Bird extinctions in the central Pacific

1994 ◽  
Vol 344 (1307) ◽  
pp. 27-33 ◽  
Keyword(s):  
Endangered Species ◽  
Bird Species ◽  
Western Pacific ◽  
Extinction Rate ◽  
Human Occupation ◽  
Central Pacific ◽  
Fossil Species ◽  
The Pacific ◽  
Island Group ◽  
The Western Pacific

The first wave of human colonists spread across the Pacific from 4000 to 1000 years ago. That they caused many extinctions is well known from fossil finds. We estimate how many fossil species were missed - the answer is roughly half - and so estimate the true extinction rate. The first colonists exterminated roughly half the species on each island group. Some of these extinctions are falsely attributed to the first colonists, because intensive collection often began a half century after the damage initiated by European discovery. Even taken at face value, these recent extinctions are too few. Many species are so critically endangered that we know neither whether they still survive or how to save them. Interestingly, there are fewer recent extinctions and currently endangered species in the islands of the western Pacific, which were the islands occupied first by humans. We suggest that the species sensitive to human occupation died out long ago in these areas. If so, these islands would have lost even more than half of their bird species.

scholarly journals A root for massive crown-of-thorns starfish outbreaks in the Pacific Ocean

2021 ◽  
Author(s):  
Nina Yasuda ◽  
June Inoue ◽  
Michael R. Hall ◽  
Manoj R. Nair ◽  
Mehdi Adjeroud ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Environmental Changes ◽  
French Polynesia ◽  
The Philippines ◽  
Marshall Islands ◽  
Western Pacific ◽  
Central Pacific ◽  
The Pacific ◽  
The Pacific Ocean ◽  
The Western Pacific

AbstractRecurring outbreaks of crown-of-thorns starfish (COTS) severely damage healthy corals in the Western Pacific Ocean. To determine the source of outbreaking COTS larvae and their dispersal routes across the Western Pacific, complete mitochondrial genomes were sequenced from 243 individuals collected in 11 reef regions. Our results indicate that Pacific COTS comprise two major clades, an East-Central Pacific clade (ECP-C) and a Pan-Pacific clade (PP-C). The ECP-C consists of COTS from French Polynesia (FP), Fiji, Vanuatu and the Great Barrier Reef (GBR), and does not appear prone to outbreaks. In contrast, the PP-C, which repeatedly spawns outbreaks, is a large clade comprising COTS from FP, Fiji, Vanuatu, GBR, Papua New Guinea, Vietnam, the Philippines, Japan, Micronesia, and the Marshall Islands. Given the nature of Pacific Ocean currents, the vast area encompassing FP, Fiji, Vanuatu, and the GBR likely supplies larvae for repeated outbreaks, exacerbated by anthropogenic environmental changes, such as eutrophication.

scholarly journals Changes in Independency between Two Types of El Niño Events under a Greenhouse Warming Scenario in CMIP5 Models

2015 ◽  
Vol 28 (19) ◽  
pp. 7561-7575 ◽  
Author(s):  
Yoo-Geun Ham ◽  
Yerim Jeong ◽  
Jong-Seong Kug
Keyword(s):  
Global Warming ◽  
El Niño ◽  
El Nino ◽  
Western Pacific ◽  
Cmip5 Models ◽  
Greenhouse Warming ◽  
Central Pacific ◽  
El Niño Events ◽  
The Western Pacific ◽  
El Nino Events

Abstract This study uses archives from phase 5 of the Coupled Model Intercomparison Project (CMIP5) to investigate changes in independency between two types of El Niño events caused by greenhouse warming. In the observations, the independency between cold tongue (CT) and warm pool (WP) El Niño events is distinctively increased in recent decades. The simulated changes in independency between the two types of El Niño events according to the CMIP5 models are quite diverse, although the observed features are simulated to some extent in several climate models. It is found that the climatological change after global warming is an essential factor in determining the changes in independency between the two types of El Niño events. For example, the independency between these events is increased after global warming when the climatological precipitation is increased mainly over the equatorial central Pacific. This climatological precipitation increase extends convective response to the east, particularly for CT El Niño events, which leads to greater differences in the spatial pattern between the two types of El Niño events to increase the El Niño independency. On the contrary, in models with decreased independency between the two types of El Niño events after global warming, climatological precipitation is increased mostly over the western Pacific. This confines the atmospheric response to the western Pacific in both El Niño events; therefore, the similarity between them is increased after global warming. In addition to the changes in the climatological state after global warming, a possible connection of the changes in the El Niño independency with the historical mean state is discussed in this paper.

scholarly journals Annonaceae in the Western Pacific: geographic patterns and four new species

2017 ◽  
Author(s):  
Ian M. Turner ◽  
Timothy M.A. Utteridge
Keyword(s):  
New Species ◽  
Solomon Islands ◽  
New Guinea ◽  
Western Pacific ◽  
New Combinations ◽  
Geographic Patterns ◽  
The Pacific ◽  
Two New Species ◽  
The Western Pacific ◽  
A New Species

