cover
Contact Name
Sugeng Nugroho
Contact Email
stagaw.kototabang@bmkg.go.id
Phone
+62752-7446089
Journal Mail Official
megasains@gawbkt.id
Editorial Address
Jalan Raya Bukittinggi - Medan KM.17 Palupuh, Kabupaten Agam, Provinsi Sumatera Barat 26151
Location
Kab. agam,
Sumatera barat
INDONESIA
Megasains
ISSN : 20865589     EISSN : 27232239     DOI : https://doi.org/10.46824/megasains
Core Subject : Science,
Buletin MEGASAINS diterbitkan oleh Stasiun Pemantau Atmosfer Global (GAW) Bukit Kototobang sebagai media apresiasi Karya Tulis Ilmiah (KTI) yang bersumber dari kegiatan penelitian berbasis ilmu-ilmu meteorologi, klimatologi, kualitas udara, dan geofisika (MKKuG), serta lingkungan.
Articles 214 Documents
PERBANDINGAN MODEL PREDIKSI RADIASI MATAHARI BERBASIS MESIN PEMBELAJARAN PADA STASIUN METEOROLOGI FATMAWATI SOEKARNO BENGKULU Dodi Ardiansyah
Megasains Vol 14 No 1 (2023): Megasains Vol.14 No.1Tahun 2023
Publisher : Stasiun Pemantau Atmosfer Global Bukit Kototabang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.46824/megasains.v14i1.129

Abstract

Radiasi matahari adalah sumber energi terbesar dan memiliki peran dalam keseimbangan radiasi permukaan, siklus hidrologi, fotosintesis vegetasi, cuaca dan iklim. Sangat penting untuk menganalisis radiasi matahari dalam berbagai keperluan. Makalah ini bertujuan untuk mempelajari dan mengevaluasi kelayakan metode-metode didalam mesin learning dalam membuat prediksi radiasi matahari. Parameter Tekanan Udara, Temperatur Udara, Dew Point, Kelembaban Udara yang diukur bersama dengan Radiasi Matahari digunakan untuk membuat prediksi. Tiga metode yang di gunakan dalam makalah ini yaitu Linear Regression (LR), Random Forest Regressor (RFR), dan Decision Tree Regressor (DTR). Untuk menentukan kinerja hasil prediksi dilakukan evaluasi dengan tiga matrik statistic yaitu Mean Absolute Error (MAE), Root Mean Squared Error (RMSE) dan R-Squared (R2). Hasil Prediksi menunjukkan bahwa metode Random Forest Regressor memberikan nilai prediksi yang paling baik dari dua metode lainnya yang dicoba dengan nilai MAE 51,4 nilai RMSE 106,0 dan R2 0,87.
Studi Tren Kenaikan CO2 Hasil Pengukuran pada GAW Bukit Kototabang dan Perbandingannya dengan Data Global Tanti Tritama Okaem
Megasains Vol 13 No 2 (2022): Megasains Vol.13 No.02 Tahun 2022
Publisher : Stasiun Pemantau Atmosfer Global Bukit Kototabang

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

Abstract

Aktivitas manusia pasca revolusi industri telah menggeser fungsi komposisi alamiah Gas Rumah Kaca (GRK) di atmosfer. Konsentrasi GRK yang berlebihan menyebabkan peningkatan temperatur udara di permukaan bumi. Kajian ini bertujuan untuk mengkaji karakteristik Karbon Dioksida (CO2) yang diamati oleh SPAG Bukit Kototabang. Pengukuran CO2 ini menggunakan Air Kit Flask Sampler yang dikirim ke NOAA. Data dianalisis dengan menggunakan metode Statistik Deskriptif dengan 2 periode data CO2 tahun 2005-2018. Periode pertama (2005-2011) laju kenaikan data sebesar 0.1306 ppm/bulan dan periode kedua (2012-2018) sebesar 0.1988 ppm/bulan serta kenaikan nilai minimum sebesar 3.64% pada periode kedua. Pengukuran CO2 di SPAG Bukit Kototabang masih berada di bawah rata-rata pengukuran Global dan Mauna Loa meskipun memiliki tren kenaikan yang sama. Kata Kunci : Gas Rumah Kaca, Karbon Dioksida, Airkit Flask Sampler, Statistik deskriptif
PENGARUH GELOMBANG ULTRA LOW FREQUENCY (ULF) DALAM PERILAKU CACING TANAH DI SOLO DAN KLATEN I Putu Pudja
Megasains Vol 14 No 2 (2023): Megasains Vol.14 No.2 Tahun 2023
Publisher : Stasiun Pemantau Atmosfer Global Bukit Kototabang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.46824/megasains.v14i2.71

