WorldWideScience

Sample records for central north pacific

  1. Systematic and integrated approach to tropical cyclone track forecasting in the eastern and central North Pacific

    OpenAIRE

    White, Sean R.

    1995-01-01

    This study is the application of the meteorological framework in the Systematic Approach to tropical cyclone track forecasting of Carr and Elsberry to the eastern and central North Pacific tropical cyclones. All eastern and central North Pacific tropical cyclones from 1990-1993 are examined using 500 mb Navy Operational Global Atmospheric Prediction System streamline and isotach analyses, geostationary satellite imagery, and the tropical cyclone best track information. Application of the Syst...

  2. Decadal oscillation of autumn precipitation in Central Vietnam modulated by the East Pacific-North Pacific (EP-NP) teleconnection

    Science.gov (United States)

    Li, R.; Wang, S.-Y.; Gillies, R. R.; Buckley, B. M.; Truong, L. H.; Cho, C.

    2015-02-01

    Autumn precipitation over Central Vietnam is associated with an increase in the occurrence of tropical cyclones that lead to frequent flooding and pose a significant threat to lives and property. The present analyses reveal a pronounced decadal oscillation of autumn precipitation in Central Vietnam within the 8-11 year frequency band that is modulated by the East Pacific-North Pacific (EP-NP) teleconnection. The negative phase of the EP-NP pattern is associated with a positive sea surface temperature (SST) anomaly in the South China Sea (SCS) that induces low-level convergence, enhances convection, and increases precipitation over Central Vietnam and adjacent islands including Hainan (China) and the Philippines. This circulation feature around the SCS is embedded in a large-scale circulation associated with SST anomalies across the Pacific Ocean—i.e., cooling in the Eastern and Central tropical Pacific sandwiched by warming in the North and South Pacific as well as the Western Pacific Ocean. The positive phase of the EP-NP features opposite SST and circulation anomalies, with the result being reduced rainfall in Central Vietnam. This out-of-phase relationship and shared decadal spectral coherence between the EP-NP index and autumn precipitation in Central Vietnam might be useful for future climate predictions and flood management.

  3. Changing central Pacific El Niños reduce stability of North American salmon survival rates.

    Science.gov (United States)

    Kilduff, D Patrick; Di Lorenzo, Emanuele; Botsford, Louis W; Teo, Steven L H

    2015-09-01

    Pacific salmon are a dominant component of the northeast Pacific ecosystem. Their status is of concern because salmon abundance is highly variable--including protected stocks, a recently closed fishery, and actively managed fisheries that provide substantial ecosystem services. Variable ocean conditions, such as the Pacific Decadal Oscillation (PDO), have influenced these fisheries, while diminished diversity of freshwater habitats have increased variability via the portfolio effect. We address the question of how recent changes in ocean conditions will affect populations of two salmon species. Since the 1980s, El Niño Southern Oscillation (ENSO) events have been more frequently associated with central tropical Pacific warming (CPW) rather than the canonical eastern Pacific warming ENSO (EPW). CPW is linked to the North Pacific Gyre Oscillation (NPGO), whereas EPW is linked to the PDO, different indicators of northeast Pacific Ocean ecosystem productivity. Here we show that both coho and Chinook salmon survival rates along western North America indicate that the NPGO, rather than the PDO, explains salmon survival since the 1980s. The observed increase in NPGO variance in recent decades was accompanied by an increase in coherence of local survival rates of these two species, increasing salmon variability via the portfolio effect. Such increases in coherence among salmon stocks are usually attributed to controllable freshwater influences such as hatcheries and habitat degradation, but the unknown mechanism underlying the ocean climate effect identified here is not directly subject to management actions. PMID:26240365

  4. A comparison of plastic and plankton in the North Pacific central gyre

    Energy Technology Data Exchange (ETDEWEB)

    Moore, C.J.; Moore, S.L. [Algalita Marine Research Foundation, Long Beach, CA (United States); Leecaster, M.K.; Weisberg, S.B. [Southern California Coastal Water Research Project, Westminster, CA (United States)

    2001-07-01

    The potential for ingestion of plastic particles by open ocean filter feeders was assessed by measuring the relative abundance and mass of neustonic plastic and zooplankton in surface waters under the central atmospheric high-pressure cells of the North Pacific Ocean. Neuston samples were collected at 11 random sites, using a manta trawl lined with 333 u mesh. The abundance and mass of neustonic plastic was the largest recorded anywhere in the Pacific Ocean at 334271 pieces km{sup 2} and 5114gkm{sup 2}, respectively. Plankton abundance was approximately five times higher than that of plastic, but the mass of plastic was approximately six times that of plankton. The most frequently sampled types of identifiable plastic were thin films, polypropylene/monofilament line and unidentified plastic, most of which were miscellaneous fragments. Cumulatively, these three types accounted for 98% of the total number of plastic pieces. (Author)

  5. Decadal oscillation of autumn precipitation in Central Vietnam modulated by the East Pacific–North Pacific (EP–NP) teleconnection

    International Nuclear Information System (INIS)

    Autumn precipitation over Central Vietnam is associated with an increase in the occurrence of tropical cyclones that lead to frequent flooding and pose a significant threat to lives and property. The present analyses reveal a pronounced decadal oscillation of autumn precipitation in Central Vietnam within the 8–11 year frequency band that is modulated by the East Pacific–North Pacific (EP–NP) teleconnection. The negative phase of the EP–NP pattern is associated with a positive sea surface temperature (SST) anomaly in the South China Sea (SCS) that induces low-level convergence, enhances convection, and increases precipitation over Central Vietnam and adjacent islands including Hainan (China) and the Philippines. This circulation feature around the SCS is embedded in a large-scale circulation associated with SST anomalies across the Pacific Ocean—i.e., cooling in the Eastern and Central tropical Pacific sandwiched by warming in the North and South Pacific as well as the Western Pacific Ocean. The positive phase of the EP–NP features opposite SST and circulation anomalies, with the result being reduced rainfall in Central Vietnam. This out-of-phase relationship and shared decadal spectral coherence between the EP–NP index and autumn precipitation in Central Vietnam might be useful for future climate predictions and flood management. (letter)

  6. Food of Flesh-footed shearwaters Puffinus carneipes associated with high-seas driftnets in the central North Pacific Ocean

    Science.gov (United States)

    Gould, P.; Ostrom, P.; Walker, W.

    1997-01-01

    We examined digestive tract contents and stable nitrogen isotope ratios in breast muscles of Flesh-footed Shearwaters Puffinus carneipes associated with high-seas driftnet fisheries in the central North Pacific Ocean. Small fish, Lanternfish (Myctophidae) and Pacific Saury Cololabis saira, were the principal prey found in the digestive tracts. Pieces of unidentified fish, possibly Pacific Pomfret Brama japonica, and shredded squid tissue, mostly Neon Flying Squid Ommastrephes bartrami, in the digestive tracts indicate scavenging at driftnet fishing operations. Although softbodied animals such as Velella sp. were rare in the digestive tracts, low stable nitrogen isotope values (??15N) suggest Flesh-footed Shearwaters feed heavily on such low trophic level animals.

  7. Spatiotemporal variability in bigeye tuna ( Thunnus obesus) dive behavior in the central North Pacific Ocean

    Science.gov (United States)

    Howell, Evan A.; Hawn, Donald R.; Polovina, Jeffrey J.

    2010-07-01

    Data from 29 pop-up archival transmission (PAT) tags deployed on commercial-size bigeye tuna ( Thunnus obesus) in the central North Pacific Ocean from 4°N to 32°N were analyzed to describe variability in their dive behavior across space and time. During the day, bigeye tuna generally spent time in the 0-50 m and 300-400 m depth ranges, with spatial and temporal variability in the deep mode. At night, bigeye tuna generally inhabited the 0-100 m depth range. Three daily dive types were defined based on the percentage of time tuna spent in specific depth layers during the day. These three types were defined as shallow, intermediate, and deep and represented 24.4%, 18.8%, and 56.8% of the total number of days in the study, respectively. More shallow and intermediate dive-type behavior was found in the first half of the year, and in latitudes from 14°N to 16°N and north of 28°N. A greater amount of deep-dive behavior was found in the regions south of 10°N and between 18°N and 28°N during the third and fourth quarters of the year. Dive-type behavior also varied with oceanographic conditions, with more shallow and intermediate behavior found in colder surface waters. Intermediate and deep-dive types were pooled to reflect the depths where bigeye tuna may have potential interactions with fishing gear. A Generalized Additive Model was used to quantify the effects of time, space, and sea surface temperature on this pooled dive type. Results from the model showed that while latitude and quarter of the year were important parameters, sea surface temperature had the most significant effect on the pooled intermediate and deep-dive behavior. Model predictions indicated that the largest percentage of potential interaction would occur in the fourth quarter in the region from 18°N-20°N, which corresponds to the time and place of the highest bigeye tuna catch rates by the Hawaii-based long-line fishery. These results suggest that a model framework using these three

  8. Impacts of decaying eastern and central Pacific El Niños on tropical cyclone activities over the western North Pacific in summer

    Science.gov (United States)

    Yang, Yuxing; Xie, Ruihuang; Wang, Faming; Huang, Fei

    2016-07-01

    We investigate the influences of the decaying eastern Pacific El Niño (EP-El Niño) and central Pacific El Niño (CP-El Niño) on tropical cyclone (TC) activities in the western North Pacific (WNP) during July, August, and September (JAS). During this period, TC geneses and tracks are reduced in the central and eastern WNP. However, TC tracks reaching the Philippines increase, and more TC geneses appear west of 145°E during EP-El Niño. During CP-El Niño, tracks reaching the South China Sea (SCS) and southeast coast of China increase, and positive anomalies of TC genesis are found in the southern part of the central WNP and southern SCS. It is possible that the different variations of the anomalous anticyclone over east of the Philippines in the WNP induced by El Niños are instrumental to the different TC variations in the two types of decaying El Niños during JAS. Compared with EP-El Niño, strengthening and northward expansion of the anomalous anticyclone during CP-El Niño cause a westward shift of the western Pacific subtropical high in summer, which is responsible for more westward TC tracks over the SCS and southeast coast of China. This northward expansion can cause the center of suppressed TC geneses in the central WNP to migrate further north during CP-El Niño. A decreased magnitude of vertical shear dominates the southern part of the central WNP and southern SCS, which enhances TC formation in these regions during CP-El Niño.

  9. Impacts of decaying eastern and central Pacific El Niños on tropical cyclone activities over the western North Pacific in summer

    Science.gov (United States)

    Yang, Yuxing; Xie, Ruihuang; Wang, Faming; Huang, Fei

    2015-05-01

    We investigate the influences of the decaying eastern Pacific El Niño (EP-El Niño) and central Pacific El Niño (CP-El Niño) on tropical cyclone (TC) activities in the western North Pacific (WNP) during July, August, and September (JAS). During this period, TC geneses and tracks are reduced in the central and eastern WNP. However, TC tracks reaching the Philippines increase, and more TC geneses appear west of 145°E during EP-El Niño. During CP-El Niño, tracks reaching the South China Sea (SCS) and southeast coast of China increase, and positive anomalies of TC genesis are found in the southern part of the central WNP and southern SCS. It is possible that the different variations of the anomalous anticyclone over east of the Philippines in the WNP induced by El Niños are instrumental to the different TC variations in the two types of decaying El Niños during JAS. Compared with EP-El Niño, strengthening and northward expansion of the anomalous anticyclone during CP-El Niño cause a westward shift of the western Pacific subtropical high in summer, which is responsible for more westward TC tracks over the SCS and southeast coast of China. This northward expansion can cause the center of suppressed TC geneses in the central WNP to migrate further north during CP-El Niño. A decreased magnitude of vertical shear dominates the southern part of the central WNP and southern SCS, which enhances TC formation in these regions during CP-El Niño.

  10. Sup(14)C activity of dissolved organic carbon fractions in the north-central Pacific and Sargasso Sea

    International Nuclear Information System (INIS)

    Radiocarbon measurements of dissolved organic carbon (DOC) oxidizable by ultraviolet irradiation (DOCuv) yielded apparent ages of ∼6,000 yr in the deep waters of the oligotrophic north-central Pacific gyre. Recent reports of a potentially larger pool of DOC as measured by high-temperature catalytic combustion (DOChtc) using discrete injections of sea water have led to speculation that 'younger', more recently produced DOC could contribute significantly to overall oceanic organic carbon fluxes, owing to its suspected greater biological lability. Here we present a comparison of Δ14C (the deviation in parts per thousand from the 14C activity of nineteenth-century wood) of the DOChtc, DOCuv and humic substances in profiles from the oligotrophic north-central Pacific and Sargasso Sea. For each ocean, the Δ14C values of all three fractions are remarkably similar, yielding no evidence for a component of DOC that is cycled through the system on timescales shorter than several thousands of years. We observe an age difference between the two oceans of ∼2,000 yr for the deepest DOC, which can largely be accounted for by differences in the Δ14C of the DOC sources to the deep basins, and by the different deep-water circulation patterns and transit times in the two oceans. (author)

  11. AFSC/NMML: Shore-based counts of the Eastern North Pacific gray whale stock from central California, 1967 - 2007

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Marine Fisheries Service (NMFS) has conducted shore-based counts of the Eastern North Pacific stock of gray whales (Eschrichtius robustus) 26 years...

