Atmospheric Chemistry and Physics Discussions
www.atmos-chem-phys-discuss.net
1680-7367
1680-7375
9
1
2009
10.5194/acpd-9-2967-2009
http://www.atmos-chem-phys-discuss.net/9/2967/2009/
http://www.atmos-chem-phys-discuss.net/9/2967/2009/acpd-9-2967-2009.html
http://www.atmos-chem-phys-discuss.net/9/2967/2009/acpd-9-2967-2009.pdf
2967
3006
2009-01-29
Impact of dust aerosols on the radiative budget, surface heat fluxes, heating rate profiles and convective activity over West Africa during March 2006
M. Mallet
malm@aero.obs-mip.fr
P. Tulet
D. Serça
F. Solmon
O. Dubovik
J. Pelon
V. Pont
O. Thouron
Université de Toulouse, UPS, LA (Laboratoire d'Aérologie), 14 avenue Edouard Belin, 31400 Toulouse, France
CNRS, LA (Laboratoire d'Aérologie), 31400 Toulouse, France
GAME/CNRM, METEO-FRANCE – CNRS, Toulouse, France
Laboratoire d'Optique de l'Atmosphère, Université des Sciences et Technologies de Lille, CNRS, Villeneuve d'Ascq, France
Service d'Aéronomie, Institut Pierre Simon Laplace, Paris, France
The present work analyzes the effect of dust aerosols on the surface
and top of atmosphere radiative budget, surface temperature, sensible
heat fluxes, atmospheric heating rate and convective activity over
West Africa. The study is focused on the regional impact of a major
dust event over the period of 9–13 March. Numerical simulations have
been performed with the MesoNH model in which full interactions
between radiation and dynamics are introduced, through various
components representing size-resolved aerosol and cloud microphysics,
radiative properties of particles and clouds, dynamics, and a surface
model. Due to its importance on radiative budgets, a specific
attention has been paid to the representation of dust SSA in MesoNH by
using AERONET inversions. The radiative impacts are estimated using
two parallel simulations, one including radiative effects of dust and
the other without them. The simulations of dust aerosol impacts on the
radiative budget indicate remarkable instantaneous decrease of
shortwave (SW) radiations, with regional (09°–17° N,
10° W–20° E) mean of −160 W/m<sup>2</sup> during
the 9 to 13 March period. The surface dimming resulting from the
presence of dust is shown to cause important reduction of both surface
temperature (up to 4°C over regions where high AODs occur) and
sensible heat fluxes (up to 100 W/m<sup>2</sup>), which is consistent
with experimental observations performed over the same region. At the
top of the atmosphere, the SW cooling (regional mean of −13.5 W/m<sup>2</sup>) induced by mineral dust, although moderated by
the longwave (LW) warming (regional mean of +5 W/m<sup>2</sup>),
dominates the total net (shortwave + longwave)
effect. The maximum SW heating occurs within the dusty layer with
values comprised between 4 and 7°K by day and LW effect
results in strong cooling (−6 to −16°K by day)
below the dust layer. Finally, the simulations suggest the decrease of
the convective available potential energy (CAPE) over the region in
the presence of mineral dust.
Abel, S. J., Highwood, E. J., Haywood, J. M., and Stringer, M. A.: The direct radiative effect of biomass burning aerosols over southern Africa, Atmos. Chem. Phys., 5, 1999–2018, 2005.
Affre,~C., Lopez,~A., Carrara,~A., Druilhet,~A., and Fontan,~J.: The analysis of energy and ozone flux data from the LANDES 94 experiment, Atmos. Environ., 34, 803–821, 2000.
Beverland,~I J., Moncrieff,~J B., Ónéill,~C., Hargreaves,~K J., and Milne,~R.: Measurement of methane and carbon dioxide fluxes from peatland ecosystems by the conditional-sampling technique, Q. J. R. Meteorol. Soc., 122, 819–838, 1996.
