Features of the spatial distribution and size structure of the Pacific lamprey Lampetra tridentata in the North Pacific

2008 ◽  
Vol 34 (5) ◽  
pp. 276-287 ◽  
Author(s):  
A. M. Orlov ◽  
V. F. Savinyh ◽  
D. V. Pelenev
Paleobiology ◽  
1989 ◽  
Vol 15 (4) ◽  
pp. 335-356 ◽  
Author(s):  
Geerat J. Vermeij

Geographical restriction to refuges implies the regional extinction of taxa in areas of the previous range falling outside the refuge. A comparison of the circumstances in the refuge with those in areas from which the taxa were eliminated is potentially informative for pinpointing the causes of extinction. A synthesis of data on the geographical and stratigraphical distributions of cool-water molluscs of the North Pacific and North Atlantic Oceans during the late Neogene reveals four patterns of geographical restriction, at least two of which imply that climatic cooling was not the only cause of extinction during the last several million years. These four patterns are (1) the northwestern Pacific restriction, involving 15 taxa whose amphi-Pacific distributions during the late Neogene became subsequently restricted to the Asian side of the Pacific; (2) the northwestern Atlantic restriction, involving six taxa whose early Pleistocene distribution is inferred to have been amphi-Atlantic, but whose present-day and late Pleistocene ranges are confined to the northwestern Atlantic; (3) a vicariant Pacific pattern, in which many ancestral amphi-Pacific taxa gave rise to separate eastern and western descendants; and (4) the circumboreal restriction, involving six taxa whose early Pleistocene distribution, encompassing both the Atlantic and Pacific Oceans, became subsequently limited to the North Pacific. Like the Pliocene extinctions in the Atlantic, previously studied by Stanley and others, the vicariant Pacific pattern is most reasonably interpreted as having resulted from regional extinction of northern populations in response to cooling. The northwestern Pacific and Atlantic restrictions, however, cannot be accounted for in this way. In contrast to the northeastern margins of the Pacific and Atlantic, the northwestern margins are today characterized by wide temperature fluctuations and by extensive development of shore ice in winter. Northeastern, rather than northwestern, restriction would be expected if cooling were the overriding cause of regional extinction. Among the other possible causes of extinction, only a decrease in primary productivity can account for the observed northwestern and circumboreal patterns of restriction. Geographical patterns of body size and the distribution of siliceous deposits provide supporting evidence that primary productivity declined after the Miocene in the northeastern Pacific, but remained high in the northwestern Pacific, and that productivity in the Pacific is generally higher than it is in the Atlantic. The patterns of geographical restriction in the northern oceans thus provide additional support to previous inferences that reductions in primary productivity have played a significant role in marine extinctions.


2006 ◽  
Vol 134 (12) ◽  
pp. 3567-3587 ◽  
Author(s):  
Linda M. Keller ◽  
Michael C. Morgan ◽  
David D. Houghton ◽  
Ross A. Lazear

Abstract A climatology of large-scale, persistent cyclonic flow anomalies over the North Pacific was constructed using the National Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP–NCAR) global reanalysis data for the cold season (November–March) for 1977–2003. These large-scale cyclone (LSC) events were identified as those periods for which the filtered geopotential height anomaly at a given analysis point was at least 100 m below its average for the date for at least 10 days. This study identifies a region of maximum frequency of LSC events at 45°N, 160°W [key point 1 (KP1)] for the entire period. This point is somewhat to the east of regions of maximum height variability noted in previous studies. A second key point (37.5°N, 162.5°W) was defined as the maximum in LSC frequency for the period after November 1988. The authors show that the difference in location of maximum LSC frequency is linked to a climate regime shift at about that time. LSC events occur with a maximum frequency in the period from November through January. A composite 500-hPa synoptic evolution, constructed relative to the event onset, suggests that the upper-tropospheric precursor for LSC events emerges from a quasi-stationary long-wave trough positioned off the east coast of Asia. In the middle and lower troposphere, the events are accompanied by cold thickness advection from a thermal trough over northeastern Asia. The composite mean sea level evolution reveals a cyclone that deepens while moving from the coast of Asia into the central Pacific. As the cyclone amplifies, it slows down in the central Pacific and becomes nearly stationary within a day of onset. Following onset, at 500 hPa, a stationary wave pattern, resembling the Pacific–North American teleconnection pattern, emerges with a ridge immediately downstream (over western North America) and a trough farther downstream (from the southeast coast of the United States into the western North Atlantic). The implications for the resulting sensible weather and predictability of the flow are discussed. An adjoint-derived sensitivity study was conducted for one of the KP1 cases identified in the climatology. The results provide dynamical confirmation of the LSC precursor identification for the events. The upper-tropospheric precursor is seen to play a key role not only in the onset of the lower-tropospheric height falls and concomitant circulation increases, but also in the eastward extension of the polar jet across the Pacific. The evolution of the forecast sensitivities suggest that LSC events are not a manifestation of a modal instability of the time mean flow, but rather the growth of a favorably configured perturbation on the flow.


