| dc.description.abstract | This research is inspired by Floating City Project which is going to be implemented by American and Netherland Cooperated Institution in 2020. The floating city has been planned to construct over the eastern equatorial Pacific Ocean near Central America in the project. Consider to the future water resource problem of the floating city, this research is dedicated to understand inter-annual precipitation variation over Target Area (6N-12N, 86W-94W) in rainy season. Target Area is actually a place where the floating city would be built in 2020. In this research, climatology rainy season of Target Area has been classified as three periods. Period-1, Period-2 and Period-3 are represent of May-June, July-August and September-October respectively. Wet years and dry years are picked up in each period, then analysis of atmospheric and oceanic gridded datasets would be conducted through composite analysis method according to these wet and dry years.
Follow the diagnostic results of moisture budget over Target Area, Period-1 and Period-2 has dry advection and downward motion anomaly contribution for less precipitation in Dry year. Conversely, wet advection and upward motion anomaly contributed for more precipitation in Wet year. With regard to Period-3, contribution intensity of vertical motion anomaly is much higher than Period-1 and Period-2, but for advection term contribution is much less than former two periods. From the results of correlation analysis between global sea surface temperatures (SST) and Target Area precipitation, precipitation has found to have related with Pacific and Atlantic SST. Therefore, this research further applied Empirical Orthogonal Function (EOF) with SST datasets to separate out the most three significant climate oscillation signals of Pacific and Atlantic Ocean. Through correlation and multi-regression analysis of climate oscillation signals and precipitation, Period-1 and Period-2 precipitation are demonstrated that affected by Central Pacific ENSO (CP), Eastern Pacific ENSO (EP) and North Atlantic Oscillation (NAO). When getting into Period-3, precipitation only affected by CP and EP in this time. Especially for Walker Circulation variation during CP and EP events, Atlantic Subtropical High variation during NAO event, these phenomenon are the main cause of vertical motion and advection anomaly contribution, it is also consistent with the diagnostic results of moisture budget.
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