Spatial analysis of paleoclimate variations based on proxy records in the south-central Andes (18°-35° S) from 32 to 4 ka

The long-term climate dynamics of the central Andes are part of an ongoing international research effort to reconstruct past climatic variations and sensitivity to different regional and global drivers during the last 50,000 years. The large number of diverse records, however, makes it difficult to compare results without an integrated spatial analysis that considers the nature of the record and whether they are integrating environmental conditions across a large basin (i.e., a lake record) or at a very local scale (such as a rodent midden). We compiled 92 records from the southern sector of the central Andes (SCA, 18 & DEG;- 35 & DEG;S). Recalibrated records were further compared by converting the original author's interpretation into a scale of relative moisture anomalies (compared to the present) that ranges from -2 (very dry) to very wet (+2). Moisture anomaly maps were generated for intervals at 4, 6, 9.5,14, 17, 21 and 32 ka BP (103 calibrated 14C years before present) using records within a 5% age uncertainty. Our compilations show a surprising degree of agreement in the extent and magnitude of past climate changes during late Pleis-tocene, but less spatial agreement during the Holocene. The TRACE21 transient climate model shows similar results, with better agreement during the Pleistocene compared to the Holocene. Our analyses not only reveal discrepancies between proxy record interpretations at sites from the same region but show which regions in the SCA require more study. & COPY; 2023 Elsevier Ltd. All rights reserved.

Automated summary

The long-term climate dynamics of the central Andes have been studied to understand past climate variations and their sensitivity to different drivers. Compiling and comparing 92 records from the southern sector of the central Andes, it was found that there is a high degree of agreement in late Pleistocene climate changes, but less agreement during the Holocene. The TRACE21 climate model also confirmed these results, showing better agreement in the Pleistocene compared to the Holocene. This analysis not only reveals discrepancies between proxy records, but also highlights regions in the southern central Andes that require further study.