  12. Localized double-array stacking analysis of PcP: D″ and ULVZ structure beneath the Cocos plate, Mexico, central Pacific, and north Pacific

    Science.gov (United States)

    Hutko, Alexander R.; Lay, Thorne; Revenaugh, Justin

    2009-01-01

    A large, high quality P-wave data set comprising short-period and broadband signals sampling four separate regions in the lowermost mantle beneath the Cocos plate, Mexico, the central Pacific, and the north Pacific is analyzed using regional one-dimensional double-array stacking and modelling with reflectivity synthetics. A data-screening criterion retains only events with stable PcP energy in the final data stacks used for modelling and interpretation. This significantly improves the signal stacks relative to including unscreened observations, allows confident alignment on the PcP arrival and allows tight bounds to be placed on P-wave velocity structure above the core–mantle boundary (CMB). The PcP reflections under the Cocos plate are well modelled without any ultra-low velocity zone from 5 to 20°N. At latitudes from 15 to 20°N, we find evidence for two P-wave velocity discontinuities in the D″ region. The first is ∼182 km above the CMB with a δln Vp of +1.5%, near the same depth as a weaker discontinuity (<+0.5%) observed from 5 to 15°N in prior work. The other reflector is ∼454 km above the CMB, with a δln Vp of +0.4%; this appears to be a shallower continuation of the joint P- and S-wave discontinuity previously detected south of 15° N, which is presumed to be the perovskite to post-perovskite phase transition. The data stacks for paths bottoming below Mexico have PcP images that are well matched with the simple IASP91 structure, contradicting previous inferences of ULVZ presence in this region. These particular data are not very sensitive to any D″ discontinuities, and simply bound them to be <∼2%, if present. Data sampling the lowermost mantle beneath the central Pacific confirm the presence of a ∼15-km thick ultra-low velocity zone (ULVZ) just above the CMB, with δln Vp and δln Vs of around −3 to −4% and −4 to −8%, respectively. The ULVZ models predict previous S-wave data stacks well. The data for this region

  13. Direct observation of 134Cs and 137Cs in surface seawater in the western and central North Pacific after the Fukushima Dai-ichi nuclear power plant accident

    Directory of Open Access Journals (Sweden)

    H. Kaeriyama

    2013-06-01

    Full Text Available The horizontal distribution of radioactive cesium (Cs derived from the Fukushima Dai-ichi nuclear power plant (FNPP in the North Pacific is still unclear due to the limitation of direct measurement of the seawater in the open ocean. We present the result of direct observation of radioactive Cs in surface seawater collected from a broad area in the western and central North Pacific in July 2011, October 2011 and July 2012. We also conducted a simple particle tracking experiment to estimate the qualitative spatial distribution of radioactive Cs in the North Pacific. 134Cs was detected at 94 stations out of 123 stations, and 137Cs was detected at all stations. High 134Cs and 137Cs concentrations more than 10 m Bq kg−1 were observed in the area of the northern part of Kuroshio Extension at 144° E and 155° E in July 2011, in the area 147–175° E around 40° N in October 2011, and the northern part of Kuroshio Extension at 155° E and 175°30´ E in July 2012. Combining the result of direct observations and particle tracking experiment, the radioactive Cs derived from the FNPP had been dispersed eastward to the central North Pacific during 2011. It was considered from the horizontal distribution that radioactive Cs was dispersed not only eastward but also north- and southward in the central North Pacific. Pronounced dilution process of radioactive Cs from the FNPP during study period is suggested from temporal change in the activity ratio of 134Cs / 137Cs, which was decay-corrected on 6 April 2011, and relationships between radioactive Cs and temperature.

  14. The North Pacific Gyre Mode

    Science.gov (United States)

    Schneider, N.; di Lorenzo, E.

    2007-12-01

    Discussion of North Pacific Decadal decadal variability has focused primarily on the Pacific Decadal Oscillation, the leading mode of sea surface temperature anomalies north of the tropics. The PDO appears to result from a superposition of SST pattern forced by the North Pacific atmosphere due to its intrinsic dynamics and teleconnected from the tropics, with a regional impact of the ocean circulation in the frontal regions associated with the Kuroshio/Oyashio and their extensions into the interior. Recent modeling, however, suggest that previously unexplained decadal changes of salinity, nutrient upwelling and chlorophyl in the California Current are not dominated by the PDO. Rather, these are associated with a mode of variability associated with wind driven changes of the North Pacific Gyre. Consideration of this mode variability may thus be important to understand present and future variations of the North Pacific ecosystem, and in the interpretation of climate proxies.

  15. Feature Analysis of Ocean Waves in North Central Pacific Ocean Based ASAR Wave Spectral Data and Wave Model

    Science.gov (United States)

    Wang, Jichao; Zhang, Jie; Yang, Jungang; Meng, Junmin

    2013-01-01

    Directional Spectrum of the ocean waves could be obtained form Envisat advanced synthetic aperture radar (ASAR) wave spectral data. The wave model WAVEWATCH III (WW3) is applied to simulate the ocean wave field. Study area is 185°E-215°E and 15°N-30°N, time range is from 1 January 2008 to 31 December 2008. Based on ASAR and buoy data, the wave numerical simulation and assimilation of the north central Pacific Ocean is carried out. The validation and assessment of ASAR ocean wave spectra products is performed. The optimal interpolation (OI) algorithm is used in model WW3 for assimilating ASAR wave spectra data. Based on the result of the simulation and assimilation, mean waves direction (MWD), significant wave height (SWH) and mean wave period (MWP) are analysed. SWH and MWP are larger in winter and SWH reach to more than 2.5 meters. Seasonal change of SWH and MWP are significant.

  16. Uranium and thorium enrichment in rocks from the base of DSDP Hole 465A, Hess Rise, central North Pacific

    Science.gov (United States)

    Hein, J.R.; Koski, R.A.; Morgenson, L.A.

    1982-01-01

    Uranium and thorium are concentrated in Cretaceous limestone, chert, ash, basalt, and other rock types at Deep Sea Drilling Project Site 465 located on the southern Hess Rise in the central North Pacific. U concentrations, up to 194 ppm on a carbonate-free basis, are among the highest recorded for any deep-sea deposits. U was initially derived from seawater and concentrated by absorption on terrigenous (humic) organic matter in limestone in a shallow marine environment. U and Th were probably concentrated further by low-temperature hydrothermal fluids emanating from the basaltic basement. Mainly montmorillonite, an alteration product of basalt and ash, and organic matter in sedimentary rocks acted as hosts for U and Th. The unique combination of sediments rich in humic organic matter, abundant smectite in altered ash and basalt, and warm hydrothermal solutions provided the necessary conditions for migration and concentration of U and Th. To better understand the conditions limiting the migrating and concentration of U and Th, other rocks deposited during the ocean-wide Cretaceous anoxic events should be analyzed for these elements. ?? 1982.

  17. Temperature, salinity, nutrients, oxygen and other data profiles from CTD and bottle casts from NOAA/NMFS cruises of the R/V Townsend Cromwell in the central north Pacific, 1997-2002 (NODC Accession 0100295)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains measurements from CTD hydrocast stations from seven cruises of the R/V Townsend Cromwell in the central north Pacific from 1997 to 2002...

  18. The interdecadal trend and shift of dry/wet over the central part of North China and their relationship to the Pacific Decadal Oscillation (PDO)

    Institute of Scientific and Technical Information of China (English)

    MA ZhuGuo

    2007-01-01

    Based on monthly precipitation and monthly mean surface air temperature (SAT), the dry/wet trends and shift of the central part of North China and their relationship to the Pacific Decadal Oscillation (PDO) from 1951 to 2005 have been analyzed through calculating surface wetness index (SWI). The results indicate that there was a prominent drying trend and an abrupt change in the analysis period. A persistent warming period with less precipitation from the mid and late 1970s to present was found, and a shift process exists from the wet to the dry in the central part of North China during 1951-2005. The transition is located in the mid to late 1970s, which should be related to the shift variation of large-scale climate background. The correlation analysis has brought about a finding of significant correlativity between PDO index (PDOI) and SAT, precipitation and SWI in this region. The correlation exhibits that the positive phase of PDOI (warm PDO phase) matches warming, less precipitation and the drought period, and the negative PDOI phase corresponds to low SAT, more precipitation and the wet period. The duration of various phases is more than 25 years. The decadal variation of sea surface temperature (SST) in the North Pacific Ocean is one of the possible causes in forming the decadal dry/wet trend and shift of the central part of North China.

  19. North Pacific Pelagic Seabird Database (NPPSD)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The North Pacific Pelagic Seabird Database (NPPSD) was created in 2005 to consolidate data on the oceanic distribution of marine bird species in the North Pacific....

  20. Cesium-134 and 137 activities in the central North Pacific Ocean after the Fukushima Dai-ichi nuclear power plant accident

    Directory of Open Access Journals (Sweden)

    J. Kameník

    2013-03-01

    Full Text Available Surface seawater 134Cs and 137Cs samples were collected in the central and western North Pacific Ocean during the 1.5 yr after the Fukushima Dai-ichi nuclear power plant accident to monitor dispersion patterns of these radioisotopes towards the Hawaiian Islands. In the absence of other recent sources and due to its short half-life only those parts of the Pacific Ocean would have detectable 134Cs that were impacted by Fukushima releases. Between March and May 2011, 134Cs was not detected around the Hawaiian Islands and Guam. Here, most 137Cs activities (1.2–1.5 Bq m−3 were in the range of expected preexisting levels. Some samples north of the Hawaiian Islands (1.6–1.8 Bq m−3 were elevated above the 18-month baseline established in surface seawater in Hawaii indicating that those might carry atmospheric fallout. The 18-month time-series analysis of surface seawater from Hawaii did not reveal any seasonal variability or trends, with an average activity of 1.46 ± 0.06 Bq m−3 (Station Aloha, 17 values. In contrast, samples collected between Japan and Hawaii contained 134Cs activities in the range of 1–4 Bq m−3 and 137Cs levels were about 2–3 times above the preexisting activities. We found that the southern boundary of the Kuroshio and Kuroshio extension currents represented a boundary for radiation dispersion with higher activities detected within and north of the major currents. The radiation plume has not been detected over the past 1.5 yr at the main Hawaiian Islands due to the transport patterns across the Kuroshio and Kuroshio extension currents.

  1. Cesium-134 and 137 activities in the central North Pacific Ocean after the Fukushima Dai-ichi Nuclear Power Plant accident

    Directory of Open Access Journals (Sweden)

    J. Kameník

    2013-09-01

    Full Text Available Surface seawater 134Cs and 137Cs samples were collected in the central and western North Pacific Ocean during the 2 yr after the Fukushima Dai-ichi Nuclear Power Plant accident to monitor dispersion patterns of these radioisotopes towards the Hawaiian Islands. In the absence of other recent sources and due to its short half-life, only those parts of the Pacific Ocean would have detectable 134Cs values that were impacted by Fukushima releases. Between March and May 2011, 134Cs was not detected around the Hawaiian Islands and Guam. Here, most 137Cs activities (1.2–1.5 Bq m–3 were in the range of expected preexisting levels. Some samples north of the Hawaiian Islands (1.6–1.8 Bq m–3 were elevated above the 23-month baseline established in surface seawater in Hawaii indicating that those might carry atmospheric fallout. The 23-month time-series analysis of surface seawater from Hawaii did not reveal any seasonal variability or trends, with an average activity of 1.46 ± 0.06 Bq m–3 (Station Aloha, 18 values. In contrast, samples collected between Japan and Hawaii contained 134Cs activities in the range of 1–4 Bq m–3, and 137Cs levels were about 2–3 times above the preexisting activities. We found that the southern boundary of the Kuroshio and Kuroshio extension currents represented a boundary for radiation dispersion with higher activities detected within and north of the major currents. The radiation plume has not been detected over the past 2 yr at the main Hawaiian Islands due to the transport patterns across the Kuroshio and Kuroshio extension currents.

  2. Impact of the Interdecadal Pacific Oscillation on Tropical Cyclone Activity in the North Atlantic and Eastern North Pacific

    OpenAIRE

    Wenhong Li; Laifang Li; Yi Deng

    2015-01-01

    Tropical cyclones (TCs) are among the most devastating weather systems affecting the United States and Central America (USCA). Here we show that the Interdecadal Pacific Oscillation (IPO) strongly modulates TC activity over the North Atlantic (NA) and eastern North Pacific (eNP). During positive IPO phases, less (more) TCs were observed over NA (eNP), likely due to the presence of stronger (weaker) vertical wind shear and the resulting changes in genesis potential. Furthermore, TCs over NA te...

  3. North Central Thailand

    Science.gov (United States)

    1998-01-01

    This radar image shows the dramatic landscape in the Phang Hoei Range of north central Thailand, about 40 kilometers (25 miles) northeast of the city of Lom Sak. The plateau, shown in green to the left of center, is the area of Phu Kradung National Park. This plateau is a remnant of a once larger plateau, another portion of which is seen along the right side of the image. The plateaus have been dissected by water erosion over thousands of years. Forest areas appear green on the image; agricultural areas and settlements appear as red and blue. North is toward the lower right. The area shown is 38 by 50 kilometers (24 by 31 miles) and is centered at 16.96 degrees north latitude, 101.67 degrees east longitude. Colors are assigned to different radar frequencies and polarizations as follows: red is L-band horizontally transmitted and horizontally received; green is L-band horizontally transmitted and vertically received; blue is C-band horizontally transmitted and vertically received. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture (SIR-C/X-SAR) imaging radar on October 3, 1994, when it flew aboard the space shuttle Endeavour. SIR-C/X-SAR is a joint mission of the U.S./German and Italian space agencies.Spaceborne Imaging Radar-C and X-Band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA

  4. Legacy and contemporary persistent organic pollutants in North Pacific albatross.

    Science.gov (United States)

    Harwani, Suhash; Henry, Robert W; Rhee, Alexandra; Kappes, Michelle A; Croll, Donald A; Petreas, Myrto; Park, June-Soo

    2011-11-01

    Here we report the first measurements of polybrominated diphenyl ethers (PBDE 47, 99, and 153) alongside 11 organochlorine pesticides (OCPs) and 28 polychlorinated biphenyls (PCBs) in the plasma of albatross from breeding colonies distributed across a large spatial east-west gradient in the North Pacific Ocean. North Pacific albatross are wide-ranging, top-level consumers that forage in pelagic regions of the North Pacific Ocean, making them an ideal sentinel species for detection and distribution of marine contaminants. Our work on contaminant burdens in albatross tissue provides information on transport of persistent organic pollutants (POPs) to the remote North Pacific and serves as a proxy for regional environmental quality. We sampled black-footed (Phoebastria nigripes; n = 20) and Laysan albatross (P. immutabilis; n = 19) nesting on Tern Island, Hawaii, USA, and Laysan albatross (n = 16) nesting on Guadalupe Island, Mexico. Our results indicate that North Pacific albatross are highly exposed to both PCBs and OCPs, with levels ranging from 8.8 to 86.9 ng/ml wet weight and 7.4 to 162.3 ng/ml wet weight, respectively. A strong significant gradient exists between Laysan albatross breeding in the Eastern Pacific, having approximately 1.5-fold and 2.5-fold higher levels for PCBs and OCPs, respectively, compared to those from the Central Pacific. Interspecies levels of contaminants within the same breeding site also showed high variation, with Tern black-footed albatross having approximately threefold higher levels of both PCBs and OCPs than Tern Laysan albatross. Surprisingly, while PBDEs are known to travel long distances and bioaccumulate in wildlife of high trophic status, we detected these three PBDE congeners only at trace levels ranging from not detectable (ND) to 0.74 ng/ml wet weight in these albatross. PMID:21898564

  5. North Pacific sea ice cover, a predictor for the Western North Pacific typhoon frequency?

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The relationship between the sea ice cover in the North Pacific and the typhoon frequency has been studied in this paper. It follows that the index for the sea ice cover in the North Pacific (ISA) both in December-January-February (DJF) and in March-April-May (MAM) is negatively correlated with annual typhoon number over the western North Pacific (TNWNP) during 1965―2004, with correlation coeffi-cients of -0.42 and -0.49 respectively (above 99% significant level). Large sea ice cover in the North Pacific tends to decrease TNWNP. Positive ISA (MAM) is associated with the tropical circulation and SST anomalies in the North Pacific, which may lead to unfavorable dynamic and thermal conditions for typhoon genesis over WNP from June to October (JJASO). The variability of the atmospheric circula-tion over the North Pacific, associated with the ISA anomaly in MAM is connected to the tropical at-mospheric circulation variability in MAM via the teleconnection wave train. Besides, as the tropical circulation has strong seasonal persistency from the MAM to JJASO, thus, the ISA in MAM-related variability of the tropical atmospheric circulation as well as the SST can affect the typhoon activity over the western North Pacific.

