厦门大学郭香会团队近日揭示了2023年夏季的干旱和高温使东海从长江口的二氧化碳汇变成了二氧化碳源。2025年5月29日出版的《中国科学：地球科学》杂志发表了这项成果。

研究组报告了2023年8月长江口附近东海陆架的地表水二氧化碳分压（pCO₂）和海气二氧化碳通量。地表水pCO₂范围为110 μatm至910 μatm，平均值427±154 μatm。调查区域的海气二氧化碳通量范围为-20.6 mmol m⁻² d⁻¹至35.9 mmol m⁻² d⁻¹，平均3.0±8.9 mmol m⁻² d⁻¹（中等来源），这与该地区在夏季通常是二氧化碳汇相反。 

长江流量在调节地表水pCO₂中起着关键作用；2023年8月长江流量的减少显著增加了邻近内陆架的地表水pCO₂，而高海面温度进一步提高了地表水pCO₂。2023年8月的干旱和高温的综合影响使研究区域从二氧化碳汇变成了二氧化碳源。在全球变化的背景下，洪水、干旱和热浪等气候事件的发生频率更高，这将继续增加以大河为主的边缘海二氧化碳汇/源评估的复杂性，并表明需要进一步的研究。

附：英文原文

Title: The 2023 summer drought and high temperatures turned the East China Sea off the Changjiang estuary from a CO2 sink to a CO2 source

Author: Yi XU, Dezhi BU, Xianghui GUO, Shiping LEI, Yi YANG, Kuanbo ZHOU

Issue&Volume: 2025/05/29

Abstract: This study reports the surface water partial pressure of CO2 (pCO2) and air-sea CO2 fluxes on the East China Sea shelf off the Changjiang estuary in August 2023. Surface water pCO2 ranged from 110μatm to 910μatm with an average value of 427±154μatm. Air-sea CO2 fluxes in the surveyed area ranged from 20.6mmolm2d1 to 35.9mmolm2d1 and averaged 3.0±8.9mmolm2d1 (a moderate source), which was contrary to this region generally being a CO2 sink during summer. Changjiang discharge played a key role in regulating surface water pCO2; the decreased Changjiang discharge in August 2023 increased surface water pCO2 on the adjacent inner shelf substantially, and the high sea surface temperature further elevated the surface water pCO2. The combined effect of drought and high temperatures in August 2023 turned the study area from a CO2 sink to a CO2 source. Under the context of global change, climate events such as floods, droughts and heatwaves occur more frequently, which will continue to add more complexity to CO2 sink/source evaluations in large river-dominated marginal seas and suggest further research is needed.

DOI: 10.1007/s11430-024-1580-0

Source: https://www.sciengine.com/SCES/doi/10.1007/s11430-024-1580-0