Abstract

Deformed rocks emit Ultra Low Frequency (ULF) waves and affect the earth's magnetic field. So that ULF gives anomalies to the surroundings. ULF emissions also influence animal behavior. Changes in earthworm behavior in Solo and Klaten on 18 April 2020 coincided with the peak lead time period of deformation calculated by the ULF anomaly on the BMKG magnetograph in Yogyakarta. The location of the discharge area of ​​earthworms is in the deformation coverage area in accordance with the purpose of the interference in the results of the analysis of the magnetograph records. The ULF anomaly in Indonesia is being developed for earthquake prediction, as well as the phenomenon of animal behavior being widely studied for earthquake prediction. Collaboration on animal behavior research, including earthworms and ULF research, provides hope for the development of earthquake predictions in Indonesia.
ANALISIS KUALITAS UDARA PARAMETER PM2.5 DI WILAYAH KOTA SORONG BERBASIS ISPU Ayu Diah Syafaati
Megasains Vol 14 No 2 (2023): Megasains Vol.14 No.2 Tahun 2023
Publisher : Stasiun Pemantau Atmosfer Global Bukit Kototabang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.46824/megasains.v14i2.131

Abstract

Sorong City has an area of 1.105 km2 and is the most densely populated area in the Provinces of West Papua and Southwest Papua. As the population in Sorong City increases, human activities also increase which can contribute to increasing PM2,5 particulate concentrations. Sources of particulates in Sorong City came from anthropogenic activities such as city development projects, transportations, biomass burning, and other public activities in the area. PM2,5 that exceeds ambient air quality standards can harm human health. PM2,5 Observations were carried out at Global Atmosphere Watch Sorong Station using BAM Met-One 1020 automatic instrument. BAM-1020 automatically measures and records the level of particle concentrations in the air using Beta Ray Attenuation principle, namely the attenuation of beta particles through the collected solid matter. on fiber filters. PM2,5 solid matter collected in the fiber filter in a volume of ambient air that is drawn by the pump. In general, during September 2021 – June 2023, PM2,5 concentrations tend to increase. The results of the analysis showed that the daily average concentration of PM2,5 measured during September 2021 – June 2023 was in the range 1.21 – 18.71 ug/m3; still below the PM2,5 threshold value of 65 ug/m3 (24 hours). Based on the calculation of the PM2,5 parameter Air Pollutant Standard Index (ISPU), it is known that the ISPU value is in the range 0 – 50. Air quality conditions in Sorong area during this time were in the good category. The influence of meteorological parameters of rainfall and air temperature on PM2,5 concentrations in Sorong City has the most significant and strongest correlation, with a value of r=0.8 (air temperature) and r=-0.7 (rainfall).
Evaluasi Luaran Model S2S (Subseasonal To Seasonal) Ecmwf Dalam Menangkap Variabilitas Hujan Ekstrem Di Sumatera Barat Charisma Reyhan
Megasains Vol 14 No 2 (2023): Megasains Vol.14 No.2 Tahun 2023
Publisher : Stasiun Pemantau Atmosfer Global Bukit Kototabang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.46824/megasains.v14i2.137

Abstract

Extreme rain events pose challenges regarding disaster preparedness. Accurate rain prediction is one of the contributions to reducing the impact of extreme events. Predictions on subseasonal to seasonal (S2S) have been developed to fill the gap between short-term weather predictions and long-term seasonal forecasts. This study aims to assess the performance of the S2S model in predicting extreme rainfall events with extreme indices R95p, R99p PRCPTOT, and Rx1day. The data used are the S2S ECMWF data and observational data that were tested at the Stasiun Klimatologi Sumatera Barat and Stasiun Meteorologi Minangkabau during 2017-2022 period. Bias correction of S2S ECMWF data is corrected using the Distribution Mapping method. The results showed that the correlation value at Stasiun Klimatologi Sumatera Barat for daily rainfall ranged from 0.16 to 0.47 and ranged from 0.05 to 0.86 for monthly rainfall. Corrected model data correlation values at the Stasiun Meteorologi Minangkabau ranged from 0.24 to 0.41 for daily rainfall and ranged from 0.27 to 0.62 for monthly rainfall. The RMSE value at the Stasiun Klimatologi Sumatera Barat is smaller than Stasiun Meteorologi Minangkabau. The calculated extreme indices show underestimated values for the R95p, R99p, and overestimated values for the PRCPTOT, and Rx1day.
PENERAPAN IMPUTASI LOCF DAN CROSS MEAN DALAM PENGISIAN DATA KOSONG PADA CURAH HUJAN HARIAN ARG Siti Risnayah
Megasains Vol 14 No 2 (2023): Megasains Vol.14 No.2 Tahun 2023
Publisher : Stasiun Pemantau Atmosfer Global Bukit Kototabang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.46824/megasains.v14i2.138

