Possible Tidal Modulation of the Indian Monsoon Onset.
Abstract
The a priori hypothesis that soli-lunar atmospheric tides can induce an element of the variability in mean monthly climatic data is tested using precipitation (1985-1960), station pressure (1895-1960) and 300 mb height data (1950-1977) for India during the monsoon onset month of June. Since the monsoon onset occurs, on average, very late in the month in northern India, this region is very sensitive to small departures from normal in the onset date. These departures can be seen in the year to year fluctuations of June rainfall amounts. To test the hypothesis involving lunar atmospheric tides, a time series of mean monthly lunar tidal potential for June (1985-1960) was calculated. The results of this research showed that there is an important periodic component (on the order of one standard deviation during hemispherically cold periods) in the interannual variability of pressure, precipitation, and upper air winds for the Indian monsoon onset month of June at the two dominant lunar frequencies and that the atmospheric response is in phase with the forcing. This strongly suggests that lunar atmospheric tides to produce an element of the observed interannual variability.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1983
- Accession Number
- ADA135441
Entities
People
- W. H. Campbell
Organizations
- Air Force Institute of Technology