1993 ◽  
Vol 50 (12) ◽  
pp. 2608-2625 ◽  
Author(s):  
William G. Pearcy ◽  
Joseph P. Fisher ◽  
Mary M. Yoklavich

Abundances of Pacific pomfret (Brama japonica), an epipelagic fish of the North Pacific Ocean, were estimated from gillnet catches during the summers of 1978–1989. Two size modes were common: small pomfret <1 yr old, and large fish ages 1–6. Large and small fish moved northward as temperatures increased, but large fish migrated farther north, often into the cool, low-salinity waters of the Central Subarctic Pacific. Lengths of small fish were positively correlated with latitude and negatively correlated with summer surface temperature. Interannual variations in the latitude of catches correlated with surface temperatures. Large catches were made in the eastern Gulf of Alaska (51–55°N) but modes of small pomfret were absent here, and large fish were rare at these latitudes farther to the west. Pomfret grow rapidly during their first two years of life. They are pectoral fin swimmers that swim continuously. They prey largely on gonatid squids in the region of the Subarctic Current in the Gulf of Alaska during summer. No evidence was found for aggregations on a scale ≤1 km. Differences in the incidence of tapeworm, spawning seasons, and size distributions suggest the possibility of discrete populations in the North Pacific Ocean.


1965 ◽  
Vol 43 (2) ◽  
pp. 381-405 ◽  
Author(s):  
L. Margolis ◽  
Hilda Lei Ching

The generic diagnoses of Bacciger and Pentagramma are emended. Recognized as members of the genus Bacciger are the type, B. bacciger (Rudolphi, 1819), from the Mediterranean, Black, and Azov Seas; B. nicolli Palombi, 1934, from Atlantic waters near the British Isles; and B. opisthonemae Nahhas and Cable, 1964, from Jamaican waters. Pentagramma consist of P. symmetricum Chnlkova, 1939, the type, from the Black and Azov Seas and P. petrowi (Layman, 1930) n. comb, from the northern part of the North Pacific region. Synonyms of P. petrowi are Monorcheides(?) petrowi Layman, 1930: Orientophorus sayori Yamaguti, 1942; Faustula sayori (Yamaguti, 1942); Orientophorus petrowi (Layman, 1930); and Bacciger petrowi (Layman, 1930). Pentagramma petrowi is redescribed and additional details of morphology are included for P. symmetricum, B. bacciger, and B. nicolli. Measurements of the species discussed and extensive host and locality records are tabulated.


2017 ◽  
Author(s):  
Marisa Borreggine ◽  
Sarah E. Myhre ◽  
K. Allison S. Mislan ◽  
Curtis Deutsch ◽  
Catherine V. Davis

Abstract. We assessed sediment coring, data acquisition, and publications from the North Pacific (north of 30˚ N) from 1951–2016. There are 2134 sediment cores collected by American, French, Japanese, Russian, and international research vessels across the North Pacific (including the Pacific Subarctic Gyre, Alaskan Gyre, Japan Margin, and California Margin, 1391 cores), Sea of Okhotsk (271 cores), Bering Sea (123 cores), and Sea of Japan (349 cores) reported here. All existing metadata associated with these sediment cores are documented, including coring date, location, core number, cruise number, water depth, vessel metadata, and coring technology. North Pacific age models are based on isotope stratigraphy, radiocarbon dating, magnetostratigraphy, biostratigraphy, tephrochronology, % opal, color, and lithophysical proxies. Here, we evaluate the iterative generation of each published age model and provide documentation of each dating technique used, as well as sedimentation rates and age ranges. We categorized cores according to availability of a variety of proxy evidence, including biological (e.g. benthic and planktonic foraminifera assemblages), geochemical (e.g. heavy metal concentrations), isotopic (e.g. bulk sediment nitrogen and carbon isotopes), and stratigraphic (e.g. preserved laminations) proxies. This database is a unique resource to the paleoceanographic and paleoclimate communities, and provides cohesive accessibility to sedimentary sequences, age model development, and proxies. The data set is publicly available through PANGAEA at https://doi.org/10.1594/PANGAEA.875998.