  6. What happened to Pacific salmon in the North Pacific Ocean during the years of an El Nino event?

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, Y.; Azumaya, T.; Ito, S.; Ueno, Y.; Wakabayashi, K. [National Research Inst. of Far Seas Fisheries, Shimizu, Shizuoka (Japan)

    1998-12-31

    This study compared the relative abundance of salmon in the North Pacific Ocean in an El Nino year with that of normal years. Beginning in 1991, four Japanese salmon research vessels in the Gulf of Alaska and Bering Sea collected data of the sea surface temperature in the North Pacific Ocean. The data showed that the magnitude of the El Nino event in 1997-98 was different from the 1991-92 El Nino event. The relative abundance of salmon was compared between normal years from 1993 to 1996 and the 1997 El Nino year. It was determined that sockeye salmon abundance increased in the Bering Sea and Gulf of Alaska, but decreased in the western and central North Pacific in 1997. Chum salmon abundance decreased in the Gulf of Alaska, but increased in the western and central North Pacific in 1997. 1 tab., 4 figs.

  7. Extreme winds in the Western North Pacific

    DEFF Research Database (Denmark)

    Ott, Søren

    2006-01-01

    A statistical model for extreme winds in the western North Pacific is developed, the region on the Planet where tropical cyclones are most common. The model is based on best track data derived mostly from satellite images of tropical cyclones. The methodsused to estimate surface wind speeds from...

  8. Analysis of ''echo sounding'' data North-Central Pacific (including R/V VEMA marine geology/geophysics cruise in the North Pacific). Progress report, July 1, 1975--May 15, 1976. [Geophysical surveys in North Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, D.E.; Moody, R.

    1976-01-01

    Marine geological and geophysical data have been collated and synthesized for the area in the North Pacific bounded by 29/sup 0/N and 31/sup 0/N; 156/sup 0/W and 160/sup 0/W. Particular emphasis has been given to assessing the disposition of the sediment blanket and underlying crystalline basement (layer 2) through the examination of a variety of seismic observations. In July 1975 a 15-day cruise aboard R/V VEMA focused on the collection of a suite of piston cores, heat-flow measurements, high and low frequency seismic profiling, wide angle seismic reflection/refraction using sonobuoys, special near-bottom seismic experiments bathymetric measurements, special heat-transfer experiments, and a variety of complementary marine geological and geophysical observations. The preliminary results of the cruise and their interpretation in the framework of other existing data is summarized.

  9. Dynamics of the Central American Pacific

    Science.gov (United States)

    Vieytez, Begonia; Marrero-Díaz, Ángeles; José Machín, Francisco; José Gavidia, Francisco; Castro, Mi

    2014-05-01

    The Central American Pacific (CAP) is the area located in front of the Central America coast, within the Eastern Tropical Pacific region (ETP). The CAP dynamic is strongly influenced by the NE and SE trade winds, also this area is characterized by the presence of coastal wind jets at Gulf of Papagayo and Gulf of Panama, which are product of wind pulses blowing through the mountain gaps of the central cordillera, generating important eddies as the cyclonic eddy of Costa Rica Dome (CRD). Nevertheless, the implications of the topography of the continental margin of Central America in the determination of the dynamic processes in the area related to the action of winds and currents are still unknown. Between November and December 2010 (dry season), onboard the R/V Miguel Oliver, oceanographic parameters were measured in the CAP area, which despite its importance, has been poorly investigated until date. Available oceanographic information was processed in order to describe the dynamic along the Pacific coast of Central America, which is notable for its particularly strong stratification in the water column and the distribution of properties, as response to the presence of areas with high temperatures (above 28° C) and other areas with salinity minimum (less than 24). In this study was possible to distinguish three hydrographic zones: PM, south, in the adjacent region to Gulf of Panama, PY, in the center, in the adjacent region to Gulf of Papagayo, and FC, to the north, in the adjacent region to Gulf of Fonseca. The surface transformations of the water bodies, from south to north, observed in these zones could be indicting the presence of Costa Rica current. The prevailing wind system is the main force of variations in the surface distribution of the temperature in the area, and they are responsible of important structures as the anticyclonic eddy in front Gulf of Fonseca, eddies derived from the wind pulses of Gulf of Papagayo, and the relatively low temperatures in

  10. Immunohistochemical localization of CYP1A, vitellogenin and Zona radiata proteins in the liver of swordfish (Xiphias gladius L.) taken from the Mediterranean Sea, South Atlantic, South Western Indian and Central North Pacific Oceans

    International Nuclear Information System (INIS)

    Cytochrome P4501A (CYP1A) monoxygenase, vitellogenin (Vtg) and Zona radiata proteins (Zrp) are frequently used as biomarkers of fish exposure to organic contaminants. In this work, swordfish liver sections obtained from the Mediterranean Sea, the South African coasts (South Atlantic and South Western Indian Oceans) and the Central North Pacific Ocean were immunostained with antisera against CYP1A, Zrp, and Vtg. CYP1A induction was found in hepatocytes, epithelium of the biliary ductus and the endothelium of large blood vessels of fish from the Mediterranean Sea and South African waters, but not from the Pacific Ocean. Zrp and Vtg were immunolocalized in hepatocytes of male swordfish from the Mediterranean Sea and from South African waters. Plasma Dot-Blot analysis, performed in Mediterranean and Pacific specimens, revealed the presence of Zrp and Vtg in males from Mediterranean but not from Pacific. These results confirm previous findings about the potential exposure of Mediterranean swordfish to endocrine, disrupting chemicals and raise questions concerning the possible presence of xenobiotic contaminants off the Southern coasts of South Africa in both the South Atlantic and South Western Indian Oceans

  11. The isotopic signature of fallout plutonium in the North Pacific

    International Nuclear Information System (INIS)

    Plutonium analyses of a dated coral record from the French Frigate Shoals in the central North Pacific indicate that there are two major sources of Pu in this basin: close-in (tropospheric) fallout from nuclear weapons testing at the Pacific Proving Grounds in the Marshall Islands in the 1950s and global (stratospheric) fallout which peaked in 1962. Furthermore, the 240Pu/239Pu atom ratio of fallout from the Pacific Proving Grounds is characteristically higher (0.24) than that of global fallout Pu (0.18-0.19). Seawater and sediment samples from the North Pacific exhibit a wide range of 240Pu/239Pu values (0.19-0.34), with a trend towards higher ratios in the subsurface waters and sediment. Deep water 240Pu/239Pu ratios are higher in the vicinity of the Marshall Islands relative to stations further from this close-in fallout source. These preliminary data suggest that fallout Pu from the Pacific Proving Grounds is more rapidly removed from the surface waters than is global fallout Pu. Plutonium geochemistry appears to be related to the physical/chemical form of Pu-bearing particles generated by different fallout sources. (author)

  12. Intensified impact of tropical Atlantic SST on the western North Pacific summer climate under a weakened Atlantic thermohaline circulation

    OpenAIRE

    Chen, Wei; Lee, June-Yi; Lu, Riyu; Dong, Buwen; Ha, Kyung-Ja

    2015-01-01

    The tropical North Atlantic (TNA) sea surface temperature (SST) has been identified as one of regulators on the boreal summer climate over the western North Pacific (WNP), in addition to SSTs in the tropical Pacific and Indian Oceans. The major physical process proposed is that the TNA warming induces a pair of cyclonic circulation anomaly over the eastern Pacific and negative precipitation anomalies over the eastern to central tropical Pacific, which in turn lead to an anticyclonic circulati...

  13. Impact of the Interdecadal Pacific Oscillation on Tropical Cyclone Activity in the North Atlantic and Eastern North Pacific

    Science.gov (United States)

    Li, Wenhong; Li, Laifang; Deng, Yi

    2015-07-01

    Tropical cyclones (TCs) are among the most devastating weather systems affecting the United States and Central America (USCA). Here we show that the Interdecadal Pacific Oscillation (IPO) strongly modulates TC activity over the North Atlantic (NA) and eastern North Pacific (eNP). During positive IPO phases, less (more) TCs were observed over NA (eNP), likely due to the presence of stronger (weaker) vertical wind shear and the resulting changes in genesis potential. Furthermore, TCs over NA tend to keep their tracks more eastward and recurve at lower latitudes during positive IPO phases. Such variations are largely determined by changes in steering flow instead of changes in genesis locations. Over the eNP, smaller track variations are observed at different IPO phases with stable, westward movements of TCs prevailing. These findings have substantial implications for understanding decadal to inter-decadal fluctuations in the risk of TC landfalls along USCA coasts.

  14. Vulnerability in north- central Vietnam

    DEFF Research Database (Denmark)

    Casse, Thorkil; Milhøj, Anders; Nguyen, Thao Phuong

    2015-01-01

    This article examines changes in livelihood strategies in response to flooding. It does so on the basis of a household survey which was undertaken in three provinces in north central Vietnam. All households in the survey were regularly affected by flooding, but only poor households experience...

  15. Monitoring cetaceans in the North Pacific

    OpenAIRE

    Stafford, Kathleen M.

    2009-01-01

    Two projects were undertaken in order to monitor cetaceans in the North Pacific. The first was designed to obtain passive acoustic data from the U.S. Navy's Northern Edge Range. Three instruments were deployed in April 2008 to monitor both high (up to 25 kHz) and low (up to 1 kHz) frequencies for odontocetes and mysticetes, respectively. Unfortunately, these instruments did not record any data. The second project was to analyses retrospective data obtained by analysts at the Whidbey Island N...

  16. Shore-based counts of the Eastern North Pacific gray whale stock from central California conducted from 1967-12-18 to 2007-02-22 (NCEI Accession 0138007)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Marine Fisheries Service (NMFS) has conducted shore-based counts of the Eastern North Pacific stock of gray whales (Eschrichtius robustus) 26 years...

  17. Climate Prediction Center (CPC) East Pacific/ North Pacific Teleconnection Pattern Index

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monthly tabulated index of the East Pacific/ North Pacific teleconnection pattern. The data spans the period 1950 to present. The index is derived from a rotated...

  18. North America and Asia Pacific LNG markets

    International Nuclear Information System (INIS)

    The liquefied natural gas (LNG) export opportunities in the Asia Pacific market were reviewed. Some of the differences that affect a North American LNG projects compared to more typical LNG projects were also outlined. The two main aspects of the LNG market in North America include the establishment of LNG import terminals on the east and southern coasts of the United States and the development of export oriented LNG projects. The Pac-Rim LNG project calls for initial delivery to South Korea of 4.0 MTPA by the end of 2000. A large LNG project has also been proposed for the year 2005 which would use Prudhoe Bay gas. Generally, in North America, there is little use for large scale LNG import projects because of the vast pipeline network that delivers gas reliably and at low cost anywhere in North America. However, LNG remains a good alternative for the Asia Pacific region because of the lack of a pipeline network. Also, Japan, Korea and Taiwan, the three main centers for LNG demand, have no domestic energy supplies and rely on imported energy sources. China is another major market opportunity for LNG. The Pac-Rim LNG project differs from others of its kind in that usually, an LNG project is based on the availability of large reservoirs of natural gas owned by state governments and involves production agreements with multi-national oil and gas companies. This scenario is simply not possible in Canada's deregulated environment. In contrast, the existence of upstream facilities, technical expertise, and low capital costs, hence reduced risks and time to develop an LNG project, gives Canada significant advantages. 3 tabs., 3 figs

  19. The response of the North Pacific Decadal Variability to strong tropical volcanic eruptions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Tao [Chinese Academy of Sciences, Nansen-Zhu International Research Center, Institute of Atmospheric Physics, Beijing (China); Otteraa, Odd Helge [Uni Bjerknes Centre, Uni Research, Bergen (Norway); Bjerknes Center for Climate Research, Bergen (Norway); Gao, Yongqi [Chinese Academy of Sciences, Nansen-Zhu International Research Center, Institute of Atmospheric Physics, Beijing (China); Bjerknes Center for Climate Research, Bergen (Norway); Nansen Environmental and Remote Sensing Center, Bergen (Norway); Wang, Huijun [Chinese Academy of Sciences, Nansen-Zhu International Research Center, Institute of Atmospheric Physics, Beijing (China); Chinese Academy of Sciences, Climate Change Research Center, Institute of Atmospheric Physics, Beijing (China)

    2012-12-15

    In this study, the effects of volcanic forcing on North Pacific climate variability, on interannual to decadal time scales, are examined using climate model simulations covering the last 600 years. The model used is the Bergen Climate Model, a fully coupled atmosphere-ocean general circulation model. It is found that natural external forcings, such as tropical strong volcanic eruptions (SVEs) and variations in total solar irradiance, play an important role in regulating North Pacific Decadal Variability (NPDV). In response to tropical SVEs the lower stratospheric pole-to-equator temperature gradient is enhanced. The North polar vortex is strengthened, which forces a significant positive Arctic Oscillation. At the same time, dipole zonal wind anomalies associated with strong polar vortex propagate downward from the lower stratosphere. Through positive feedbacks in the troposphere, the surface westerly winds across the central North Pacific are significantly weakened, and positive sea level pressure anomalies are formed in the North Pacific. This anomalous surface circulation results in changes in the net heat fluxes and the oceanic advection across the North Pacific. As a result of this, warm water converges in the subtropical western North Pacific, where the surface waters in addition are heated by significantly reduced latent and sensible heat fluxes from the ocean. In the eastern and high-latitude North Pacific the ocean loses more heat, and large-scale decreases in sea surface temperatures are found. The overall response of this chain of events is that the North Pacific enters a negative phase of the Pacific decadal oscillation (PDO), and this negative phase of the PDO is maintained for several years. It is thus concluded that the volcanic forcing plays a key role in the phasing of the PDO. The model results furthermore highlight the important role of troposphere-stratosphere coupling, tropical-extratropical teleconnections and extratropical ocean

  20. The History, Present Condition, and Future of the Molluscan Fisheries of North and Central America and Europe: Volume 2, Pacific Coast and Supplemental Topics

    OpenAIRE

    MacKenzie, Jr., Clyde L.; Burrell, Jr. , Victor G.; Rosenfield, Aaron; Hobart, Willis L.

