388 resultados para Pan-Pacific relations.
Resumo:
TOPIC 1: In terms of seasonal scale, temperature effect dominates the annual change of steric height in the open ocean whereas salinity effect controls it along the continental shelf. Large portion of the annual change of height relative to the 1000-db surface is contained in the upper 100m layer. However, in interannual scale large anomalies of steric height in the open ocean, are more often than not, caused by halosteric rather than thermosteric effect. At least in the open ocean the heights are almost totally determined by the behavior of deep water. Their interannual variability appears to be related to the cumulative effect of Eckman pumping. TOPIC 2: There is a "trend" that over the past 28 years the water at Station P has warmed. Least-square analysis indicates that this warming may be significant but shortening of the time-series data by approximately 10 years fails to show that this is the case. These "trends" have to be interpreted with care. The warming may be "apparent" in that it is not indicated clearly in the deep isopynal surfaces which, during the above period, have deepened. Thus warming at the isobaric surfaces may be the effect of the downward migration of the isopynal surfaces.
Resumo:
A preliminary statistical analysis was undertaken to evaluate whether the effect of El Nino events is apparent in variables related to hydrologic behavior. Annual precipitation, temperature and streamflow were used for three locations in Oregon representing coastal, Willamette Valley/Cascade and eastern Oregon regions. The mean and variance for periods of El Nino occurrence vs. those with no El Nino were computed. Numerical differences were observed but were not consistent across all stations. The coastal area showed a decrease in mean precipitation and increase in mean streamflow during El Nino events. Other stations showed a positive increase in mean for both precipitation and streamflow for El Nino events. Variance of precipitation was greater in the coastal area but smaller in other areas and vice versa for streamflow during El Nino events. Statistical analyses indicated no significant differences of means, variances or distributions using nonparametric tests for El Nino vs. non-El Nino series.
Resumo:
EXTRACT (SEE PDF FOR FULL ABSTRACT): The annual cycle and non-seasonal variability of streamflow over a network of stations in western North America and Hawaii is studied in terms of atmospheric forcing elements. The phase lag between the annual cycle of streamflow and precipitation varies considerably over this network, as does the persistence of monthly streamflow anomalies. This lag effect appears to be largely a function of the relative amount of snow laid down in a particular basin. In addition to the rather strong annual cycle that exists in mean streamflow and its variance at most of the stations, there is also a distinct annual cycle in the autocorrelation of streamflow anomalies that is related to the interplay between the temperature and precipitation annual cycles; of particular importance is the existence of stored water in the form of a snow pack.
Resumo:
EXTRACT (SEE PDF FOR FULL ABSTRACT): Time-series flux variabilities of biogenic opal particles were measured during 1982-1986 at pelagic Station PAPA (50° N, 145° W) located just south of the Gulf of Alaska, eastern North Pacific. PARFLUX sediment traps with two week sampling increments were deployed at 1000 m and 3800 m in 4200 m deep water, yielding nearly continuous time-series flux records for four years. The flux data allowed us to examine interannual and seasonal variabilities of siliceous phytoplankton production as well as environmental signals retained within the siliceous shells, which can be used to reconstruct environments.
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EXTRACT (SEE PDF FOR FULL ABSTRACT): Pollen from the upper 2.75 m of a core taken 200 km west of the Golfo de Guayaquil, Ecuador (Trident 163-13, 3° S, 84° W, 3,000 m water depth) documents changes in Andean vegetation and climate of the Cordillera Occidental for ~17,000 years before and after the last glacial maximum.
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Twenty-seven years (1956-1983) of oceanographic data collected at Ocean Station P (50°N/145°W), as well as supplementary data obtained in its neighborhood, have been examined for trends and interannual variability in the northeast Pacific Ocean. There is evidence that the water is warming and freshening and that the isopycnal surfaces are deepening. Trends in oxyty are mostly not significant. The most common periods for the interannual variability appear to be 2 1/2 and 6-7 years. The vertical movement of water accounts for one half of the changes in temperature and salinity and 30% of those in oxyty. Other factors, such as a shift of water masses, may also be important.
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Jumbo squid (Dosidicus gigas) and purpleback squid (Sthenoteuthis oualaniensis) (Teuthida: Ommastrephidae) are thought to spawn in the eastern tropical Pacific. We used 10 years of plankton tow and oceanographic data collected in this region to examine the reproductive habits of these 2 ecologically important squid. Paralarvae of jumbo squid and purpleback squid were found in 781 of 1438 plankton samples from surface and oblique tows conducted by the Southwest Fisheries Science Center (NOAA) in the eastern tropical Pacific over the 8-year period of 1998–2006. Paralarvae were far more abundant in surface tows (maximum: 1588 individuals) than in oblique tows (maximum: 64 individuals). A generalized linear model analysis revealed sea-surface temperature as the strongest environmental predictor of paralarval presence in both surface and oblique tows; the likelihood of paralarval presence increases with increasing temperature. We used molecular techniques to identify paralarvae from 37 oblique tows to species level and found that the purpleback squid was more abundant than the jumbo squid (81 versus 16 individuals).
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Stichaeidae, commonly referred to as pricklebacks, are intertidal and subtidal fishes primarily of the North Pacific Ocean. Broad distribution in relatively inaccessible and undersampled habitats has contributed to a general lack of information about this family. In this study, descriptions of early life history stages are presented for 25 species representing 18 genera of stichaeid fishes from the northeastern Pacific Ocean, Bering Sea, and Arctic Ocean Basin. Six of these species also occur in the North Atlantic Ocean. Larval stages of 16 species are described for the first time. Additional information or illustrations intended to augment previous descriptions are provided for nine species. For most taxa, we present adult and larval distributions, descriptions of morphometric, meristic, and pigmentation characters, and species comparisons, and we provide illustrations for preflexion through postflexion or transformation stages. New counts of meristic features are reported for several species.