scholarly journals Variability of Diurnal Sea Surface Temperature during Short Term and High SST Event in the Western Equatorial Pacific as Revealed by Satellite Data

2020 ◽  
Vol 12 (19) ◽  
pp. 3230
Author(s):  
Anindya Wirasatriya ◽  
Kohtaro Hosoda ◽  
Joga Dharma Setiawan ◽  
R. Dwi Susanto

Near-surface diurnal warming is an important process in the climate system, driving exchanges of water vapor and heat between the ocean and the atmosphere. The occurrence of the hot event (HE) is associated with the high diurnal sea surface temperature amplitude (δSST), which is defined as the difference between daily maximum and minimum sea surface temperature (SST). However, previous studies still show some inconsistency for the area of HE occurrence and high δSST. The present study produces global δSST data based on the SST, sea surface wind data derived from microwave radiometers, and solar radiation data obtained from visible/infrared radiometers. The value of δSSTs are estimated and validated over tropical oceans and then used for investigating HE in the western equatorial Pacific. A three-way error analysis was conducted using in situ mooring buoy arrays and geostationary SST measurements by the Himawari-8 and Geostationary Operational Environmental Satellite (GOES). The standard deviation error of daily and 10-day validation is around 0.3 °C and 0.14–0.19 °C, respectively. Our case study in the western Pacific (from 110°E to 150°W) shows that the area of HE occurrence coincided well with the area of high δSST. Climatological analysis shows that the collocated area between high occurrence rate of HE and high δSST, which coincides with the western Pacific warm pool region in all seasons. Thus, this study provides more persuasive evidence of the relation between HE occurrence and high δSST.

2020 ◽  
Author(s):  
Niklas Meinicke ◽  
Maria Reimi ◽  
Christina Ravelo ◽  
Nele Meckler

<p>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 TEX<sub>86</sub> data suggest a gradual cooling by ~2℃ (O’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.</p><p> </p><p>References:</p><p>O’Brien CL, Foster GL, Martínez-Botí 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.</p><p>Zhang YG, Pagani M, Liu Z. A 12-million-year temperature history of the tropical Pacific Ocean. Science. 2014;344(6179):84-7.</p><p>Dowsett H. Faunal re-evaluation of Mid-Pliocene conditions in the western equatorial Pacific. Micropaleontology. 2007;53(6):447-56.</p><p>Wara MW, Ravelo AC, Delaney ML. Permanent El Nino-like conditions during the Pliocene warm period. Science. 2005;309(5735):758-61.</p><p>Evans D, Brierley C, Raymo ME, Erez J, Müller W. Planktic foraminifera shell chemistry response to seawater chemistry: Pliocene–Pleistocene seawater Mg/Ca, temperature and sea level change. Earth and Planetary Science Letters. 2016;438:139-48.</p>


1996 ◽  
Vol 46 (1) ◽  
pp. 72-77 ◽  
Author(s):  
Robert C. Thunell ◽  
Qingmin Miao

High resolution (∼200 yr sample spacing) records of sea surface temperature for the past 15,000 yr have been inferred from planktonic foraminiferal assemblages in a sediment core from the South China Sea. Although the assemblages imply a large glacial-to-interglacial temperature change (∼7°C for winter temperatures), they give no indication of a cooling during Younger Dryas time. This suggests that the Younger Dryas increase in δ18O observed in cores from the western equatorial Pacific is not due to a climatic cooling but rather to a change in the isotopic composition of the oceans.


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