Abstract

The number of installed Automatic Rain Gauges (ARG) today has not been optimally utilized. It is because ARG that works automatically often has missing data due to technical and network problems raising doubts about its accuracy. The data used are ARG rainfall data in 10 minute periods during 2021 and rainfall data from conventional gauge at the same location. The data will be processed until it becomes daily data and will be recovered by missing data entry worked by the Python programming language. Because the ARG data is the longitudinal data type, missing data entry will use LOCF and cross mean imputation. The validity test will compare the recovered ARG data with the conventional gauge data by calculating the MAE, RMSE, and correlation coefficient. The results showed that missing data entry could reduce the percentage of missing from 21.4% to 1.1%. The result of validity tests showed that ARG could produce accurate data determined by a lower error (MAE=0.998mm, RMSE=2.253mm) and a very high correlation (r=0.966). With a higher percentage of data completeness and excellent accuracy, the data usage will become more extensive to provide more benefits, especially for the need of analysis, forecasting, data services, and research.
PREDIKSI KEJADIAN PETIR DENGAN ARTIFICIAL NEURAL NETWORK DI WILAYAH KABUPATEN KEPULAUAN TANIMBAR Indra Prawiro Adiredjo
Megasains Vol 14 No 2 (2023): Megasains Vol.14 No.2 Tahun 2023
Publisher : Stasiun Pemantau Atmosfer Global Bukit Kototabang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.46824/megasains.v14i2.140

Abstract

Various research efforts have been made to determine thunderstorm prediction methods, one of which involves using upper air data. However, the use of atmospheric stability threshold values as a reference does not always apply uniformly to all locations due to differences in the characteristics of each region. Therefore, a more objective and precise approach is needed in predicting thunderstorm events, including the application of artificial neural network (ANN) techniques. In this study, the Artificial Neural Network (ANN) method, which is an implementation of artificial intelligence, is used to predict thunderstorm events in the Saumlaki region. The ANN input not only relies on raw data in the form of atmospheric instability index values but also uses feature selection processing to reduce the dimensionality of multivariate input data, minimizing the loss of input data. This process focuses only on essential information and eliminates linear dependencies between features, a technique known as Principal Component Analysis (PCA). The research results indicate that ANN with PCA technique has a higher level of accuracy in predicting thunderstorm events in the Saumlaki region.
IDENTIFIKASI KONSENTRASI CO, CO2, NO2, SO2, DAN PM10 YANG TERUKUR DI STASIUN GAW BUKIT KOTOTABANG SELAMA MUDIK LEBARAN TAHUN 2019-2023 Kiagus Ardi Zulistyawan
Megasains Vol 14 No 2 (2023): Megasains Vol.14 No.2 Tahun 2023
Publisher : Stasiun Pemantau Atmosfer Global Bukit Kototabang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.46824/megasains.v14i2.143

Abstract

West Sumatra is regarded as one of the provinces that serves as a prominent location for the annual Eid homecoming tradition among migrants in Indonesia. In addition to this, West Sumatra serves as a popular tourist destination for individuals seeking leisure and recreation during the Eid holidays. Therefore, the rise in population activity and vehicle volume is expected to result in an escalation in air pollution levels. Furthermore, the influence of air pollution on respiratory health disorders is also substantial. Hence, the primary objective of this study is to ascertain alterations in the atmospheric concentrations of Carbon monoxide (CO), Carbon dioxide (CO2), Nitrogen dioxide (NO2), Sulphur dioxide (SO2), PM10 pollutants over the Eid period from 2019 to 2023 in the region of West Sumatra. The designated time intervals are H-10 following the conclusion of Eid and H+10. The data utilized in this study is derived from observations conducted at the Global Atmosphere Watch Bukit Kototabang Station. The findings of this study indicate that the observance of Eid activities has a discernible impact on the elevation of concentrations of carbon monoxide (CO), carbon dioxide (CO2), and nitrogen dioxide (NO2). In the interim, it has been shown that PM10 concentrations tend to be altered by ENSO conditions. However, there was no significant change seen in the SO2 parameter concerning population activity within the specified time frame. The parameters' conditions during 2019-2023 remain within the favourable category.
Potensi Hujan Ekstrem Nusa Tenggara Barat Kaitannya dengan Tropical Cyclone di Samudera Hindia Suci Agustiarini; Made Dwi Jendra Putra
Megasains Vol 10 No 2 (2019): Vol 10 No 2 (2019)
Publisher : Stasiun Pemantau Atmosfer Global Bukit Kototabang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.46824/megasains.v10i2.162

