Abstract
The air–sea \(\text{ CO }_{2}\) flux was measured from a research vessel in the North Yellow Sea in October 2007 using an open-path eddy-covariance technique. In 11 out of 64 samples, the normalized spectra of scalars (\(\text{ CO }_{2}\), water vapour, and temperature) showed similarities. However, in the remaining samples, the normalized \(\text{ CO }_{2}\) spectra were observed to be greater than those of water vapour and temperature at low frequencies. In this paper, the noise due to cross-sensitivity was identified through a combination of intercomparisons among the normalized spectra of three scalars and additional analyses. Upon examination, the cross-sensitivity noise appeared to be mainly present at frequencies \({<}0.8\,\text{ Hz }\). Our analysis also suggested that the high-frequency fluctuations of \(\text{ CO }_{2}\) concentration (frequency \({>}0.8\,\text{ Hz }\)) was probably less affected by the cross-sensitivity. To circumvent the cross-sensitivity issue, the cospectrum in the high-frequency range 0.8–1.5 Hz, instead of the whole range, was used to estimate the \(\text{ CO }_{2}\) flux by taking the contribution of the high frequency to the \(\text{ CO }_{2}\) flux to be the same as the contribution to the water vapour flux. The estimated air–sea \(\text{ CO }_{2}\) flux in the North Yellow Sea was \(-0.039\,\pm \,0.048\,\text{ mg } \text{ m }^{-2}\,\text{ s }^{-1},\) a value comparable to the estimates using the inertial dissipation method and Edson’s method (Edson et al., J Geophys Res 116:C00F10, 2011).
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Bariteau L, Helmig D, Fairall CW, Hare JE, Hueber J, Lang EK (2010) Determination of oceanic ozone deposition by ship-borne eddy covariance flux measurements. Atmos Meas Tech 3:441–455
Businger JA (1986) Evaluation of the accuracy with which dry deposition can be measured with current micrometeorological techniques. J Clim Appl Meteorol 25(8):1100–1124
Chen CTA, Borges AV (2009) Reconciling opposing views on carbon cycling in the coastal ocean: continental shelves as sinks and near-shore ecosystems as sources of atmospheric \(\text{ CO }_{2}\). Deep Sea Res II 56:578–590
Edson JB, Fairall CW, Mestayer PG, Larsen SE (1991) A study of the inertial-dissipation method for computing air–sea fluxes. J Geophys Res 96:10689–10711
Edson JB, Hinton AA, Prada KE, Hare JE, Fairall CW (1998) Direct covariance flux estimates from mobile platforms at sea. J Atmos Ocean Technol 15:547–562
Edson JB, Fairall CW, Bariteau L, Zappa CJ, Cifuentes-Lorenzen A, McGillis WR, Pezoa S, Hare JE, Helmig D (2011) Direct covariance measurement of \(\text{ CO }_{2}\) gas transfer velocity during the 2008 Southern ocean gas exchange experiment: wind speed dependency. J Geophys Res 116:C00F10
Fairall CW, Larsen SE (1986) Inertial-dissipation methods and turbulent fluxes at the air–ocean interface. Boundary-Layer Meteorol 34:287–301
Fairall CW, Hare JE, Edson JB, McGillis W (2000) Parameterization and micrometeorological measurement of air–sea gas transfer. Boundary-Layer Meteorol 96:63–106
Ho DT, Law CS, Smith MJ, Schlosser P, Harvey M, Hill P (2006) Measurements of air–sea gas exchange at high wind speeds in the Southern Ocean: implications for global parameterizations. Geophys Res Lett 33:L16611
Iwata T, Yoshikawa K, Higuchi Y, Yamashita T, Kato S, Ohtaki E (2005) The spectral density technique for the determination of \(\text{ CO }_{2}\) flux over the ocean. Boundary-Layer Meteorol 117:511–523
Jacobs C, Kjeld JF, Nightingale P, Upstill-Goddard R, Larsen S, Oost W (2002) Possible errors in \(\text{ CO }_{2}\) air–sea transfer velocity from deliberate tracer releases and eddy covariance measurements due to near-surface concentration gradients. J Geophys Res 107(C9):3128