    1997-01-01

    Over 100 molluscan species are landed in Mexico. About 30% are harvested on the Pacific coast and 70% on the Atlantic coast. Clams, scallops, and squid predominate on the Pacific coast (abalone, limpets, and mussels are landed there exclusively). Conchs and oysters predominate on the Atlantic coast. In 1988, some 95,000 metric tons (t) of mollusks were landed, with a value of $33 million. Mollusks were used extensively in prehispanic Mexico as food, tools, and jewelry. Their use as food an...

  1. Dissolved inorganic radiocarbon in the North Pacific Ocean and Sargasso Sea

    OpenAIRE

    Druffel, Ellen R. M.; Bauer, James E; Griffin, Sheila; Beaupré , Steven R; Hwang, Jeomshik

    2008-01-01

    We present radiocarbon measurements of dissolved inorganic carbon (DIC) in depth profiles from reoccupations of our central North Pacific Ocean and Sargasso Sea (SS) sites. From 1985 to 1999, an increase in Δ14C values of 6–17‰ was measured between 1150 and 2400 m depth in the North Central Pacific. Natural changes in deep circulation are likely responsible for variability of Δ14C signatures in the deep ocean, though we cannot rule out the presence of bomb 14C at this depth range. Bomb 14C ha...

  2. Invasive range expansion by the Humboldt squid, Dosidicus gigas, in the eastern North Pacific

    OpenAIRE

    Zeidberg, Louis D.; Robison, Bruce H.

    2007-01-01

    A unique 16-year time series of deep video surveys in Monterey Bay reveals that the Humboldt squid, Dosidicus gigas, has substantially expanded its perennial geographic range in the eastern North Pacific by invading the waters off central California. This sustained range expansion coincides with changes in climate-linked oceanographic conditions and a reduction in competing top predators. It is also coincident with a decline in the abundance of Pacific hake, the most important commercial grou...

  3. Abundance and ecological implications of microplastic debris in the North Pacific Subtropical Gyre

    OpenAIRE

    Goldstein, Miriam Chanita

    2012-01-01

    Plastic pollution in the North Pacific Subtropical Gyre (NPSG), dubbed the "Great Pacific Garbage Patch," has been the subject of substantial public concern. However, there is relatively limited scientific understanding of how microplastic affects pelagic ecosystems. The motivation for this dissertation is to provide scientific information on the extent and impact of microplastic in the NPSG. The dissertation is organized around two central questions : 1) What are the abundance, distribution,...

  4. Analysis of echo sounding data North-Central Pacific (and west North Atlantic). Final technical report, September 1, 1976--March 31, 1978. [Site selection for marine disposal of high-level radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, D.E.

    1978-05-01

    Recognizing the need to consider several potentially suitable sites for disposal of high-level radioactive wastes, a very preliminary search was made through available data for such sites in the North Pacific and West North Atlantic Oceans. The criteria used were: the site must be between high-productivity belts and outside of 200 mile limit; a minimum of 50 meters of sediment, preferably 100 to 150 meters; the sediment should be red clay with minimum or no biogenic components; the sediment should contain no unconformities; and no strong discontinuous internal reflectors; the area should have no tele-seismicity, be topographically subdued, have minimal bottom currents, have no or low economical potential (Mn nodules, etc.), and be large enough (1 to 2/sup 0/ on a side) to be feasible for disposal. Some of these criteria may need to be relaxed; others may need to be added. Seismic data were the basic information used to cull out potential areas, and there are very few areas that meet the criteria as interpreted seismically. Initial site specific data assessment reported included examination of all available geophysical/geological data in and around the MPG-1 area (approximately 29/sup 0/ to 31/sup 0/N; approximately 156/sup 0/ to 160/sup 0/W); a topographic relief was described and the disposition of the thin (less than 100 m) sediment blanket and the acoustic character was mapped. A 15-day cruise was conducted in the MPG-1 area aboard the R/V VEMA and included detailed seismic measurements and heatflow/coring experiments to discern the variability of these parameters.

  5. Subtropical Air-Sea Interaction and Development of Central Pacific El Ni(n)o

    Institute of Scientific and Technical Information of China (English)

    XIE Ruihuang; HUANG Fei; REN Hongli

    2013-01-01

    The standard deviation of the central Pacific sea surface temperature anomaly (SSTA) during the period from October to February shows that the central Pacific SSTA variation is primarily due to the occurrence of the Central Pacific El Ni(n)o (CP-El Ni(n)o)and has a connection with the subtropical air-sea interaction in the northeastern Pacific.After removing the influence of the Eastern Pacific El Ni(n)o,an S-EOF analysis is conducted and the leading mode shows a clear seasonal SSTA evolving from the subtropical northeastern Pacific to the tropical central Pacific with a quasi-biennial period.The initial subtropical SSTA is generated by the wind speed decrease and surface heat flux increase due to a north Pacific anomalous cyclone.Such subtropical SSTA can further influence the establishment of the SSTA in the tropical central Pacific via the wind-evaporation-SST (WES) feedback.After established,the central equatorial Pacific SSTA can be strengthened by the zonal advective feedback and thermocline feedback,and develop into CP-El Ni(n)o.However,as the thermocline feedback increases the SSTA cooling after the mature phase,the heat flux loss and the reversed zonal advective feedback can cause the phase transition of CP-El Ni(n)o.Along with the wind stress variability,the recharge (discharge) process occurs in the central (eastern) equatorial Pacific and such a process causes the phase consistency between the thermocline depth and SST anomalies,which presents a contrast to the original recharge/discharge theory.

  6. Status of marine mammals in the eastern North Pacific Ocean

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers the status or marine mammals in the eastern north Pacific Ocean. Species covered are: sea otter, northern, Guadalupe fur seals, stellar,...

  7. 75 FR 53951 - North Pacific Fishery Management Council; Public Meetings

    Science.gov (United States)

    2010-09-02

    ... Council;s Gulf of Alaska (GOA) and Bering Sea/Aleutian Islands (BS/AI) Groundfish Plan Teams will meet in... (GOA Plan Team) and Traynor Room (BS/AI Plan Team), Seattle, WA. Council address: North Pacific...

  8. 76 FR 71321 - North Pacific Fishery Management Council; Public Meetings

    Science.gov (United States)

    2011-11-17

    ... Anchorage Hilton Hotel. DATES: The Council will begin its plenary session at 8 a.m. on Wednesday, December 7... Hilton Hotel, 500 West Third Avenue, Anchorage, AK. Council address: North Pacific Fishery...

  9. Invasive range expansion by the Humboldt squid, Dosidicus gigas, in the eastern North Pacific.

    Science.gov (United States)

    Zeidberg, Louis D; Robison, Bruce H

    2007-07-31

    A unique 16-year time series of deep video surveys in Monterey Bay reveals that the Humboldt squid, Dosidicus gigas, has substantially expanded its perennial geographic range in the eastern North Pacific by invading the waters off central California. This sustained range expansion coincides with changes in climate-linked oceanographic conditions and a reduction in competing top predators. It is also coincident with a decline in the abundance of Pacific hake, the most important commercial groundfish species off western North America. Recognizing the interactive effects of multiple changes in the environment is an issue of growing concern in ocean conservation and sustainability research. PMID:17646649

  10. Dynamic Mechanism of Interannual Sea Surface Height Variability in the North Pacific Subtropical Gyre

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yong-Chui; ZHANG Li-Feng; L(U) Qing-Ping

    2011-01-01

    In this study, the dynamic mechanisms of interannual sea surface height (SSH) variability are investigated based on the first-mode baroclinic Rossby wave model, with a focus on the effects of different levels of wind stress curl (WSC)、 Maximum covariance analysis (MCA) of WSC and SSH anomalies displays a mode with significant WSC anomalies located primarily in the mid-latitude eastern North Pacific and central tropical Pacific with corresponding SSH anomalies located to the west. This leading mode can be attributed to Ekman pumping induced by local wind stress and the westward-propagating Rossby wave driven by largescale wind stress. It is further found that in the middle latitudes, the SSH anomalies are largely determined by WSC variations associated with the North Pacific Gyre Oscillation (NPGO)、 rather than the Pacific Decadal Oscillation (PDO). The sensitivity of the predictive skill of the linear first-mode baroclinic model to different wind products is also examined.

  11. Preliminary result of dissolved organic radiocarbon in the western North Pacific Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Takayuki, E-mail: tanaka.takayuki@jaea.go.j [AMS Management Section, Japan Atomic Energy Agency, 4-24 Minatomachi, Mutsu, Aomori 035-0064 (Japan); Otosaka, Shigeyoshi [Research Group for Environmental Science, Japan Atomic Energy Agency, 2-4 Shirakata-Shirane, Tokai, Ibaraki 319-1195 (Japan); Wakita, Masahide [Mutsu Institute for Oceanography, Japan Agency for Marine-Earth Science and Technology, 690 Kitasekine, Sekine, Mutsu, Aomori 035-0022 (Japan); Amano, Hikaru [Japan Chemical Analysis Center, 293-5 Sanno-cho, Inage-ku, Chiba-shi 263-0002 (Japan); Togawa, Orihiko [Research Group for Environmental Science, Japan Atomic Energy Agency, 2-4 Shirakata-Shirane, Tokai, Ibaraki 319-1195 (Japan)

    2010-04-15

    Radiocarbon in dissolved organic matter in seawater gives information on the dynamics and origin of the dissolved organic matter. Here, we present the vertical profile of DELTA{sup 14}C of dissolved organic carbon in the western North Pacific Ocean. The profile was almost parallel to that for DELTA{sup 14}C of dissolved inorganic carbon, indicating that the time scale of seawater circulation was the main influence on the DELTA{sup 14}C signature of dissolved organic carbon. On the basis of the DELTA{sup 14}C differences between dissolved organic carbon and dissolved inorganic carbon, and a comparison with DELTA{sup 14}C of dissolved organic carbon in the central North Pacific Ocean, we suggest that there may be a source of younger dissolved organic carbon in the western North Pacific Ocean.

  12. Extreme winds in the Western North Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Ott, S.

    2006-11-15

    A statistical model for extreme winds in the western North Pacific is developed, the region on the Planet where tropical cyclones are most common. The model is based on best track data derived mostly from satellite images of tropical cyclones. The methods used to estimate surface wind speeds from satellite images is discussed with emphasis on the empirical basis, which, unfortunately, is not very strong. This is stressed by the fact that Japanese and US agencies arrive at markedly different estimates. On the other hand, best track data records cover a long period of time and if not perfect they are at least coherent over time in their imperfections. Applying the the Holland model to the best track data, wind profiles can be assigned along the tracks. From this annual wind speed maxima at any particular point in the region can be derived. The annual maxima, in turn, are fitted to a Gumbel distribution using a generalization Abild's method that allows for data wind collected from multiple positions. The choice of this method is justified by a Monte Carlo simulation comparing it to two other methods. The principle output is a map showing fifty year winds in the region. The method is tested against observed winds from Philippine synoptic stations and fair agreement is found for observed and predicted 48 year maxima. However, the almost biasfree performance of the model could be fortuitous, since precise definitions of 'windspeed' in terms averaging time, height above ground and assumed surface roughness are not available, neither for best tracks nor for the synoptic data. The work has been carried out under Danish Research Agency grant 2104-04-0005 'Offshore wind power' and it also covers the findings and analysis carried out in connection with task 1.6 of the project 'Feasibility Assessment and Capacity Building for Wind Energy Development in Cambodia, The Philippines and Vietnam' during 2005-06 under contract 125-2004 with EU

  13. Paleoceanography of the Eastern Tropical North Pacific on millennial timescales

    OpenAIRE

    Arellano-Torres, Elsa

    2010-01-01

    The occurrence of large scale and rapid climate shifts at millennial time-scales (suborbital) remains an enigma between records from high and low latitudes spanning the Late Quaternary. This thesis studies such variations in the eastern tropical North Pacific (ETNP) using marine sediment cores retrieved from Mexico and Nicaragua. The main goals are to understand the nature of millennial timescale climate-changes in the Pacific low latitudes, to identify the atmospheric and ocea...

  14. Westward shift of western North Pacific tropical cyclogenesis

    Science.gov (United States)

    Wu, Liguang; Wang, Chao; Wang, Bin

    2015-03-01

    Tropical cyclones (TCs) in the western North Pacific or typhoons account for one third of all TCs in the world and the change of the mean TC genesis location can affect billions of people in Pacific islands and Asian countries. The annual mean TC genesis longitude is generally controlled by the east-west shift of the tropical upper tropospheric trough (TUTT). A pronounced westward shift in the TUTT is found in all of the available reanalysis data sets during 1979-2012, suppressing TC genesis in the eastern portion (east of 145°E) of the western North Pacific basin due to the enhanced vertical wind shear associated with the TUTT shift. As a result, the annual mean TC genesis longitude has significantly shifted westward since 1979. The westward shifting trends in the TUTT and TC genesis are associated with the enhanced tropical tropospheric warming, which is consistent with the response of the tropospheric temperature to global warming.

  15. 78 FR 27366 - North Pacific Fishery Management Council; Public Meetings

    Science.gov (United States)

    2013-05-10

    ... Hall, 101 Egan Drive, Juneau, AK. DATES: The Council will begin its plenary session at 8 a.m. on..., June 4, from 1 p.m. to 5 p.m. at the Goldbelt Hotel, 51 Egan Drive, Chilkat Room, Juneau, AK. All... Centennial Hall, 101 Egan Drive, Juneau, AK. Council address: North Pacific Fishery Management Council, 605...