Abstract

Siklon tropis merupakan suatu sistem tekanan rendah kuat yang terbentuk di atas perairan laut yang hangat di wilayah lintang rendah dan biasanya ditandai hujan lebat di sekitar wilayah yang dilaluinya. Besarnya potensi hujan lebat bahkan ekstrem tentunya berbeda-beda disetiap wilayah. Penelitian ini dilakukan untuk mengetahui wilayah mana saja di sekitar NTB yang berpotensi terjadi hujan lebat hingga ekstrem saat terjadi siklon tropis di sekitar perairan Samudera Hindia bagian barat hingga barat laut, sehingga dapat memberikan peringatan dini sebelum munculnya bencana hidrometeorologi seperti banjir dan longsor sebagai dampak dari siklon tropis tersebut. Data yang digunakan dalam penelitian ini yaitu data curah hujan harian dan data kejadian siklon tropis dalam 10 tahun (2008-2017). Besarnya potensi hujan lebat hingga ekstrem dihitung menggunakan metode komposit seluruh kejadian siklon pada setiap tahapannya yang telah dikategorikan oleh BOM terhadap nilai curah hujan harian. Hasil dari penelitian ini menunjukkan wilayah yang berpotensi cukup besar terjadi hujan ekstrem saat siklon tropis yaitu sebagian kota Mataram dengan peluang mencapai >15%. Saat dalam tahapan depresi tropis dan badai tropis sebagian Lombok barat bagian selatan, Lombok Utara, Lombok Timur bagian utara, Sumbawa bagian tengah, dan Kota Bima juga berpotensi terjadi hujan ekstrem namun dengan peluang yang sangat kecil yaitu <10%.Siklon tropis yang dapat memicu terjadinya hujan dengan kategori lebat sangat berpeluang ketika masih dalam tahapan depresi tropis dengan wilayah terdampak yang hampir merata di seluruh NTB, namun ketika terus berkembang menjadi siklon tropis maka potensialnya akan semakin meningkat mencapai >30% dan diiringi dengan wilayah terdampak yang semakin kecil.
Creation of NCEP/NOAA Data Correction Factors with Data Observations to Fill in Blank Data Firsta Zukhrufiana Setiawati; Fanni Aditya
Megasains Vol 10 No 2 (2019): Vol 10 No 2 (2019)
Publisher : Stasiun Pemantau Atmosfer Global Bukit Kototabang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.46824/megasains.v10i2.163

Abstract

Banyaknya data kosong memicu para ahli terus meneliti untuk menemukan metode pengisian data kosong seperti yang dilakukan dalam penelitian ini. Dalam penelitian ini penulis mencoba menemukan metode alternatif pengisian data kosong dengan bantuan data satelit NCEP/ NOAA. Untuk mengisi data kosong, ditentukan faktor koreksi data satelit terhadap data observasi. Data satelit yang berbentuk gridded dilakukan pendekatan dengan interpolasi pembobotan jarak atau Inversed Distance Weighting (IDW). Faktor koreksi yang dihitung dari pengurangan data observasi dan IDW satelit (NCEP/ NOAA) dikumpulkan dalam tabel distribusi frekuensi berkelas terhadap data observasi. Maka akan ditemukan modus, dan selanjutnya faktor koreksi pada wilayah tersebut merupakan median dari modus. Penelitian ini dilakukan di wilayah Kalimantan Barat dengan menggunakan 6 titik observasi yaitu Mempawah, Ketapang, Paloh, Nangapinoh, Sintang dan Putussibau. Hasil penelitian menunjukkan bahwa semakin tinggi elevasi suatu wilayah maka semakin besar nilai koreksinya (elevasi paling tinggi di Putusibau 40-50 mdpl, nilai koreksi paling besar 1.5 oC). Nilai koreksi ini dapat diaplikasikan untuk pengisian data kosong, dengan menjumlahkannya pada data satelit unsur yang sama

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