TITLE:
The Variability of Partial Pressure of Carbon Dioxide (pCO2) in a River-Influenced Coastal Upwelling System: A Case of the Northeast Pacific Coast
AUTHORS:
Charles Izuma Addey, Zong-Pei Jiang, Jianfang Chen, Ademolawa John Afelumo, Babatunde Rasheed Adesina, Abiola John Osanyintuyi
KEYWORDS:
pCO2 Variability, Coastal Upwelling, River-Influenced Coastal Systems, Northeast Pacific Coast, Climate Change
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.9 No.7,
July
28,
2021
ABSTRACT: The
Northeast Pacific coastal ocean, as a typical river-influenced coastal
upwelling system, is characterized by significant variability of sea surface
partial pressure of carbon dioxide (pCO2, 1000 μatm). This
study reviewed the pCO2 variability
and its underlying controlling mechanism in this highly dynamic region by
bringing together previous scientific findings and historical data. The large pCO2 variability reflects the complex interactions between physical processes
(riverine input and coastal upwelling) and the biological responses to the nutrient transportation
associated with these physical processes, while temperature and air-sea
gas exchange play a minor role in affecting pCO2. Both the
river water and upwelled subsurface water are characterized by higher
concentrations of pCO2 and nutrients when compared to the
coastal surface water. The presence of high chlorophyll-a and low pCO2 in river plumes and areas adjacent to upwelling locations showed the intense
biological CO2 uptake. The influences of riverine input and coastal
upwelling thus mainly depend on the competing effect of high background pCO2 of river water and upwelled subsurface water vs. the biological dropdown of pCO2 resulting from the riverine- and upwelling-associated nutrient supplies. The
strength of upwelling-favorable wind plays an important role in the pCO2 variability by affecting the intensity of coastal upwelling, with stronger wind
speed causing more intense upwelling. The long-term pCO2 increasing rate in the Northeast Pacific coast is observed to be lower than
that in the North Pacific open ocean.