Earth Institute Staff Directory

Mr. Nicholas A O'Mara

Graduate Student , Department of Earth and Environmental Sciences (DEES) , Lamont-Doherty Earth Observatory (LDEO) , The Earth Institute

61 US-9W
104 Geoscience
Palisades, New York 10964

BIOGRAPHY: I am a Ph.D. student in the organic geochemistry group at the Lamont-Doherty Earth Observatory. My research focuses on using molecular-fossils or "biomarkers" preserved in marine sediments to reconstruct different attributes of the Earth's climate system in the geologic past on timescales of decades to millions of years. In particular, I measure the flux, distribution and hydrogen and carbon isotopic composition of plant-waxes to investigate how vegetation and precipitation have varied in the monsoon region of West Africa on orbital timescales in the Pleistocene. I also have projects focused on improving the understanding of wildfires in ecosystem transitions in West Africa using molecular flux records of pyrosugars and polycyclic aromatic hydrocarbons (PAHs) during the Green Sahara period in the mid-Holocene and on reconstructing changes in the paleo-ocean circulation of the North Atlantic in the Neogene using alkenone-based sea surface temperature records.


O’Mara, N.A.; Cheung, A. H.; Kelly, C.S.; Sandwick, S.; Herbert, T.D.; Russell, J.M.; Abella-Gutiérrez, J.; Dee, S.G.; Swarzenski, P.W.; Herguera, J.C. (2019) Subtropical Pacific Ocean temperature fluctuations in the Common Era: Multidecadal variability and its relationship with Southwestern North American megadroughts Geophysical Research Letters (

O’Mara, N.A. and Dunne, J.P. (2019) Hot spots of carbon and alkalinity cycling in the coastal oceans. Scientific Reports 9, Article number: 4434 (