Inter-hemispheric asymmetry in the early Pleistocene Pacific warm pool

As the largest modern reservoir of oceanic heat, the Western Pacific Warm Pool (WPWP) plays an important role in atmospheric and oceanic circulation patterns. Little is known about how regional deposition patterns have changed over the past 10 Ma. To understand the interplay between regional processes and global climate evolution in the WPWP, we explore the late Neogene evolution of biogenic (carbonate/siliceous) versus terrigenous deposition.We collected high-resolution (2 cm/~0.5 kyr) X-Ray fluorescence (XRF) core scanning data at IODP Site U1488 (Exp. 363) in the central WPWP. These data were especially useful for estimating the carbonate, siliceous and terrigenous components below 65 m CCSF, where the shipboard track data were less robust. The shipboard splice was verified and revised using the Ba/Sr ratio to ensure a continuous composite section down to ~330 m revised CCSF-A at Site U1488. Fe and Si likely reflect terrigenous and partially biogenic silica components. We calibrated the high-resolution ln(Ca/K) record to %CaCO3 using discrete shipboard %CaCO3 measurements.Fe and Si decrease, whilst ln(Ca/K) increases downcore, in agreement with shipboard data showing increasing %CaCO3 and decreasing terrigenous/siliceous input&#173;. During the late Pleistocene, the site shows high amplitude %CaCO3, Fe and Si cycles superimposed on low carbonate. The amplitude decreases during the early Pleistocene-mid Pliocene, although clear variability remains. The early Pliocene-late Miocene is dominated by high CaCO3 (80-90%). The %CaCO3, Fe and Si variability is considerably reduced, although clear obliquity-precession interference patterns are visible, in addition to longer-term ~400 kyr eccentricity modulation. The high-carbonate interval at IODP Site U1488 likely reflects the early Pliocene to late Miocene Biogenic Bloom (LMBB). The expression of the LMBB in the WPWP is distinctly different to the Atlantic and eastern equatorial Pacific. This indicates that although productivity was enhanced during the late Miocene-early Pliocene, regional processes determined the exact expression and timing of the LMBB in different areas.

Download Full-text

THE EVOLUTION OF UPPER WATER IN THE CENTER OF WEST PACIFIC WARM POOL DURING THE LAST 360KYR

Marine Geology & Quaternary Geology ◽

10.3724/sp.j.1140.2013.02087 ◽

2014 ◽

Vol 33 (2) ◽

pp. 87-96 ◽

Cited By ~ 4

Author(s):

Shuai ZHANG ◽

Tiegang LI ◽

Fengming CHANG ◽

Haixia WANG ◽

Zhifang XIONG ◽

...

Keyword(s):

Warm Pool ◽

West Pacific ◽

Pacific Warm Pool

Download Full-text

Effect of the Indo-Pacific Warm Pool on Lower-Stratospheric Water Vapor and Comparison with the Effect of ENSO

Journal of Climate ◽

10.1175/jcli-d-17-0575.1 ◽

2018 ◽

Vol 31 (3) ◽

pp. 929-943 ◽

Cited By ~ 6

Author(s):

Fei Xie ◽

Xin Zhou ◽

Jianping Li ◽

Quanliang Chen ◽

Jiankai Zhang ◽

...

Keyword(s):

Water Vapor ◽

Climate Model ◽

Southern Oscillation ◽

Deep Convection ◽

Warm Pool ◽

Latent Heat Release ◽

Stratospheric Water Vapor ◽

Asymmetric Effects ◽

Pacific Warm Pool ◽

Tropopause Temperature

Abstract Time-slice experiments with the Whole Atmosphere Community Climate Model, version 4 (WACCM4), and composite analysis with satellite observations are used to demonstrate that the Indo-Pacific warm pool (IPWP) can significantly affect lower-stratospheric water vapor. It is found that a warmer IPWP significantly dries the stratospheric water vapor by causing a broad cooling of the tropopause, and vice versa for a colder IPWP. Such imprints in tropopause temperature are driven by a combination of variations in the Brewer–Dobson circulation in the stratosphere and deep convection in the troposphere. Changes in deep convection associated with El Niño–Southern Oscillation (ENSO) reportedly have a small zonal mean effect on lower-stratospheric water vapor for strong zonally asymmetric effects on tropopause temperature. In contrast, IPWP events have zonally uniform imprints on tropopause temperature. This is because equatorial planetary waves forced by latent heat release from deep convection project strongly onto ENSO but weakly onto IPWP events.

