Papers by Dr. ARIES KRISTIANTO, ST, M.Si STMKG
JOURNAL OF METEOROLOGY AND GEOPHYSICS – SPECIAL ISSUE VOL. 23 NO. 3 2022: 45 - 56, 2022
In Pulau Muda Village, hail occurred on September 23rd, 2019 when the entire Riau area was covere... more In Pulau Muda Village, hail occurred on September 23rd, 2019 when the entire Riau area was covered by smoke due to forest and land fires phenomenon. The hail was not accompanied by extreme rain and did not cause material harm. However, a study of atmospheric conditions before, during, and after hail occurred is needed to reference for the early warning of future events. The identification of hail cloud stage used the C-Band Radar Reflecticity, Himawari-8 Satellite, and Rain Gauge data. Model data processed by GrADS are used to support the analysis of meteorological parameter. The surface condition are the opposite to the previous study that the surface air temperature increases 2 o C and RH decreased 10% from h-1 caused by dry air of the smoke phenomenon. The hail occurred from one single cell CB cloud that developed within 30 minutes reaching the mature stage with its maximum reflectivity core was 65 dBZ and cloud top temperature decreased to-75 o C at 06.00 UTC. The convective activity with maximum updraft-1.9 Pa.s-1 developed the cloud as the CAPE index increased from 150 to 700 J.kg-1 from 05.00 to 06.00 UTC. The decrease of specific ice water content with maximum downdraft 0,2 Pa.s-1 from 06.00-07.00 UTC evidenced that the cloud ice layer produced the hail at the mature to dissipation stage of the cloud. Further study is needed by providing chemistry model data in order to understand more about hail in tropics especially in this unique situation that is among the smoke phenomenon.
PROSIDING SIKLON TROPIS : PERINGATAN 10 TAHUN TCWC JAKARTA, 2018
Pada periode akhir November sampai dengan awal Desember 2017 terjadi dua siklon secara berurutan.... more Pada periode akhir November sampai dengan awal Desember 2017 terjadi dua siklon secara berurutan. Siklon tropis Cempaka yang terbentuk di perairan selatan Pulau Jawa dan siklon tropis Dahlia di perairan selatan Pulau Sumatera telah menyebabkan terjadinya hujan ekstrem di beberapa wilayah di bagian selatan Pulau Jawa dan Pulau Sumatera. Dalam penelitian ini dilakukan analisis pola transpor uap air yang didukung dengan analisis spasial indeks konvektif dan spasial curah hujan di Indonesia sebagai dampak terjadinya siklon tropis Cempaka dan Dahlia. Data yang digunakan dalam penelitian ini adalah data European Centre for Medium-Range Weather Forecast (ECMWF), data satelit Global Satellite Mapping of Precipitation (GSMaP), dan data satelit Himawari-8 mulai pada tanggal 25 November sampai dengan4Desember2017. DataECMWFdigunakanuntukmenghasilkanpetatransporuapair. Data satelit GSMaP digunakan untuk menghasilkan peta spasial curah hujan. Data kanal Infrared (IR1) satelit Himawari-8 digunakan untuk menghasilkan peta spasial indeks konvektif. Hasil penelitian menunjukkan bahwa pada saat terjadinya siklon tropis Cempaka dan Dahlia terdapat pemusatan konsentrasi uap air di wilayah selatan Pulau Jawa dan Pulau Sumatera. Pemusatan konsentrasi uap air tersebut dibuktikan dengan tingginya nilai indeks konvektif dan akumulasi curah hujan di wilayah bagian selatan Pulau Sumatera dan Pulau Jawa mengikuti lintasan siklon tropis Cempaka dan Dahlia. Berdasarkan perbandingan intensitas uap air, nilai indeks konvektif, dan akumulasi curah hujan di sekitar pusat siklon diketahui bahwa siklon tropis Dahlia memiliki dampak yang lebih kuat daripada siklon tropis Cempaka.
Low-level Moisture (LLM) plays role for developing rain clouds. Global Positioning System (GPS) i... more Low-level Moisture (LLM) plays role for developing rain clouds. Global Positioning System (GPS) is capable for extracting low-level moisture by applying the combination method from upper-level PWV is estimated from ECMWF and then subtracted from the total PWV GPS. Variation of LLM based on GPS around western part of Indonesia, specially in the western part of Java analysed the active phase of Madden Julian Oscillation (MJO) as one of the important variable in tropics. In November 2009, MJO around the western part of Java influenced to diurnal variation of LLM. During MJO onset, diurnal anomaly increased along with the decreased of OLR anomalies, and decreased post MJO. In the northern part, it showed that the concentration of LLM decreased from west to east, meanwhile is variabled in the south. In the east, LLM increased southwards appropriate by wind vector analysis. The concentrations of LLM has higher on active mode than pre and post-MJO. By analyzing of the convective indices using MTSAT-IR1 during MJO event in November 2009 indicated that LLM related to convective activities on all MJO's phases.
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Papers by Dr. ARIES KRISTIANTO, ST, M.Si STMKG