Distribution and Propagation Features of Multi-time Scale Precipitation over Huaihe River Basin in the Summer of 2007
Distribution and Propagation Features of Multi-time Scale Precipitation over Huaihe River Basin in the Summer of 2007
The research on the heavy rainfall causing the flood Huaihe River basin during May to August in 2007 was focused on, using NCEP/NCAR reanalysis day-to-day data, the distribution and propagation features of multi-time scale precipitation over Huaihe River basin in the summer of 2007 were investigated. Morlet wavelet analysis results showed that there existed periodic change phenomenon of precipitation in quasi-35 days, quasi-18 days and quasi-8 days oscillaation. Periodic low frequency precipitation of quasi-35 days was from southwest propagation to the south of Huaihe River basin, and on the other hand from northwest propagation to the south central Huai River Basin; it was aslo clear that Nanhai was the propagation source of low frequency precipitation. The more short period of precipitation, the propagation features was not obvious. It was a very good corresponding relation that between horizontal divergence balance of from 200 hPa with 850 hPa and precipitation, horizontal divergence balance>0 corresponding to precipitation area, and horizontal divergence balance<0 to no precipitation area. The propagation of precipitation was mainly accord to horizontal divergence balance. The between horizontal divergence balance of from 200 hPa with 850 hPa was predictor of multi-time scale precipitation.
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