Journal of Earth System Science

, Volume 117, Supplement 1, pp 315–323 | Cite as

Size segregated aerosol mass concentration measurements over the Arabian Sea during ICARB

  • Vijayakumar S. Nair
  • K. Krishna Moorthy
  • S. Suresh Babu
  • K. Narasimhulu
  • L. Siva Sankara Reddy
  • R. Ramakrishna Reddy
  • K. Rama Gopal
  • V. Sreekanth
  • B. L. Madhavan
  • K. Niranjan
Article

Abstract

Mass concentration and mass size distribution of total (composite) aerosols near the surface are essential inputs needed in developing aerosol models for radiative forcing estimation as well as to infer the environment and air quality. Using extensive measurements onboard the oceanographic research vessel, Sagar Kanya, during its cruise SK223B in the second phase of the ocean segment of the Integrated Campaign for Aerosols, gases and Radiation Budget (ICARB), the spatial distribution of the mass concentration and mass size distribution of near-surface aerosols are examined for the first time over the entire Arabian Sea, going as far as 58°E and 22°N, within a span of 26 days. In general, the mass concentrations (MT ) were found to be low with the mean value for the entire Arabian Sea being 16.7 ± 7 μg m−3; almost 1/2 of the values reported in some of the earlier campaigns. Coarse mode aerosols contributed, on an average, 58% to the total mass, even though at a few pockets accumulation mode contribution dominated. Spatially, significant variations were observed over central and northern Arabian Sea as well as close to the west coast of India. In central Arabian Sea, even though the MT was quite low, contribution ofs accumulation aerosols to the total mass concentration was greater than 50%. Effective radius, a parameter important in determining scattering properties of aerosol size distribution, varied between 0.07 and 0.4 μm with a mean value of 0.2 μm. Number size distributions, deduced from the mass size distributions, were approximated to inverse power-law form and the size indices (ν) were estimated. It was found to vary in the range 3.9 to 4.2 with a mean value of 4.0 for the entire oceanic region. Extinction coefficients, estimated using the number-size distributions, were well-correlated with the accumulation mode mass concentration with a correlation coefficient of 0.82.

