0 引言
1 数据和方法
1.1 数据
1.2 方法
2 结果与分析
2.1 海底压强变化的时空特征
图1 GRACE卫星观测的海底压强多年(2002—2024年)标准差(a),中心区平均海底压强的时间序列(b)、逐月平均值(c)和能谱密度(d)(图a中的黑色等值线为200 m等深线;图b中缺失的数据采用线性插值法补全,其中2017年7月至2018年5月段的缺失数据未作插值处理;图d中的蓝色虚线表示95%置信区间。) Fig.1 The multi-year (2002-2024) standard deviation of ocean bottom pressure observed by GRACE satellites at the Arabian Sea (a), time series of the mean ocean bottom pressure (MOBP) (b), multi-year monthly average variation (c), and power spectral density (d) in the central area (The black contour lines in Fig.1a represent the 200 m isobaths; the missing data in Fig.1b are filled by linear interpolation, except for the missing data from July 2017 to May 2018,which is not interpolated; the blue dotted line in Fig.1d indicates the 95%confidence interval.) |
2.2 海底压强季节变化的动力机制
图5 埃克曼输运和埃克曼抽吸垂向速度(wE)的月平均空间分布(埃克曼输运以矢量箭头表示;wE以颜色等值表示,向下为正。) Fig.5 The monthly mean spatial distribution of the Ekman transport and Ekman pumping/suction vertical velocity(wE) (Ekman transport is represented by vector arrows; wE is represented by color contour, downward showing positive values.) |
图6 2002—2024年阿拉伯海多年平均的冬季(12月—2月)和夏季(6月—8月)海表面大气压和风场空间分布[填色表示海表面大气压,箭头表示风速矢量,黑色等值线表示经向平均大气压标准差 (±3.7 hPa)。] Fig.6 The spatial distribution of the multi-year average sea surface atmospheric pressure and wind field in the Arabian Sea during winter (December to February) and summer (June to August) from 2002 to 2024 [The colors indicate sea surface atmospheric pressure and the arrows indicate wind velocity vectors. The black contour represents the standard deviation of meridional mean sea surface atmospheric pressure (±3.7 hPa).] |
图7 冬/夏季平均海底压强与各月DMI的相关系数(夏季平均海底压强指7月—9月的平均值,冬季为1月—3月的平均值。其中上下两条黑色虚线分别表示95%和90%置信水平。) Fig.7 The correlation coefficients of the averaged MOBP in winter and summer with the DMI for each month (The average bottom pressure in summer refers to the mean value of July to September, and that in winter is the average of January to March. The upper and lower black dashed lines represent the 95%and 90%confidence levels, respectively.) |

