PlioMioVAR Scientific goals

Anna Joy Drury. It’s Site 926 from Wilkens et al., 2017 (https://cp.copernicus.org/articles/13/779/2017/) with composite core photos from IODP. — Site 926 composite core image from Wilkens et al., 2017 (https://cp.copernicus.org/articles/13/779/2017/) compiled from ODP core photos from Anna Joy Drury.

The overall goal of PlioMioVAR is to co-ordinate a synthesis of terrestrial and marine data to characterise spatial and temporal variability of Pliocene and Miocene climate. Our programme builds on key priorities identified by the community in the PAGES PlioVAR working group.

We have three over-arching goals:

(1) Synthesize Pliocene and Miocene climate data with orbital, sub-orbital, and low resolution and include age model quality in metadata. Orbital scale synthesis will focus on the MPWP and identifying a Miocene target for as data-model comparison targets (possibly the Miocene Climate Optimum).
(2) Examine tools and experimental design for new climate modelling studies to characterise Pliocene climate variability, including transient model simulations and biogeochemistry coupled models.
(3) Compare and contrast the long-term evolution of Pliocene and Miocene climate and consider the role of ocean gateways and CO2 forcing in the evolution of the Earth system. Age model quality might limit detailed orbital comparisons.

The objectives for PlioMioVAR:

Update PlioVAR database and expand the Miocene database with marine and terrestrial data, which enables regional and global syntheses of spatial and temporal climate variability
Co-ordinate efforts to address missing data e.g. through initiation of projects to generate new/better resolved data
Evaluate chronostratigraphic tools and their constraints, and recommend protocols on stratigraphic reporting for database metadata
Quantify and compare uncertainties in proxies, and develop methods for assigning and reporting confidence in proxy records for database metadata
Assess regional expressions of Pliocene and Miocene climate variability through data synthesis, modelling experiments, and data-model integration
Identify future targets
We will organize four workshops to gather community ideas and delegate database tasks including data assimilation and quality control. Additionally, regular meetings of the working group will be facilitated by session proposals at international conferences (i.e. AGU, EGU).

Main integrative activities:

1) data stewardship (through database construction and maintenance); and
2) thresholds, tipping points, and multiple equilibria in the Earth System (e.g. thresholds: mid-Miocene Climate Transition; equilibria: mid-Pliocene Warm Period, mid-Miocene Climate Optimum).

The main stakeholders are members of the Paleoclimate Modelling Intercomparison Project (PMIP) community – those involved with the established PlioMIP and those coordinating for the future MioMIP.