Keywords

Aerosol mass concentration Arabian Sea ICARB 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Ball W P, Dickerson R R, Doddridge B G, Stehr J W, Miller T L, Savoie D L and Carsey T P 2003 sBulk and size-segregated aerosol composition observed during INDOEX 1999: Overview of meteorology and continental impacts; J. Geophys. Res. 108 8001, doi:10.1029/2002JD002467.CrossRefGoogle Scholar
  2. Charlson R J, Schwartz S E, Hales J M, Cess R D, Coakley J A, Hansen J E and Hoffman D J 1992 Climate forcing by anthropogenic aerosols; Science 255 423–430.CrossRefGoogle Scholar
  3. Hess M, Koepke P and Schult I 1998 Optical properties of aerosols and clouds: The software package OPAC; Bull. Am. Meteorol. Soc. 79 831–844.CrossRefGoogle Scholar
  4. Hoell C, O’dowd C, Osborne S and Johnson D 2000 Time scale analysis of marine aerosol evolution: Lagrangian case studies under clean and polluted cloudy condition; Tellus 52 423–438.CrossRefGoogle Scholar
  5. Hoppel W A, Frick G M and Fitzgerald J W 2002 Surface source function for sea-salt and aerosol dry deposition on the ocean surface; J. Geophys. Res. 107 4382, doi:10.1029/2001JD002014.CrossRefGoogle Scholar
  6. IPCC 2007 Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (Cambridge, United Kingdom and New York: Cambridge University Press).Google Scholar
  7. Kamra A K, Murugavel P, Pawar S D and Gopalakrishnan V 2001 Background aerosol concentration derived from the atmospheric electric conductivity measurements made over the Indian ocean during INDOEX; J. Geophys. Res. 106 28,643–28,651.CrossRefGoogle Scholar
  8. Lubin D, Satheesh S K, Macfarquar G and Heymsfield A 2002 The longwave radiative forcing of Indian Ocean trophospheric aerosol; J. Geophys. Res. 107 doi:10.1029/2001JD001183.Google Scholar
  9. Mc Cartney E J 1976 Optics of the Atmosphere (New York: John Wiley) 135–136.Google Scholar
  10. Moorthy K K and Saha A 2000 Aerosol study during INDOEX: Observation of enhanced aerosol activity over the mid Arabian Sea during the northern winter; J. Atmos. Sol. Terr. Phys. 62 65–72.CrossRefGoogle Scholar
  11. Moorthy K K, Saha A, Prasad B S N, Niranjan K, Jhurry D and Pillai P S 2001 Aerosol optical depth over peninsular India and adjoining oceans during INDOEX campaigns: Spatial, temporal, and spectral characteristics, J. Geophys. Res. 106 28,539–28,554.CrossRefGoogle Scholar
  12. Moorthy K K, Babu S S and Satheesh S K 2005a Aerosol characteristics and radiative impacts over the Arabian Sea during the intermonsoon season: Results from ARMEX Field Campaign; J. Atmos. Sci. 62 192–206.CrossRefGoogle Scholar
  13. Moorthy K K et al 2005b Wintertime spatial characteristics of boundary layer aerosols over peninsular India; J. Geophys. Res. 110 D08207, doi:10.1029/2004JD005520.CrossRefGoogle Scholar
  14. Moorthy K K, Satheesh S K, Babu S S and Saha A 2005c Large latitudinal gradients and temporal heterogeneity in aerosol black carbon and its mass mixing ratio over southern and northern oceans during a transcontinental cruise experiment; Geophys. Res. Lett. 32 14818, doi:10.1029/2005GL023267.CrossRefGoogle Scholar
  15. Moorthy K K, Satheesh S K and Babu S S 2006 ICARB-An integrated Campaign for Aerosols, gases and Radiation Budget; Proc. of SPIE, 6408 64080P, 0277-786X/06/$15, doi: 10.1117/12.696110.CrossRefGoogle Scholar
  16. Nair P R, Parameswaran K, Abraham A and Jacob S 2005 Wind-dependence of sea-salt and non-sea-salt aerosols over the oceanic environment; J. Atmos. Solar. Terres. Phys. 67 884–898.CrossRefGoogle Scholar
  17. Novakov T, Andreae M O, Gabriel R, Kirchstetter T W, Mayol-Bracero O L and Ramanathan V 2000 Origin of carbonaceous aerosols over the tropical Indian Ocean: Boimass burning or fossil fuels?; Geophys. Res. Lett. 27(24) 4061–4064.CrossRefGoogle Scholar
  18. O’Dowd C D and Smith M H 1993 Physio chemical properties of aerosols over the northeast Atlantic: Evidence for wind speed related sub micron sea-salt aerosol production; J. Geophys. Res. 98 1137–1149.CrossRefGoogle Scholar
  19. O’Dowd C D, Smith M H, Consterdine I E and Lowe J A 1997 Marine aerosol, sea-salt, and the marine sulphur cycle: A short review, Atmos. Environ. 31 73–80.CrossRefGoogle Scholar
  20. Parameswaran K, Nair P R, Rajan R and Ramana M V 1999 Aerosol loading in coastal and marine environments in the Indian Ocean region during winter season; Curr. Sci. 76 947–955.Google Scholar
  21. Pillai P S and Moorthy K K 2001 Aerosol mass-size distributions at a tropical coastal environment: Response to mesoscale and synoptic scale processes; Atmos. Environ. 35 4099–4122.CrossRefGoogle Scholar
  22. Prospero J M 1979 Mineral and sea salt aerosol concentrations in various ocean regions; J. Geophys. Res. 84 725–731.CrossRefGoogle Scholar
  23. Quinn P K, Coffman D J, Bates T S, Miller T L, Johnson J E, Welton E J, Neusüss C, Miller M and Sheridan P J 2002 Aerosol optical properties during INDOEX 1999: Means, variability, and controlling factors; J. Geophys. Res. 107(D19) 8020, doi:10.1029/2000JD000037.CrossRefGoogle Scholar
  24. Ramachandran S and Jayaraman A 2002 Premonsoon aerosol loading and size distribution over the Arabian Sea and the Tropical Indian Ocean; J. Geophys. Res. 107 4738, doi:10.1029/2002JD002386.CrossRefGoogle Scholar
  25. Ramanathan V et al 2001 Indian Ocean Experiment: An integrated analysis of the climate and the great Indo-Asian haze: J. Geophys. Res. 106 28,371–28,398.CrossRefGoogle Scholar
  26. Sakerin S M and Kabanov D M 2002 Spatial inhomogeneities and the spectral behavior of atmospheric aerosol optical depth over the Atlantic Ocean; J. Atmos. Sci. 59 484–450.CrossRefGoogle Scholar
  27. Satheesh S K and Moorthy K K 1997 Aerosol characteristics over coastal regions of the Arabian Sea; Tellus 49B 417–428.Google Scholar
  28. Satheesh S K and Srinivasan J 2002 Enhanced aerosol loading over Arabian Sea during the pre-monsoon season: Natural or anthropogenic?; Geophys. Res. Lett. 29 18, doi:10.1029/2002GL015687.Google Scholar
  29. Smirnov A, Villevalde Y, O’Neill N T, Royer A and Tarussov A 1995 Aerosol optical depth over the oceans: Analysis in terms of synoptic airmass types; J. Geophys. Res. 100(D8) 16,639–16,650.CrossRefGoogle Scholar
  30. Tegen I, Lacis A A and Fung I 1996 The influence on climate forcing of mineral aerosols from disturbed soil; Nature 380 419–422.CrossRefGoogle Scholar
  31. Twomey S A 1977 The influence of pollution on the shortwave albedo of clouds; J. Atmos. Sci. 34 1149–1152.CrossRefGoogle Scholar
  32. Vinoj V and Satheesh S K 2003 Measurements of aerosol optical depth over Arabian Sea during summer monsoon season; Geophys. Res. Lett. 30 doi:10.1029/2002GL016664.Google Scholar
  33. Zhang L, Gong S, Padro J and Barrie L 2001 A sizesegregated particle dry deposition scheme for an atmospheric aerosol module; Atmos. Environ. 35 549–560.CrossRefGoogle Scholar

Copyright information

© Indian Academy of Sciences 2008

Authors and Affiliations

  • Vijayakumar S. Nair
    • 1
  • K. Krishna Moorthy
    • 1
  • S. Suresh Babu
    • 1
  • K. Narasimhulu
    • 2
  • L. Siva Sankara Reddy
    • 2
  • R. Ramakrishna Reddy
    • 1
  • K. Rama Gopal
    • 2
  • V. Sreekanth
    • 3
  • B. L. Madhavan
    • 3
  • K. Niranjan
    • 3
  1. 1.Space Physics LaboratoryVikram Sarabhai Space CentreTrivandrumIndia
  2. 2.Department of PhysicsSri Krishnadevaraya UniversityAnantapurIndia
  3. 3.Department of PhysicsAndhra UniversityVisakhapatnamIndia

Personalised recommendations