ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-10-9369-2010 Aerosol fluxes and dynamics within and above a tropical rainforest in South-East Asia Whitehead J. D. 1 Gallagher M. W. 1 Dorsey J. R. 1 Robinson N. 1 Gabey A. M. 1 Coe H. 1 McFiggans G. 1 Flynn M. J. 1 Ryder J. 1 2 Nemitz E. 2 Davies F. 3 4 Centre for Atmospheric Science, SEAES, University of Manchester, Simon Building, Brunswick Street, Manchester M13 9PL, UK Centre for Ecology and Hydrology, Edinburgh Research Station, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK School of Environment and Life Sciences, Peel Building, University of Salford, Salford, M5 4WT, UK now at: School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK 05 10 2010 10 19 9369 9382 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/10/9369/2010/acp-10-9369-2010.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/10/9369/2010/acp-10-9369-2010.pdf

Atmospheric aerosol measurements were conducted near Danum Valley, in the Malaysian state of Sabah, North-East Borneo, as part of the OP3 and ACES projects, in April and June/July 2008. Here, aerosol fluxes and diurnal variability in and above the rainforest canopy were examined in order to gain an understanding of their behaviour in the surface layer of the South-East Asian rainforest. Aerosol fluxes were calculated by eddy covariance from measurements above the rainforest canopy on the Global Atmosphere Watch (GAW) tower. Upward fluxes were seen on most mornings between 09:00 and 11:00 local time and this could be attributed to venting of the nocturnal boundary layer as it broke up in the morning. Measurements were also conducted within the canopy and trunk space at a nearby site. Profiles in aerosol number concentrations were investigated using GRIMM Optical Particle Counters (OPCs) at various levels within the rainforest canopy and trunk space, as well as a single OPC on a vertically moving platform. These showed an overnight increase in larger particles (1–20 μm) at all levels, but much more prominently near the top of the canopy, which could be attributed to fog formation. At ground level, number concentrations in this size range correlated with enhancements in biological aerosol concentrations, measured using a Wide Issue Bioaerosol Spectrometer (WIBS) located near the forest floor, suggesting that coarse particle number concentrations were dominated by biological aerosols. A comparison of particle number concentrations (in the size range 0.5–1.0 μm) between above canopy and the trunk space showed correlations, despite turbulence data suggesting persistent decoupling between the two measurement sites. These correlations often relied on a shift of the particle time-series against each other, implying a time delay in observations between the sites, which varied according to time of day. This lag time was shortest during the middle of the day by a significant margin. This was not observed for aerosols larger than 1.0 μm. Further evidence of daytime coupling between above canopy and the trunk space in terms of aerosol measurements is implied by comparison of measurements from an Aerosol Mass Spectrometer (AMS) at the GAW tower and simultaneous bag sampling at the in-canopy site, subsequently analysed with the AMS. Transport of particles through the canopy seems to occur through large-scale, sporadic turbulent events, suggesting that the coupling between the canopy space and the air above is due to these ventilation events.

