01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-04-0310 |
| Title of Abstract | Evaluation of GPM IMERG-derived diurnal precipitation over the Indian Ocean: A multi-faceted approach |
| Authors | Yashraj Upase*, Barun Kumar*, Hasibur Rahaman, Shruti Upadhyaya |
| Organisation | Indian Institute of Technology, Hyderabad, India |
| Address | B14, Academic Block B, Climate Change Department, IITH, Kandi, Hyderabad, TELANGANA, India Pincode: 502285 E-mail: cc23resch11006@iith.ac.in |
| Country | India |
| Presentation | Oral |
| Abstract | The vast tropical oceans, accounting for approximately 78% of global precipitation, are critically important for Earth's climate, yet in situ observations remain sparse, highlighting the crucial need for robust validation of global satellite precipitation products like the Integrated Multi-Satellite Retrievals for GPM (IMERG). This study reports a comprehensive validation of IMERG sub-daily estimates over the tropical Indian Ocean by utilizing the Research Moored Array for African-Asian-Australian Monsoon & Analysis and Prediction (RAMA) data. The comparison assesses skill using continuous metrics, including mean bias, Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and correlation. Analysis of wet-day occurrence and intensity separation, examining wet-day frequency bias, and mean wet-day intensity is done. Categorical metrics such as Probability of Detection (POD), False Alarm Ratio (FAR), and Critical Success Index (CSI) are computed from contingency tables at various thresholds to evaluate event detection capabilities. A detailed distributional check, including Quantileâ¿¿Quantile (QQ) analysis and probability density comparisons, is done to understand the satellite rainfall products' ability to capture precipitation characteristics accurately. The performance of satellite estimates is checked in each season to account for temporal variability in performance. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | IMERG, Validation, Moored Buoys, RAMA, diurnal variation, In situ oceanic observations |
| For Awards | no |