Derimian, Y., Leon, J.-F., Dubovik, O., et al.: Radiative properties of aerosol mixture observed during the dry season 2006 over M'Bour, Senegal (African Monsoon Multidisciplinary Analysis campaign),~J. Geophys. Res., 113, D00C09, doi:10.1029/2008JD009904, 2008.
Dubovik,~O. and King,~M D.: A~flexible inversion algorithm for retrieval of aerosol optical properties from Sun and sky radiance measurements,~J. Geophys. Res., 105, 20 673–20 696, 2000.
Dubovik,~O., Holben,~B N., Eck,~T F., Smirnov,~A., Kaufman,~Y J., King,~M D., Tanré,~D., and~I. Slutsker,~I.: Variability of absorption and optical properties of key aerosol types observed in worldwide locations,~J. Atmos. Sci., 59, 590–608, 2002.
Dufresne,~J L., Gautier,~C., Ricchiazzi,~P., and Fouquart,~Y.: Longwave scattering effects of mineral aerosols,~J. Atmos. Sci., 59, 1959–1966, 2002.
Fan,~J., Zhang,~R., Tao,~W.-K., and Mohr,~K I.: Effects of aerosol optical properties on deep convective clouds and radiative forcing,~J. Geophys. Res., 113, D08209, doi:10.1029/2007JD009257, 2008.
Feingold,~G., Jiang,~H., and Harrington,~Y.: On smoke suppression of clouds in Amazonia, Geophys. Res. Lett., 32, L02804, doi:10.1029/2004GL021369, 2005.
Foken,~T. and Wichura~B.: Tools for quality assessment of surface-based flux measurements, Agric. For. Meteor. 1996, 78, 83–105, 1996.
Fouquart,~Y. and Bonnel,~B.: Computation of solar heating of the Earth's atmosphere: A~new parametrization, Cont. Atmos. Phys., 53(1), 35–62, 1980.
Fraser,~R S. and Kaufman,~Y.: The relative importance of scattering and absorption in remote Sensing, IEEE Transactions on Geoscience and Remote Sensing, 23, 625–633, 1985.
Grini,~A., Tulet,~P., and Gomes,~L.: Dusty weather forecasts using the MesoNH mesoscale atmospheric model,~J. Geophys. Res., 111, D19205, doi:10.1029/2005JD007007, 2006.
Haywood,~J M. and Shine,~K P.: The effect of anthropogenic sulphate and soot on the clear-sky planetary radiation budget, Geophys. Res. Lett., 22, 603–606, 1995.
Haywood,~J M. and Boucher,~O.: Estimates of the direct and indirect radiative forcing due to tropospheric aerosols: a~review, Rev. Geophys., 38(4), 513–543, 2000.
Haywood,~J M. et al.: Radiative properties and direct radiative effect of Saharan dust measured by the C-130 aircraft during SHADE~: 1. Solar spectrum,~J. Geophys. Res., 108(D18), 8577, doi:10.1029/2002JD002687, 2003.
Haywood,~J M., Allan,~R P., Culverwell,~I., Slingo,~T., Milton,~S., Edwards,~J., and Clerbaux,~N.: Can desert dust explain the outgoing longwave radiation anomaly over the Sahara during July 2003?,~J. Geophys. Res., 110, D05105, doi:10.1029/2004JD005232, 2005.
Haywood,~J M., Pelon, J., Formenti, P., et al.: Overview of the dust and Biomass Burning Experiment and African Monsoon Multidisciplinary Analysis Special Observing Period-0, J. Geophys. Res., 113, D00C17, doi:10.1029/2008JD010077, 2008.
Helmert,~J., Heinold,~B., Tegen,~I., Hellmuth,~O., and Wendisch,~M.: On the direct and semidirect effects of Saharan dust over Europe: A~modeling study,~J. Geophys. Res., 112, D13208, doi:10.1029/2006JD007444, 2007.
Hess,~M., Koepke,~P., and~I. Schult,~I.: Optical properties of aerosols and clouds: The software package, Bull. Am. Meteorol. Soc., 79, 831–844, 1998.
