Help for this theory is out-of Mg/Ca study regarding a superficial drinking water web site better over the paleo-CCD, and therefore let you know a good ?2.5°C cooling along the EOT, shown in the Shape 2b [ Lear ainsi que al., 2008 ]. , 2007 ; Zanazzi et al., 2007 ; Katz ainsi que al., 2008 ; Liu et al., 2009 ; Eldrett ainsi que al., 2009 ]. Liu ainsi que al. undertook an acting investigation according to its facial skin temperature contributes to purchase to guess deep-sea air conditioning. New design managed to reproduce the brand new seen higher-latitude skin air conditioning (?5°C), as well as their design produced an intense-sea cooling regarding ?4°C over the EOT. strongly recommend its (?5°C) high-latitude epidermis cooling tends to be a low guess. 5°C, although this estimate is going to be slight while the comprehension of shade metal proxies advances [ Lear mais aussi al., 2010 ; Pusz mais aussi al., 2011 ]. That one.5°C out-of deep-water air conditioning over the EOT was much less compared to modeled deep-water air conditioning suggested of the Liu mais aussi al. .
Additional proof for it explanation is situated in other strong-sea, facial skin, and you may terrestrial temperatures proxies that also reveal an air conditioning along side EOT [ Dupont-Nivet et al
Although the modeling study of ] did not support bipolar glaciation at the EOT, it did suggest that, based on the proxy CO2 records of Pearson and Palmer and Pagani et al. , the CO2 threshold for bipolar glaciation was crossed ?25 Ma, meaning that ephemeral Northern Hemisphere ice sheets may have been present much earlier than previously thought. This potentially means that some of the sea level variations during the Miocene could be explained by changes in Northern Hemisphere ice mass. However, this is not consistent with the modeling work of de Boer et al. [2010 , 2012] , who suggested that the threshold for Northern Hemisphere glaciation was not reached in this period and that sea level variation in the Miocene was caused by the Antarctic ice sheets.
This new large-latitude SST list out of Liu et al. was revealed within the Figure 2c. The brand new cooling revealed from inside the Profile 2c during the EOT is higher compared to ?5°C out of cooling ideal by Liu et al. within fresh studies. Liu et al. demonstrated the data while the a temperature anomaly prior to the fresh new mean temperature for every web site ahead of the EOT. The details get here once the a temperature anomaly according to progressive temperature within paleolocation towards respective web sites [ Liu ainsi que al., 2009 , supplementary recommendations]. Merely Southern area Hemisphere internet come to let testing which have Pleistocene Southern area Hemisphere data about later on investigation.
The outside temperature records inside Rates 2b and you may 2c inform you pre-EOT temperatures notably hotter than simply present in the fresh Southern area Hemisphere higher latitudes and temperatures not all the values hotter regarding lowest latitudes. This reduced latitudinal temperature gradient (that is far more pronounced in the early Eocene [ Bijl mais aussi al., 2009 ]) gifts a paradox: to describe the enjoying heat about high latitudes ways enhanced temperatures 
transport in the equator for the poles; not, the lower temperatures gradient apparent away from investigation indicates less transportation off heat in the equator into the poles [ Huber, 2008 ]. The full exploration for the paradox is beyond the brand new range out-of this comment, however it will be detailed that the less latitudinal heat gradient throughout the Eocene stays a life threatening area of conflict between studies and you can weather designs [ Hollis ainsi que al., 2009 ].
