Research interests

I routinely use various numerical models in order to consider and quantify the response of each component of the climate system (ocean, atmosphere, vegetation, marine biomass, land ice…) to the forcing factor studied (please visit the section of the website dedicated to my tools for more details).

In particular, I have been developing 3 main axes of research:

1. Past climate changes: the transition toward ice ages.

During my PhD thesis at LSCE, in particular, I tried to understand the mechanisms responsible for the onset of the Ordovician glaciation (also named “Early Paleozoic Ice Age”). I published the first simulation of the Ordovician ice sheet that is supported by available geological data (see animated gif below).

gowth

Growth of the Late Ordovician ice sheet simulated using an innovative coupling method between climate models and an ice-sheet model. From Pohl et al., 2016–Paleoceanography.

2. Quantifying the impact of paleogeography on past climate changes.

The paleogeographical changes have profound impacts on the whole climate system. In 2014, I published a paper investigating the impact of the continental configuration and paleogeographical changes on the (in)stability of the Ordovician climate (see Figure below). In this paper, we notably demonstrate a major climatic instability, that allows Ordovician climate to suddenly cool in response to moderate changes in atmospheric forcing. We showed that this climatic instability results from the absence of meridional continental boundaries in the Ordovician Northern Hemisphere. These conditions limit the ocean heat transport to the pole and facilitate the growth of large sea-ice caps.

apohl_ordovician_paleogeography_changes.png

SSTs simulated using the FOAM OAGCM during the Mid (a) and Late (b) Ordovician at 3360 ppm, and their difference: 450-470Ma (c). After Pohl et al., 2014–Climate of the Past.

3. The climatic drivers and feedbacks of neritic carbonate production

During my post-doc at CEREGE, I had the opportunity to work with the sedimentologist Jean Borgomano to investigate the relationships between shallow-water carbonates and climate, both in the Modern and in deep-time periods. We notably developed the first model predicting the occurrence of platform carbonates during the Early Cretaceous (Aptian; 120 Ma).

modeldata_pohl_et_al_2019.png

Extent of the Aptian carbonate platforms (A) simulated in this study and (B) after the geological database of Kiessling et al. (2003). After Pohl et al., 2019–Paleo3.