What do past warm climates look like?
How does the ocean move around heat and carbon?
When did the ice sheets form?
ocean circulation during the Pliocene warm period
The ocean is absorbing much of the heat and carbon dioxide emissions related to human induced climate change [Pachauri et al., 2014], but the long-term impacts on heat and salt transport, carbon cycling and deep ocean circulation are poorly understood. To better understand the climate dynamics important during a globally warm climate state, we can use the Pliocene warm period (~3.0 to 4.2 million years ago) as a pseudo-analogue for future climate change.
Using minor (Mg/Ca) and trace elements (B/Ca) and trace isotopes (Nd), I am reconstructing Atlantic and Pacific transects of water mass properties and structure. This work is supported by the NERC Independent Research Fellowship.
Bottom Water Temperature and Ice Volume Records from the Mid-Pleistocene Transition
During the Mid-Pleistocene Transition (MPT), the dominant glacial-interglacial cyclicity as inferred from the marine 𝛿18O records of benthic foraminifera (𝛿18Obenthic) changed from 41 kyr to 100 kyr years in the absence of a comparable change in orbital forcing.
Using minor element (Mg/Ca) and trace element (B/Ca) ratios, I am reconstructing bottom water temperature and 𝛿18Oseawater values from different locations to understand changes in ice volume and water mass properties over the MPT. This work is supported by NSF grant OCE-1436014 (Ford and Raymo).
the Tropical Pacific Thermocline and El NiñO
The tropical Pacific thermocline strength, depth, and tilt are critical to average tropical conditions and variability. El Niño–Southern Oscillation (ENSO) is a major source of global interannual variability, but its response to climate change is uncertain.
I'm interested in reconstructing thermocline conditions on various time scales (Last Glacial Maximum, Pliocene warm period) and its relationship to ENSO variability.