研究人员利用地球同步实用环境卫星-R系列的观测结果来检验2020年美国严重热浪对生态系统光合作用的日变化的影响。研究发现，不同植被类型和干旱梯度的光合作用对热浪表现不同，旱地在光合作用中表现为广泛的中午和下午萧条。旱地的总初级生产力(GPP)的日质心和峰值时间明显向清晨移动，反映了显著的水合热应力。
在估计热浪期间，日总初级生产力和总初级生产力损失方面，研究人员基于地球同步卫星优于来自极轨卫星快照的传统，基于辐射的尺度提升方法。这些发现强调了地球同步卫星在日光合作用监测方面的潜力，并突出表明在评估碳-气候相互作用时，有必要考虑总初级生产力在压力下日益增加的日不对称性。
附：英文原文
Title: New-generation geostationary satellite reveals widespread midday depression in dryland photosynthesis during 2020 western U.S. heatwave
Author: Xing Li, Youngryel Ryu, Jingfeng Xiao, Benjamin Dechant, Jiangong Liu, Bolun Li, Sungchan Jeong, Pierre Gentine
Issue&Volume: 2023-08-02
Abstract: Emerging new-generation geostationary satellites have broadened the scope for studying the diurnal cycle of ecosystem functions. We exploit observations from the Geostationary Operational Environmental Satellite-R series to examine the effect of a severe U.S. heatwave in 2020 on the diurnal variations of ecosystem photosynthesis. We find divergent responses of photosynthesis to the heatwave across vegetation types and aridity gradients, with drylands exhibiting widespread midday and afternoon depression in photosynthesis. The diurnal centroid and peak time of dryland gross primary production (GPP) substantially shift toward earlier morning times, reflecting notable water and heat stress. Our geostationary satellite-based method outperforms traditional radiation-based upscaling methods from polar-orbiting satellite snapshots in estimating daily GPP and GPP loss during heatwaves. These findings underscore the potential of geostationary satellites for diurnal photosynthesis monitoring and highlight the necessity to consider the increased diurnal asymmetry in GPP under stress when evaluating carbon-climate interactions.
DOI: adi0775
Source: https://www.science.org/doi/full/10.1126/sciadv.adi0775