Tropical sea-surface temperature reconstruction for the early Paleogene using Mg/Ca ratios of planktonic foraminifera

Abstract The impacts of different meridional structures of tropical sea surface temperature (SST) on the Hadley circulation (HC) in the annual mean are investigated during the period 1948–2013. By decomposing the variations in SST and the HC into two components—that is, the equatorially asymmetric (SEA for SST, and HEA for HC) and the equatorially symmetric (SES for SST, and HES for HC) parts—it is shown that the long-term variability in SEA and SES captures well the temporal variations in equatorially asymmetric and symmetric variations in SST. The variation in HEA is closely linked to that of SEA, and the variation in HES is connected with that of SES. However, the response of HEA to a given amplitude variation in SEA is stronger (by ~5 times) than that of HES to the same amplitude variation in SES. This point is further verified by theoretical and numerical models, indicating that the meridional structure of SST plays a crucial role in determining the anomalies in HC. This result may explain why the principal mode of HC is dominated by an equatorially asymmetric mode in its long-term variability.

Download Full-text

Concerning the Response of the Atmosphere to a Tropical Sea Surface Temperature Anomaly

Journal of the Atmospheric Sciences ◽

10.1175/1520-0469(1989)046<1898:ctrota>2.0.co;2 ◽

1989 ◽

Vol 46 (13) ◽

pp. 1898-1921 ◽

Cited By ~ 5

Author(s):

G. J. Boer

Keyword(s):

Surface Temperature ◽

Sea Surface Temperature ◽

Temperature Anomaly ◽

Sea Surface ◽

Sea Surface Temperature Anomaly ◽

Tropical Sea

Download Full-text

Multi-species coral Sr/Ca-based sea-surface temperature reconstruction using Orbicella faveolata and Siderastrea siderea from the Florida Straits

Palaeogeography Palaeoclimatology Palaeoecology ◽

10.1016/j.palaeo.2016.10.022 ◽

2017 ◽

Vol 466 ◽

pp. 100-109 ◽

Cited By ~ 8

Author(s):

Jennifer A. Flannery ◽

Julie N. Richey ◽

Kaustubh Thirumalai ◽

Richard Z. Poore ◽

Kristine L. DeLong

Keyword(s):

Surface Temperature ◽

Sea Surface Temperature ◽

Temperature Reconstruction ◽

Sea Surface ◽

Orbicella Faveolata ◽

Florida Straits

Download Full-text

Coupled Mg/Ca and clumped isotope measurements at IODP Site U1488 confirm absence of Plio-Pleistocene sea surface temperature cooling in the Western Pacific Warm Pool

10.5194/egusphere-egu2020-16364 ◽

2020 ◽

Author(s):

Niklas Meinicke ◽

Maria Reimi ◽

Christina Ravelo ◽

Nele Meckler

Keyword(s):

Surface Temperature ◽

Sea Surface Temperature ◽

Planktonic Foraminifera ◽

Warm Pool ◽

Western Pacific ◽

Sea Surface ◽

Western Pacific Warm Pool ◽

Pacific Warm Pool ◽

The Western Pacific

The Western Pacific Warm Pool (WPWP) as a major source of heat and water vapor has a crucial influence on climate dynamics both in the tropics and globally. Yet, there is conflicting proxy evidence regarding the evolution of WPWP temperatures since the Miocene. On the one hand TEX86 data suggest a gradual cooling by ~2&#8451; (O&#8217;Brian et al., 2014, Zhang et al., 2014) from the Pliocene to today, while faunal (planktonic foraminifera) sea surface temperature estimates (Dowsett, 2007) and Mg/Ca data measured in planktonic foraminifera (Wara et al., 2005) on the other hand indicate the absence of any long-term temperature trends. It has been suggested that Mg/Ca temperatures could on these time scales be biased by long-term changes of the Mg/Ca ratio of seawater (Evans et al., 2016). To test the influence of the proposed seawater changes on Mg/Ca we combined data from two independent temperature proxies, Mg/Ca and clumped isotopes, measured on two species of planktonic foraminifera from IODP Site U1488 in the central WPWP. Our study finds good agreement between both proxies thereby verifying the validity of Mg/Ca records from the WPWP and confirming the absence of a Plio-Pleistocene cooling trend for the WPWP. This finding suggests that the persistent disagreement between foraminifer-based proxies such as Mg/Ca and biomarker data might be caused by different environmental parameters being recorded in the two archives.&#160;References:O&#8217;Brien CL, Foster GL, Mart&#237;nez-Bot&#237; MA, Abell R, Rae JWB, Pancost RD. High sea surface temperatures in tropical warm pools during the Pliocene. Nature Geoscience. 2014;7(8):606-11.Zhang YG, Pagani M, Liu Z. A 12-million-year temperature history of the tropical Pacific Ocean. Science. 2014;344(6179):84-7.Dowsett H. Faunal re-evaluation of Mid-Pliocene conditions in the western equatorial Pacific. Micropaleontology. 2007;53(6):447-56.Wara MW, Ravelo AC, Delaney ML. Permanent El Nino-like conditions during the Pliocene warm period. Science. 2005;309(5735):758-61.Evans D, Brierley C, Raymo ME, Erez J, M&#252;ller W. Planktic foraminifera shell chemistry response to seawater chemistry: Pliocene&#8211;Pleistocene seawater Mg/Ca, temperature and sea level change. Earth and Planetary Science Letters. 2016;438:139-48.

Download Full-text