  16. Diversity of Pseudo-nitzschia from the western North Pacific

    DEFF Research Database (Denmark)

    Stonik, Inna V; Orlova, Tatiana Yu; Lundholm, Nina

    2011-01-01

    Asurvey focusing on species belonging to the diatom genus Pseudo-nitzschia was conducted in the western North Pacific (the northwestern Sea of Japan and the Sea of Okhotsk). Light and electron microscopic examination of 314 phytoplankton field samples collected from 1995 to 2006 revealed the pres...

  17. North Pacific Process Study (JGOFS) (NODC Accession 0001873)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This NPPS Data Set is comprised of JGOFS data set obtained during the JGOFS NPPS as well as the JGOFS related data sets in the North Pacific. All of these data were...

  18. Impact of the central Pacific zonal wind divergence and convergence on the central Pacific El Niño event

    Institute of Scientific and Technical Information of China (English)

    ZUO Tao; CHEN Jinnian; WANG Hongna

    2014-01-01

    The central Pacific (CP) zonal wind divergence and convergence indices are defined, and the forming mech-anism of CP El Niño (La Niña) events is discussed preliminarily. The results show that the divergence and convergence of the zonal wind anomaly (ZWA) are the key process in the forming of CP El Niño (La Niña) events. A correlation analysis between the central Pacific zonal wind divergence and convergence indices and central Pacific El Niño indices indicates that there is a remarkable lag correlation between them. The central Pacific zonal wind divergence and convergence indices can be used to predict the CP events. Based on these results, a linear regression equation is obtained to predict the CP El Niño (La Niña) events 5 months ahead.

  19. Diet and Ecomorphology of the Sandpaper Skate, Bathyraja kincaidii (Garman, 1908) from the Eastern North Pacific

    OpenAIRE

    Rinewalt, Christopher S.

    2007-01-01

    To determine diet, the stomach contents of sandpaper skates, Bathyraja kincaidii (Garman, 1908), were examined from a limited depth and geographic area off central California and from a wider depth and area range along the eastern North Pacific (ENP). The overall diet was dominated by euphausiids and shrimps, but polychaetes, squids, and gammarid amphipods were important secondary prey. Shrimp-like crustaceans, polychaetes, and teleosts were of similar importance in both data sources, but sma...

  20. Causes of decadal climate variability over the North Pacific and North America

    International Nuclear Information System (INIS)

    The cause of decadal climate variability over the North Pacific and North America is investigated by analyzing data from a multi-decadal integration with a state of the art coupled ocean-atmosphere model and observations. About one third of the low-frequency climate variability in the region of interest can be attributed to a cycle involving unstable air-sea interactions between the subtropical gyre circulation in the North Pacific and the Aleutian low pressure system. The existence of this cycle provides a basis for long-range climate forecasting over the western United States at decadal time scales. (orig.)

  1. Nutrient Concentrations collected from OSCAR ELTON SETTE in North Pacific Ocean from 2008-03-01 to 2011-04-30

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Laboratory analysis of water samples collected aboard the NOAA Ship Oscar Elton Sette along a 158W transect from 26-36N in the central North Pacific. Laboratory...

  2. The probability of tropical cyclone landfalls in Western North Pacific

    Science.gov (United States)

    Bonazzi, A.; Bellone, E.; Khare, S.

    2012-04-01

    The Western North Pacific (WNP) is the most active basin in terms of tropical cyclone and typhoon occurrences. The densely populated countries that form the western boundary of WNP basin -- e.g. China, Japan and the Philippines -- are exposed to extreme wind gusts, storm surge and fresh water flooding eventually triggered by Tropical Cyclones (TC) events. Event-based catastrophe models (hereafter cat models) are extensively used by the insurance industry to manage their exposure against low-frequency/high-consequence events such as natural catastrophes. Cat models provide their users with a realistic set of stochastic events that expands the scope of a historical catalogue. Confidence in a cat model ability to extrapolate peril and loss statistics beyond the period covered by observational data requires good agreement between stochastic and historical peril characteristics at shorter return periods. In WNP risk management practitioners are faced with highly uncertain data to base their decisions. Albeit 4 national agencies maintain best track catalogues, data are generally based on satellite imageries with very limited central pressure (CP) and maximum velocity (VMAX) measurements -- regular flight reconnaissance missions stopped in 1987. As a result differences up to 20 knots are found in estimates of VMAX from different agencies as documented in experiment IOP-10 during Typhoon Megi in 2010. In this work we present a comprehensive analysis of CP and VMAX probability distributions at landfall across the WNP basin along a set of 150 gates (100 km coast segments) based on best track catalogues from Japan Meteorological Agency, Joint Typhoon Warning Center, China Meteorological Agency and Hong Meteorological Agency. Landfall distributions are then used to calibrate a random-walk statistical track model. A long simulation of 100,000 years of statistical TC tracks will ultimately constitute the central building block of a basin-wide stochastic catalogue of synthetic TC

  3. Regime Shifts in the North Pacific Simulated by a COADS-driven Isopycnal Model

    Institute of Scientific and Technical Information of China (English)

    王东晓; 王佳; 吴立新; 刘征宇

    2003-01-01

    The Miami Isopycnal Coordinate Ocean Model (MICOM) is adopted to simulate the interdecadalvariability in the Pacific Ocean with most emphasis on regime shifts in the North Pacific. The compu-tational domain covers 60°N to 40°S with an enclosed boundary condition for momentum flux, whereasthere are thermohaline fluxes across the southern end as a restoring term. In addition, sea surface salinityof the model relaxes to the climatological season cycle, which results in climatological fresh water fluxes.Surface forcing functions from January 1945 through December 1993 are derived from the ComprehensiveOcean and Atmospheric Data Set (COADS). Such a numerical experiment reproduces the observed evo-lution of the interdecadal variability in the heat content over the upper 400-m layer by a two-year lag.Subduction that occurs at the ventilated thermocline in the central North Pacific is also been simulatedand the subducted signals propagate from 35°N to 25°N, taking about 8 to 10 years, in agreement with theeXpendable Bathy Thermograph observation over recent decades. Interdecadal signals take a southwest-ward and downward path rather than westward propagation, meaning they are less associated with thebaroclinic planetary waves. During travel, the signals appear to conserve potential vorticity. Therefore,the ventilated thermocline and related subduction are probably the fundamental physics for interdecadalvariability in the mid-latitude subtropics of the North Pacific.

  4. Hazardous chemicals in marine mammals from the western North Pacific

    International Nuclear Information System (INIS)

    Marine mammals have long-term life and occupy the highest ecological niche in the marine ecosystem. Thus, higher concentration of hazardous chemicals are expected in marine mammals. In the present study, we review contamination of organochlorine compounds (DDTs, PCBs, HCHs, etc.), heavy metals (Hg, Cd, Pb, etc.) and butyltin (TBT, DBT and MBT) in marine mammals collected from the western North Pacific, and discuss the worldwide contamination of these chemicals

  5. Heat and salt transport throughout the North Pacific Ocean

    Science.gov (United States)

    Yang, Lina; Yuan, Dongliang

    2016-03-01

    Absolute geostrophic currents in the North Pacific Ocean are calculated using the P-vector method and gridded Argo profiling data from January 2004 to December 2012. Three-dimensional structures and seasonal variability of meridional heat transport (MHT) and meridional salt transport (MST) are analyzed. The results show that geostrophic and Ekman components are generally opposite in sign, with the southward geostrophic component dominating in the subtropics and the northward Ekman component dominating in the tropics. In combination with the net surface heat flux and the MST through the Bering Strait, the MHT and MST of the western boundary currents (WBCs) are estimated for the first time. The results suggest that the WBCs are of great importance in maintaining the heat and salt balance of the North Pacific. The total interior MHT and MST in the tropics show nearly the same seasonal variability as that of the Ekman components, consistent with the variability of zonal wind stress. The geostrophic MHT in the tropics is mainly concentrated in the upper layers, while MST with large amplitude and annual variation can extend much deeper. This suggests that shallow processes dominate MHT in the North Pacific, while MST can be affected by deep ocean circulation. In the extratropical ocean, both MHT and MST are weak. However, there is relatively large and irregular seasonal variability of geostrophic MST, suggesting the importance of the geostrophic circulation in the MST of that area.

  6. Spatial segregation in eastern North Pacific skate assemblages.

    Science.gov (United States)

    Bizzarro, Joseph J; Broms, Kristin M; Logsdon, Miles G; Ebert, David A; Yoklavich, Mary M; Kuhnz, Linda A; Summers, Adam P

    2014-01-01

    Skates (Rajiformes: Rajoidei) are common mesopredators in marine benthic communities. The spatial associations of individual species and the structure of assemblages are of considerable importance for effective monitoring and management of exploited skate populations. This study investigated the spatial associations of eastern North Pacific (ENP) skates in continental shelf and upper continental slope waters of two regions: central California and the western Gulf of Alaska. Long-term survey data were analyzed using GIS/spatial analysis techniques and regression models to determine distribution (by depth, temperature, and latitude/longitude) and relative abundance of the dominant species in each region. Submersible video data were incorporated for California to facilitate habitat association analysis. We addressed three main questions: 1) Are there regions of differential importance to skates?, 2) Are ENP skate assemblages spatially segregated?, and 3) When skates co-occur, do they differ in size? Skate populations were highly clustered in both regions, on scales of 10s of kilometers; however, high-density regions (i.e., hot spots) were segregated among species. Skate densities and frequencies of occurrence were substantially lower in Alaska as compared to California. Although skates are generally found on soft sediment habitats, Raja rhina exhibited the strongest association with mixed substrates, and R. stellulata catches were greatest on rocky reefs. Size segregation was evident in regions where species overlapped substantially in geographic and depth distribution (e.g., R. rhina and Bathyraja kincaidii off California; B. aleutica and B. interrupta in the Gulf of Alaska). Spatial niche differentiation in skates appears to be more pronounced than previously reported. PMID:25329312

  7. Spatial segregation in eastern North Pacific skate assemblages.

    Directory of Open Access Journals (Sweden)

    Joseph J Bizzarro

    Full Text Available Skates (Rajiformes: Rajoidei are common mesopredators in marine benthic communities. The spatial associations of individual species and the structure of assemblages are of considerable importance for effective monitoring and management of exploited skate populations. This study investigated the spatial associations of eastern North Pacific (ENP skates in continental shelf and upper continental slope waters of two regions: central California and the western Gulf of Alaska. Long-term survey data were analyzed using GIS/spatial analysis techniques and regression models to determine distribution (by depth, temperature, and latitude/longitude and relative abundance of the dominant species in each region. Submersible video data were incorporated for California to facilitate habitat association analysis. We addressed three main questions: 1 Are there regions of differential importance to skates?, 2 Are ENP skate assemblages spatially segregated?, and 3 When skates co-occur, do they differ in size? Skate populations were highly clustered in both regions, on scales of 10s of kilometers; however, high-density regions (i.e., hot spots were segregated among species. Skate densities and frequencies of occurrence were substantially lower in Alaska as compared to California. Although skates are generally found on soft sediment habitats, Raja rhina exhibited the strongest association with mixed substrates, and R. stellulata catches were greatest on rocky reefs. Size segregation was evident in regions where species overlapped substantially in geographic and depth distribution (e.g., R. rhina and Bathyraja kincaidii off California; B. aleutica and B. interrupta in the Gulf of Alaska. Spatial niche differentiation in skates appears to be more pronounced than previously reported.

  8. 75 FR 68756 - Eastern North Pacific Gray Whale; Notice of Petition Availability

    Science.gov (United States)

    2010-11-09

    ... National Oceanic and Atmospheric Administration RIN 0648-XA018 Eastern North Pacific Gray Whale; Notice of... Pacific population of gray whales (Eschrichtius robustus) as a depleted stock under the Marine Mammal... assessment report for Eastern North Pacific gray whales is available on the Internet at the following...

  9. CRED 20 m Gridded bathymetry of Jarvis Island, Pacific Remote Island Areas, Central Pacific (NetCDF Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (20 m cell size) bathymetry of the shelf and slope environments of Jarvis Island, Pacific Remote Island Areas, Central Pacific. Almost complete bottom...

  10. CRED 5 m Gridded bathymetry of Kingman Reef, Pacific Remote Island Areas, Central Pacific (Arc ASCII Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (5 m cell size) bathymetry of the lagoon, shelf and slope environments of Kingman Reef, Pacific Remote Island Areas, Central Pacific. Almost complete bottom...

  11. CRED 5 m Gridded bathymetry of Johnston Atoll, Pacific Remote Island Areas, Central Pacific (NetCDF Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry (5 m cell size) of the shelf and slope environments of Johnston Atoll, Pacific Remote Island Areas, Central Pacific. Almost complete bottom...

  12. CRED 20 m Gridded bathymetry of Johnston Atoll, Pacific Remote Island Areas, Central Pacific (Arc ASCII Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry (20 m cell size) of the shelf and slope environments of Johnston Atoll, Pacific Remote Island Areas, Central Pacific. Almost complete bottom...

  13. CRED 5 m Gridded bathymetry of Baker Island, Pacific Remote Island Areas, Central Pacific (NetCDF Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (5 m cell size) bathymetry of the shelf and slope environments of Baker Island, Pacific Remote Island Areas, Central Pacific. Almost complete bottom...

  14. CRED 5 m Gridded bathymetry of Howland Island, Pacific Remote Island Areas, Central Pacific (NetCDF Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (5 m cell size) bathymetry of the shelf and slope environments of Howland Island, Pacific Remote Island Areas, Central Pacific. Almost complete bottom...

  15. CRED 40 m Gridded bathymetry of Palmyra Atoll, Pacific Remote Island Areas, Central Pacific (Arc ASCII Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (40 m cell size) bathymetry of the lagoon, shelf and slope environments of Palmyra Atoll, Pacific Remote Island Areas, Central Pacific. Almost complete...

  16. CRED 5 m Gridded bathymetry of Jarvis Island, Pacific Remote Island Areas, Central Pacific (Arc ASCII Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (5 m cell size) bathymetry of the shelf and slope environments of Jarvis Island, Pacific Remote Island Areas, Central Pacific. Almost complete bottom...

  17. CRED 5 m Gridded bathymetry of Palmyra Atoll, Pacific Remote Island Areas, Central Pacific (NetCDF Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (5 m cell size) bathymetry of the lagoon, shelf and slope environments of Palmyra Atoll, Pacific Remote Island Areas, Central Pacific. Almost complete...