 References Ahlm, L., Nilsson, E. D., Krejci, R., Mårtensson, E. M., Vogt, M., and Artaxo, P.: Aerosol number fluxes over the Amazon rain forest during the wet season, Atmos. Chem. Phys., 9, 9381–9400, doi:10.5194/acp-9-9381-2009, 2009. Allen Jr., L. H.,, Lemon, E., and Müller, L.: Environment of a Costa Rican forest, Ecology, 53, 102–111, 1972. Andreae, M. O., Artaxo, P., Brandão, C., Carswell, F. E., Ciccioli, P., da Costa, A. L., Culf, A. D., Esteves, J. L., Gash, J. H. C., Grace, J., Kabat, P., Lelieveld, J., Malhi, Y., Manzi, A. O., Meixner, F. X., Nobre, A. D., Nobre, C., Ruivo, M. d. L. P., Silva-Dias, M. A., Stefani, P., Valentini, R., von Jouanne, J., and Waterloo, M. J.: Biogeochemical cycling of carbon, water, energy, trace gases, and aerosols in Amazonia: The LBA-EUSTACH experiments, J. Geophys. Res., 107, 8066, doi:8010.1029/2001JD000524, 2002. Artaxo, P., Maenhaut, W., Storms, H., and Grieken, R. V.: Aerosol characteristics and sources for the Amazon Basin during the wet season, J. Geophys. Res., 95, 16971–16985, 1990. Artaxo, P., Gerab, F., Yamasoe, M. A., and Martins, J. V.: Fine mode aerosol composition at three long-term atmospheric monitoring sites in the Amazon Basin, J. Geophys. Res., 99, 22857–22868, 1994. Artaxo, P., Martins, J. V., Yamasoe, M. A., Procópio, A. S., Pauliquevis, T. M., Andreae, M. O., Guyon, P., Gatti, L. V., and Leal, A. M. C.: Physical and chemical properties of aerosols in the wet and dry seasons in Rhondônia, Amazonia, J. Geophys. Res., 107, 8081, doi:8010.1029/2001JD000666, 2002. Brockman, J. E.: Sampling and transport of aerosols, in: Aerosol measurement - Principles, techniques, and applications (2nd edition), edited by: Baron, P. A. and Willeke, K., John Wiley & Sons, New York, 2001. DeCarlo, P. F., Kimmel, J. R., Trimborn, A., Northway, M. J., Jayne, J. T., Aiken, A. C., Gonin, M., Fuhrer, K., Horvath, T., Docherty, K. S., Worsnop, D. R., and Jimenez, J. L.: Field-deployable, high resolution, time-of-flight aerosol mass spectrometer, Anal. Chem., 78, 8281–8289, 2006. Farmer, D. K., Kimmel, J. R., Nemitz, E., Phillips, G., Docherty, K., Chen, Q., Martin, S., Cubison, M., and Jimenez, J.: A new approach to chemically-speciated submicron aerosol fluxes over tropical and temperate forests, American Geophysical Union, Fall Meeting 2008, San Francisco, USA, 15–19 December 2008, abstract A51H-0204, 2008. Finnigan, J.: Turbulence in plant canopies, Annu. Rev. Fluid Mech., 32, 519–571, 2000. Fitzjarrald, D. R. and Moore, K. E.: Mechanisms of nocturnal exchange between the rain forest and the atmosphere, J. Geophys. Res., 95, 16839–16850, 1990. Fitzjarrald, D. R., Moore, K. E., Cabral, O. M. R., Scolar, J., Manzi, A. O., and de Abreu, L. D., Sá: Daytime turbulent exchange between the Amazon forest and the atmosphere, J. Geophys. Res., 95, 16825–16838, 1990. Foken, T. and Wichura, B.: Tools for quality assessment of surface-based flux measurements, Agr. Forest Meteorol., 79, 83–105, 1996. Foken, T.: Micrometeorology, Springer-Verlag, Berlin, 306~pp., 2006. Foot, V. E., Kaye, P. H., Stanley, W. R., Barrington, S. J., Gallagher, M., and Gabey, A.: Low-cost real-time multiparameter bio-aerosol sensors, Proc. SPIE, 7116, 71160I, doi:10.1117/12.800226, 2008. Fowler, D., Cape, J. N., and Unsworth, M. H.: Deposition of atmospheric pollutants on forests, Philos. T. Roy. Soc. London B, 324, 247–265, 1989. Gabey, A. M., Gallagher, M. W., Whitehead, J., Dorsey, J. R., Kaye, P. H., and Stanley, W. R.: Measurements and comparison of primary biological aerosol above and below a tropical forest canopy using a dual channel fluorescence spectrometer, Atmos. Chem. Phys., 10, 4453–4466, doi:10.5194/acp-10-4453-2010, 2010. Gao, W., Shaw, R. H., and Paw U, K. T.: Observation of organized structure in turbulent flow within and above a forest canopy, Bound.