The taxonomy and distribution of Pacific Annonaceae are reviewed in light of recent changes in generic delimitations. A new species of the genus Monoon from the Solomon Archipelago is described, Monoon salomonicum I.M.Turner & Utteridge sp. nov., together with an apparently related new species from New Guinea, Monoon pachypetalum I.M.Turner & Utteridge sp. nov. The confirmed presence of the genus in the Solomon Islands extends the generic range eastward beyond New Guinea. Two new species of Huberantha are described, Huberantha asymmetrica I.M.Turner & Utteridge sp. nov. and Huberantha whistleri I.M.Turner & Utteridge sp. nov., from the Solomon Islands and Samoa respectively. New combinations are proposed: Drepananthus novoguineensis (Baker f.) I.M.Turner & Utteridge comb. nov., Meiogyne punctulata (Baill.) I.M.Turner & Utteridge comb. nov. and Monoon merrillii (Kaneh.) I.M.Turner & Utteridge comb. nov. One neotype and four lectotypes are designated. The geographic patterns exhibited by nine native Annonaceae genera, that range in the Pacific beyond New Guinea, are discussed.

scholarly journals Western Pacific SST Prediction with an Intermediate El Niño Prediction Model

2005 ◽  
Vol 133 (5) ◽  
pp. 1343-1352 ◽  
Author(s):  
Jong-Seong Kug ◽  
In-Sik Kang ◽  
Jong-Ghap Jhun
Keyword(s):  
Prediction Model ◽  
El Niño ◽  
El Nino ◽  
Vertical Mixing ◽  
Western Pacific ◽  
Central Pacific ◽  
Modified Model ◽  
Sst Variability ◽  
Predictive Skill ◽  
The Western Pacific

Abstract To improve forecasting skills in the western Pacific sea surface temperature (SST), the authors utilized and modified an intermediate El Niño prediction model. The original model does not have the major SST thermodynamics for western Pacific SST variability, so it cannot simulate interannual variation in the western Pacific correctly. Therefore, the authors have introduced some modifications, such as heat flux and vertical mixing, into the dynamical model in order to capture SST thermodynamics more realistically. The modified model has better forecast skill than the original one, not only for the western Pacific but also for the eastern-central Pacific. The model has predictive skill up to 6-months lead time as judged by a correlation exceeding 0.5.

scholarly journals Evolution of the Madden–Julian Oscillation in Two Types of El Niño

2016 ◽  
Vol 29 (5) ◽  
pp. 1919-1934 ◽  
Author(s):  
Xiong Chen ◽  
Jian Ling ◽  
Chongyin Li
Keyword(s):  
El Niño ◽  
El Nino ◽  
Moisture Flux ◽  
Early Summer ◽  
Western Pacific ◽  
Madden Julian Oscillation ◽  
Central Pacific ◽  
Cp El Niño ◽  
Ep El Niño ◽  
The Western Pacific

Abstract Evolution characteristics of the Madden–Julian oscillation (MJO) during the eastern Pacific (EP) and central Pacific (CP) types of El Niño have been investigated. MJO activities are strengthened over the western Pacific during the predeveloping and developing phases of EP El Niño, but suppressed during the mature and decaying phases. In contrast, MJO activities do not show a clear relationship with CP El Niño before their occurrence over the western Pacific, but they increase over the central Pacific during the mature and decaying phases of CP El Niño. Lag correlation analyses further confirm that MJO activities over the western Pacific in boreal spring and early summer are closely related to EP El Niño up to 2–11 months later, but not for CP El Niño. EP El Niño tends to weaken the MJO and lead to a much shorter range of its eastward propagation. Anomalous descending motions over the Maritime Continent and western Pacific related to El Niño can suppress convection and moisture flux convergence there and weaken MJO activities over these regions during the mature phase of both types of El Niño. MJO activities over the western Pacific are much weaker in EP El Niño due to the stronger anomalous descending motions. Furthermore, the MJO propagates more continuously and farther eastward during CP El Niño because of robust moisture convergence over the central Pacific, which provides adequate moisture for the development of MJO convection.

scholarly journals Winter-to-Spring Transition in East Asia: A Planetary-Scale Perspective of the South China Spring Rain Onset

2008 ◽  
Vol 21 (13) ◽  
pp. 3081-3096 ◽  
Author(s):  
L. H. LinHo ◽  
Xianglei Huang ◽  
Ngar-Cheung Lau
Keyword(s):  
East Asia ◽  
South China ◽  
Stationary Wave ◽  
Rapid Expansion ◽  
Western Pacific ◽  
Monsoon Circulation ◽  
Jet Stream ◽  
The South ◽  
Central Pacific ◽  
The Western Pacific

