Kajian Distribusi Aktivitas Petir pada Awan Cumulonimbus yang Memiliki Overshooting Tops Menggunakan Citra Satelit Himawari-9

Yuan Wianda, Dr. Retnadi Heru Jatmiko, M.Sc.; Dr. Emilya Nurjani, S.Si., M.Si.

2026 | Tesis | S2 Penginderaan Jauh

Awan cumulonimbus merupakan jenis awan yang dapat menimbulkan aktivitas petir. Pada awan ini dapat terbentuk overshooting tops, yaitu puncak dari awan cumulonimbus yang menembus lapisan tropopause. Penelitian ini bertujuan untuk mengidentifikasi overshooting tops menggunakan citra Satelit Himawari-9, kemudian mengkaji distribusi aktivitas petir secara spasial dan temporal terhadap overshooting tops yang teridentifikasi.
Analisis brightness temperature difference dilakukan terhadap citra Satelit Himawari-9 berdasarkan laporan cuaca penerbangan yang mengindikasikan aktivitas petir dalam rentang 00.00-10.00 UTC. Setelah pergeseran paralaks dikoreksi pada setiap overshooting tops yang teridentifikasi, dilakukan analisis distribusi terhadap semua tipe petir, yaitu CG Positive, CG Negative, Intra Cloud/Cloud to Cloud, dan total petir. 
Analisis terhadap 367 citra Satelit Himawari-9 berdasarkan 159 laporan cuaca penerbangan Stasiun Meteorologi Supadio selama tahun 2023, berhasil mengidentifikasi 30 kejadian overshooting tops dari 10 citra. Analisis distribusi aktivitas petir dilakukan terhadap 11 kejadian berdasarkan faktor lokasi. Aktivitas paling dominan adalah tipe petir IC/CC. Secara spasial, puncak aktivitas petir dominan berada pada radius 10-20 km dari lokasi piksel overshooting tops yang teridentifikasi. Secara temporal, puncak aktivitas petir dominan terjadi setelah overshooting tops teridentifikasi. 

Cumulonimbus clouds are a type of cloud capable of generating lightning activity. Within these clouds, overshooting tops may form—defined as the cloud tops that penetrate the tropopause layer. This study aims to identify overshooting tops using Himawari-9 satellite imagery and to examine the spatial and temporal distribution of lightning activity associated with the identified overshooting tops.
Brightness temperature difference analysis was conducted on Himawari-9 satellite imagery based on aviation weather reports indicating lightning activity within the 00:00–10:00 UTC time range. After correcting for parallax displacement in each identified overshooting top, a distribution analysis was performed for all lightning types, including CG Positive, CG Negative, Intra-Cloud/Cloud-to-Cloud, and total lightning.
An analysis of 367 Himawari-9 satellite images, based on 159 aviation weather reports from Supadio Meteorological Station throughout 2023, successfully identified 30 overshooting top events from 10 images. Lightning distribution analysis was conducted on 11 events based on location factors. The most dominant lightning type was IC/CC. Spatially, peak lightning activity was concentrated within a radius of 10–20 km from the identified overshooting top pixels. Temporally, peak lightning activity predominantly occurred after the overshooting tops were identified.

Kata Kunci : Cumulonimbus, Aktivitas Petir, Overshooting Tops, Paralaks