Subtropical sea-surface warming and increased salinity during Eocene Thermal Maximum 2
Subtropical sea-surface warming and increased salinity during Eocene Thermal Maximum 2
复制标题
DOI：
10.1130/g39658.1
复制
发表时间：
2018-02-01
期刊：
影响因子：
5.8
通讯作者：
Zachos, James C.
中科院分区：
文献类型：
--
作者：
Harper, Dustin T.;Zeebe, Richard;Zachos, James C.
始新世最大热2期（ETM-2，约54.2 Ma）是始新世第二大热期，但对关键地区的气候变化规模和速率知之甚少。本文首次详细记录了北太平洋海域1209和南大西洋海域1265两个海洋钻探项目地点的亚热带海面升温和ETM-2盐渍化过程。耦合的浮游有孔虫Mg/Ca和δ (18O)表明2-4℃的快速升温和1-2 ppt的局部盐渍化。海面温度的升高与高纬度地点报告的异常相当，并且与无冰世界（即无冰反照率反馈）对温室气体强迫的空间温度响应的预期模式理论一致。同样，观测到的盐碱化与经向水汽输送增强和世界变暖时副热带干旱增加的假设相一致。
Eocene Thermal Maximum 2 (ETM-2; ca. 54.2 Ma) represents the second largest of the major Eocene hyperthermals, yet comparatively little is known about the scale and rate of climatic change for key regions. Here we provide the first detailed records of subtropical sea- surface warming and salinization for ETM-2 at two subtropical locations, Ocean Drilling Program Sites 1209 (North Pacific) and 1265 (South Atlantic). Coupled planktic foraminiferal Mg/Ca and delta(18O) indicate 2-4 degrees C of rapid warming and local salinization of similar to 1-2 ppt at both sites. The increase in sea-surface temperature is equivalent to anomalies reported from higher latitude sites, and is consistent with theory on the expected pattern of spatial temperature response to greenhouse gas forcing in an ice-free world (i.e., no ice-albedo feedback). Similarly, the observed salinization is consistent with the hypothesis of enhanced meridional vapor transport and increased subtropical aridity in a warmer world.