  18. CRED 40 m Gridded bathymetry of Howland Island, Pacific Remote Island Areas, Central Pacific (Arc ASCII Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (40 m cell size) bathymetry of the shelf and slope environments of Howland Island, Pacific Remote Island Areas, Central Pacific. Almost complete bottom...

  19. CRED 5 m Gridded bathymetry of Howland Island, Pacific Remote Island Areas, Central Pacific (Arc ASCII Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (5 m cell size) bathymetry of the shelf and slope environments of Howland Island, Pacific Remote Island Areas, Central Pacific. Almost complete bottom...

  20. CRED 5 m Gridded bathymetry of Johnston Atoll, Pacific Remote Island Areas, Central Pacific (Arc ASCII Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry (5 m cell size) of the shelf and slope environments of Johnston Atoll, Pacific Remote Island Areas, Central Pacific. Almost complete bottom...

  1. CRED 20 m Gridded bathymetry of Jarvis Island, Pacific Remote Island Areas, Central Pacific (Arc ASCII Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (20 m cell size) bathymetry of the shelf and slope environments of Jarvis Island, Pacific Remote Island Areas, Central Pacific. Almost complete bottom...

  2. CRED 40 m Gridded bathymetry of Howland Island, Pacific Remote Island Areas, Central Pacific (NetCDF Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (40 m cell size) bathymetry of the shelf and slope environments of Howland Island, Pacific Remote Island Areas, Central Pacific. Almost complete bottom...

  3. CRED 40 m Gridded bathymetry of Baker Island, Pacific Remote Island Areas, Central Pacific (Arc ASCII Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (40 m cell size) bathymetry of the shelf and slope environments of Baker Island, Pacific Remote Island Areas, Central Pacific. Almost complete bottom...

  4. CRED 40 m Gridded bathymetry of Palmyra Atoll, Pacific Remote Island Areas, Central Pacific (NetCDF Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (40 m cell size) bathymetry of the lagoon, shelf and slope environments of Palmyra Atoll, Pacific Remote Island Areas, Central Pacific. Almost complete...

  5. CRED 20 m Gridded bathymetry of Kingman Reef, Pacific Remote Island Areas, Central Pacific (NetCDF Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (20 m cell size) bathymetry of the lagoon, shelf and slope environments of Kingman Reef, Pacific Remote Island Areas, Central Pacific. Almost complete...

  6. CRED 20 m Gridded bathymetry of Johnston Atoll, Pacific Remote Island Areas, Central Pacific (NetCDF Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry (20 m cell size) of the shelf and slope environments of Johnston Atoll, Pacific Remote Island Areas, Central Pacific. Almost complete bottom...

  7. CRED 5 m Gridded bathymetry of Baker Island, Pacific Remote Island Areas, Central Pacific (Arc ASCII Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (5 m cell size) bathymetry of the shelf and slope environments of Baker Island, Pacific Remote Isand Areas, Central Pacific. Almost complete bottom coverage...

  8. CRED 5 m Gridded bathymetry of Jarvis Island, Pacific Remote Island Areas, Central Pacific (NetCDF Format)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (5 m cell size) bathymetry of the shelf and slope environments of Jarvis Island, Pacific Remote Island Areas, Central Pacific. Almost complete bottom...

  9. CRED Reson 8101 multibeam backscatter data of Jarvis Island, Pacific Remote Island Areas, Central Pacific in netCDF format

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam backscatter imagery extracted from gridded bathymetry of the shelf and slope environments of Jarvis Atoll, Pacific Island Areas, Central Pacific. These...

  10. CRED Reson 8101 multibeam backscatter data of Jarvis Island, Pacific Remote Island Areas, Central Pacific in GeoTIFF format

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam backscatter imagery extracted from gridded bathymetry of the shelf and slope environments of Jarvis Atoll, Pacific Island Areas, Central Pacific. These...

  11. CRED Reson 8101 multibeam backscatter data of Howland Island, Pacific Remote Island Areas, Central Pacific in GeoTIFF format

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam backscatter imagery extracted from gridded bathymetry of the shelf and slope environments of Howland Atoll, Pacific Island Areas, Central Pacific. These...

  12. AFSC/RACE/GAP/Conrath: Delayed discard mortality of the North Pacific giant octopus

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The majority of octopus bycatch occurs in Pacific cod pot fisheries and recent data collected by North Pacific Groundfish Observers indicate that immediate...

  13. An interdecadal change in the relationship between January-March Arctic Oscillation and North Pacific Precipitation

    Science.gov (United States)

    Hu, Miao

    2014-05-01

    An analysis of variability in the relationships between the winter (January-March) Arctic Oscillation and precipitation over the Northern Pacific during the period of 1979 to 2011 is presented based on the monthly precipitation data (CMAP) and NCEP/NCAR Reanalysis, after subtracting ENSO signals from all datasets. The sliding correlation analysis demonstrates there is a prominent weakening in the AO-precipitation relation around the early 1990s. In the total 33 years a high (low) AO phase more likely accompanies with a stronger (weaker) precipitation in the subtropical Pacific, and the mainly significant correlation area ranges from 10°-30°N,150°E-190°W. During the year 1979 to 1989, the positive correlations over the tropical Pacific are significant and widely-ranged; however, the correlations weaken over the whole region and even negative over the central Pacific after the early 1990s. In addition, the Model BCCR-BCM2 is capable of simulating the correct overall AO-precipitation relation over North Pacific.

  14. Seasonal variation of the surface North Equatorial Countercurrent (NECC) in the western Pacific Ocean

    Science.gov (United States)

    Zhao, Jun; Li, Yuanlong; Wang, Fan

    2016-03-01

    The North Equatorial Countercurrent (NECC) is an important zonal flow in the upper circulation of the tropical Pacific Ocean, which plays a vital role in the heat budget of the western Pacific warm pool. Using satellite-derived data of ocean surface currents and sea surface heights (SSHs) from 1992 to 2011, the seasonal variation of the surface NECC in the western tropical Pacific Ocean was investigated. It was found that the intensity (INT) and axis position (Y CM) of the surface NECC exhibit strikingly different seasonal fluctuations in the upstream (128°-136°E) and downstream (145°-160°E) regions. Of the two regions, the seasonal cycle of the upstream NECC shows the greater interannual variability. Its INT and YCM are greatly influenced by variations of the Mindanao Eddy, Mindanao Dome (MD), and equatorial Rossby waves to its south. Both INT and Y CM also show semiannual signals induced by the combined effects of equatorial Rossby waves from the Central Pacific and local wind forcing in the western Pacific Ocean. In the downstream region, the variability of the NECC is affected by SSH anomalies in the MD and the central equatorial Pacific Ocean. Those in the MD region are especially important in modulating the YCM of the downstream NECC. In addition to the SSH-related geostrophic flow, zonal Ekman flow driven by meridional wind stress also plays a role, having considerable impact on INT variability of the surface NECC. The contrasting features of the variability of the NECC in the upstream and downstream regions reflect the high complexity of regional ocean dynamics.

  15. Geographic variation in Pacific herring growth in response to regime shifts in the North Pacific Ocean

    Science.gov (United States)

    Ito, Shin-ichi; Rose, Kenneth A.; Megrey, Bernard A.; Schweigert, Jake; Hay, Douglas; Werner, Francisco E.; Aita, Maki Noguchi

    2015-11-01

    Pacific herring populations at eight North Pacific Rim locations were simulated to compare basin-wide geographic variations in age-specific growth due to environmental influences on marine productivity and population-specific responses to regime shifts. Temperature and zooplankton abundance from a three-dimensional lower-trophic ecosystem model (NEMURO: North Pacific Ecosystem Model for Understanding Regional Oceanography) simulation from 1948 to 2002 were used as inputs to a herring bioenergetics growth model. Herring populations from California, the west coast of Vancouver Island (WCVI), Prince William Sound (PWS), Togiak Alaska, the western Bering Sea (WBS), the Sea of Okhotsk (SO), Sakhalin, and Peter the Great Bay (PGB) were examined. The half-saturation coefficients of herring feeding were calibrated to climatological conditions at each of the eight locations to reproduce averaged size-at-age data. The depth of averaging used for water temperature and zooplankton, and the maximum consumption rate parameter, were made specific to each location. Using the calibrated half-saturation coefficients, the 1948-2002 period was then simulated using daily values of water temperature and zooplankton densities interpolated from monthly model output. To detect regime shifts in simulated temperatures, zooplankton and herring growth rates, we applied sequential t-test analyses on the 54 years of hindcast simulation values. The detected shifts of herring age-5 growth showed closest match (69%) to the regime shift years (1957/58, 1970/71, 1976/77, 1988/89, 1998/99). We explored relationships among locations using cluster and principal component analyses. The first principal component of water temperature showed good correspondence to the Pacific Decadal Oscillation and all zooplankton groups showed a pan-Pacific decrease after the 1976/77 regime shift. However, the first principal component of herring growth rate showed decreased growth at the SO, PWS, WCVI and California

  16. North Pacific Eastern Subtropical Mode Water simulation and future projection

    Institute of Scientific and Technical Information of China (English)

    XIA Ruibin; LIU Qinyu; XU Lixiao; LU Yiqun

    2015-01-01

    The present climate simulation and future projection of the Eastern Subtropical Mode Water (ESTMW) in the North Pacific are investigated based on the Geophysical Fluid Dynamics Laboratory Earth System Model (GFDL-ESM2M). Spatial patterns of the mixed layer depth (MLD) in the eastern subtropical North Pacific and the ESTMW are well simulated using this model. Compared with historical simulation, the ESTMW is produced at lighter isopycnal surfaces and its total volume is decreased in the RCP8.5 runs, because the subduction rate of the ESTMW decreases by 0.82×10−6 m/s during February–March. In addition, it is found that the lateral induction decreasing is approximately four times more than the Ekman pumping, and thus it plays a dominant role in the decreased subduction rate associated with global warming. Moreover, the MLD during February–March is banded shoaling in response to global warming, extending northeastward from the east of the Hawaii Islands (20°N, 155°W) to the west coast of North America (30°N, 125°W), with a max-imum shoaling of 50 m, and then leads to the lateral induction reduction. Meanwhile, the increased north-eastward surface warm current to the east of Hawaii helps strengthen of the local upper ocean stratification and induces the banded shoaling MLD under warmer climate. This new finding indicates that the ocean surface currents play an important role in the response of the MLD and the ESTMW to global warming.

  17. An Analysis of North Pacific Subsurface Temperatures Using State-Space Techniques

    CERN Document Server

    Bessey, Cindy

    2012-01-01

    North Pacific subsurface temperature data from the Simple Ocean Data Assimilation model at 10m, 50m, 75m, 100m and 150m depths, are analyzed using a combination of state-space decomposition and subspace identification techniques to examine the spatial structure of thermal variability within the upper water column. We identify four common trends from our analysis that display the major broad-scale patterns in the North Pacific over a 47 year period (1958-2004): (1) a basin-wide near-surface warming trend that identifies the mid 1980's as a change point from a cooling to a warming trend; (2) a contrasting cooling in the central basin and warming along the coast of North America that began in the early 1970's; (3) a cooling along the transition zone and the west coast of North America that becomes dominant around 1998; (4) and contrasting differences in the subarctic and subtropical gyres displaying differences in processes at each depth. We also provide a detailed analysis of the temperature variability at four...

  18. Intensified impact of tropical Atlantic SST on the western North Pacific summer climate under a weakened Atlantic thermohaline circulation

    Science.gov (United States)

    Chen, Wei; Lee, June-Yi; Lu, Riyu; Dong, Buwen; Ha, Kyung-Ja

    2015-10-01

    The tropical North Atlantic (TNA) sea surface temperature (SST) has been identified as one of regulators on the boreal summer climate over the western North Pacific (WNP), in addition to SSTs in the tropical Pacific and Indian Oceans. The major physical process proposed is that the TNA warming induces a pair of cyclonic circulation anomaly over the eastern Pacific and negative precipitation anomalies over the eastern to central tropical Pacific, which in turn lead to an anticyclonic circulation anomaly over the western to central North Pacific. This study further demonstrates that the modulation of the TNA warming to the WNP summer climate anomaly tends to be intensified under background of the weakened Atlantic thermohaline circulation (THC) by using a water-hosing experiment. The results suggest that the weakened THC induces a decrease in thermocline depth over the TNA region, resulting in the enhanced sensitivity of SST variability to wind anomalies and thus intensification of the interannual variation of TNA SST. Under the weakened THC, the atmospheric responses to the TNA warming are westward shifted, enhancing the anticyclonic circulation and negative precipitation anomaly over the WNP. This study supports the recent finding that the negative phase of the Atlantic multidecadal oscillation after the late 1960s has been favourable for the strengthening of the connection between TNA SST variability and WNP summer climate and has important implications for seasonal prediction and future projection of the WNP summer climate.

  19. The plastic-associated microorganisms of the North Pacific Gyre

    International Nuclear Information System (INIS)

    Highlights: • Microorganisms mediate processes affecting the fate and impacts of marine plastic. • North Pacific Gyre (NPG) plastics were examined with scanning-electron microscopy. • Bacillus bacteria and pennate diatoms dominated the NPG plastic fouling community. • Bacterial abundance was patchily distributed but increased on foamed polystyrene. • Diatom abundance increased on rough surfaces and at sites with high plastic density. -- Abstract: Microorganisms likely mediate processes affecting the fate and impacts of marine plastic pollution, including degradation, chemical adsorption, and colonization or ingestion by macroorganisms. We investigated the relationship between plastic-associated microorganism communities and factors such as location, temperature, salinity, plankton abundance, plastic concentration, item size, surface roughness, and polymer type. Small plastic items from the surface of the North Pacific Gyre in 2011 were examined using scanning electron microscopy. Bacillus bacteria (mean 1664 ± 247 individuals mm−2) and pennate diatoms (1097 ± 154 mm−2) were most abundant, with coccoid bacteria, centric diatoms, dinoflagellates, coccolithophores, and radiolarians present. Bacterial abundance was patchy, but increased on foamed polystyrene. Diatom abundance increased on items with rough surfaces and at sites with high plastic concentrations. Morphotype richness increased slightly on larger fragments, and a biogeographic transition occurred between pennate diatom groups. Better characterizing this community will aid in understanding how it interacts with plastic pollution

  20. Scale interaction between typhoons and the North Pacific subtropical high and associated remote effects during the Baiu/Meiyu season

    Science.gov (United States)

    Hirata, Hidetaka; Kawamura, Ryuichi

    2014-05-01

    The interaction between typhoons and the North Pacific subtropical high and the associated remote impact on East Asian and North Pacific anomalous weather during the Baiu/Meiyu season have been investigated using the Japanese long-term Reanalysis project data aided by the Japan Meteorological Agency Climate Data Assimilation System. The typhoons that appeared in July have been categorized into two primary tracks, the Hainan Island course (HC) and the Okinawa Island course (OC). A typhoon gives rise to negative absolute vorticity advection along its eastern periphery, which locally reinforces the western ridge of the North Pacific subtropical high, whereas the resultant anomalous high stimulates the westward (northward) migration of the HC (OC) typhoon through its combination with the background flow. A combined effect of the typhoon and its induced anomalous anticyclonic circulation increases the transportation of moisture into the Baiu/Meiyu frontal zone in the vicinity of Japan. Over the East China Sea and the Sea of Japan, northward or northeastward moisture flux is pronounced along the western periphery of the typhoon-induced anticyclonic circulation anomaly in the HC category, triggering heavy rainfall on central Japan's Sea of Japan coast. Similar remote effects also operate in the OC category, which is responsible for the occurrence of extremely heavy rainfall along the Pacific coast of western Japan. When an OC typhoon approaches the Asian jet, it is capable of giving rise to anticyclonic vorticity within the jet, leading to the downstream development of stationary Rossby wave packets via the North Pacific waveguide.