Jones EP, Smith SD (1977) A first measurement of sea–air \(\text{ CO }_{2}\) flux by eddy correlation. J Geophys Res 82:5990–5992
Kaimal JC, Wyngaard JC, Izumi Y, Cote OR (1972) Spectral characteristics of surface-layer turbulence. Q J R Meteorol Soc 98:563–589
Kohsiek W (2000) Water vapor cross-sensitivity of open path \(\text{ H }_{2}\text{ O }/\text{ CO }_{2}\) sensors. J Atmos Ocean Technol 17:299–311
Kondo F, Tsukamoto O (2007) Air–sea \(\text{ CO }_{2}\) flux by eddy covariance technique in the equatorial Indian Ocean. J Oceanogr 63:449–456
Liss PS, Merlivat L (1986) Air–sea gas exchange rates: introduction and synthesis. In: Buat-Menard P (ed) The role of air–sea exchange in geochemical Cycling. NATO ASI Series, Reidel, Utrecht, 113–128, 549 pp
McGillis WR, Edson JB, Hare JE, Fairall CW (2001) Direct covariance air–sea \(\text{ CO }_{2}\) fluxes. J Geophys Res 106:16729–16745
Miller SD, Marandino C, Saltzman ES (2010) Ship-based measurement of air–sea \(\text{ CO }_{2}\) exchange by eddy covariance. J Geophys Res 115:D02304
Oh DC, Park MK, Kim KR (2000) \(\text{ CO }_{2}\) exchange at air–sea interface in the Huanghai sea. Acta Oceanol Sinica 19:79–89
Pryor SC, Barthelmie RJ, Spaulding AM, Larsen SE, Petroff A (2009) Size-resolved fluxes of sub-100-nm particles over forests. J Geophys Res 114:D18212
Prytherch J, Yelland MJ, Pascal RW, Moat BI, Skjelvan I, Neill CC (2010) Direct measurements of the \(\text{ CO }_{2}\) flux over the ocean: development of a novel method. Geophys Res Lett 37:L3607
Rensen LL, Larsen SE (2010) Atmosphere–surface fluxes of \(\text{ CO }_{2}\) using spectral techniques. Boundary-Layer Meteorol 136:59–81
Sahlée E, Smedman AS, Rutgersson A, Högström U (2008) Spectra of \(\text{ CO }_{2}\) and water vapour in the marine atmospheric surface layer. Boundary-Layer Meteorol 126:279–295
Smith SD, Jones EP (1985) Evidence for wind-pumping of air–sea gas exchange based on direct measurements of \(\text{ CO }_{2}\) fluxes. J Geophys Res 90:869–875
Tsukamoto O (2004) Eddy covariance \(\text{ CO }_{2}\) flux measurements over open ocean. Paper presented at the 13th Symposium on the interaction of the sea and atmosphere, American Meteorological Society, Portland, OR, 8–13 August
Wanninkhof R (1992) Relationship between wind speed and gas exchange. J Geophys Res 97:7373–7382
Wanninkhof R, McGillis WR (1999) A cubic relationship between air–sea \(\text{ CO }_{2}\) exchange and wind speed. Geophys Res Lett 26:1889–1892
Webb EK, Pearman GI, Leuning R (1980) Correction of flux measurements for density effects due to heat and water vapour transfer. Q J R Meteorol Soc 106:85–100
Wesely ML, Cook DR, Hart RL, Williams RM (1982) Air–sea exchange of \(\text{ CO }_{2}\) and evidence for enhanced upward fluxes. J Geophys Res 87:8827–8832
Acknowledgments
The authors are most grateful to Prof. M. Fang of the Hong Kong University of Science and Technology for his invaluable advice and suggestions. This study is supported by MOST 2010DFA91350 and NFSC 40976063. We thank the anonymous reviewer for her/his constructive comments.
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Duan, Z., Gao, H., Gao, Z. et al. An Approach to Minimizing Artifacts Caused by Cross-Sensitivity in the Determination of Air–Sea \(\text{ CO }_{2}\) Flux Using the Eddy-Covariance Technique. Boundary-Layer Meteorol 148, 227–239 (2013). https://doi.org/10.1007/s10546-013-9814-1
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DOI: https://doi.org/10.1007/s10546-013-9814-1