Huebert,~B J., Bates,~T., Russell,~P B., Shi,~G., Kim,~Y J., Kawamura,~K., Carmichael,~G., and Nakajima,~T.: An overview of Ace-Asia: Strategies for quantifying the relationships between Asian aerosols and their climatic impacts,~J. Geophys. Res., 108(D23), 8633, doi:10.1029/2003JD003550, 2003.
Jiang,~H. and Feingold,~G.: Effect of aerosol on warm convective clouds: Aerosol-cloud-surface flux feedbacks in a~new coupled large eddy model,~J. Geophys. Res., 111, D01202, doi:10.1029/2005JD006138, 2006.
Kim S.-W., Yoon, S.-C., Jefferson, A., Won, J.-G., Dutton, E. G., Ogren, J. A., and Anderson, T. L.: Observation of enhanced water vapor in Asian dust layer and its effect on atmospheric radiative heating rates, Geophys. Res. Lett., 31, L18113, doi:10.1029/2004GL020024, 2004.
Lafore,~J P., Stein,~J., Asencio,~N., Bougeault,~P., Ducrocq,~V., Duron,~J., Fischer,~C., Héreil,~P., Mascart,~P., Masson,~V., Pinty,~J P., Redelsperger,~J L., Richard,~E., and Vilà-Guerau de Arellano,~J.: The Meso-NH Atmospheric Simulation System. Part I: adiabatic formulation and control simulations, Ann. Geophys., 16, 90–109, 1998.
Koepke,~P., Hess,~M., Schult,~I., and Shettle,~E P.: Global Aerosol Data Set. MPI Meteorologie Hamburg Report No. 243, p 44, 1997.
Lelieveld, J., Berresheim, H., Borrmann, S., et al.:: Global Air Pollution Crossroads over the Mediterranean, Science, 298, 794, 2002.
Lio,~H. and Seinfeld,~J H.: Radiative forcing by mineral dust aerosols: sensitivity to key variables,~J. Geophys. Res., 103(D24), 31637–31645, 1998.
Mallet, M., Pont, V., Liousse, C., et al.: Aerosol direct radiative forcing over Djougou (Northern Benin) during the African Monsoon Multidisciplinary Analysis dry season experiment (Special Observation Period-0),~J. Geophys. Res., 113, D00C01, doi:10.1029/2007JD009419, 2008.
Mann,~J. and Lenschow,~D H.: Errors in airborne flux measurements J. Geophys. Res., 99, 519–526, 1994.
Marticorena,~B., Bergametti,~G., Aumont,~B., Callot,~Y.,~C. N'Doumé and Legrand,~M.: Modeling the atmospheric dust cycle: 2-Simulation of Saharan sources,~J. Geophys. Res., 102, 4387–4404, 1997.
McConnell,~C L. et al.: Seasonal variations of the physical and optical characteristics of Saharan dust: results from the Dust Outflow and Deposition to the Ocean (DODO) Experiment,~J. Geophys. Res., 113, D14S05, doi:10.1029/2007JD009606, 2008.
Milton,~S F G., Greed,~G., Brooks,~M E., Haywood,~J., Johnson,~B., Allan,~R P., Slingo,~A., and Grey,~M F.: Modeled and observed atmospheric radiation balance during the West African dry season: Role of mineral dust, biomass burning aerosol, and surface albedo,~J. Geophys. Res., 113, D00C02, doi:10.1029/2007JD009741, 2008.
Mohalfi,~S., Bedi,~H S., Krishnamurti,~T N., and Cocke,~S D.: Impact of shortwave effects on the summer season heat low over Saudi Arabia, Mon. Weather Rev., 126, 3153–3168, 1998.
Morcrette,~J. and Fouquart,~Y.: The overlapping of cloud layers in shortwave radiation parameterizations,~J. Atmos. Sci., 43(4), 321–328, 1986.
Osborne,~S R., Johnson,~B T., Haywood,~J M., Baran,~A J., Harrison,~M A J., and McConnell,~C L.: Physical and optical properties of mineral dust aerosol during the Dust and Biomass- burning Experiment,~J. Geophys. Res., 113, D00C03, doi:10.1029/2007JD009551, 2008.
