Observations of solar‐induced chlorophyll a fluorescence (SIF) from spaceborne spectrometers can advance our understanding of terrestrial and aquatic carbon cycles. Here we present the first global retrievals of SIF at red wavelengths from the TROPOspheric Monitoring Instrument (TROPOMI). Despite the weak signal level, considerable uncertainties, and subtle measurement artifacts, spatial patterns and magnitudes agree with independent data sets. Over land, spatial patterns of our red SIF estimates covary with the far‐red SIF data. Red SIF over the ocean is highly consistent with the normalized fluorescence line height (nFLH) inferred from measurements of the MODerate resolution Imaging Spectroradiometer (MODIS), even when comparing single days and fine spatial scales. Major advantages of our Fraunhofer line‐based SIF retrievals include the capability to sense SIF through optically thin cloud/aerosol layers and an insensitivity to ocean color. This opens up new avenues for studying ocean biogeochemistry from space.

中文翻译：

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使用 TROPOMI 在红光波长下全局检索太阳诱导的叶绿素荧光

来自星载光谱仪的太阳诱导叶绿素 a 荧光 (SIF) 的观察可以增进我们对陆地和水生碳循环的理解。在这里，我们展示了对流层监测仪器 (TROPOMI) 在红色波长处首次全球反演 SIF。尽管信号电平微弱、不确定性相当大和测量伪影很细微，但空间模式和幅度与独立数据集一致。在陆地上，我们的红色 SIF 估计的空间模式与远红色 SIF 数据共变。海洋上的红色 SIF 与从中等分辨率成像光谱仪 (MODIS) 的测量结果推断的归一化荧光线高度 (nFLH) 高度一致，即使在比较单日和精细空间尺度时也是如此。我们基于 Fraunhofer 线的 SIF 反演的主要优势包括能够通过光学薄云/气溶胶层感知 SIF，并且对海洋颜色不敏感。这为从太空研究海洋生物地球化学开辟了新途径。