Nicholas A O'Mara

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.

Fields of Interest

Climate science, organic geochemistry, oceanography, ecology


  • 2021, M.Phil., Columbia University, Earth and Environmental Sciences
  • 2019, M.A., Columbia University, Earth and Environmental Sciences 
  • 2017, Sc.B., Brown University, Geology-Chemistry

Honors & Awards

  • 2022, Kenneth and Linda Ciriacks Graduate Fellowship in Earth and Environmental Sciences
  • 2019, 2017 National Science Foundation Graduate Research Fellowship Honorable Mention 
  • 2017 Elected to Brown University chapter of Sigma Xi Scientific Research Honor Society 
  • 2017 Senior Award for Outstanding Research, Academics, and Service; Department of Earth Environmental and Planetary Sciences; Brown University 
  • 2016 Sarah LaMendola Award for Outstanding Potential in Undergraduate Research, Department of Earth Environmental and Planetary Sciences, Brown University 
  • 2015 National Oceanic and Atmospheric Administration (NOAA) Hollings Scholar Award 
  • 2015 Brown Undergraduate Teaching and Research Award (UTRA) 
  • 2013 High School Valedictorian

O’Mara, N.A.; Skonieczny, C.; McGee, D.; Winckler, G.; Bory, A. J.-M.; Bradtmiller, L. I.; Malaizé, B.; Polissar, P.J. (2022) Pleistocene drivers of Northwest African hydroclimate and vegetation, Nature Communications (

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 (