Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 9 6 2009 10.5194/acpd-9-24511-2009 http://www.atmos-chem-phys-discuss.net/9/24511/2009/ http://www.atmos-chem-phys-discuss.net/9/24511/2009/acpd-9-24511-2009.html http://www.atmos-chem-phys-discuss.net/9/24511/2009/acpd-9-24511-2009.pdf 24511 24529 2009-11-18 Relationship between wind speed and aerosol optical depth over remote ocean H. Huang huang@atm.ox.ac.uk G. E. Thomas R. G. Grainger Atmospheric, Oceanic and Planetary Physics, University of Oxford, OX1 3PU, Oxford, UK The effect of wind speed on aerosol optical depth (AOD) at 550 nm over remote ocean regions is investigated. Remote ocean regions are defined by the combination of AOD from satellite observation and wind direction from ECMWF. According to our definition, many oceanic regions cannot be taken as remote ocean regions due to long-range transportation of aerosols from continents. Highly correlated linear relationships are found in remote ocean regions with a wind speed range of 4–20 ms^−1. The enhancement of AOD at high wind speed is explained as the increase of sea salt aerosol production. Andreas, E L.: A New Sea Spray Generation Function for Wind Speeds up to 32 m s1, J. Phys. Oceanogr., 28, 2175–2184, 1998. Clarke, A., Kapustin, V., Howell, S., and Moore, K.: Sea-Salt Size Distributions from Breaking Waves: Implications for Marine Aerosol Production and Optical Extinction Measurements during SEAS, J. Atmos. Ocean. Tech., 20, 1362–1374, 2003. Exton, H J., Latham, J., Park, P M., Perry, S J., Smith, M H., and Allan, R R.: The production and dispersion of marine aerosol, Q. J. Roy. Meteorol. Soc., 111, 817–837, 1985. Fitzgerald, J W.: Marine aerosols: a review, Atmos. Environ., 25A, 533–546, 1991. Ghan, S J., Guzman, G., and Abdul-Razzak, H.: Competition between Sea Salt and Sulfate Particles as Cloud Condensation, J. Atmos. Sci., 55, 3340–3347, 1998. Glantz, P., Nilsson, E N., and Hoyningen-Huene, W.: Estimating a relationship between aerosol optical thickness and surface wind speed over the ocean, Atmos. Res., 92, 58–68, 2009. Gras, J L. and Ayers, G P.: Marine aerosol at southern mid-latitudes, J. Geophys. Res., 88, 10661–10666, 1983. Hegg, D A.: Modelling the effects of heterogeneous cloud chemistry on the marine particle size distribution, J. Geophys. Res., 97, 12927–12933, 1992. Heintzenberg, J., Covent, D C., and Dongenen, R V.: Size distribution and chemical composition of marine aerosols: a compilation and review, Tellus~B, 52, 1104–1122, 2003. Hoppel, W A., Fitzgerald, J W., and Mack, E J.: Aerosol size distributions and optical properties found in the marine boundary layer over the Atlantic Ocean, J. Geophys. Res., 95, 3659–3686, 1990. Jennings, S G., Kleefeld, C., O'Dowd, C D., Junker, C., Spain, T G., O'Brien, P., Roddy, A F., and O'Connor, T C.: Mace Head Atmospheric Research Station Characterization of aerosol radiative parameters, Boreal Environ. Res., 8, 303–314, 2003. Latham, J. and Smith, M H.: Effect on global warming of wind-dependent aerosol generation at the ocean surface, Nature, 347, 372–373, 1990. Lohmann, U. and Feichter, J.: Global indirect aerosol effects: a review, Atmos. Chem. Phys., 5, 715–737, 2005. McDonald, R L., Unni, C K., and Duce, R A.: Estimation of atmospheric sea salt dry deposition: Wind speed and particle size dependence, J. Geophys. Res., 87(C2), 1246–1250, 1982. Moorthy, K K. and Satheesh, S K.: Characteristics of aerosols over a remote island, Minicoy in the Arabian Sea: Optical properties and retrieved size characteristics, Q. J. Roy. Meteorol. Soc., 126, 81–109, 2000. Moorthy, K K., Satheesh, S K., and Murthy, B. V K.: Investigations of marine aerosols over the tropical Indian Ocean, J. Geophys. Res., 102, 827–842, 1997. Mulcahy, J P., O'Dowd, C D., and Ceburnis, S. G. J D.: Significant enhancement of aerosol optical depth in marine air under high wind conditions, Geophys. Res. Lett., 35, L16810–L16813, 2008. Nilsson, E D., Rannik, U., and Norman, M.: Turbulent aerosol fluxes over the Arctic Ocean 2 Wind-driven sources from the sea, J. Geophys. Res., 106, 32139–32154, 2001. O'Dowd, C D. and de~Leeuw, G.: Marine aerosol production: a review of the current knowledge, Philos. T. Roy. Soc, 365, 1753–1774, 2007. O'Dowd, C D. and Smith, M H.: Physicochemical properties of aerosols over the northeast Atlantic: Evidence for wind-speed-related submicron sea-salt production, J. Geophys. Res., 98, 1137–1149, 1993. O'Dowd, C D., Smith, M H., Consterdine, I E., and Lowe, J A.: Marine aerosol, sea-salt, and the marine sulphur cycle: a short review, Atmos. Environ., 10, 1352–2310, 2001. Platt, C. M R. and Patterson, G R.: The interpretation of baseline atmospheric turbidity measurements at Cape Grim, Tasmania, J. Atmos. Chem., 4, 187–197, 1986. Sanderson, M G.: Emission of carbon monoxide by vegetation and soils, Tech rep., 1–3, 2002. Satheesha, S K. and Moorthy, K K.: Radiative effects of natural aerosols: A review, Atmos. Environ., 39, 2089–2110, 2005. Sayer, A.: Aerosol Remote Sensing Using AATSR, Ph.D thesis, University of Oxford, 2008. Singer, S F.: The Changing global environment, D Reidel Publ Co., Dordrecht-Holland/Boston-USA, 1975. Smirnov, A., Villevalde, Y., O'Neill, N T., Royer, A., and Tarussov, A.: Aerosol optical depth over the oceans: Analysis in terms of synoptic air mass types, J. Geophys. Res., 16, 639–650, 1995. Smirnov, A., Holben, B N., Dubovik, O., Frouin, R., Eck, T F., and Slutsker, I.: Maritime component in aerosol optical models derived from Aerosol Robotic Network data, J. Geophys. Res., 108(D1), 1–100, 2003. Thomas, G E., Carboni, E., Poulsen, C., Siddans, R., Grainger, D., Kerridge, B., and Gomez, C.: GlobAerosol: A 12~year global aerosol dataset from European satellite instruments, 2nd MERIS/(A)ATSR User Workshop, 2008. Villevalde, Y V., Smirnov, A V., O'Neill, N T., Smyshlyaev, S P., and Yakovlev, V V.: Measurement of aerosol optical depth in the Pacific Ocean and the North Atlantic, J. Geophys. Res., 99, 983–988, 1994.