-Lay. Meteorol., 47, 349–377, 1989. Garland, J. A.: The dry deposition of sulphur dioxide to land and water surfaces, Proc. Roy. Soc. Lond. A, 354, 245–268, 1977. Gerber, H.: Direct measurement of suspended particulate volume concentration and far-infrared extinction coefficient with a laser-diffraction instrument, Appl. Optics, 30, 4824–4831, 1991. Guyon, P., Graham, B., Roberts, G. C., Mayol-Bracero, O. L., Maenhaut, W., Artaxo, P., and Andreae, M. O.: In-canopy gradients, composition, sources, and optical properties of aerosol over the Amazon forest, J. Geophys. Res., 108, 4591, doi:4510.1029/2003JD003465, 2003. Heim, M., Kasper, G., Reischl, G. P., and Gerhart, C.: Performance of a New Commercial Electrical Mobility Spectrometer, Aerosol Sci. Tech., 38(S2), 3–14, 2004. Hewitt, C. N., Lee, J. D., MacKenzie, A. R., Barkley, M. P., Carslaw, N., Carver, G. D., Chappell, N. A., Coe, H., Collier, C., Commane, R., Davies, F., Davison, B., DiCarlo, P., Di Marco, C. F., Dorsey, J. R., Edwards, P. M., Evans, M. J., Fowler, D., Furneaux, K. L., Gallagher, M., Guenther, A., Heard, D. E., Helfter, C., Hopkins, J., Ingham, T., Irwin, M., Jones, C., Karunaharan, A., Langford, B., Lewis, A. C., Lim, S. F., MacDonald, S. M., Mahajan, A. S., Malpass, S., McFiggans, G., Mills, G., Misztal, P., Moller, S., Monks, P. S., Nemitz, E., Nicolas-Perea, V., Oetjen, H., Oram, D. E., Palmer, P. I., Phillips, G. J., Pike, R., Plane, J. M. C., Pugh, T., Pyle, J. A., Reeves, C. E., Robinson, N. H., Stewart, D., Stone, D., Whalley, L. K., and Yin, X.: Overview: oxidant and particle photochemical processes above a south-east Asian tropical rainforest (the OP3 project): introduction, rationale, location characteristics and tools, Atmos. Chem. Phys., 10, 169–199, doi:10.5194/acp-10-169-2010, 2010. Helfter, C., Phillips, G. J., Coyle, M., Di Marco, C. F., Langford, B., Whitehead, J., Dorsey, J. R., Gallagher, M. W., Sei, E. Y., Fowler, D., and Nemitz, E.: Momentum and heat exchange above South East Asian rainforest in complex terrain, Atmos. Chem. Phys. Discuss., in preparation, 2010. Horst, T. W.: A simple formula for attenuation of eddy fluxes measured with first-order-response scalar sensors, Bound.-Lay. Meteorol., 82, 219–233, 1997. Intergovernmanetal Panel on Climate Change (IPCC): Climate change 2007: The fourth assessment report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge, 2007. Järvi, L., Rannik, Ü., Mammarella, I., Sogachev, A., Aalto, P. P., Keronen, P., Siivola, E., Kulmala, M., and Vesala, T.: Annual particle flux observations over a heterogeneous urban area, Atmos. Chem. Phys., 9, 7847–7856, doi:10.5194/acp-9-7847-2009, 2009. Kaimal, J. C., Wyngaard, J. C., Izumi, Y., and Coté, O. R.: Spectral characteristics of surface-layer turbulence., Q. J. Roy. Meteorol. Soc., 98, 563–589, 1972. Kavouras, I. G., Mihalopoulas, N., and Stephanou, E. G.: Formation of atmospheric particles from organic acids produced by forests, Nature, 395, 683–686, 1998. Kaye, P. H., Stanley, W. R., Hirst, E., Foot, E. V., Baxter, K. L., and Barrington, S. J.: Single particle multichannel bio-aerosol fluorescence sensor, Optics Express, 13, 3583–3593, 2005. Kruijt, B., Malhi, Y., Lloyd, J., Nobre, A. D., Miranda, A. C., Pereira, M. G. P., Culf, A., and Grace, J.: Turbulence statistics above and within two Amazon rain forest canopies, Bound.-Lay. Meteorol., 94, 297–331, 2000. Kulmala, M., Toivonen, A., Mäkelä, J. M., and Laaksonen, A.: Analysis of the growth of nucleation mode particles observed in Boreal forest, Tellus, 50B, 449–462, 1998. Langford, B., Misztal, P. K., Nemitz, E., Davison, B., Helfter, C., Pugh, T. A. M., MacKenzie, A. R., Lim, S. F., and Hewitt, C. N.: Fluxes and concentrations of volatile organic compounds from a South-East Asian tropical rainforest, Atmos. Chem. Phys., 10, 8391–8412, doi:10.5194/acp-10-8391-2010, 2010. Liu, W., Meng, F. R., Zhang, Y., Liu, Y., and Li, H.: Water input from fog drip in the tropical seasonal rain forest of Xishuangbanna, South-West China, J. Trop. Ecol., 20, 517–524, 2004. McMillen, R. T.: An eddy correlation technique with extended applicability to non-simple terrain, Bound.