Start Submission Become a Reviewer

Reading: Kinetic limitations on cloud droplet formation and impact on cloud albedo

Download

A- A+
Alt. Display

Original Research Papers

Kinetic limitations on cloud droplet formation and impact on cloud albedo

Authors:

Athanasios Nenes ,

Department of Chemical Engineering, US
X close

Steven Ghan,

Pacific Northwest National Laboratory, US
X close

Hayder Abdul-Razzak,

Texas A&M University-Kingsville, US
X close

Patrick Y. Chuang,

NCARUS
X close

John H. Seinfeld

Department of Chemical Engineering, US
X close

Abstract

Under certain conditions mass transfer limitations on the growth of cloud condensation nuclei (CCN) may have a significant impact on the number of droplets that can form in a cloud. The assumption that particles remain in equilibrium until activated may therefore not always be appropriate for aerosol populations existing in the atmosphere. This work identifies three mechanisms that lead to kinetic limitations, the effect of which on activated cloud droplet number and cloud albedo is assessed using a one-dimensional cloud parcel model with detailed microphysics for a variety of aerosol size distributions and updraft velocities. In assessing the effect of kinetic limitations, we have assumed as cloud droplets not only those that are strictly activated (as dictated by classical Köhler theory), but also unactivated drops large enough to have an impact on cloud optical properties. Aerosol number concentration is found to be the key parameter that controls the significance of kinetic effects. Simulations indicate that the equilibrium assumption leads to an overprediction of droplet number by less than 10% for marine aerosol; this overprediction can exceed 40% for urban type aerosol. Overall, the effect of kinetic limitations on cloud albedo can be considered important when equilibrium activation theory consistently overpredicts droplet number by more than 10%. The maximum change in cloud albedo as a result of kinetic limitations is less than 0.005 for cases such as marine aerosol; however albedo differences can exceed 0.1 under more polluted conditions. Kinetic limitations are thus not expected to be climatically significant on a global scale, but can regionally have a large impact on cloud albedo.

How to Cite: Nenes, A., Ghan, S., Abdul-Razzak, H., Chuang, P.Y. and Seinfeld, J.H., 2001. Kinetic limitations on cloud droplet formation and impact on cloud albedo. Tellus B: Chemical and Physical Meteorology, 53(2), pp.133–149. DOI: http://doi.org/10.3402/tellusb.v53i2.16569
  Published on 01 Jan 2001
 Accepted on 2 Oct 2000            Submitted on 3 Feb 2000

REFERENCES

  1. Abdul-Razzak , H. , Ghan , S. J. and Rivera-Carpio , C . 1998 . A parameterization of aerosol activation. Part I: Single aerosol type . J. Geophys. Res . 103 , 6123 – 6132 .  

  2. Chuang , P. Y. , Charlson , R. J. and Seinfeld , J. H . 1997 . Kinetic limitations on droplet formation in clouds . Nature 390 , 594 – 596 .  

  3. Considine , G. and Curry , J. A . 1998 . Effects of entrain-ment and droplet sedimentation on the microphysical structure of stratus and stratocumulus clouds . Q. J. R. Meteorol. Soc . 124 , 123 – 150 .  

  4. Duynkerke , P. G. , Zhang , H. Q. and Jonker , P. J . 1995 . Microphysical and turbulent structure of nocturnal stratocumulus as observed during ASTEX . J. Atmos. Sci . 52 , 2763 – 2777 .  

  5. Facchini , M. C. , Mircea , M. , Fuzzi , S. and Charlson , R. J . 1999a . Cloud albedo enhancement by surface-active organic solutes in growing droplets , Nature 401 , 257 – 259 .  

  6. Frisch , A. S. , Fairall , C. W. and Snider , J. B . 1995a . Measurement of stratus cloud and drizzle parameters in ASTEX with a K„-band doppler radar and a micro-wave receiver . J. Atmos. Sci . 52 , 2788 – 2799 .  

  7. Frisch , A. S. , Lenschow , D. H. , Fairall , C. W. , Schubert , W. H. and Gibson , J. S . 1995b . Doppler radar meas-urements of turbulence in marine stratiform cloud during ASTEX . J. Atmos. Sci . 52 , 2800 – 2808 .  

  8. Ghan , S. J. , Chuang , C. C. and Penner , J. E . 1993 . A parameterization of cloud droplet nucleation. Part I: Single aerosol species . Atmos. Res . 30 , 197 – 222 .  

  9. Hatzianastassiou , N. , Wobrock , W. and Flossman , A. I . 1997 . The role of droplet spectra for cloud radiative properties. Q. J. R. Meteorol. Soc . 123 , 2215 – 2230 .  

  10. Hindmarsh , A. C. 1983. ODEPACK: a systemetized col-lection of ODE solvers. Scientific Computing , edited by R. S. Stepleman et al., pp. 55 - 64, North-Holland, New York .  

  11. Laaksonen , A. , Korhonen , P. , Kulmala , M. and Charl-son , R. J . 1998 . Modification of the Kohler equation to include soluble trace gases and slightly soluble sub-stances . J. Atmos. Sci . 55 , 853 – 862 .  

  12. Lacis , A. A. and Hansen , J. E . 1974 . A parameterization of the absorption of solar radiation in the Earth's atmosphere , J. Atmos. Sci . 31 , 118 – 133 .  

  13. Liu , X. H. and Wang , M. K . 1996 . A parameterization of the efficiency of nucleation scavenging of aerosol particles and some related physicochemical factors . Atmos. En v . 30 , 2335 – 2341 .  

  14. Nichols , S . 1984 . The dynamics of stratocumulus: aircraft observations and comparisons with a mixed layer model . Quart J. R. Met. Soc . 110 , 783 – 820 .  

  15. Pandis , S. P. , Seinfeld , J. H. and Pilinis , C . 1990 . The smog-fog-smog cycle and acid deposition . J. Geophys. Res . 95 , 18,489 – 18,500 .  

  16. Pruppacher , H. R. and Klett , J. D . 1997 . Microphysics of clouds and precipitation . Kluwer , Dordrecht .  

  17. Seinfeld , J. H. and Pandis , S. N . 1998 . Atmospheric chem-istry and physics . John Wiley , New York .  

  18. Whitby , K. T . 1978 . The physical characteristics of sulfur aerosols . Atmos. Environ . 12 , 135 – 159 .  

  19. White , A. B. , Fairall , C. W. and Snider , J. B . 1995 . Sur-face-based remote sensing of marine boundary-layer cloud properties. J. Atmos. Sci . 52 , 2827 – 2838 .  

  20. Young , K. C. and Warren , A. J . 1992 . A reexamination of the derivation of the equilibrium supersatura-tion curve for soluble particles. J. Atmos. Sci . 49 , 1138 – 1143 .  

comments powered by Disqus