Azimuthal variations of the microwave radiation from a slightly non‐Gaussian sea surface
Azimuthal variations of the microwave radiation from a slightly non‐Gaussian sea surface
复制标题
轻微非高斯海面微波辐射的方位角变化
DOI：
10.1029/1999rs900104
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
V. Irisov
中科院分区：
文献类型：
--
作者：
V. Irisov
利用小斜率展开法研究了海洋粗糙面的微波辐射。重点是与风生海浪的各向异性相关的亮温的方位角变化。第一和第二谐波，分别描述了逆风-顺风和逆风-逆风的差异，被认为是使用现有的海谱模型。对于一次谐波的建模，从高斯统计的海面的小偏差被引入到估计长波不对称性的影响和涟漪的分布在长波。数值分析表明，长波不对称性不能解释观测到的亮温方位角变化的一次谐波值。涟漪调制长波是一种可能的机制，解释在中等风的第一谐波，虽然泡沫和波浪破碎必须包括在电磁模型，以实现定量协议与实验。
Microwave radiation from the ocean rough surface is considered using a small slope expansion. The emphasis is on azimuthal variations of the brightness temperature, related to the anisotropy of wind‐generated sea waves. The first and second harmonics, describing the upwind‐downwind and upwind‐crosswind differences, respectively, are considered using existing models of the sea spectrum. For modeling of the first harmonic the small deviation from Gaussian statistics of the sea surface is introduced to estimate the effect of longwave asymmetry and the distribution of ripples over the long waves. Numerical analysis shows that the longwave asymmetry cannot explain the observed values of the first harmonic in azimuthal variations of the brightness temperature. The ripple modulation by long waves is a possible mechanism explaining the first harmonic in moderate winds, although foam and wave breaks have to be included in electromagnetic modeling to achieve a quantitative agreement with experiments.