Western pacific warm pool and ENSO asymmetry in CMIP3 models

2013 ◽  
Vol 30 (3) ◽  
pp. 940-953 ◽  
Author(s):  
Yan Sun ◽  
De-Zheng Sun ◽  
Lixin Wu ◽  
Fan Wang
Keyword(s):  
Warm Pool ◽  
Western Pacific ◽  
Western Pacific Warm Pool ◽  
Pacific Warm Pool ◽  
Enso Asymmetry

scholarly journals KETERKAITAN PERUBAHAN IKLIM PADA GLASIAL AKHIR - HOLOSEN TERHADAP TINGKAT KEANEKARAGAMAN FORAMINIFERA DI LAUT HALMAHERA

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Fitria Ratna Pratiwi ◽  
Suwarno Hadisusanto ◽  
Luli Gustiantini ◽  
Nazar Nurdin ◽  
Mira Yosi
Keyword(s):  
Younger Dryas ◽  
Warm Pool ◽  
Western Pacific ◽  
Western Pacific Warm Pool ◽  
Pacific Warm Pool

Laut Halmahera terletak pada Western Pacific Warm Pool (WPWP), yaitu pusat konveksi panas di Samudera Pasifik Barat tropis. Laut ini merupakan salah satu jalur masuk Arlindo yang menghubungkan massa air Samudera Pasifik dengan Samudera Hindia. Sehingga area ini penting untuk rekonstruksi paleoklimat. Peristiwa perubahan glasial akhir-interglasial (Holosen) merupakan peristiwa di masa lalu yang sangat mempengaruhi kondisi Laut Halmahera. Salah satu proksi yang dapat digunakan untuk mencatat perubahan iklim di masa lalu adalah sisa-sisa makhluk hidup, termasuk foraminifera. Perubahan yang terjadi pada foraminifera dapat diamati dari tingkat  keanekaragaman, kemelimpahan, dominansi, dan keseragaman. Penelitian dilakukan dengan menggunakan sampel sedimen bor MD10-3339, yang diambil di Laut Halmahera (00o26,67’LS dan 128o50,33’BT) pada kedalaman 1.919 m, dalam survei MONOCIR 2 tahun 2010. Sampel yang digunakan pada rentang 20 cm hingga 1.930 cm dengan interval 60 cm pada tiap sampel, yang dianggap mewakili waktu terjadinya glasial-interglasial. 30 sampel kemudian diamati dan dilakukan analisis secara kuantitatif. Teridentifikasi 52 spesies yang terdiri dari 32 spesies foraminifera bentonik dan 21 spesies foraminifera planktonik. Nilai indeks keanekaragaman, nilai indeks keseragaman, dan indeks dominansi menunjukkan nilai yang fluktuatif sejak glasial-interglasial, dengan nilai rata-rata 1,66; 0,35; dan 0,3. Walaupun tidak menunjukkan pola glasial-interglasial, namun pada sekitar umur 12.519 BP, nilai indeks keanekaragaman dan nilai keseragaman menunjukkan nilai yang lebih rendah dibandingkan dengan nilai yang lain yaitu 1,102 dan 0,26. Sebaliknya, indeks dominansi mencapai nilai tertinggi yaitu 0,55.  Selain itu, persentase P. obliqueloculata pada umur ini menjadi sangat dominan yaitu 73,05%. Hal tersebut kemungkinan berkaitan dengan peristiwa Younger Dryas.

Role of Abnormally Enhanced MJO over the Western Pacific in the Formation and Subseasonal Predictability of the Record-Breaking Northeast Asian Heatwave in the Summer of 2018

2020 ◽  
Vol 33 (8) ◽  
pp. 3333-3349 ◽  
Author(s):  
Pang-Chi Hsu ◽  
Yitian Qian ◽  
Yu Liu ◽  
Hiroyuki Murakami ◽  
Yingxia Gao
Keyword(s):  
Real Time ◽  
Time Scale ◽  
Wave Train ◽  
Northeast Asia ◽  
Warm Pool ◽  
Western Pacific ◽  
Western Pacific Warm Pool ◽  
Pacific Warm Pool ◽  
Northeast Asian ◽  
The Western Pacific

AbstractIn the summer of 2018, Northeast Asia experienced a heatwave event that broke the existing high-temperature records in several locations in Japan, the Korean Peninsula, and northeastern China. At the same time, an unusually strong Madden–Julian oscillation (MJO) was observed to stay over the western Pacific warm pool. Based on reanalysis diagnosis, numerical experiments, and assessments of real-time forecast data from two subseasonal-to-seasonal (S2S) models, we discovered the importance of the western Pacific MJO in the generation of this heatwave event, as well as its predictability at the subseasonal time scale. During the prolonged extreme heat period (11 July–14 August), a high pressure anomaly with variability at the intraseasonal (30–90 days) time scale appeared over Northeast Asia, causing persistent adiabatic heating and clear skies in this region. As shown in the composites of MJO-related convection and circulation anomalies, the occurrence of this 30–90-day high anomaly over Northeast Asia was linked with an anomalous wave train induced by tropical heating associated with the western tropical Pacific MJO. The impact of the MJO on the heatwave was further confirmed by sensitivity experiments with a coupled GCM. As the western Pacific MJO-related components were removed by nudging prognostic variables over the tropics toward their annual cycle and longer time scales (>90 days) in the coupled GCM, the anomalous wave train along the East Asian coast disappeared and the surface air temperature in Northeast Asia lowered. The MJO over the western Pacific warm pool also influenced the predictability of the extratropical heatwave. Our assessments of two S2S models’ real-time forecasts suggest that the extremity of this Northeast Asian heatwave can be better predicted 1–4 weeks in advance if the enhancement of MJO convection over the western Pacific warm pool is predicted well.

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

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

<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>

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