Ocean Science Journal

, Volume 52, Issue 3, pp 329–335 | Cite as

Recent increase in surface fCO2 in the western subtropical North Pacific

  • Dongseon Kim
  • Yujeong Choi
  • Tae-Wook Kim
  • Geun-Ha Park


We observed unusually high levels (> 440 μatm) of carbon dioxide fugacity (fCO2) in surface seawater in the western subtropical North Pacific, the area where Subtropical Mode Water is formed, during summer 2015. The NOAA Kuroshio Extension Observatory moored buoy located in this region also measured high CO2 values, up to 500 μatm during this period. These high sea surface fCO2 (fCO2SW) values are explained by much higher normalized total dissolved inorganic carbon and slightly higher normalized total alkalinity concentrations in this region compared to the equatorial Pacific. Moreover, these values are much higher than the climatological CO2 values, even considering increasing atmospheric CO2, indicating a recent large increase in sea surface CO2 concentrations. A large seasonal change in sea surface temperature contributed to higher surface fCO2SW in the summer of 2015.

Key words

surface CO2 Kuroshio Extension western subtropical North Pacific 


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Copyright information

© Korea Institute of Ocean Science & Technology (KIOST) and the Korean Society of Oceanography (KSO) and Springer Science+Business Media B.V. 2017

Authors and Affiliations

  • Dongseon Kim
    • 1
  • Yujeong Choi
    • 1
  • Tae-Wook Kim
    • 2
  • Geun-Ha Park
    • 3
  1. 1.Marine Chemistry & Geochemistry Research CenterKIOSTAnsanKorea
  2. 2.Department of Marine Science, College of Natural SciencesIncheon National UniversityIncheonKorea
  3. 3.East Sea Environment Research Center, East Sea Research InstituteKIOSTUljinKorea

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