Abstract Analysis of observations from 1979 to 2002 shows that the seasonal transition from winter to spring in East Asia is marked with a distinctive event—the onset of the south China spring rain (SCSR). In late February, the reduced thermal contrast between ocean and land leads to weakening of the Asian winter monsoon as well as the Siberian high and the Aleutian low. Meanwhile, convection over Australia and the western Pacific Maritime Continent is suppressed on the passage of the dry phase of a Madden–Julian oscillation (MJO). In conjunction with the seasonal march of monsoon circulation in the Indonesian–Australian sector, this MJO passage weakens the local thermally direct cell in the East Asia–Australia sector. This development is further accompanied by a series of adjustments in both the tropics and midlatitudes. These changes include attenuation of the planetary stationary wave, considerable weakening of the westerly jet stream over much of the central Pacific adjacent to Japan, and reduction of baroclinicity near the East Asian trough. The influence of concurrent local processes in midlatitudes on the SCSR onset is also important. The weakened jet stream is associated with confinement of frontal activities to the coastal regions of East Asia as well as with rapid expansion of the subtropical Pacific high from the eastern Pacific to the western Pacific. A parallel analysis using output from an experiment with a GFDL-coupled GCM shows that the above sequence of circulation changes is well simulated in that model.

scholarly journals 40Ar/39Ar Ages and Geochemistry of Seamount Basalts from the Western Pacific Province

2022 ◽  
Vol 10 (1) ◽  
pp. 54
Author(s):  
Qian Liu ◽  
Limei Tang ◽  
Ling Chen ◽  
Peng Gao
Keyword(s):  
Geochemical Characteristics ◽  
Western Pacific ◽  
Primitive Mantle ◽  
Magma Source ◽  
Ocean Island Basalts ◽  
The Pacific ◽  
Three Samples ◽  
Formation And Evolution ◽  
Geochemical Profiles ◽  
The Western Pacific

Seamounts are features generated by hot spots and associated intraplate volcanic activity. The geochemical characteristics of igneous rocks constituting seamounts provide evidence of important details of dynamic processes in the Earth, such as mantle magma source areas, and are key to understanding how mantle plume processes control the formation and evolution of seamounts and their resulting geochemical characteristics. The Pacific Ocean contains a large number of hitherto unstudied seamounts, whose ages and geochemical characteristics remain poorly known. This study presents the geochemical characteristics of six basalt samples from five seamounts in the Western Pacific and the 40Ar/9Ar ages of three samples are determined. The new analysis yielded 40Ar/39Ar ages for seamounts samples MP3D21, MP5D11, and MP5D15A of 95.43 ± 0.33, 62.4 ± 0.26, and 99.03 ± 0.4 Ma, respectively. The geochemical profiles of seamounts samples MP3D04, MP3D21, MP5D11, MP5D15A, MPID201, and MPID202 are consistent with alkaline basalts, as evidence by alkali-rich, silicon-poor compositions along with high titanium concentrations. The primitive mantle normalized rare-earth elements and trace elements spider pattern are similar to those of ocean island basalts. The Ta/Hf and Nb/Zr ratios and La/Zr-Nb/Zr discriminant diagrams indicate that the six seamounts formed from magma that originated in the deep mantle.

Eastward Eddy Shedding of the Asian Summer Monsoon Anticyclone

2021 ◽  
Author(s):  
Xinyue Wang ◽  
William Randel ◽  
Yutian Wu
Keyword(s):  
North America ◽  
Summer Monsoon ◽  
Asian Summer Monsoon ◽  
Lower Troposphere ◽  
Western Pacific ◽  
The North ◽  
The Pacific ◽  
Asian Summer ◽  
The Western Pacific ◽  
Eddy Shedding

<p>Eastward eddy shedding of the Asian summer monsoon (ASM) anticyclone has a large impact on the chemical composition of the upper troposphere and lower stratosphere (UTLS) over the western Pacific. Here we investigate the dynamical mechanism of eastward eddy shedding in July and August using 41 years of the ERA5 6-hourly reanalysis data. We perform composite analyses of meteorological variables focusing on the eastward eddy shedding events with the presence of anticyclonic centers falling between 135<sup>•</sup>-140<sup>•</sup>E. The composited outgoing longwave radiation anomalies suggest enhanced convection near the Philippines Sea and the East China Sea one week beforehand. In the tropopause level, we see evident eastward propagating geopotential and meridional wind anomalies from the North Atlantic jet exit toward the western Pacific embedded along the extratropical westerly jet during day -10 to day 0. In the lower troposphere, we find that the geopotential anomalies aligned meridionally from the east Asian coast to the North Pacific to the northern North America during day -7 to day 0. The wave-activity flux is evaluated to identify the origin and propagation of the energy of the Rossby wave–like perturbation. In the UTLS we find a strong southeastward-pointing flux along 40<sup>•</sup>-50<sup>•</sup>N, resembling the Silk Road pattern. While in the lower troposphere, we also see a northeastward-pointing flux originating from tropical Philippine Sea across Japan to North America, resembling the Pacific-Japan pattern. Additional analysis is needed to study the relationship between the Silk Road pattern and the Pacific-Japan pattern.</p>

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