Tropical Quasi-Biennial Oscillation of the 10-mb wind and Indian monsoon rainfall-implications for forecasting
✍ Scribed by Bhalme, H. N. ;Rahalkar, S. S. ;Sikder, A. B.
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1987
- Weight
- 549 KB
- Volume
- 7
- Category
- Article
- ISSN
- 2314-6214
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✦ Synopsis
The interannual variability of the Indian monsoon (June-September) rainfall has been examined in relation to the monthly zonal wind anomaly for 10-mb (30 km) and 30-mb (24 km) at Balboa for the 28-year period 1958-85. The fluctuations in the zonal wind anomalies in January at 10-mb appear to be highly related to the monsoon rainfall, with rainfall tending to be less (more) than normal during easterly (westerly) anomaly, suggesting some predictive value for the Indian monsoon rainfall. The zonal wind anomalies at 10-mb lead those at 30-mb by 6 months. This lead time is consistent with the well-known downward phase propagation with a speed of 1 km/month in the QBO of tropical stratospheric wind. Large-scale flood never occurred during easterly wind anomalies, and drought almost never during westerly anomalies in January at 10-mb. This suggests that useful probability forecasts of droughts or floods could be prepared.