TY - JOUR
T1 - Seasonal and short-term variations in atmospheric potential oxygen at Ny-Ålesund, Svalbard
AU - Goto, Daisuke
AU - Morimoto, Shinji
AU - Aoki, Shuji
AU - Patra, Prabir K.
AU - Nakazawa, Takakiyo
N1 - Publisher Copyright:
© 2017 The Author(s).
PY - 2017/4/11
Y1 - 2017/4/11
N2 - Oxygen in the atmosphere undergoes variations and changes in response to biospheric activities, ocean-atmosphere exchange and fossil fuel combustion. Continuous in situ measurements of atmospheric δ(O2/N2) and CO2 mole fraction were started at Ny-Ålesund, Svalbard (78.93°N, 11.83°E, 40 m a.s.l.) in November 2012. Atmospheric potential oxygen (APO) calculated from the measured O2 and CO2 values during November 2012-January 2015 show a clear seasonal cycle with a peak-to-peak amplitude of approximately 50 per meg. The seasonal cycle of APO simulated using an atmospheric transport model, with prescribed oceanic O2, N2 and CO2 fluxes at monthly time intervals, is in excellent agreement with the observed APO. However, in spring and early summer, high values of APO are observed irregularly on a timescale of hours to days. By comparing backward trajectories of air parcels released from the site with distributions of marine net primary production (NPP), and tagged tracer experiments made using the atmospheric transport model for APO, it is found that these high APO fluctuations are primarily attributable to O2 emissions from the Greenland Sea, the Norwegian Sea and the Barents Sea, due to marine biological productivity. Marine net community production, estimated based on the sea-to-air O2 flux derived from observed APO fluctuations, agrees with NPP obtained from satellite observations within an order of magnitude. The results obtained in this study have still some uncertainties, but our continuous observations of atmospheric δ(O2/N2) and CO2 mole fraction at Ny-Ålesund can play an important role in detecting possible changes in the carbon cycle in the near future.
AB - Oxygen in the atmosphere undergoes variations and changes in response to biospheric activities, ocean-atmosphere exchange and fossil fuel combustion. Continuous in situ measurements of atmospheric δ(O2/N2) and CO2 mole fraction were started at Ny-Ålesund, Svalbard (78.93°N, 11.83°E, 40 m a.s.l.) in November 2012. Atmospheric potential oxygen (APO) calculated from the measured O2 and CO2 values during November 2012-January 2015 show a clear seasonal cycle with a peak-to-peak amplitude of approximately 50 per meg. The seasonal cycle of APO simulated using an atmospheric transport model, with prescribed oceanic O2, N2 and CO2 fluxes at monthly time intervals, is in excellent agreement with the observed APO. However, in spring and early summer, high values of APO are observed irregularly on a timescale of hours to days. By comparing backward trajectories of air parcels released from the site with distributions of marine net primary production (NPP), and tagged tracer experiments made using the atmospheric transport model for APO, it is found that these high APO fluctuations are primarily attributable to O2 emissions from the Greenland Sea, the Norwegian Sea and the Barents Sea, due to marine biological productivity. Marine net community production, estimated based on the sea-to-air O2 flux derived from observed APO fluctuations, agrees with NPP obtained from satellite observations within an order of magnitude. The results obtained in this study have still some uncertainties, but our continuous observations of atmospheric δ(O2/N2) and CO2 mole fraction at Ny-Ålesund can play an important role in detecting possible changes in the carbon cycle in the near future.
KW - Air-sea Oexchange
KW - Atmospheric potential oxygen (APO)
KW - Atmospheric transport model
KW - Net community production
KW - Ny-Ålesund
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U2 - 10.1080/16000889.2017.1311767
DO - 10.1080/16000889.2017.1311767
M3 - Article
AN - SCOPUS:85019357269
SN - 0280-6509
VL - 69
JO - Tellus, Series B: Chemical and Physical Meteorology
JF - Tellus, Series B: Chemical and Physical Meteorology
IS - 1
M1 - 1311767
ER -