Zootaxa ◽  
2020 ◽  
Vol 4868 (4) ◽  
pp. 543-559
Author(s):  
DENNIS M. OPRESKO ◽  
DANIEL WAGNER

Three new species of antipatharian corals are described from deep-sea (677–2,821 m) seamounts and ridges in the North Pacific, including Antipathes sylospongia, Alternatipathes venusta, and Umbellapathes litocrada. Most of the material for these descriptions was collected on expeditions aboard NOAA Ship Okeanos Explorer that were undertaken as part of the Campaign to Address Pacific Monument Science, Technology, and Ocean Needs (CAPSTONE). One of the main goals of CAPSTONE was to characterize the deep-sea fauna in protected waters of the U.S. Pacific, as well as in the Prime Crust Zone, the area with the highest known concentration of commercially valuable deep-sea minerals in the Pacific. Species descriptions and distribution data are supplemented with in situ photo records, including those from deep-sea exploration programs that have operated in the North Pacific in addition to CAPSTONE, namely the Hawaii Undersea Research Laboratory (HURL), the Ocean Exploration Trust (OET), and the Monterey Bay Aquarium Research Institute (MBARI). 


2021 ◽  
pp. 1-54
Author(s):  
Ying Dai ◽  
Peter Hitchcock

AbstractThe canonical tropospheric response to a weakening of the stratospheric vortex—an equatorward shift of the eddy-driven jet—is mostly limited to the North Atlantic following sudden stratospheric warmings (SSWs). A coherent change in the Pacific eddy-driven jet is notably absent. Why is this so? Using daily reanalysis data, we show that air-sea interactions over the North Pacific are responsible for the basin-asymmetric response to SSWs. Prior to the onset of some SSWs, their tropospheric precursors produce a dipolar SST pattern in the North Pacific, which then persists as the stratospheric polar vortex breaks down following the onset of the SSW. By reinforcing the lower tropospheric baroclinicity, the dipolar SST pattern helps sustain the generation of baroclinic eddies, strengthening the near-surface Pacific eddy-driven jet and maintaining its near-climatological-mean state. This prevents the jet from being perturbed by the downward influence of the stratospheric anomalies. As a result, these SSWs exhibit a highly basin-asymmetric surface response with only the Atlantic eddy-driven jet shifted equatorward. For SSWs occurring without the atmospheric precursors in the North Pacific troposphere, the dipolar SST pattern is absent due to the lack of the atmospheric forcing. In the absence of the dipolar SST pattern and the resultant eddy-mean flow feedbacks, these SSWs exhibit a basin-symmetric surface response with both the Atlantic and the Pacific eddy-driven jets shifted equatorward. Our results provide an ocean-atmosphere coupled perspective on stratosphere-troposphere interaction following SSW events and have potential for improving subseasonal to seasonal forecasts for surface weather and climate.


2021 ◽  
pp. 1-43
Author(s):  
Jae-Heung Park ◽  
Mi-Kyung Sung ◽  
Young-Min Yang ◽  
Jiuwei Zhao ◽  
Soon-Il An ◽  
...  

AbstractThe North Pacific Oscillation (NPO), a primary atmospheric mode over the North Pacific in boreal winter, is known to trigger the El Niño-Southern Oscillation (ENSO) in the following winter, the process of which is recognized as the seasonal footprinting mechanism (SFM). Based on the analysis of model simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5), we found that the SFM acts differently among models, and the correlation between the NPO and subsequent ENSO events, called the SFM efficiency, depends on the background mean state of the model. That is, SFM efficiency becomes stronger as the climatological position of the Pacific Intertropical Convergence Zone (ITCZ) moves poleward, representing an intensification of the northern branch of the ITCZ. When the Pacific ITCZ is located poleward, the wind-evaporation-sea surface temperature (SST) feedback becomes stronger as the precipitation response to the SST anomaly is stronger in higher latitudes compared to that of lower latitudes. In addition, such active ocean-atmosphere interactions enhance NPO variability, favoring the SFM to operate efficiently and trigger an ENSO event. Consistent with the model results, the observed SFM efficiency increased during the decades in which the northern branch of the climatological ITCZ was intensified, supporting the importance of the tropical mean state of precipitation around the Pacific ITCZ.


Sign in / Sign up

Export Citation Format

Share Document