Cropland Carbon Uptake Delayed and Reduced by 2019 Midwest Floods

AGU Advances

Tobias Gerken¹  Sha Feng¹  Kenneth J. Davis¹  Christian Frankenberg²  Liyin He²  Rupesh Jeyaram²  Troy Magney²  Vincent Humphrey²  Yi Yin²  Philipp Köhler²  Paul O. Wennberg²  Junjie Liu³  Joshua P. Digangi⁴  Brendan Byrne⁵ 

[1] Department of Meteorology and Atmospheric Science Pennsylvania State University University Park PA USA;Division of Geological and Planetary Sciences California Institute of Technology Pasadena CA USA;Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA;Langley Research Center National Aeronautics and Space Administration Hampton VA USA;NASA Postdoctoral Program Fellow, Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA;

关键词: flood;    crop;    carbon cycle;    SIF;    TROPOMI;    OCO‐2;   

DOI  :  10.1029/2019AV000140

来源: DOAJ

【 摘 要 】

Abstract While large‐scale floods directly impact human lives and infrastructures, they also profoundly impact agricultural productivity. New satellite observations of vegetation activity and atmospheric CO2 offer the opportunity to quantify the effects of such extreme events on cropland carbon sequestration. Widespread flooding during spring and early summer 2019 induced conditions that delayed crop planting across the U.S. Midwest. As a result, satellite observations of solar‐induced chlorophyll fluorescence from TROPOspheric Monitoring Instrument and Orbiting Carbon Observatory reveal a 16‐day shift in the seasonal cycle of photosynthesis relative to 2018, along with a 15% lower peak value. We estimate a reduction of 0.21 PgC in cropland gross primary productivity in June and July, partially compensated in August and September (+0.14 PgC). The extension of the 2019 growing season into late September is likely to have benefited from increased water availability and late‐season temperature. Ultimately, this change is predicted to reduce the crop productivity in the Midwest Corn/Soy belt by ~15% compared to 2018. Using an atmospheric transport model, we show that a decline of ~0.1 PgC in the net carbon uptake during June and July is consistent with observed CO2 enhancements of up to 10 ppm in the midday boundary layer from Atmospheric Carbon and Transport‐America aircraft and over 3 ppm in column‐averaged dry‐air mole fractions from Orbiting Carbon Observatory. This study quantifies the impact of floods on cropland productivity and demonstrates the potential of combining solar‐induced chlorophyll fluorescence with atmospheric CO2 observations to monitor regional carbon flux anomalies.

【 授权许可】

Unknown