Ramadhan, Ravidho and Marzuki, Marzuki and Suryanto, Wiwit and Sholihun, Sholihun and Yusnaini, Helmi and Hashiguchi, Hiroyuki and Shimomai, Toyoshi (2024) Bias Correction of IMERG Data in the Mountainous Areas of Sumatra Based on A Single Gauge Observation. Trends in Sciences, 21 (4): 7592. ISSN 27740226
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Abstract
The performance of surface precipitation data from satellite precipitation products (SPPs) in mountainous areas has greater error and bias than in plain areas. In this study, linear scaling (LS), local intensity (LOCI), power transformation (PT), and cumulative distribution function (CDF) methods are used to correct the bias of Integrated Multi-Satellite Retrievals for Global Precipitation Measurement (IMERG) data in the mountainous region of Sumatra based on long-term and high-resolution optical rain gauge (ORG) observations. The ORG is installed at Equatorial Atmospheric Observatory (EAO) in Kototabang, West Sumatra, Indonesia (100.32 °E, 0.20 °S, 865 m above sea level (ASL) with an observation period from 2002 to 2016. The impact of the bias correction method is tested based on accuracy and capability detection tests. The bias correction method is more effective at the daily resolution than the hourly resolution of the IMERG data in the mountainous region of Sumatra. The LS method exhibited the best improvement in accuracy with reduced root-mean-square error (RMSE) and relative bias (RB), although there was no significant increase in coefficient correlation (CC) values. However, the accuracy improvement was not observed in the bias correction for hourly data. The lack of improvement in the accuracy of the hourly IMERG data is due to the high local variability of rainfall in the mountainous area of Sumatra. The high data variability causes large differences in the mean and variance of the IMERG calibration and evaluation data periods. On the other hand, the LOCI, PT, and CDF methods were successfully improved the rain detection capability of IMERG, as indicated by the better critical succession index (CSI) values compared to the original hourly and daily IMERG data. It increased the CSI value by reducing false alarms for rain with intensity below 2 mm/h. Furthermore, the CDF method can improve the analysis of extreme rainfall in the mountainous region of Sumatra by improving the estimation of the extreme rainfall index. Therefore, these methods can be applied to improve the accuracy and detectability of IMERG data in the mountainous region of Sumatra. However, the scale factor and transfer function constructed in this study need to be further evaluated on other rain gauge observation data in Sumatra’s mountainous region to improve performance. © 2024, Walailak University. All rights reserved.
Item Type: | Article |
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Additional Information: | Cited by: 0; All Open Access, Hybrid Gold Open Access |
Uncontrolled Keywords: | IMERG, Mountainous, Bias correction, Optical rain gauge, Kototabang |
Subjects: | Q Science > QC Physics |
Divisions: | Faculty of Mathematics and Natural Sciences > Physics Department |
Depositing User: | Yulistiarini Kumaraningrum KUMARANINGRUM |
Date Deposited: | 05 Nov 2024 03:02 |
Last Modified: | 05 Nov 2024 03:02 |
URI: | https://ir.lib.ugm.ac.id/id/eprint/10704 |