Parameterization of the Optical Properties of Sulfate Aerosols

Li, J.; Wong, J.; Dobbie, J. S.; Chýlek, Petr

doi:10.1175/1520-0469(2001)058<0193:potopo>2.0.co;2

Cited by 49 publications

(36 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Under the assumption that ammonium sulphate ((NH 4 ) 2 SO 4 ) dominates the chemical composition of sulphate aerosols, their optical properties are parameterized using Li, Wong, Dobbie, and Chýlek (2001). Sea salt and mineral dust optical properties are parameterized using Lesins, Chýlek, and Lohmann (2002) while the optical properties of black and organic carbon are parameterized using Bäumer, Lohmann, Lesins, Li, and Croft (2007).…”

Section: Cloud Microphysicsmentioning

confidence: 99%

The Canadian Fourth Generation Atmospheric Global Climate Model (CanAM4). Part I: Representation of Physical Processes

et al. 2013

View full text Add to dashboard Cite

The Canadian Centre for Climate Modelling and Analysis (CCCma) has developed the fourth generation of the Canadian Atmospheric Global Climate Model (CanAM4). The new model includes substantially modified physical parameterizations compared to its predecessor. In particular, the treatment of clouds, cloud radiative effects, and precipitation has been modified. Aerosol direct and indirect effects are calculated based on a bulk aerosol scheme. Simulation results for present-day global climate are analyzed, with a focus on cloud radiative effects and precipitation. Good overall agreement is found between climatological mean short-and longwave cloud radiative effects and observations from the Clouds and Earth's Radiant Energy System (CERES) experiment. An analysis of the responses of cloud radiative effects to variations in climate will be presented in a companion paper.RÉSUMÉ [Traduit par la rédaction] Le Centre canadien de la modélisation et de l'analyse climatique (CCmaC) a mis au point la quatrième génération du modèle canadien de circulation générale de l'atmosphère (CanAM4). Le nouveau modèle comprend des paramétrisations physiques passablement modifiées comparativement à son prédé-cesseur. En particulier, le traitement des nuages, des effets radiatifs des nuages et des précipitations a été modifié. Les effets directs et indirects des aérosols sont calculés à l'aide d'un schéma d'aérosols en bloc. Nous analysons des résultats de simulation pour le climat général du jour présent en mettant l'accent sur les effets radiatifs des nuages et les précipitations. Nous trouvons un bon accord général entre la moyenne climatologique des effets radiatifs des nuages pour les courtes et les grandes longueurs d'onde et les observations de l'expérience CERES (Clouds and Earth's Radiant Energy System). Une analyse de la réponse des effets radiatifs des nuages aux variations du climat sera présentée dans un article connexe.

show abstract

Section: Cloud Microphysicsmentioning

confidence: 99%

The Canadian Fourth Generation Atmospheric Global Climate Model (CanAM4). Part I: Representation of Physical Processes

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Hygroscopic growth of particles are calculated based on growth factor parameterizations of Li et al (2001) for inorganic components, of Varutbangkul et al (2006) for SOA, and of Gerber (1985) for sea salt. With these parameterizations, we can obtain the wet size of different particles for the simulations of various microphysical processes.…”

Section: Hygroscopic Growth Gravitational Settling and Dry Depositionmentioning

confidence: 99%

Simulation of particle size distribution with a global aerosol model: contribution of nucleation to aerosol and CCN number concentrations

