Oxygenated volatile organic carbon in the western Pacific convective centre: ocean cycling, air–sea gas exchange and atmospheric transport
Cathleen Schlundt1,a, Christa A. Marandino1, Susann Tegtmeier1, Sinikka T. Lennartz1, Astrid Bracher2,3, Wee Cheah2,b, Kirstin Krüger4, and Birgit Quack11GEOMAR Helmholtz Centre for Ocean Research, Kiel, Düsternbrooker Weg, 20, 24105 Kiel, Germany 2Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, 27570, Germany 3Institute of Environmental Physics, University of Bremen, Bremen, 28359, Germany 4Meteorology and Oceanography Department of Geosciences, University of Oslo, Oslo, 0315, Norway anow at: Josephine Bay Paul Center, Marine Biological Laboratory, Woods Hole, 7 MBL Street, 02540, MA, USA bnow at: Research Center for Environmental Changes, Academia Sinica, Taipei, 128 Academia Road, 11529 Taipei, Taiwan
Received: 03 Jan 2017 – Accepted for review: 13 Mar 2017 – Discussion started: 16 Mar 2017
Abstract. A suite of oxygenated volatile organic compounds (OVOCs – acetaldehyde, acetone, propanal, butanal and butanone) were measured concurrently in the surface water and atmosphere of the South China Sea and Sulu Sea in November 2011. A strong correlation was observed between all OVOC concentrations in the surface seawater along the entire cruise track, except for acetaldehyde, suggesting similar sources and sinks in the surface ocean. Additionally, several phytoplankton groups, such as haptophytes or pelagophytes, were also correlated to all OVOCs indicating that phytoplankton may be an important source for marine OVOCs in the South China and Sulu Seas. Humic and protein like fluorescent dissolved organic matter (FDOM) components seemed to be additional precursors for butanone and acetaldehyde. The atmospheric OVOC mixing ratios were relative high compared with literature values, suggesting the coastal region of North Borneo as a local hot spot for atmospheric OVOCs. The flux of atmospheric OVOCs was largely into the ocean for all 5 gases, with a few important exceptions near the coast of Borneo. The calculated amount of OVOCs entrained into the ocean seemed to be an important source of OVOCs to the surface ocean. When the fluxes were out of the ocean, marine OVOCs were found to be enough to control the local measured OVOC distribution in the atmosphere. Based on our model calculations, at least 0.4 ppb of marine derived acetone and butanone can reach the upper troposphere, where they may have an important influence on hydrogen oxide radical formation over the western Pacific Ocean.
Schlundt, C., Marandino, C. A., Tegtmeier, S., Lennartz, S. T., Bracher, A., Cheah, W., Krüger, K., and Quack, B.: Oxygenated volatile organic carbon in the western Pacific convective centre: ocean cycling, air–sea gas exchange and atmospheric transport, Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2017-9, in review, 2017.