Analysis of temporal and spatial changes of wind speed and significant wave height in the South Atlantic based on ERA5
XIA Wusong
WEI Yongliang
LU Hengxing
ZHOU Nan
Abstract：Based on the monthly average wind speed and significant wave height of the European Centre for Medium-Range Weather Forecasts(ECMWF)ERA5 from 1979 to 2019,the temporal and spatial characteristics of wind speed and significant wave height were analyzed.The Mann-Kendall test method was used to analyze its inter-annual variation and the Empirical Orthogonal Function(EOF)analysis method was used to study the spatial distribution characteristics.The results showed that:(1)The wind direction of the South Atlantic Ocean rotated counter clock wise with 30°S and 10°W as the center.The areas with high wind speed were mainly controlled by the southeast trade wind belt and the west wind belt,and the low value areas were controlled by the subtropical high and low pressure zone.The wind speed in winter was higher than other seasons,and the wind speed and wind direction distribution throughout the year were related to the seasonal changes of the weather system.(2)There was a strong correlation between wind speed and significant wave height,and both of them were distributed in a zonal ring shape.The overall significant wave height was the largest in winter and smaller in sum-mer.(3)Mann-Kendall test results showed that the inter-annual variation of wind speed and significant wave height both showed an upward trend.The wind speed had abrupt changes around 2006 and 2009,and the significant wave was higher than around 1994 and had abrupt changes.(4)The first mode of EOF of the wind speed showed that the trade wind belt-westerly belt and the subtropical high belt-low pressure belt were distributed in the opposite pattern.The wind speed of the former showed a signifi-cant upward trend,and the latter showed a downward trend.The first modal of EOF of the significant wave height showed that the significant wave height variability in the north sea area of 60°S was the positive phase,and the south was the negative phase.The significant wave height in the positive phase region had a significant increasing trend,and the significant wave height in the negative phase region had a significant decreasing trend.
Keywords：South Atlanticsea surface wind speedsignificant wave heighttemporal and spatial dis-tribution
Publication Date：2024-02-28
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：11( 1-11 )