Satellite evidence for enhancement of the column mixing ratio of atmospheric co2 over e. huxleyi blooms

Emiliania huxleyi algae are known to enhance CO2 partial pressure in their ambient water, (pCO2)w. Thus, over such bloom areas, the atmospheric column-averaged dry air mole fraction of carbon dioxide (XCO2) is likely to increase, which has not been yet quantified on basin scales. Here we report on an Orbiting Carbon Observatory (OCO-2) satellite study of the influence of E. huxleyi blooms on XCO2 over the Black Sea. We established that concurrently with a (pCO2)w significant rise, there is an increase in the overlying XCO2 within the range ~1 to nearly 2 ppmv, which is on the order of the planetary annual increase of XCO2. As we found, (∆pCO2)w in the Back Sea and Subpolar and Polar seas are closely comparable. This strongly indicates that E. huxleyi blooms do weaken carbon sinks in the ocean on a large scale, which can be consequential for global climatology and marine biogeochemistry.