Cloud Condensation Nuclei Studies

Long term measurements of cloud condensation nuclei (CCN), which have as yet an unquantified influence on the radiative properties of cloud, and hence on global climate, have been ongoing at Mace Head since January 1994. Air mass and meteorological effects on the CCN population are being studied. This work has been given added impetus through the establishment of the Mace Head field station as a WMO Global Atmosphere Watch (GAW) site. Relevant refereed work relating to the above topics are given below:
 

Intensive Field Studies of Aerosol-Cloud Interactions

Group members have participated in numerous international airborne field studies of aerosol-cloud interactions, including CAR (Clouds, Aerosol and Radiation, MAST (Monterey Area Ship Track Experiment) and ACE-2 (Aerosol Characterisation experiment.

Modelling of Aerosol-Cloud Interactions and CCN production

Modelling of aerosol-cloud chemistry systems have been performed with particular focus on marine clouds and the interaction between sea-salt ans sulpahte nuclei. More recent studies have focused on the production of CCN from DMS and also from coastal iodine emissions. A non-exhaustive list of related manuscripts are given on the right-hand side.

References:

Durkee, P, Johnson, DW, RN Ferek, T Garrett, PV Hobbs, J Hudson, KJ Noone, LM Russell, S Platnick, JP Taylor, CD O'Dowd, W Hooper, P Durkee, K Nielson, A Ackerman, C Bretherton, G Innis, Y Kogan, R Flagan, J Seinfield, MH Smith, WA Hoppel. The impact of ship produced aerosols on the micro-physical characteristics of warm stratocumulus clouds: A test of Hypotheses 1.1a and 1.1b, J. Atmos. Sci, 57, 2554-2569, 2000. PDF

Noone, K.J., D. W. Johnson, J.P. Taylor, R.J. Ferek, T. Garrett, P.V. Hobbs, P.A. Durkee, K. Neilson, S. Platnick, M.D. King, E. Östrom, C.D. O'Dowd, M.H. Smith, L.M. Russell, R.C. Flagan, J.H. Seinfeld, L. De Bock, R. E. Van Grieken, J.G. Hudson, I. M. Brooks, R. F. Gasparovic, and R. A. Pockalny. A case study of ship track formation in a polluted boundary layer. J. Atmos. Sci, 57, 2748-2764, 2000. PDF

Noone, K.J., E. Östrom, R.J. Ferek, T. Garrett, P.V. Hobbs, D. W. Johnson, J.P. Taylor, L.M. Russell, R.C. Flagan, J.H. Seinfeld, C.D. O'Dowd, M.H. Smith, P.A. Durkee, K. Neilson, J.G. Hudson, R. A. Pockalny L. De Bock, R. E. Van Grieken, R. F.Gasparovic, and, I. M. Brooks,. A case study of ships forming and not forming tracks in moderately polluted clouds. J. Atmos. Sci, 57, 2729-2747, 2000. PDF

Hobbs, PV, Garrett, T, RN Ferek, SR Strader, DA Hegg, GM Frick, WA Hoppel, R Gasparovic, LM Russell, DW Johnson, CD O'Dowd, PA Durkee, KE Nielsen and G Innis. Emissions from ships with reference to their effects on clouds. J. Atmos. Sci, 75, 2570-2590, 2000. PDF

O'Dowd, C.D., J. Lowe, M.H. Smith and A.D. Kaye, The relative importance of sea-salt and nss-sulphate aerosol to the marine CCN population: An improved multi-component aerosol-droplet parameterisation. Q. J. Roy. Met. Soc., 125, 1295-1313. 1999 PDF

O'Dowd, CD, J.A. Lowe, and MH Smith, Coupling sea-salt and sulphate interactions and its impact on predicting cloud droplet concentrations, Geophys. Res. Letts, 26, 1311-1314, 1999. PDF

O'Dowd, CD. On the spatial extent and evolution of coastal aerosol plumes. J. Geophys. Res., in press 2002.

Pirjola, L., C.D. O'Dowd and M. Kulmala, A model prediction of the yield of CCN from coastal nucleation events. In press J. Geophys. Res., 2002.

Hämeri, K. J.M. Mäkelä, L. Pirjola, M. Väkevä, P. Aalto, P. Miikkulainen, and C.D. O'Dowd, Hygroscopic properties of boreal forest aerosol during nucleation events. Tellus B, 53, 359-378, 2001

O'Dowd, C.D., Biogenic coastal aerosol production and its influence on aerosol radiative properties, Jr. Geophys. Res., 106, 1545-1550, 2001

Jennings, S.G., Geever, M., Mc Govern, F.M., Francis, J.,  Spain, T. G. and Donaghy, T. (1997). Microphysical and physico-chemical characterisation of atmospheric aerosol at Mace Head. Atmos. Environ., 31, 2795-2808.

Jennings, S.G., Geever, M., and O'Connor, T.C. (1997). Coastal CCN measurements at Mace Head with enhanced concentrations in strong winds. Atmos. Res., 46, 243-252.

 
Gras, J.L., Jennings, S.G., and Geever, M., (1996). CCN determination comparing counters with single drop counting and photometric detectors at Mace Head, Ireland. Idojaras, 100, 171-182.
 
McGovern, F.M., Jennings, S.G., O'Connor, T.C. and Simmonds, P.G. (1996). Aerosol and trace gas measurements during the Mace Head experiment. Atmos. Environ., 30, 3891-3902.
 
Jennings, S.G., (1993). Introduction to aerosol effects on climate in Aerosol Effects on Climate, S.G. Jennings, Ed., the University of Arizona Press, Tucson & London, 1-8.