Influence of continental outflow on aerosol chemical characteristics over the Arabian Sea during winter

Abstract The chemical composition of aerosol over the Arabian Sea was investigated during December 2007. Elemental Carbon (EC), Organic Carbon (OC), water soluble organic and inorganic constituents and crustal elements (Al, Fe, Ca, and Mg) were measured in total suspended particulate samples (TSP) collected from marine boundary layer of the Arabian Sea when the oceanic region is influenced by continental outflow. Anthropogenic and natural mineral aerosol originating from continental regions dominates the aerosol composition contributing ∼88% of total aerosol mass. The sea-salt aerosol comprises only ∼12% of TSP. The carbonaceous aerosol exhibits spatial trend similar to that of K + suggesting major source could be biomass burning. Secondary organic aerosol (SOA) contribution estimated by EC-tracer method suggests that up to 67% of OC can be of secondary origin. Average water soluble organic carbon to OC ratio is ∼0.9, indicates significant formation of SOA during transport of continental air masses. These results demonstrate the dominance of continental aerosol over the Arabian Sea during wintertime where deposition may have major impact on surface ocean biogeochemistry.

[1]  Maria Cristina Facchini,et al.  Characterization of the organic composition of aerosols from Rondonia, Brazil, during the LBA-SMOCC 2002 experiment and its representation through model compounds , 2005 .

[2]  A. Wexler,et al.  Formation of nitrate and non-sea-salt sulfate on coarse particles , 1999 .

[3]  D. Streets,et al.  A technology‐based global inventory of black and organic carbon emissions from combustion , 2004 .

[4]  Robert J. Charlson,et al.  Perturbation of the northern hemisphere radiative balance by backscattering from anthropogenic sulfate aerosols , 1991 .

[5]  P. Pease,et al.  Aerosols over the Arabian Sea: Atmospheric transport pathways and concentrations of dust and sea salt , 1999 .

[6]  Corinne Le Quéré,et al.  Climate Change 2013: The Physical Science Basis , 2013 .

[7]  H. Sievering,et al.  Ozone oxidation of sulfur in sea‐salt aerosol particles during the Azores Marine Aerosol and Gas Exchange experiment , 1995 .

[8]  Ashwini Kumar,et al.  Mineral and anthropogenic aerosols in Arabian Sea–atmospheric boundary layer: Sources and spatial variability , 2008 .

[9]  B. Hicks,et al.  The atmospheric input of trace species to the world ocean , 1991 .

[10]  J. Seinfeld,et al.  The distribution of ammonium salts among a size and composition dispersed aerosol , 1990 .

[11]  J. Galloway,et al.  Heterogeneous sulfur conversion in sea-salt aerosol particles: the role of aerosol water content and size distribution , 1991 .

[12]  M. Andreae,et al.  Emission of trace gases and aerosols from biomass burning , 2001 .

[13]  M. Facchini,et al.  A simplified model of the water soluble organic component of atmospheric aerosols , 2001 .

[14]  M. Andreae.  Soot Carbon and Excess Fine Potassium: Long-Range Transport of Combustion-Derived Aerosols , 1983, Science.

[15]  Jay R. Turner,et al.  A method for on‐line measurement of water‐soluble organic carbon in ambient aerosol particles: Results from an urban site , 2004 .

[16]  M. Sarin,et al.  Chemical characteristics of atmospheric aerosols over southwest coast of India , 2007 .

[17]  R. Rengarajan,et al.  Carbonaceous and inorganic species in atmospheric aerosols during wintertime over urban and high‐altitude sites in North India , 2007 .

[18]  G. Carmichael,et al.  Marine boundary layer dust and pollutant transport associated with the passage of a frontal system over eastern Asia , 2004 .

[19]  P. Quinn,et al.  Aerosol optical properties measured on board the Ronald H. Brown during ACE-Asia as a function of aerosol chemical composition and source region , 2004 .

[20]  P. Crutzen,et al.  Atmospheric aerosols: Biogeochemical sources and role in atmospheric chemistry , 1997 .

[21]  R. Rengarajan,et al.  Aerosol acidity and secondary organic aerosol formation during wintertime over urban environment in western India , 2011 .

[22]  Glenn E. Shaw,et al.  Indian Ocean Experiment: An integrated analysis of the climate forcing and effects of the great Indo-Asian haze , 2001 .

[23]  J. Prospero,et al.  Particle size distribution of nitrate and sulfate in the marine atmosphere , 1982 .

[24]  P. Saxena,et al.  Water-soluble organics in atmospheric particles: A critical review of the literature and application of thermodynamics to identify candidate compounds , 1996 .

[25]  S. Fitzwater,et al.  Iron deficiency limits phytoplankton growth in the north-east Pacific subarctic , 1988, Nature.

[26]  M. Sarin,et al.  Carbonaceous aerosols in MABL of Bay of Bengal: Influence of continental outflow , 2008 .

