Extratropical tree ring network locations (IMAGE) Johannes Gutenberg Universitaet Mainz Caption Extratropical tree ring network locations in the Northern Hemisphere: 100 sampling locations (black-and-white circles) including monitoring locations (red circles) Credit ill./©: Jan Esper Usage Restrictions This image may only be used in connection with the press release "Jan Esper receives ERC Advanced Grant to improve climate reconstructions from tree rings", issued by Johannes Gutenberg University Mainz on April 14, 2020. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.