujan atau raindrop size distribution (RDSD) arah vertikal dari ketinggian 0,15 km hingga 4,65 km di Kototabang, Sumatera Barat, telah diteliti melalui pengamatan Micro Rain Radar (MRR) selama Januari-Desember 2012. Intensitas curah hujan (rainfall rate) dari Optical Rain Gauge (ORG) dan RDSD dari Parsivel digunakan untuk menguji kinerja MRR. Pengujian memperlihatkan bahwa MRR berfungsi dengan baik dimana intensitas curah hujan dari ORG berkorelasi dengan baik dengan MRR (r = 0,98) dan RDSD dari MRR secara umum juga memperlihatkan pola dan nilai yang sama dengan yang didapatkan Parsivel.  Selanjutnya, RDSD dari MRR dimodelkan dengan distribusi gamma dan parameternya didapatkan menggunakan metode momen.  Terlihat bahwa pertumbuhan RDSD di Kototabang dari ketinggian 4,65 km hingga 0,15 km sangat kuat yang kemungkinan disebabkan oleh proses tumbukan-penggabungan.  Hal ini ditandai dengan peningkatan konsentrasi butiran berukuran besar dengan penurunan ketinggian.  Peningkatan konsentrasi butiran hujan berukuran besar terhadap penurunan ketinggian berpengaruh kepada parameter-parameter hujan seperti radar reflectivity (Z) dan rainfall rate (R) yang menyebabkan peningkatan koefisien A (Z= ARb) terhadap penurunan ketinggian.  Dengan demikian, penggunaan persamaan Z-R yang konstan untuk setiap ketinggian bagi radar meteorologi di kawasan tropis khususnya Sumatera Barat tidak  tepat.Kata kunci: raindrop size distribution, MRR, Kototabang, distribusi gamma.
Perbandingan Karakteristik Distribusi Butiran Hujan yang Berasal dari Awan Laut dan Awan Darat di Kototabang Fadillah, Nur; Marzuki, Marzuki; Harjupa, Wendi; Shimomai, Toyoshi; Hashiguchi, Hiroyuki
Jurnal Fisika Unand Vol 5 No 3 (2016)
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jfu.5.3.273-282.2016

Abstract

Karakteristik distribusi ukuran butiran hujan atau raindrop size distribution (RDSD) dari hujan yang berasal dari awan laut dan awan darat di Kototabang, Sumatera Barat, telah dibandingkan. Asal hujan diamati menggunakan X-band Doppler radar (XDR) selama proyek Coupling Processes in the Equatorial Atmosphere (CPEA)-I (10 April 2004 - 9 Mei 2004). Data RDSD berasal dari pengamatan two-dimensional video disdrometer (2DVD). RDSD dimodelkan dengan distribusi gamma dan parameternya didapatkan menggunakan metode momen. Dari penelitian ini terlihat bahwa intensitas curah hujan yang tinggi lebih banyak pada hujan dari awan darat dibandingkan dengan yang dari awan laut. Selain itu, butiran hujan yang berukuran besar pada awan darat lebih banyak daripada awan laut. Banyaknya butiran hujan dengan ukuran yang besar ini berdampak kepada nilai radar reflectivity (Z) pada awan darat yang lebih besar dibandingkan dengan awan laut untuk intensitas curah hujan yang sama. Hal ini mengakibatkan persamaan Z-R antara awan darat dan awan laut berbeda dimana nilai koefisien A dari persamaan Z-R untuk awan darat lebih besar daripada awan laut. Dengan demikian, perbedaan karaktersitik RDSD antara awan darat dan laut sebaiknya dipertimbangkan dalam pengembangan radar meteorologi di kawasan tropis. Penggunaan Z-R tunggal (Z = 200R1,6) untuk mengkoversi data radar cuaca di Sumatera terutama Sumatera Barat tidak akan akurat terutama untuk hujan dari awan laut.Kata kunci: distribusi butiran hujan (RDSD), awan darat, awan laut, Kototabang
Comparison of Bright Band Radar from GPM and MRR Observation in West Sumatera Ramadhan, Ravidho; Marzuki, Marzuki; Vonnisa, Mutya; Harmadi, Harmadi; Hashiguchi, Hiroyuki; Shimomai, Toyoshi
Jurnal Penelitian Fisika dan Aplikasinya (JPFA) Vol. 11 No. 1 (2021)
Publisher : Universitas Negeri Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26740/jpfa.v11n1.p50-62

Abstract

The Bright band (BB) observation can be used as an indication of the melting layer height. Measurement of BB from Normal Scan (NS) on Global Precipitation Measurement (GPM) had been compared with Micro Rain Radar (MRR), which is installed in Kototabang, West Sumatera (0.23° S; 100.32°E; 865 m above sea level). The GPM data were collected from December 2014 to June 2018 and compared with MRR observation from January 2012 to August 2016. The BB values from these instruments were compared with those recommended by the International Telecommunication Union Recommendation (ITU-R) P.839. The BB from GPM and MRR showed slightly diurnal and seasonal variations. BB observations from GPM and MRR show good agreement with slight diurnal and seasonal variations differences. BB observations are more similar when the intensity of solar radiation is lower, i.e., at night (18.00-24.00 LT) until early morning (00.00-06.00 LT). Furthermore, MRR showed a slight bimodal pattern in the seasonal variation, while GPM did not. Thus, the seasonal variation in the observation of both instruments is different. The most significant difference from the seasonal variation was observed in the summer season (June-August (JJA)). The mean BB of the two instruments is lower than the Freezing Height Level (FHL) value calculated from the ITU-R model. However, many BB from the two instruments (>36 %) have a BB altitude higher than FHL. Thus, the constant assumption of FHL in West Sumatera for the rain attenuation estimation of microwaves may not be appropriate.