Didier M. Roche

CL Climate: Past, Present & Future

The 2012 Division Outstanding Young Scientist Award is awarded to Didier M. Roche for his innovative development of forward models of isotopic proxies and his contribution to the understanding of past climate changes.

Didier Roche focuses his research on understanding of rapid climate changes that occurred in the last glacial cycle, especially on the complex interactions between different components of the climate system (oceans, atmosphere and cryosphere) and the sensitivity of climate to various forcings. This has important implications for present-day and future climate variability. For his research, Roche has developed and applied earth system models of intermediate complexity, and coupled these to innovative forward models of isotopic proxies such as 18O. This methodology implies an important step forward in the integration of numerical models and proxy data. The 18O forward modeling has enabled him to constrain the characteristics (volume and duration) of the meltwater forcing associated with the so-called Heinrich event 4, which was one of several episodes with massive iceberg discharges that occurred in the last glacial. Using an earth system model of intermediate complexity, he performed one of the first transient simulations of the last glacial-interglacial transition to unravel the causes for spatial and temporal variability of the warming during the last deglaciation. He has also shown that climate has a very specific response to meltwater discharges originating from different locations around the globe. These specific responses can be used as ‘fingerprints’ to track down the sources of the meltwater.

Publication resulting from the award

Roche, D. M., Waelbroeck, C., Metcalfe, B., and Caley, T.: FAME (v1.0): a simple module to simulate the effect of planktonic foraminifer species-specific habitat on their oxygen isotopic content, Geosci. Model Dev., 11, 3587–3603, https://doi.org/10.5194/gmd-11-3587-2018, 2018.