  1. North Pacific seasonality and the glaciation of North America 2.7 million years ago

    OpenAIRE

    Haug, G. H.; Ganopolski, A.; Sigman, D. M.; Rosell-Mele, A.; G. E. A. Swann; R. Tiedemann; S. L. Jaccard; J. Bollmann; Maslin, M. A.; Leng, M. J.; Eglinton, G.;  ,

    2005-01-01

    In the context of gradual Cenozoic cooling, the timing of the onset of significant Northern Hemisphere glaciation 2.7 million years ago is consistent with Milankovitch’s orbital theory, which posited that ice sheets grow when polar summertime insolation and temperature are low. However, the role of moisture supply in the initiation of large Northern Hemisphere ice sheets has remained unclear. The subarctic Pacific Ocean represents a significant source of water vapour to boreal North America, ...

  2. Numerical simulation on the long-term variation of radioactive cesium concentration in the North Pacific due to the Fukushima disaster

    International Nuclear Information System (INIS)

    Numerical simulations on oceanic 134Cs and 137Cs dispersions were intensively conducted in order to assess an effect of the radioactive cesium on the North Pacific environment with a focus on the long-term variation of the radioactive cesium concentration after the Fukushima disaster that occurred in March 2011. The amounts of 134Cs and 137Cs released into the ocean were estimated using oceanic monitoring data, whereas the atmospheric deposition was calculated through atmospheric dispersion simulations. The highly accurate ocean current reanalyzed through a three-dimensional variational data assimilation enabled us to clarify the time series of the 134Cs and 137Cs concentrations in the North Pacific. It was suggested that the main radioactive cesium cloud due to the direct oceanic release reached the central part of the North Pacific, crossing 170°W one year after the Fukushima disaster. The radioactive cesium was efficiently diluted by meso-scale eddies in the Kuroshio Extension region and its concentration in the surface, intermediate, and deep layers had already been reduced to the pre-Fukushima background value in the wide area within the North Pacific 2.5 years after the Fukushima disaster. - Highlights: • We assessed an effect of the Fukushima disaster on the North Pacific. • The main radioactive cloud reached the central North Pacific one year later. • The 137Cs had been reduced to the pre-Fukushima value 2.5 years later

  3. 50 CFR 226.215 - Critical habitat for the North Pacific Right Whale (Eubalaena japonica).

    Science.gov (United States)

    2010-10-01

    ... Right Whale (Eubalaena japonica). 226.215 Section 226.215 Wildlife and Fisheries NATIONAL MARINE... DESIGNATED CRITICAL HABITAT § 226.215 Critical habitat for the North Pacific Right Whale (Eubalaena japonica). (a) Primary Constituent Elements. The primary constituent elements of the North Pacific right...

  4. Final Report for UW-Madison Portion of DE-SC0005301, "Collaborative Project: Pacific Decadal Variability and Central Pacific Warming El Niño in a Changing Climate"

    Energy Technology Data Exchange (ETDEWEB)

    Vimont, Daniel [University of Wisconsin - Madison

    2014-06-13

    This project funded two efforts at understanding the interactions between Central Pacific ENSO events, the mid-latitude atmosphere, and decadal variability in the Pacific. The first was an investigation of conditions that lead to Central Pacific (CP) and East Pacific (EP) ENSO events through the use of linear inverse modeling with defined norms. The second effort was a modeling study that combined output from the National Center for Atmospheric Research (NCAR) Community Atmospheric Model (CAM4) with the Battisti (1988) intermediate coupled model. The intent of the second activity was to investigate the relationship between the atmospheric North Pacific Oscillation (NPO), the Pacific Meridional Mode (PMM), and ENSO. These two activities are described herein.

  5. Tropical-North Pacific Climate Linkages derived from Tree Rings and Corals

    Science.gov (United States)

    D'Arrigo, R.; Wilson, R.

    2007-12-01

    We use tree-ring analysis to extend the understanding of North Pacific climate variability and the tropical-high latitude climate connection over recent centuries. A tree-ring reconstruction of the December-May North Pacific Index (NPI) - an atmospheric circulation index related to the Aleutian Low pressure cell - spans from 1600-1983 and shows evidence for the three regime shifts seen in the instrumental NPI data (including the noteworthy 1976 transition in Pacific climate) and additional events in prior centuries. A 1300-year tree-ring based record for the Gulf of Alaska (GOA) provides additional extended information on North Pacific multi-decadal temperature variability. These records correlate significantly with both instrumental tropical climate indices and a coral-based reconstruction of an optimal tropical Indo-Pacific climate index, supporting evidence for a tropical-North Pacific climate link extending as far west as the Indian Ocean. The coral-based reconstruction (1781-1993) shows the twentieth century regime shifts evident in the instrumental NPI and tropical Indo-Pacific climate index, as well as additional shifts. Changes in the strength of correlation between the reconstructions over time, and differences in identified shifts in the tropical vs North Pacific series prior to the instrumental period suggest a varying tropical influence on North Pacific climate, with greater influence in the twentieth century.

  6. Ultrasonic whistles of killer whales (Orcinus orca) recorded in the North Pacific (L).

    Science.gov (United States)

    Filatova, Olga A; Ford, John K B; Matkin, Craig O; Barrett-Lennard, Lance G; Burdin, Alexander M; Hoyt, Erich

    2012-12-01

    Ultrasonic whistles were previously found in North Atlantic killer whales and were suggested to occur in eastern North Pacific killer whales based on the data from autonomous recorders. In this study ultrasonic whistles were found in the recordings from two encounters with the eastern North Pacific offshore ecotype killer whales and one encounter with the western North Pacific killer whales of unknown ecotype. All ultrasonic whistles were highly stereotyped and all but two had downsweep contours. These results demonstrate that specific sound categories can be shared by killer whales from different ocean basins. PMID:23231094

  7. Deep electrical conductivity structure beneath the North-West Pacific

    International Nuclear Information System (INIS)

    Complete text of publication follows. Since August, 2001, we have been conducting seafloor electromagnetic (EM) observation at a site called NWP on the North-West Pacific basin (Toh et al., 2004; Toh et al., 2006). We applied the magnetotelluric (MT) and geomagnetic depth sounding methods to the observed 5-component EM field of approximately 1200-day long to yield electrical conductivity in the deep mantle. The one-dimensional (1D) electrical conductivity structure was then estimated using both the static shift corrected MT response and the scalar MT response converted from the so-called Schmucker's C-response. The characteristics of the derived 1D model that penetrates to depths well below the 660-km seismic discontinuity are summarized as follows: 1) The resistivity-thickness product of the uppermost lithosphere is of the order of 1010 Ωm, which is one order of magnitude larger than those reported in the northeast Pacific (e.g., Cox et al., 1986). This means a very cold lithosphere beneath NWP depleted in volatile elements including water. 2) A conductive asthenosphere centred at a depth of 200km has been detected, which is, in turn, consistent with the result beneath the northeast Pacific (Lizarralde et al., 1995). The cause of the conductive asthenosphere can be explained by the presence of small amount of water (∼0.06 wt %), which is less than what is necessary for the onset of hydrous melting. 3) Discontinuous jumps of electrical conductivity at depths of 410 km and 660 km are within factors of approximately 10 and 2, respectively, where latter of the two is a more reliable estimate.

  8. Orbital control of the western North Pacific summer monsoon

    Science.gov (United States)

    Wu, Chi-Hua; Chiang, John C. H.; Hsu, Huang-Hsiung; Lee, Shih-Yu

    2016-02-01

    Orbital forcing exerts a strong influence on global monsoon systems, with higher summer insolation leading to stronger summer monsoons in the Northern Hemisphere. However, the associated regional and seasonal changes, particularly the interaction between regional monsoon systems, remain unclear. Simulations using the Community Earth System Model demonstrate that the western North Pacific (WNP) summer monsoon responds to orbital forcing opposite to that of other major Northern Hemisphere monsoon systems. Compared with its current climate state, the simulated WNP monsoon and associated lower-tropospheric trough is absent in the early Holocene when the precession-modulated Northern Hemisphere summer insolation is higher, whereas the summer monsoons in South and East Asia are stronger and shift farther northward. We attribute the weaker WNP monsoon to the stronger diabatic heating of the summer Asian monsoon—in particular over the southern Tibetan Plateau and Maritime Continent—that in turn strengthens the North Pacific subtropical high through atmospheric teleconnections. By contrast, the impact of the midlatitude circulation changes on the WNP monsoon is weaker when the solar insolation is higher. Prior to the present WNP monsoon onset, the upper-tropospheric East Asian jet stream weakens and shifts northward; the monsoon onset is highly affected by the jet-induced high potential vorticity intrusion. In the instance of the extreme perihelion-summer, the WNP monsoon is suppressed despite a stronger midlatitude precursor than present-day, and the midlatitude circulation response to the enhanced South Asian precipitation is considerable. These conditions indicate internal monsoon interactions of an orbital scale, implying a potential mechanistic control of the WNP monsoon.

  9. WATER TEMPERATURE, DISSOLVED OXYGEN, and others collected from OSCAR ELTON SETTE in Hawaii EEZ, central North Pacific Ocean, and others from 2010-04-20 to 2010-04-30 (NCEI Accession 0155996)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CTD data were collected during a Pacific Islands Fisheries Science Center's Cetacean Research Program's shipboard cetacean survey (Cruise ID: SE 10-04). A total of...

  10. Storm track activity over the North Pacific associated with the Madden-Julian Oscillation under ENSO conditions during boreal winter

    Science.gov (United States)

    Takahashi, Chiharu; Shirooka, Ryuichi

    2014-09-01

    The present study investigates modulation by the Madden-Julian Oscillation (MJO) of storm track activity (STA) over the North Pacific (NP) during boreal winter for El Niño and La Niña periods. STA defined by vertically averaged synoptic eddy kinetic energy (EKE) greatly intensifies over the western North Pacific (WNP) and central eastern North Pacific during La Niña and El Niño years, respectively, when the MJO convection is located over the central Indian Ocean (IO)-Maritime Continent. When the MJO moves into the western central Pacific, the STA in La Niña years is suppressed (enhanced) at higher (lower) latitudes than in El Niño years. Diagnoses of EKE and eddy available potential energy budgets indicate that the difference in STA over the WNP for the MJO phases between El Niño-Southern Oscillation (ENSO) years is mainly contributed by baroclinic energy conversion and potential energy conversion between background and eddy (BCPE). We reveal that BCPE is mainly attributed to intraseasonal baroclinicity and eddy heat flux (EHF) anomalies and their interactions with strong winter mean baroclinic fields in the WNP. Through the EHF, synoptic eddies act to counterbalance an intraseasonal temperature that is primarily caused by the anomalous horizontal advection of mean temperature by MJO-related flow. The intraseasonal circulation and associated temperature and EHF anomalies dominate in northwest (southeast) portion of the NP during La Niña (El Niño), leading to BCPE difference. Changes in the spatial pattern and strength of the NP circulation and STA are caused by dominance of strong MJO amplification over the IO (central Pacific) during La Niña (El Niño).

  11. Relationships between the tropical SST and summertime subtropical high over the western North Pacific

    Science.gov (United States)

    Chung, Pei-Hsuan; Sui, Chung-Hsiung; Li, Tim

    2010-05-01

    The interannual variability of the western North Pacific Subtropical High (WNPSH) in summer is investigated with the use of the NCEP/NCAR reanalysis data for the period of 1958-2005. The most significant change appears at the western edge of WNPSH, with dominant 2-3-yr and 3-5-yr power spectrum peaks. The 2-3-yr oscillation of WNPSH and associated circulation and sea surface temperature (SST) patterns possess a coherent eastward-propagating feature, with a warm SST anomaly (SSTA) and anomalous ascending motion migrating from the tropical Indian Ocean in the preceding winter to the maritime continent in the concurrent summer of a strong WNPSH. A strong WNPSH is characterized by anomalous anticyclonic circulation and maximum subsidence in the western North Pacific (WNP). The anomalous WNPSH circulation has an equivalent barotropic vertical structure and resides in the sinking branch of local Hadley circulation, triggered by enhanced convection over the maritime continent in the summer. A heat budget analysis reveals that WNPSH is maintained by radiative cooling, which overcomes the decent induced adiabatic warming. The 3-5-yr oscillation of WNPSH exhibits a quasi stationary feature, with a warm SSTA (anomalous ascending motion) located in the equatorial central-eastern Pacific and Indian Ocean and a cold SSTA (anomalous descending motion) located in the western Pacific. The anomaly pattern persists from the preceding winter to the concurrent summer of a high WNPSH. The maximum descent is located to the east of the anomalous anticyclone center, where a baroclinic vertical structure is identified. The anomalous anticyclone on this timescale is a Rossby wave response to a negative convective heating associated with the local cold SSTA.

  12. Soil indigenous knowledge in North Central Namibia

    Science.gov (United States)

    Prudat, Brice; Bloemertz, Lena; Kuhn, Nikolaus J.

