New global observations of the terrestrial carbon cycle from GOSAT: Patterns of plant fluorescence with gross primary productivity
New global observations of the terrestrial carbon cycle from GOSAT: Patterns of plant fluorescence with gross primary productivity
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DOI：
10.1029/2011gl048738
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发表时间：
2011-09-14
影响因子：
5.2
通讯作者：
Yokota, Tatsuya
中科院分区：
文献类型：
--
作者：
Frankenberg, Christian;Fisher, Joshua B.;Yokota, Tatsuya
我们关闭地球的碳预算和预测气候变暖反馈的能力，关键取决于我们知道二氧化碳在何时、何地以及如何在陆地和大气之间交换。陆地初级生产总值（GPP）是全球碳收支中最大的通量组成部分，但GPP估算值及其季节性仍存在很大的不确定性。从经验上看，我们表明，在光合作用过程中，太阳诱导的叶绿素荧光的全球星载观测与GPP表现出很强的线性相关性。我们发现，即使没有任何额外的气候或模式信息，荧光发射在估计GPP方面也具有与使用辅助数据和模式假设的传统遥感植被指数相同或更好的预测能力。在北方夏季，由于稀树草原/农田（通过简单线性缩放得出的荧光GPP高18-48%）和高纬度针叶林（荧光GPP低28-32%）的差异，荧光与GPP模型之间普遍较强的线性相关性减弱。我们的研究结果表明，叶绿素荧光的反演为GPP提供了直接的全球观测约束，并为全球碳循环开辟了一个全新的视角。我们预计，全球荧光数据与统一的植物生理荧光模型相结合，将是碳循环研究的一个阶段性变化，并使对当前和未来碳循环的理解具有前所未有的稳健性。引用本文：Frankenberg， C.等（2011），来自GOSAT的陆地碳循环的全球新观测：植物荧光与总初级生产力的模式，地球物理学报。卷。， 38, L17706, doi: 10.1029/2011GL048738。
Our ability to close the Earth's carbon budget and predict feedbacks in a warming climate depends critically on knowing where, when and how carbon dioxide is exchanged between the land and atmosphere. Terrestrial gross primary production (GPP) constitutes the largest flux component in the global carbon budget, however significant uncertainties remain in GPP estimates and its seasonality. Empirically, we show that global spaceborne observations of solar induced chlorophyll fluorescence - occurring during photosynthesis - exhibit a strong linear correlation with GPP. We found that the fluorescence emission even without any additional climatic or model information has the same or better predictive skill in estimating GPP as those derived from traditional remotely-sensed vegetation indices using ancillary data and model assumptions. In boreal summer the generally strong linear correlation between fluorescence and GPP models weakens, attributable to discrepancies in savannas/croplands (18-48% higher fluorescence-based GPP derived by simple linear scaling), and high-latitude needleleaf forests (28-32% lower fluorescence). Our results demonstrate that retrievals of chlorophyll fluorescence provide direct global observational constraints for GPP and open an entirely new viewpoint on the global carbon cycle. We anticipate that global fluorescence data in combination with consolidated plant physiological fluorescence models will be a step-change in carbon cycle research and enable an unprecedented robustness in the understanding of the current and future carbon cycle. Citation: Frankenberg, C., et al. (2011), New global observations of the terrestrial carbon cycle from GOSAT: Patterns of plant fluorescence with gross primary productivity, Geophys. Res. Lett., 38, L17706, doi: 10.1029/2011GL048738.