es0c00344_si_001.pdf (1.64 MB)
Prediction of Photochemically Produced Reactive Intermediates in Surface Waters via Satellite Remote Sensing
journal contribution
posted on 2020-05-21, 18:10 authored by Yiling Chen, Raymond M. Hozalski, Leif G. Olmanson, Benjamin P. Page, Jacques C. Finlay, Patrick L. Brezonik, William A. ArnoldAbsorption of solar radiation by colored dissolved organic matter
(CDOM) in surface waters results in the formation of photochemically
produced reactive intermediates (PPRIs) that react with pollutants
in water. Knowing the steady-state concentrations of PPRIs ([PPRI]ss) is critical to predicting the persistence of pollutants
in sunlit surface waters. CDOM levels (a440) can be measured remotely for lakes over large areas using satellite
imagery. Laboratory measurements of [PPRI]ss and apparent
quantum yields (Φ) of three PPRIs (3DOM*, 1O2, and •OH) were made for 24 lake samples
under simulated sunlight. The total rate of light absorption by the
water samples (Ra), the rates of formation
(Rf), and [PPRI]ss of 3DOM* and 1O2 linearly increased with
increasing a440. The
production rate of •OH was linearly correlated with a440, but the steady-state concentration was
best fit by a logarithmic function. The relationship between measured a440 and Landsat 8 reflectance was used to map a440 for more than 10 000 lakes across
Minnesota. Relationships of a440 with Rf, [PPRIs]ss, and Ra were coupled with satellite-based a440 assessments to map reactive species production rates
and concentrations as well as contaminant transformation rates. This
study demonstrates the potential for using satellite imagery for estimating
contaminant loss via indirect photolysis in lakes.