Analysis of Wind Field Characteristics of Satallite Remote Sensing Image Based on EOF Change

Abstract

By using empirical orthogonal function (EOF) and statistical analysis methods expansion, the paper analyzed the daily and monthly data of the ASCAT satellite in the Taiwan Strait in 2016 to explore the seasonal variation characteristics and spatial pattern of the sea wind field in the Taiwan Strait. The results showed the sea surface wind field of 2016 in the Taiwan Strait had obvious seasonal change with a trend of decreasing after increasing firstly throughout the year of 2016, the wind speed decreased from January to June, and increased from June to December through the whole year. The EOF expansion of wind speed showed that the maximum center of outliers deviation existed in the narrow straits of Taiwan Strait and distributed along the coastline from the first modal space pattern, revealed the influences of Taiwan island topography were obvious. Furthermore, the winter-summer monsoon oscillation was reflected from the time curve of the year of 2016, and the typhoon influence signal could be well corresponded in details, shown as strong amplitude in the time curve. The spatial pattern of second modal presented in zonal distribution, characterized by reverse structure from south to north. The EOF expansion of wind direction showed the spatial pattern distributions of the first and second modals were zonal, and the maximum center of outliers deviation existed in the north and south sides of Taiwan island affected by the island terrain, in particular, the typhoon influences on the direction of the wind were obvious from the time curves.