[27]  K. Okada,et al.  Nature of coarse nitrate particles in the atmosphere—A single particle approach , 1994 .

[28]  J. Lelieveld,et al.  Role of mineral aerosol as a reactive surface in the global troposphere , 1996 .

[29]  W. Chameides,et al.  Aqueous‐phase chemical processes in deliquescent sea‐salt aerosols: A mechanism that couples the atmospheric cycles of S and sea salt , 1992 .

[30]  R. Harrison,et al.  Validation of techniques for fast response measurement of HNO3 and NH3 and determination of the [NH3][HNO3] concentration product , 1994 .

[31]  S. Bonnet,et al.  Biomass burning as a source of dissolved iron to the open ocean? , 2005 .

[32]  P. Buat-Ménard.  The role of air-sea exchange in geochemical cycling , 1986 .

[33]  T. Jickells.  The inputs of dust derived elements to the Sargasso Sea; a synthesis , 1999 .

[34]  R. Cary,et al.  Elemental Carbon-Based Method for Monitoring Occupational Exposures to Particulate Diesel Exhaust , 1996 .

[35]  John H. Seinfeld,et al.  Relative humidity and temperature dependence of the ammonium nitrate dissociation constant , 1982 .

[36]  Nalin Rastogi,et al.  Chemistry of aerosols over a semi‐arid region: Evidence for acid neutralization by mineral dust , 2006 .

[37]  Y. Tsai,et al.  PM2.5 aerosol water content and chemical composition in a metropolitan and a coastal area in southern Taiwan , 2005 .

[38]  Ashwini Kumar,et al.  Mineral aerosols from western India: Temporal variability of coarse and fine atmospheric dust and elemental characteristics , 2009 .

[39]  K. R. Arrigo,et al.  Impacts of Atmospheric Anthropogenic Nitrogen on the Open Ocean , 2008, Science.

[40]  J. Hansen,et al.  Aerosol organic carbon to black carbon ratios: Analysis of published data and implications for climate forcing , 2005 .

[41]  S. Taylor,et al.  The continental crust: Its composition and evolution , 1985 .

[42]  Roy M. Harrison,et al.  Carbonaceous aerosol in urban and rural European atmospheres: estimation of secondary organic carbon concentrations , 1999 .

[43]  R. Hillamo,et al.  Substitution of chloride in sea-salt particles by inorganic and organic anions , 1998 .

[44]  Richard Arimoto,et al.  Eolian dust and climate: relationships to sources, tropospheric chemistry, transport and deposition , 2001 .

[45]  Ashwini Kumar,et al.  Anthropogenic sulphate aerosols and large Cl-deficit in marine atmospheric boundary layer of tropical Bay of Bengal , 2010 .

[46]  N. Mahowald,et al.  Combustion iron distribution and deposition , 2007 .

[47]  A. Johansen,et al.  Chemical characterization of ambient aerosol collected during the northeast monsoon season over the Arabian Sea: Anions and cations , 2004 .

[48]  J. A. de Gouw,et al.  Airborne measurements of carbonaceous aerosol soluble in water over northeastern United States: Method development and an investigation into water-soluble organic carbon sources , 2006 .

[49]  M. Uematsu,et al.  Chemical interactions between mineral dust particles and acid gases during Asian dust events , 2005 .

[50]  J. Schauer,et al.  The origin of water soluble particulate iron in the Asian atmospheric outflow , 2005 .

[51]  S. Tripathi,et al.  A 1 year record of carbonaceous aerosols from an urban site in the Indo‐Gangetic Plain: Characterization, sources, and temporal variability , 2010 .

[52]  K. Prather,et al.  Direct observations of the atmospheric processing of Asian mineral dust , 2006 .

[53]  V. Ramanathan,et al.  Aerosols, Climate, and the Hydrological Cycle , 2001, Science.

[54]  N. Mahowald,et al.  Global Iron Connections Between Desert Dust, Ocean Biogeochemistry, and Climate , 2005, Science.

[55]  Y. Mamane,et al.  Nitrate formation on sea-salt and mineral particles—A single particle approach , 1992 .

[56]  R. Rengarajan,et al.  Aerosol NO' 3 and 210Pb distribution over the central-eastern Arabian Sea and their air-sea deposition fluxes , 1999 .

[57]  R. Duce,et al.  Atmospheric transport of iron and its deposition in the ocean , 1991 .

[58]  Barbara J. Turpin,et al.  Species Contributions to PM2.5 Mass Concentrations: Revisiting Common Assumptions for Estimating Organic Mass , 2001 .

[59]  James N. Galloway,et al.  Sea‐salt corrections and interpretation of constituent ratios in marine precipitation , 1986 .

[60]  H. D. Holland.  The chemistry of the atmosphere and oceans , 1978 .