Publication Date:
2024-01-09
Description:
The tropical Pacific thermocline strength, depth, and tilt are critical to tropical mean state and variability. During the early Pliocene (~3.5 to 4.5 Ma), the Eastern Equatorial Pacific (EEP) thermocline was deeper and the cold tongue was warmer than today, which resulted in an mean state with a reduced zonal sea surface temperature gradient, or El Padre. However, it is unclear whether the deep thermocline was a local feature of the EEP or a basin-wide condition with global implications. Our measurements of Mg/Ca of Globorotalia tumida in a western equatorial Pacific site indicate Pliocene subsurface temperatures warmer than today; thus, El Padre included a basin-wide thermocline that was relatively warm, deep, and weakly tilted. At ~4 Ma, thermocline steepening was coupled to cooling of the cold tongue. Since ~4 Ma, the basin-wide thermocline cooled/shoaled gradually, with implications for thermocline feedbacks in tropical dynamics and the interpretation of TEX86-derived temperatures.
Keywords:
130-806; AGE; Calculated from Mg/Ca ratios (Mohtadi et al. 2011); COMPCORE; Composite Core; DEPTH, sediment/rock; DSDP/ODP/IODP sample designation; Globorotalia tumida, Magnesium/Calcium ratio; ICP-OES, Inductively coupled plasma - optical emission spectrometry; Joides Resolution; Leg130; North Pacific Ocean; Ocean Drilling Program; ODP; Sample code/label; Sub-surface temperature
Type:
Dataset
Format:
text/tab-separated-values, 1356 data points
Permalink