Pelon, J., Mallet, M., Mariscal, A., et al.: Microlidar observations of biomass burning aerosol over Djougou (Benin) during African Monsoon Multidisciplinary Analysis Special Observation Period 0: Dust and Biomass-Burning Experiment, J. Geophys. Res., 113, D00C18, doi:10.1029/2008JD009976, 2008.
Ramanathan, V., Crutzen, P. J., Lelieveld, J., et al.: Indian Ocean experiment: an integrated analysis of the climate forcing and effects of the great Indo-Asian haze,~J. Geophys. Res., 106, 28 371–28 398, 2001.
Ramanathan, V., Li, F., Ramana, M. V., et al.: Atmospheric brown clouds: Hemispherical and regional variations in long- range transport, absorption, and radiative forcing,~J. Geophys. Res., 112, D22S21, doi:10.1029/2006JD008124, 2007.
Redelsperger,~J., Thorncroft,~D., Diedhiou,~A., Lebel,~T., Parker,~D., and Polcher,~J.: African monsoon multiplidisciplinary analysis: An international research project and field campaign, Bull. Am. Meteorol. Soc., 87, 1739–1746, 2006.
Roger,~J C., Mallet,~M., Dubuisson,~P., Cachier,~H., Vermote,~E., Dubovik,~O., and Despiau~S.: A~synergetic approach for estimating the local direct aerosol forcing: Application to an urban zone during the Experience sur Site pour Contraindre les Modeles de Pollution et de Transport d'Emission (ESCOMPTE) experiment,~J. Geophys. Res., 111, D13208, doi:10.1029/2005JD006361, 2006.
Slingo, A., Ackerman, T. P., Allan, R. P., et al.: Observations of the impact of a~major Saharan dust storm on the atmospheric radiation balance, Geophys. Res. Lett., 33, L24817, doi:10.1029/2006GL027869, 2006.
Tanré,~D., Haywood,~J M., Pelon,~J., Léon,~J F., Chatenet,~B., Formenti,~P., Francis,~P., Goloub,~P., Highwood,~E J., and Myhre,~G.: Measurements and modelling of the Saharan dust radiative impact: Overview of the Saharan Dust Experiment (SHADE),~J. Geophys. Res., 108(D18), 8574, doi:10.1029/2002JD003273, 2003.
Tulet~P., Crassier,~V., Cousin,~F., Suhre,~K., and Rosset~R.: ORILAM, a~three-moment lognormal aerosol scheme for mesoscale atmospheric model: online coupling into the Meso-NH-C model and validation on the Escompte campaign,~J. Geophys. Res., 110, D18201, doi:10.1029/2004JD005716, 2005.
Tulet,~P., Mallet,~M., Pont,~V., Pelon,~J., and Boon,~A.: The 7–13 March 2006 dust storm over West Africa: generation, transport, and vertical stratification,~J. Geophys. Res., 113, D00C08, doi:10.1029/2008JD009871, 2008.
Wendisch, M., Hellmuth, O., Ansmann, A., et al.: Radiative and dynamic effects of absorbing aerosol particles over the Pearl River Delta, China, Atmos. Environ., 42, 6408–6416, 2008.
Woodward,~S.: Modeling the atmospheric life-cycle and radiative impact of mineral dust in the Hadley Centre climate model,~J. Geophys. Res., 106, 18155–18166, 2001.
Yoshioka,~M. et al.: Impact of desert radiative forcing on Sahel precipitation: relative importance of dust compared to sea surface temperature variations, vegetation changes, and greenhouse gas warming, J. Climate, 20, 1445–1467, doi:10.1175/JCLI4056.1, 2007.
Zhu~A., Ramanathan,~V., Kim,~F., and Li,~D.: Dust plumes over the Pacific, Indian, and Atlantic oceans: climatology and radiative impact,~J. Geophys. Res., 112, D16208, doi:10.1029/2007JD008427, 2007.