全球陆地表面的表面特性 微波发射率 源自FY-3D/MWRI测量
Ronghan Xu1,2, Zharong Pan3, Yang Han4
1Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites, National Satellite Meteorological Center (National Center for Space Weather), China Meteorological Administration, Beijing 100081, China.
Sensors (Basel, Switzerland)
|July 8, 2023
概括
这项研究使用云-3卫星数据估计了陆地表面的微波发射率. 导出的排放性捕捉了土壤水分和植被密度,显示了土地覆盖类型和季节的变化.
科学领域:
- 地球科学 地球科学 地球科学
- 遥感 遥感 遥感 遥感
- 大气科学 大气科学
背景情况:
- 准确的陆地表面微波发射率对于检索表面/大气参数和将微波数据同化为模型至关重要.
- 配备微波辐射成像仪 (MWRI) 传感器的FengYun-3 (FY-3) 系列卫星提供了有价值的全球测量.
研究的目的:
- 用FY-3卫星的MWRI数据来估计全球陆地表面的辐射率.
- 为了研究空间分布,光谱特征和不同土地覆盖类型的辐射率的季节性变化.
- 在排放率检索过程中识别潜在的错误来源.
主要方法:
- 使用了近似的微波辐射转移方程.
- 采用了MWRI传感器的亮度温度观测.
- 从ERA-Interim重新分析数据中获得的纳入的土地和大气特性.
- 在多个频率 (10.65,18.7,23.8,36.5,89 GHz) 和偏振的衍生发射率.
主要成果:
- 估计的发射率成功捕获了大规模的特征,并提供了对土壤水分和植被密度的见解.
- 发射率通常随频率增加,较低的值与表面粗和散射有关.
- 在不同的土地覆盖类型中观察到不同的发射率模式,包括夏季落叶针叶森林的高值和冬季在89 GHz显著下降.
- 在沙漠地区发现了高微波极化差异指数 (MPDI) 值.
结论:
- FY-3卫星数据具有持续全球表面微波发射率监测的巨大潜力.
- 了解发射率的时空变异性对于改善气候和天气模型至关重要.
- 错误的主要来源包括陆地表面温度,射频干扰和高频的云效应.
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