Holocene Temperature: A Spatial and Temporal Reconstruction using Paleoclimate Data Assimilation
Abstract
The spatial and temporal evolution of Holocene climate provides a valuable perspective on natural climate variability on long timescales. To better understand past temperature changes using data assimilation, proxies and climate models provide complementary pieces of information. Proxies provide climate information for specific locations, seasons, and time spans while output from climate models can be used to quantify the relationships between the available data and the rest of the climate system. In this work, we use data assimilation to reconstruct temperature variations over the past 12,000 years. This period is well suited for exploration due to the abundance of proxy records as well as its relevance to modern climate. To compute the reconstruction, we use data from the Temperature 12k proxy network as well as a transient HadCM3 simulation of glacial-to-present climate. Results show mild mid-Holocene warmth with a cooling toward the present day. Spatially, temperatures in North America and Europe correspond with previously-reconstructed ice sheets in those areas, despite the methodology having no knowledge of the timing of ice sheet changes outside of calibrated temperature data from the proxy network. Pseudoproxy experiments illustrate the skill of the data assimilation approach but also show that results could be improved through either a more uniform proxy network or, perhaps more importantly, a more reliable quantification of climate system relationships in the chosen model output.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFMPP55A0635E