-Lay. Meteorol., 43, 231–245, 1988. Mertes, S., Shröder, F., and Wiedensohler, A.: The particle detection efficiency curve of the TSI-3010 CPC as a function of the temperature difference between saturator and condenser, Aerosol Sci. Tech., 23, 257–261, 1995. Muller, J. B. A., Coyle, M., Helfter, C., Dorsey, J. R., Gallagher, M. W., Nemitz, E., and Fowler, D.: Ozone fluxes over South-East Asian tropical rainforest and oil palm plantation, Atmos. Chem. Phys. Discuss., in preparation, 2010. Newbery, D. M., Kennedy, D. N., Petol, G. H., Madani, L., and Ridsdale, C. E.: Primary forest dynamics in lowland dipterocarp forest at Danium Valley, Sabah, Malaysia, and the role of the understorey, Philos. T. Roy. Soc. London B, 354, 1763–1782, 1999. Paulson, C. A.: The mathematical representation of wind speed and temperature profiles in the unstable atmospheric surface layer, J. Appl. Meteorol., 9, 857–861, 1970. Pearson, G., Davies, F., and Collier, C.: An analysis of the performance of the UFAM pulsed doppler lidar for observing the boundary layer, J. Atmos. Ocean. Tech., 26, 240–250, 2009. Pearson, G., Davies, F., and Collier, C.: Remote sensing of the tropical rain forest boundary layer using pulsed Doppler lidar, Atmos. Chem. Phys., 10, 5891–5901, doi:10.5194/acp-10-5891-2010, 2010. Phillips, G. J., Di Marco, C. F., Farmer, D., Kimmel, J., Sueper, D., Jimenez, J. L., and Nemitz, E.: Fluxes of sub-micron aerosol chemical components above South East Asian rainforest, Atmos. Chem. Phys. Discuss., in preparation, 2010. Pinker, R. T. and Holland, J. Z.: Turbulence structure of a tropical forest, Bound.-Lay. Meteorol., 43, 43–63, 1988. Prenni, A. J., Petters, M. D., Kreidenweis, S. M., Heald, C. L., Martin, S. T., Artaxo, P., Garland, R. M., Wollny, A. G., and Pöschl, U.: Relative roles of biogenic emissions and Saharan dust as ice nuclei in the Amazon basin, Nature Geosci., 2, 402–405, 2009. Pryor, S. C., Gallagher, M. W., Sievering, H., Larsen, S. E., Barthelmie, R. J., Birsan, F., Nemitz, E., Rinne, J., Kulmala, M., Grönholm, T., Taipale, R., and Vesala, T.: A review of measurement and modelling results of particle atmosphere-surface exchange, Tellus, 60B, 42–75, 2008. Quant, F. R., Caldow, R., Sem, G. J., and Addison, T. J.: Performance of Condensation Particle Counters with Three Continuous-Flow Designs, J. Aerosol Sci., 23, S405–S408, 1992. Rissler, J., Vestin, A., Swietlicki, E., Fisch, G., Zhou, J., Artaxo, P., and Andreae, M. O.: Size distribution and hygroscopic properties of aerosol particles from dry-season biomass burning in Amazonia, Atmos. Chem. Phys., 6, 471–491, doi:10.5194/acp-6-471-2006, 2006. Rummel, U., Ammann, C., and Meixner, F. X.: Characterizing turbulent trace gas exchange above a dense tropical rain forest using wavelet and surface renewal analysis, 15th AMS Symposium on Boundary Layers and Turbulence, Boston, Mass., 602–605, 2002. Ryder, J., Langford, B., Oram, D., Coyle, M., Phillips, G. J., Helfter, C., Misztal, P., Cape, J. N., and Nemitz, E.: Sources and sinks of biogenic volatile organic compounds inside a South-East Asian rainforest canopy, Atmos. Chem. Phys. Discuss., in preparation, 2010. Vickers, D. and Mahrt, L.: Quality control and flux sampling problems for tower and aircraft data, J. Atmos. Ocean. Tech., 14, 512–526, 1997. Whitehead, J. D., McFiggans, G., Gallagher, M. W., and Flynn, M. J.: Simultaneous coastal measurements of ozone deposition fluxes and iodine-mediated particle emission fluxes with subsequent CCN formation, Atmos. Chem. Phys., 10, 255–266, doi:10.5194/acp-10-255-2010, 2010. Williams, P., Gallagher, M., Choularton, T., Coe, H., Bower, K., and McFiggans, G.: Aerosol development and interaction in an urban plume, Aerosol Sci. Tech., 32, 120-126, 2000. Zhou, J., Swietlicki, E., Hansson, H.-C., and Artaxo, P.: Submicrometer aerosol particle size distribution and hygroscopic growth measured in the Amazon rain forest during the wet season, J. Geophys. Res., 107, 8055, doi:8010.1029/2000JD000203, 2002.