IDENTIFICATION OF SQUALL LINE TYPE MESOSCALE CONVECTIVE SYSTEM USING RADAR IMAGE DATABASE (CASE STUDY: TANGERANG, BANTEN)

• Main Author: Dhemi Kintani, Tias
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/75019
• Institution: Institut Teknologi Bandung

Squall line or Mesoscale Convective System (MCS) linear type can be identified using BMKG radar image data based on the value of reflectivity, length of convective echoes, event duration, and eccentricity value. Identification of MCS with radar images has been developed by converting radar images into reflectivity values. However, the reflectivity value database obtained is inaccurate because there are missing reflectivity values due to truncation coastline, name, and area boundaries. Therefore, a database will be created by improving the interpolation method so that it can be used to identify and analyze the characteristics of the squall line type MCS. The processing of radar image data consists of the conversion process of the radar image RGB composite into a reflectivity value,georeferencing, convolution interpolation with the kernel matrix gaussian blur, and conversion of radar image data into reflectivity data (CMAX) repeatedly. Identification Squall line uses reflectivity data to calculate reflectivity, length, duration, and eccentricity values of convective echoes. Verification process squall line carried out using satellite imagery data. Convolution interpolation method with gaussian blur kernel matrix was able to repair the lost reflectivity value due to being cut coastline, name and area boundaries. Kernel matrix gaussian blur used in the interpolation process measuring 7 × 7. By filling up the missing reflectivity values, the reflectivity database that will be used for the identification process becomes more continuous. In addition, areas that were previously separated are reunited so that the convective cloud area becomes larger and makes the identification process easier. In 2022, there were 73 cases of squall lines which were successfully identified with radar imagery data and verified with satellite imagery. Cases of squall line which were identified mostly occurred at night from 18.00 to 00.00 WIB. Based on the scene, squall line detected occurred in sea, land and coastal areas near the coastline.