Schematic showing two independent methods used to estimate the change in CO2 fluxes due to widespread flooding across the U.S. Midwest region in spring and summer 2019.
Two independent methods were used to estimate the change in CO2 fluxes due to widespread flooding across the U.S. Midwest region in the spring and summer of 2019. The “bottom up” method used satellite-based solar-induced chlorophyll fluorescence (SIF) data to estimate gross primary productivity (GPP) and net ecosystem exchange (NEE) of CO2. The “top down” approach combined atmospheric models with estimates of atmospheric CO2 concentrations from the OCO-2 satellite. These two approaches yielded similar estimates of anomalous reduced fluxes due to the unusual flooding event. Credit: Yin et al. [2020], Figure S
Source: AGU Advances

Climate change is increasing extreme weather events, such as regional flooding, which affects when farmers can plant their crops, subsequent crop productivity, and regional carbon fluxes.

For periods during and following the 2019 spring flood in the U.S. Midwest, Yin et al. [2020] quantified reductions in the usual patterns of crop productivity and its uptake of atmospheric CO2 using two measurements made with satellites: (1) atmospheric CO2 concentrations and (2) the fluorescence (re-emission of the Sun’s light) by leaves of the crops. The two parameters yielded similar carbon flux estimates, thus conferring confidence in the conclusion that regional carbon uptake declined due to the flood.

Although this was a retrospective study of recent months, these satellite data are available in near-real time. Further development and application of these technologies and analyses could enable improved agricultural and ecological forecasting of crop productivity and carbon fluxes, similar to current weather forecasting based on assimilation of atmospheric observations.

Citation: Yin, Y., Byrne, B., Liu, J., Wennberg, P., Davis, K., Magney, T., et al. [2020]. Cropland carbon uptake delayed and reduced by 2019 Midwest floods. AGU Advances, 1, e2019AV000140.

—Eric Davidson, Editor, AGU Advances

Text © 2020. The authors. CC BY-NC-ND 3.0
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