A global climatology of the ocean surface during the Last Glacial Maximum mapped on a regular grid (GLOMAP)

• Main Authors: Paul, André, Mulitza, Stefan, Stein, Rüdiger, Werner, Martin
• Format: Text
• Language: English
• Published: 2020
• Subjects: Sea ice
• Online Access: https://doi.org/10.5194/cp-2019-154; https://cp.copernicus.org/preprints/cp-2019-154/

We present a climatology of the sea-surface temperature (SST) anomaly and the sea-ice extent during the Last Glacial Maximum (LGM, 23 000–19 000 years before present) mapped on a global regular 1° × 1° grid. It is an extension of the Glacial Atlantic Ocean Mapping (GLAMAP) reconstruction of the Atlantic SST based on the results of the Multiproxy Approach for the Reconstruction of the Glacial Ocean Surface (MARGO) project and several recent estimates of the LGM sea-ice extent. Such a gridded climatology is highly useful for the visualization of the LGM climate, calculation of global and regional SST averages and estimation of the equilibrium climate sensitivity, as well as a boundary condition for atmospheric general circulation models. The gridding of the sparse SST reconstruction was done in an optimal way using the Data-Interpolating Variational Analysis (DIVA) software, which takes into account the uncertainty on the reconstruction and includes the calculation of an error field. The resulting Glacial Ocean Map (GLOMAP) confirmed the previous findings by the MARGO project regarding longitudinal and meridional SST differences that were greater than today in all oceans and an equilibrium climate sensitivity at the lower end of the currently accepted range.