2009

View full text Add to dashboard Cite

Abstract. An advanced particle microphysics model with a number of computationally efficient schemes has been incorporated into a global chemistry transport model (GEOSChem) to simulate particle number size distributions and cloud condensation nuclei (CCN) concentrations in the atmosphere. Size-resolved microphysics for secondary particles (i.e., those formed from gaseous species) and sea salt has been treated in the present study. The growth of nucleated particles through the condensation of sulfuric acid vapor and equilibrium uptake of nitrate, ammonium, and secondary organic aerosol is explicitly simulated, along with the scavenging of secondary particles by primary particles (dust, black carbon, organic carbon, and sea salt). We calculate secondary particle formation rate based on ion-mediated nucleation (IMN) mechanism and constrain the parameterizations of primary particle emissions with various observations. Our simulations indicate that secondary particles formed via IMN appear to be able to account for the particle number concentrations observed in many parts of the troposphere. A comparison of the simulated annual mean concentrations of condensation nuclei larger than 10 nm (CN10) with those measured values show very good agreement (within a factor of two) in near all 22 sites around the globe that have at least one full year of CN10 measurements. Secondary particles appear to dominate the number abundance in most parts of the troposphere. Calculated CCN concentration at supersaturation of 0.4% (CCN0.4) and the fraction of CCN0.4 that is secondary (f sec CCN ) have large spatial variations. Over the middle latitude in the Northern Hemisphere, zonally averaged CCN0.4 decreases from ∼400-700 cm −3 in the boundary layer (BL) to below 100 cm −3 above altitude of ∼4 km, the correspondCorrespondence to: F. Yu (yfq@asrc.cestm.albany.edu) ing f sec CCN values change from 50-60% to above ∼70%. In the Southern Hemisphere, the zonally averaged CCN0.4 is below 200 cm −3 and f sec CCN is generally above 60% except in the BL over the Southern Ocean.

show abstract

“…Equations (11)- (14) are different from the corresponding formulae in Li et al (2001), Li and Min (2002), and Bäumer et al (2007), since this work is directly based on the wet particle distribution. The upper bound in integrations for Eqs.…”

Section: Parameterization Of Sea-salt Optical Propertiesmentioning

confidence: 99%

Parameterization of sea-salt optical properties and physics of the associated radiative forcing

Salzen

et al. 2008

Atmos. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

Abstract. The optical properties of sea-salt aerosol have been parameterized at shortwave and longwave wavelengths. The optical properties were parameterized in a simple functional form in terms of the ambient relative humidity based on Mie optical property calculations. The proposed parameterization is tested relative to Mie calculations and is found to be accurate to within a few percent. In the parameterization, the effects of the size distribution on the optical properties are accounted for in terms of effective radius of the sea-salt size distribution. This parameterization differs from previous works by being formulated directly with the wet sea-salt size distribution and, to our knowledge, this is the first published sea-salt parameterization to provide a parameterization for both shortwave and longwave wavelengths.We have used this parameterization in a set of idealized 1-D radiative transfer calculations to investigate the sensitivity of various attributes of sea-salt forcing, including the dependency on sea-salt column loading, effective variance, solar angle, and surface albedo. From these sensitivity tests, it is found that sea-salt forcings for both shortwave and longwave spectra are linearly related to the sea-salt loading for realistic values of loadings. The radiative forcing results illustrate that the shortwave forcing is an order of magnitude greater than the longwave forcing results and opposite in sign, for various loadings. Forcing sensitivity studies show that the influence of effective variance for sea-salt is minor; therefore, only one value of effective variance is used in the parameterization. The dependence of sea-salt forcing with solar zenith angle illustrates an interesting result that sea-salt can generate a positive top-of-the-atmosphere result (i.e. warming) when the solar zenith angle is relatively small (i.e. <30 • ). FiCorrespondence to: J. Li (jiangnan.li@ec.gc.ca) nally, it is found that the surface albedo significantly affects the shortwave radiative forcing, with the forcing diminishing to zero as the surface albedo tends to unity.

show abstract

Parameterization of the Optical Properties of Sulfate Aerosols

Cited by 49 publications

References 38 publications

The Canadian Fourth Generation Atmospheric Global Climate Model (CanAM4). Part I: Representation of Physical Processes

The Canadian Fourth Generation Atmospheric Global Climate Model (CanAM4). Part I: Representation of Physical Processes

Simulation of particle size distribution with a global aerosol model: contribution of nucleation to aerosol and CCN number concentrations

Parameterization of sea-salt optical properties and physics of the associated radiative forcing

Contact Info

Product

Resources

About