Download Full-text

Mixed layer modeling in the East Pacific warm pool during 2002

Climate Dynamics ◽

10.1007/s00382-011-1130-1 ◽

2011 ◽

Vol 38 (11-12) ◽

pp. 2559-2573 ◽

Cited By ~ 3

Author(s):

Luke P. Van Roekel ◽

Eric D. Maloney

Keyword(s):

Mixed Layer ◽

Warm Pool ◽

East Pacific ◽

Pacific Warm Pool

Download Full-text

On the Convective Coupling and Moisture Organization of East Pacific Easterly Waves

Journal of the Atmospheric Sciences ◽

10.1175/jas-d-15-0056.1 ◽

2015 ◽

Vol 72 (10) ◽

pp. 3850-3870 ◽

Cited By ~ 15

Author(s):

Adam V. Rydbeck ◽

Eric D. Maloney

Keyword(s):

Life Cycle ◽

Zonal Wind ◽

Wind Shear ◽

Warm Pool ◽

Moisture Gradient ◽

Easterly Waves ◽

East Pacific ◽

Pacific Warm Pool ◽

Meridional Winds ◽

The Mean

Abstract Processes associated with the local amplification of easterly waves (EWs) in the east Pacific warm pool are explored. Developing EWs favor convection in the southwest and northeast quadrants of the disturbance. In nascent EWs, convection favors the southwest quadrant. As the EW life cycle progresses, convection in the northeast quadrant becomes increasingly prominent and southwest quadrant convection wanes. The EW moisture budget reveals that anomalous meridional winds acting on the mean meridional moisture gradient of the ITCZ produce moisture anomalies supportive of convection in the southwest quadrant early in the EW life cycle. As EWs mature, moisture anomalies on the poleward side of the EW begin to grow and are supported by the advection of anomalous moisture by the mean zonal wind. In the southwest and northeast portions of the wave, where convection anomalies are favored, lower-tropospheric vorticity is generated locally through vertical stretching that supports a horizontal tilt of the wave from the southwest to the northeast. EWs with such tilts are then able to draw energy via barotropic conversion from the background cyclonic zonal wind shear present in the east Pacific. Convection anomalies associated with EWs vary strongly with changes in the background intraseasonal state. EWs during westerly and neutral intraseasonal periods are associated with robust convection anomalies. Easterly intraseasonal periods are, at times, associated with very weak EW convection anomalies because of weaker moisture and diluted CAPE variations.

Download Full-text

Global vegetation productivity responses to the West Pacific Warm Pool

The Science of The Total Environment ◽

10.1016/j.scitotenv.2018.11.170 ◽

2019 ◽

Vol 655 ◽

pp. 641-651

Author(s):

Mei Huang ◽

Zhaosheng Wang ◽

Shaoqiang Wang ◽

Fengxue Gu ◽

He Gong ◽

...

Keyword(s):

Warm Pool ◽

The West ◽

Vegetation Productivity ◽

West Pacific ◽

Pacific Warm Pool ◽

Global Vegetation

Download Full-text

The climate response of the Indo‐Pacific warm pool to glacial sea level

Paleoceanography ◽

10.1002/2015pa002890 ◽

2016 ◽

Vol 31 (6) ◽

pp. 866-894 ◽

Cited By ~ 34

Author(s):

Pedro N. Di Nezio ◽

Axel Timmermann ◽

Jessica E. Tierney ◽

Fei‐Fei Jin ◽

Bette Otto‐Bliesner ◽

...

Keyword(s):

Sea Level ◽

Warm Pool ◽

Climate Response ◽

Pacific Warm Pool

Download Full-text

Human-caused Indo-Pacific warm pool expansion

Science Advances ◽

10.1126/sciadv.1501719 ◽

2016 ◽

Vol 2 (7) ◽

pp. e1501719 ◽

Cited By ~ 28

Author(s):

Evan Weller ◽

Seung-Ki Min ◽

Wenju Cai ◽

Francis W. Zwiers ◽

Yeon-Hee Kim ◽

...

