Vector Empirical Orthogonal Function Analysis of the Satellite Scatterometer Wind Data

Ocean surface winds derived from NSCAT, QuikSCAT and ERS-1/2 scatterometer observations during a period from January 1992 to April 2000 were analyzed using the vector empirical orthogonal function (VEOF) method. The first three VEOF modes account for 44.9%, 11.3%, and 8.5% of the total variance, respectively. With an annual cycle of the boreal summer and winter oscillation, the first VEOF modes show the features of the Indian and East Asian monsoons as well as the annual variability of the trade wind. The second VEOF modes represent a boreal autumn and spring oscillation, revealing a transition state between the winter and summer. The temporal mode of VEOF 3 has a high correlation of 0.8 with the Southern Oscillation Index (SOI). The spatial mode of VEOF 3 shows the pattern related to the Walker Circulation. Further more, the third mode reveals the tele-connection of the Indian monsoon and wind variability over high latitude oceans, such as the Aleutian Low system, with ENSO events.