The Warm Winter Paradox in the mid-Pliocene Warm Period (mPWP).
Abstract
Modelling results from PlioMIP2 (Pliocene Model Intercomparison Project Phase 2) focussing on MIS KM5c; ~3.205Ma, suggest that global mean surface air temperature was 1.7 5.2 C higher than the preindustrial. This warming was amplified at the poles and over land. The results are in reasonable agreement with paleodata over the ocean. Over the land the situation is more complicated. Model and data are in very good agreement at lower latitudes, however at high latitudes much warmer mPWP temperatures are obtained from data than from models. Further analysis suggests that this data-model mismatch is due to strong disagreement on winter temperatures, where the models are simulating temperatures ~20C cooler than the data. We term this the warm winter paradox Here we consider possible reasons for the winter temperature data-model disagreement at high latitudes. Accounting for modelling uncertainties (such as CO2 and orbital forcing), and local site-specific conditions reduce the model-data discrepancy. However, these uncertainties are unlikely to be able to fully resolve the model-data disagreement.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFMPP55D0703T