Keyword(s):

Climate Model ◽

Hydrological Cycle ◽

Heat Content ◽

Warm Pool ◽

Small Island ◽

Past Century ◽

The Pacific ◽

Pacific Warm Pool ◽

Basin Scale ◽

Climate Model Simulations

The Indo-Pacific warm pool (IPWP) has warmed and grown substantially during the past century. The IPWP is Earth’s largest region of warm sea surface temperatures (SSTs), has the highest rainfall, and is fundamental to global atmospheric circulation and hydrological cycle. The region has also experienced the world’s highest rates of sea-level rise in recent decades, indicating large increases in ocean heat content and leading to substantial impacts on small island states in the region. Previous studies have considered mechanisms for the basin-scale ocean warming, but not the causes of the observed IPWP expansion, where expansion in the Indian Ocean has far exceeded that in the Pacific Ocean. We identify human and natural contributions to the observed IPWP changes since the 1950s by comparing observations with climate model simulations using an optimal fingerprinting technique. Greenhouse gas forcing is found to be the dominant cause of the observed increases in IPWP intensity and size, whereas natural fluctuations associated with the Pacific Decadal Oscillation have played a smaller yet significant role. Further, we show that the shape and impact of human-induced IPWP growth could be asymmetric between the Indian and Pacific basins, the causes of which remain uncertain. Human-induced changes in the IPWP have important implications for understanding and projecting related changes in monsoonal rainfall, and frequency or intensity of tropical storms, which have profound socioeconomic consequences.

Download Full-text

Subseasonal SST Variability in the Tropical Eastern North Pacific during Boreal Summer

Journal of Climate ◽

10.1175/2007jcli1856.1 ◽

2008 ◽

Vol 21 (17) ◽

pp. 4149-4167 ◽

Cited By ~ 35

Author(s):

Eric D. Maloney ◽

Dudley B. Chelton ◽

Steven K. Esbensen

Keyword(s):

Costa Rica ◽

Warm Pool ◽

Boreal Summer ◽

Sst Variability ◽

East Pacific ◽

Pacific Warm Pool ◽

Northern Edge ◽

Precipitation Anomalies ◽

Sst Anomalies ◽

Costa Rica Dome

Abstract Boreal summer intraseasonal (30–90-day time scale) sea surface temperature (SST) variability in the east Pacific warm pool is examined using Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) sea surface temperatures during 1998–2005. Intraseasonal SST variance maximizes at two locations in the warm pool: in the vicinity of 9°N, 92°W near the Costa Rica Dome and near the northern edge of the warm pool in the vicinity of 19°N, 108°W. Both locations exhibit a significant spectral peak at 50–60-day periods, time scales characteristic of the Madden–Julian oscillation (MJO). Complex empirical orthogonal function (CEOF) and spectra coherence analyses are used to show that boreal summer intraseasonal SST anomalies are coherent with precipitation anomalies across the east Pacific warm pool. Spatial variations of phase are modest across the warm pool, although evidence exists for the northward progression of intraseasonal SST and precipitation anomalies. Intraseasonal SSTs at the north edge of the warm pool lag those in the vicinity of the Costa Rica Dome by about 1 week. The MJO explains 30%–40% of the variance of intraseasonal SST anomalies in the east Pacific warm pool during boreal summer. Peak-to-peak SST variations of 0.8°–1.0°C occur during MJO events. SST is approximately in quadrature with MJO precipitation, with suppressed (enhanced) MJO precipitation anomalies leading positive (negative) SST anomalies by 7–10 days. Consistent with the CEOF and coherence analyses, MJO-related SST and precipitation anomalies near the Costa Rica Dome lead those at the northern edge of the warm pool by about 1 week.

Download Full-text

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

JURNAL GEOLOGI KELAUTAN ◽

10.32693/jgk.18.1.2020.635 ◽

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.

Download Full-text