REVISITING TROPICAL CYCLONE ACTIVITIES OVER NORTH INDIAN OCEAN BASED ON MULTIPLE NUMERICAL WEATHER PREDICTION MODELS OUTPUT

摘要

The present study examines the cyclonic activities that have occurred in North Indian Ocean (NIO) during the period 1997 to 2019. Moreover, the performance of four Numerical Weather Prediction (NWP) models, namely, India Meteorological Department-Global Forecast System (IMD-GFS), United Kingdom Meteorological Office (UKMO), European Centre for Medium Range Weather Forecasts (ECMWF) and IMD Multi-Model Ensemble (IMD-MME) have been also analysed based on annual average track forecasts error of tropical cyclones which formed during the period 2015-19 over the North Indian Ocean. For this purpose, 12-hourly annual average track forecasts errors have been taken up to 120 hours. Present studies elucidate the trend of the occurrence of number of tropical disturbances based on its stages and inter annual variation of track forecasts error (i.e., direct position error) of four NWP models. Present results show that 94 tropical cyclones were formed during 1997-2019, out of which 61 (around 65%) were in Bay of Bengal and 33 (around 35%) were in Arabian Sea. This shows that the number of tropical cyclones formation in Bay of Bengal was higher than the Arabian Sea. However, last ten years (from 2010-19) analysis shows that the percentage contribution of Arabian Sea tropical cyclones has been increased by 5%. Furthermore, the overall track forecast error analysis during 2015-19 reveals that the Multi-Model Ensemble (MME) consensus forecast was outperformed among the four models.