Modified Convective Stratiform Technique (CSTm) Performance on Rainfall Estimation in Indonesia

Abstract

Abstract.This study has analyzed a rainfall estimation using a modified convective stratiform technique (CSTm). Unlike the original convective stratiform technique (CST), which only utilizes infrared (IR) data, CSTm applies not only IR data but also passive microwave (PMW) data. Two major modifications contained in CSTm are: (1) the application of a variability index (VI) method that uses PMW data to perform convective and stratiform separation, and (2) the ability to determine the average extensive coverage of the new areas of each pixel point as a result of the utilization of the PMW data. In this study, rainfall estimation was conducted for 23 points spread over four major islands in Indonesia. The estimation was performed based only on IR and PMW data obtained from coincident observations. For verification, the estimation results were compared with real observations. The main verification action conducted in this study used multi-category contingency tables for 4 categories and this action was supported by the root mean square error (RMSE) method. The verification results of the hourly estimation conducted for 4 days in early November 2011 showed that CSTm can effectively improve the performance quality of CST.

The Effect of Soil Preparation Methods on Rain Water Infiltration as The Basis of Irrigation Application for Dry Land Rice

“…It can be calculated that artificial rain in this study is equivalent to a rain intensity of 4.61 mm/h. According to the BMKG classification, the artificial rain intensity is in the range of light rain (<5 mm/h) (Endarwin et al, 2014). Likewise, according to Wang et al (2021), rainfall in the range of <5 mm/h is classified as light rain.…”

Analisis perbandingan metode CST dan MCST terhadap curah hujan observasi saat banjir

“…Metode CST merupakan metode pemisahan antara awan konvektif dan awan stratiform dengan menggunakan data satelit kanal IR [7]. Kemudian metode CST ini dikembangkan menjadi metode Convective Stratiform Technique (mCST) yang diterapkan untuk wilayah Indonesia dengan memodifikasi nilai intensitas curah hujan dari awan konvektif (Rc) dan stratiform (Rs) serta nilai cakupan area rata-rata yang dilingkupi oleh piksel (A) [8].…”

“…Apabila S telah memenuhi persamaan tersebut maka merupakan inti awan konvektif, namun apabila tidak memenuhi maka merupakan inti awan statiform. Metode mCST, perhitungan yang digunakan pada metode ini sama seperti perhitungan pada metode CST namun nilai Rc dimodifikasi dengan nilai 26 mm/jam, Rs dimodifiksi dengan nilai 0,8 mm/jam sedangkan A dimofikasi dengan nilai 202,1243 km 2[8].…”

Comparative Test of Several Rainfall Estimation Methods Using Himawari-8 Data

“…With c = amount of convective cell in a grid Ac = convective rain area A = average area for a pixel (km 2 ) T = period in average (hour) Rc = intensity of convective rain = 20 mm/hr s = amount of stratiform cell in a grid As = stratiform rain area Rs = intensity of stratiform rain = 3,5 mm/hr c. CSTm CSTm is development of the CST by changing the intensity of the rainfall becomes Rc = 26 mm/hour and Rs = 0.8 mm/hour (Endarwin et al, 2014) d. IMSRA According to Gairola (2011) …”

“…Determining of cloud type is based on cloud top temperature gradient brightness value that were obtained from geostationary satellite data IR1 channel. Endarwin et al (2014) modified CST method with a change rate of rainfall from convective and stratiform clouds. The results of research show that the accuracy of CST and CSTm applied in 23 research points spread in Java, Kalimantan, Sumatra and Sulawesi had detection accuracy of rainfall event in July 2011, November 2011, and January 2012 the method CST respectively 0,936, 0,658, and 0,689 while the method CSTm in the same month in a row is 0,974, 0,745, and 0,709.…”