COSMIC与ERA-Interim折射率数据分析海洋边界层时空分布的对比

Temporal and spatial distribution of oceanic boundary layer based on COSMIC and ERA-Interim refractive index

本文基于小波协方差变换法,使用COSMIC和ERA-Interim两种数据的折射率获取了全球海洋边界层的时空分布情况并进行了对比分析.结果表明:在空间上,由两种数据反演出的海洋边界层高度所显示出的分布特征大致相同,即沿着赤道呈不完全对称分布,仅在个别海域有所差别;在季节及月变化方面,两者均呈现出夏季较高的特点;在日变化特征上,两者变化均不明显,但ERA-Interim数据的海洋边界层高度的日变化特征与太阳辐射的日变化特征更加符合;在数值差异上,COSMIC数据要比ERA-Interim数据的结果高500~1000 m,且低纬度地区两者差异大于高纬度地区,夏季两者差异小于冬季.

The spatial and temporal distribution of the oceanic boundary layer height is determined by wavelet covariance transform method using COSMIC and ERA-Interim refractive index data independently,then the difference between results of the two datasets is comparatively analyzed.The results show that a roughly same spatial pattern of not completely symmetrical distribution of the boundary layer height along the equator is observed for the inversion results of the two datasets.As for the seasonal and monthly variations,the oceanic boundary layer is relatively high in summer.Though no obvious diurnal variation is observed,it should be noted that the diurnal variation of boundary layer height from ERA-Interim data is more consistent with that of solar radiation.The comparison shows that the inversion results of COSMIC data are about 500-1000 meters higher than those of ERA-Interim data,and the difference is greater in high latitudes than in low latitudes and smaller in summer than in winter.