How wet was the Arctic Eocene rain forest? Estimates of precipitation from Paleogene Arctic macrofloras

摘要

The Eocene was the warmest part of the Cenozoic, when warm climates extended into the Arctic, and substantive paleobotanical evidence indicates broadleaf and coniferous polar forests. Paleontological temperature proxies provide a basis for understanding Arctic early Paleogene climates; however, there is a lack of corresponding proxy data on precipitation. Both leaf physiognomic analysis and quantitative analysis of nearest living relatives of an Arctic macroflora indicate upper microthermal to lower mesothermal moist climates (mean annual temperature 13–15 °C; cold month mean temperature 4 °C; mean annual precipitation