School of Earth and Environment

Daniel (Danny) O'Sullivan Dr Daniel (Danny) O'Sullivan

Research Fellow

Email address: d.osullivan@leeds.ac.uk
Room: 10.128

Affiliation: Institute for Climate and Atmospheric Science

Biography

Following the completion of my Ph.D. at University College Cork, Ireland, I began as a Postdoctoral Research Fellow at Leeds in 2011. My research focuses on quantifying the efficiency with which biological particles, such as pollen, spores and bacteria nucleate ice when immersed in supercooled water droplets. Despite their relatively large abundance in our atmosphere, the impact of such particles on heterogeneous cloud ice formation remains poorly understood. In particular, their currently exists a shortfall of basic data required to establish whether biogenic particles from terrestrial and marine environments do indeed make a substantial contribution to the formation of cloud ice on a global scale. To address this issue, my work has focused uncovering the sources of these biogenic particles, and developing our capabilities in detecting them in both the laboratory and the field.

Qualifications

B.Sc. (1st Class hon.) University College Cork, 2007

Ph.D. University College Cork, 2011

Research Interests

Current Research Interests

An overarching theme behind my current research is investigating the links between primary biological aerosol particle (PBAP) emissions and cloud ice formation. Areas of interest include:

  • Profiling the nature of the sites responsible for the high ice nucleating activity of pollens and fungi
  • Characterisation of the ice nucleating activities of fertile soil dusts
  • Identifying the pathways through which fragments of biogenic particles come to be incorporated into bioprecipitation cycles.
  • Development of field research infrastructure to allow for persistent INP measurements in challenging environments such as onboard marine research vessels.

Previous Research

• Characterisation of low temperature, solid phase chemical processes of atmospheric interest through the use of modern surface science techniques such as reflection absorption IR and Thermal Desorption spectroscopy

(a) The solid phase reactivity of mixed sulfur dioxide-water ices through the use of modern surface science techniques including

(b) The photochemical reactivities of alkyl and peroxyacyl nitrates trapped within thin ice matrices

(c) The photochemical reactivity of alkyl nitrites in the condensed phase: A novel pathway to the formation of Nitrous Oxide

• Reaction dynamics of the freeze-induced formation of iodine-bromine interhalogens from aqueous halide ion solutions in the presence of environmentally relevant oxidants such as HONO and H2O2

• Projection to latent structures (PLS) multivariate data analysis as a means to link inorganic chemical fingerprints of ambient PM2.5–0.1samples with in vitro biological effects

• The freeze-induced generation of bioavailable mercury compounds from dissolved elemental mercury in the presence of oxidants common to polar snowpacks

• Pattern Recognition Techniques to facilitate the rapid, automated classification of Pollen and Fungal Spore samples on the basis of their Intrinsic Fluorescence Characteristics

Publications