    2016-04-01

    Mapping and classifying soils is part of an important learning process to improve soil management practices, soil quality and increase productivity. In order to assess soil quality improvement related to an ongoing land reform in North-Central Namibia, the characteristics that determine soil quality in the local land use context were determined in this study. To do so, we collated the indigenous soil knowledge in North-Central Namibia where the Ovakwanyama cultivate pearl millet for centuries. Local soil groups are defined mostly based on their productivity potential, which varies depending on the rainfall pattern. The morphological criteria used by the farmers to differentiate the soil groups (colour, consistence) were supported by a conventional analysis of soil physical and chemical properties. Now, they can be used to develop a soil quality assessment toolbox adapted to the regional use. The characteristics of the tool box do not directly indicate soil quality, but refer to local soils groups. The quality of these groups is relatively homogenous at the local scale. Our results show that understanding of indigenous soil knowledge has great potential to improve soil quality assessment with regards to land use. The integration of this knowledge with the conventional soil analysis improves the local meaning of such a "scientific" assessment and thus facilitates dialog between farmers and agronomists, but also scientists working in different regions of the world, but in similar conditions. Overall, the integration of indigenous knowledge in international classification systems (e.g. WRB) as attempted in this study has thus a major potential to improve soil mapping in the local context.

  13. North Central Project: Environment act proposal

    International Nuclear Information System (INIS)

    Manitoba Hydro proposes to construct a power transmission and distribution line system to connect 12 northern Manitoba communities to the utility's central power grid. The purpose of this North Central Project (NCP) is to provide reliable and unrestricted electric service to remote communities now largely receiving limited diesel-generated power. The NCP is composed of a 138-kV transmission line running ca 350 km from the Kelsey Generating Station, ca 160 km of 25-kV distribution lines, new transformer stations at four communities, upgraded internal distribution systems within the communities, removal of existing diesel stations and restoration of the sites, modifications and additions to the Kelsey switchyard, and a communications system. The NCP is described in detail, including proposed line routes and transformer station locations, rationales for site and route selection, projected impacts on the environment and local societies, and consultations with the communities to be affected. Potential impacts are expected to be modest, with few unmitigable adverse impacts and a number of potentially significant positive benefits. Impact management measures are proposed to prevent or mitigate adverse effects and to create or enhance positive impacts such as local employment of native peoples. 49 figs., 1 tab

  14. Contrasting Effects of Central Pacific and Eastern Pacific El Nino on Stratospheric Water Vapor

    Science.gov (United States)

    Garfinkel, Chaim I.; Hurwitz, Margaret M.; Oman, Luke D.; Waugh, Darryn W.

    2013-01-01

    Targeted experiments with a comprehensive chemistry-climate model are used to demonstrate that seasonality and the location of the peak warming of sea surface temperatures dictate the response of stratospheric water vapor to El Nino. In spring, El Nino events in which sea surface temperature anomalies peak in the eastern Pacific lead to a warming at the tropopause above the warm pool region, and subsequently to more stratospheric water vapor (consistent with previous work). However, in fall and in early winter, and also during El Nino events in which the sea surface temperature anomaly is found mainly in the central Pacific, the response is qualitatively different: temperature changes in the warm pool region are nonuniform and less water vapor enters the stratosphere. The difference in water vapor in the lower stratosphere between the two variants of El Nino approaches 0.3 ppmv, while the difference between the winter and spring responses exceeds 0.5 ppmv.

  15. Coastal Carbon Synthesis for the Continental Shelf of the North American Pacific Coast (NAPC)

    Science.gov (United States)

    Siedlecki, S. A.; Alin, S. R.

    2015-12-01

    The West Coast represents the longest coastline in North America, stretching from Panama all the way northward to the Aleutians. Key advances in the carbon cycling of this margin have been made since the North American Continental Margins report (Hales et al., 2008), notably the convergence of models and observations on air-sea fluxes; more sophisticated coastal carbon cycle models; and increased observational coverage in space and time, allowing for more data synthesis and model-data comparison. The coast was divided up into sub-regions based on differences in oceanographic drivers of coastal carbon cycling. Those sub-regions include the Gulf of Alaska, the Central American Isthmus, and the California Current System (CCS), which is further subdivided into northern, central, and southern sectors. The carbon budget for the Pacific Coast of North America identifies the best-known fluxes as the air-sea exchange of CO2 and terrestrial inputs. The least constrained fluxes include respiration, cross-shelf exchange, and carbon metabolism in estuaries. Spatial trends were typically consistent among models and observations, but the magnitude of the fluxes varied widely. While more modeling and observational studies exist than are presented here, relevant fluxes for the carbon budget were often unreported. In the long-term, investments in research and monitoring will be needed to better constrain the fluxes of many of the highly variable regions described in this study. In addition to the budget, this synthesis identifies gaps and priorities for future research.

  16. Central-north China precipitation as reconstructed from the Qing dynasty: Signal of the Antarctic Atmospheric Oscillation

    Science.gov (United States)

    Wang, Huijun; Fan, Ke

    2005-12-01

    Based on the long-term Central-north China precipitation (CNCP) time series reconstructed from the Qing Dynasty Official Document, the relationship between CNCP and the Antarctic Atmospheric Oscillation (AAO) in June-July is examined. The analysis yields a (significant) negative correlation of -0.22. The signal of AAO in CNCP is further studied through analyses of the atmospheric general circulation variability related to AAO. It follows that AAO-related variability of convergence and convection over the tropical western Pacific can exert impact on the circulation condition and precipitation in north China (actually, the precipitation in the Yangtze River Valley as well) through atmospheric teleconnection known as the East Asia-Pacific (or Pacific-Japan) teleconnection wave pattern. There is also an AAO-connected wave train in the vorticity field at high troposphere over Eurasia, providing an anti-cyclonic circulation in central-north China favorable to the decline of precipitation in positive phase of AAO.

  17. North and equatorial Pacific Ocean circulation in the CORE-II hindcast simulations

    Science.gov (United States)

    Tseng, Yu-heng; Lin, Hongyang; Chen, Han-ching; Thompson, Keith; Bentsen, Mats; Böning, Claus W.; Bozec, Alexandra; Cassou, Christophe; Chassignet, Eric; Chow, Chun Hoe; Danabasoglu, Gokhan; Danilov, Sergey; Farneti, Riccardo; Fogli, Pier Giuseppe; Fujii, Yosuke; Griffies, Stephen M.; Ilicak, Mehmet; Jung, Thomas; Masina, Simona; Navarra, Antonio; Patara, Lavinia; Samuels, Bonita L.; Scheinert, Markus; Sidorenko, Dmitry; Sui, Chung-Hsiung; Tsujino, Hiroyuki; Valcke, Sophie; Voldoire, Aurore; Wang, Qiang; Yeager, Steve G.

    2016-08-01

    We evaluate the mean circulation patterns, water mass distributions, and tropical dynamics of the North and Equatorial Pacific Ocean based on a suite of global ocean-sea ice simulations driven by the CORE-II atmospheric forcing from 1963-2007. The first three moments (mean, standard deviation and skewness) of sea surface height and surface temperature variability are assessed against observations. Large discrepancies are found in the variance and skewness of sea surface height and in the skewness of sea surface temperature. Comparing with the observation, most models underestimate the Kuroshio transport in the Asian Marginal seas due to the missing influence of the unresolved western boundary current and meso-scale eddies. In terms of the Mixed Layer Depths (MLDs) in the North Pacific, the two observed maxima associated with Subtropical Mode Water and Central Mode Water formation coalesce into a large pool of deep MLDs in all participating models, but another local maximum associated with the formation of Eastern Subtropical Mode Water can be found in all models with different magnitudes. The main model bias of deep MLDs results from excessive Subtropical Mode Water formation due to inaccurate representation of the Kuroshio separation and of the associated excessively warm and salty Kuroshio water. Further water mass analysis shows that the North Pacific Intermediate Water can penetrate southward in most models, but its distribution greatly varies among models depending not only on grid resolution and vertical coordinate but also on the model dynamics. All simulations show overall similar large scale tropical current system, but with differences in the structures of the Equatorial Undercurrent. We also confirm the key role of the meridional gradient of the wind stress curl in driving the equatorial transport, leading to a generally weak North Equatorial Counter Current in all models due to inaccurate CORE-II equatorial wind fields. Most models show a larger

  18. Frequency of marine heatwaves in the North Atlantic and North Pacific since 1950

    Science.gov (United States)

    Scannell, Hillary A.; Pershing, Andrew J.; Alexander, Michael A.; Thomas, Andrew C.; Mills, Katherine E.

    2016-03-01

    Extreme and large-scale warming events in the ocean have been dubbed marine heatwaves, and these have been documented in both the Northern and Southern Hemispheres. This paper examines the intensity, duration, and frequency of positive sea surface temperature anomalies in the North Atlantic and North Pacific Oceans over the period 1950-2014 using an objective definition for marine heatwaves based on their probability of occurrence. Small-area anomalies occur more frequently than large-area anomalies, and this relationship can be characterized by a power law distribution. The relative frequency of large- versus small-area anomalies, represented by the power law slope parameter, is modulated by basin-scale modes of natural climate variability and anthropogenic warming. Findings suggest that the probability of marine heatwaves is a trade-off between size, intensity, and duration and that region specific variability modulates the frequency of these events.

  19. CRED Reson 8101 multibeam backscatter data of Johnston Island, Pacific Remote Island Areas, Central Pacific in GeoTIFF format

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam backscatter imagery extracted from gridded bathymetry of the lagoon, shelf, and slope environments of Palmyra Atoll, Pacific Island Areas, Central...

  20. CRED Reson 8101 multibeam backscatter data of Johnston Island, Pacific Remote Island Areas, Central Pacific in netCDF format

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam backscatter imagery extracted from gridded bathymetry of the lagoon, shelf, and slope environments of Palmyra Atoll, Pacific Island Areas, Central...

  1. North Pacific Transition Zone Thickness From SS-Precursors

    Science.gov (United States)

    Mayeau, T. M.; Wysession, M. E.; Aleqabi, G. I.

    2005-12-01

    The thickness variation of the mantle transition zone is one key to understanding mantle dynamics, in particular, as a possible indicator of lateral temperature variations at that depth. As a result of the Clapeyron slopes of the 410 and 660 km phase transitions, the transition zone is expected to thin in regions of high heat and thicken in cooler areas. Thus, these variations can be used to look for large scale mantle convection features, such as down going slabs and mantle plumes. The thickness of the transition zone can be effectively measured by the differential travel times of phases reflecting off the 410 km and 660 km discontinuities. Here we search for transition zone thickness variations using SS-precursors from the North Pacific recorded by the IRIS PASSCAL Florida-to-Edmonton (FLED) Array of broadband seismometers (and neighboring North American stations), which were operational from May 2001 to September 2002. Records are first rotated into transverse components, converted to displacements with the instrument responses removed, and then subdivided into 20 degree by 20 degree bins. The traces from earthquakes with strong SS arrivals were binned by the location of the SS bounce point, and the bins stacked into vespagrams using the MATLAB-based MATSEIS program. From the vespagrams we determine the S660S-S410S differential travel times for each stack, which yield measurements of transition zone thickness. We then compare thickness measurements from different events and with previously published maps of transition zone thickness to determine the robustness of our technique. This work was supported by an IRIS Undergraduate Summer Internship.

  2. Geochemical evolution of the central Pacific Ocean over the past 56 Myr

    Science.gov (United States)

    Ziegler, Christa L.; Murray, Richard W.

    2007-06-01

    We measured the elemental concentrations of 69 sediment samples collected at Ocean Drilling Program Site 1215 and employed a suite of statistical methods and elemental ratios to quantify the lithogenic, biogenic, and authigenic/hydrogenous/hydrothermal (AHH) components. We show that the changes in their abundance record (1) northwestward migration of the Pacific Plate, (2) changes in climatic and oceanographic processes associated with the transition from the Eocene "greenhouse" into the Oligocene "icehouse," and (3) changes in Pacific spreading rates and plate reorganization. The distributions of three separate lithogenic end-members depend on the latitudinal positioning of the site underneath the different wind belts. Locations north of 22°N received material from Asia, which was transported to the central Pacific via the westerlies. Locations between 20° and 22°N display a silicic volcanic composition and may reflect the boundary between westerlies and northeast trade winds. Locations south of 20°N are geochemically (e.g., Cr/Ta, Sc/Th, etc.) distinct from locations north of 22°N and suggest a North American origin. Rb/Sc significantly increases from values of 2.8 g g-1 at ˜20-22 Ma to 5.7 g g-1 in the modern, recording the development of the east Asian monsoon and formation of Asian loess. During the early to mid-Eocene (53-54 Ma), when Site 1215 was located at ˜11°-13°N and was above the carbonate compensation depth, export production increased by 40-55% and was ˜25% greater than the modern value at 9°N. The AHH component dominated from late Eocene to the late Miocene and during the late Eocene may have been driven by elevated hydrothermal activity during increased seafloor spreading.

  3. Seasonal Climate Associated with Major Shipping Routes in the North Pacific and North Atlantic

    Directory of Open Access Journals (Sweden)

    Jau-Ming Chen

    2014-01-01

    Full Text Available The major shipping routes in the North Pacific (NP and North Atlantic (NA are analyzed via ship-reported records compiled by the International Comprehensive Ocean-Atmosphere Data Set (ICOADS. The shipping route seasonal characteristics and associated climatic features are also examined. In the NP, the dominant cross-basin route takes a great-circle path between East Asia and North America along 54°N54°N north of the Aleutian Islands throughout the year. This route penetrates the Aleutian low center where ocean waves and winds are relatively weaker than those in the _ southern section south of 50°N.50°N. Moreover, the _ spherical shape makes a higher-latitude route shorter in navigational distance across the NP than a lower-latitude route. Two additional mid-latitude routes through the 40°40° - 50°N50°N region appear in summer when the Aleutian low vanishes. In the NA, the major shipping routes form an X-shaped pattern in the oceans south of 40°N40°N to connect North America/the Panama Canal and the Mediterranean Sea/the British Isles and Europe. These major shipping routes are far from the influence of the Icelandic low and thus are used throughout the year due to the stability in marine conditions and their general efficiency. A third and more zonal route appears to the north of the X-shaped routes in the 40°40° - 50°N50°N region. Weak influence from the Icelandic low on marine conditions during summer and spring means that more ships take this route in summer and spring than in winter and fall.

  4. Contrail properties over the eastern North Pacific from AVHRR data

    Energy Technology Data Exchange (ETDEWEB)

    Minnis, P. [Sciences Directorate, NASA Langley Research Center (United States); Palikonda, R.; Walter, B.J.; Kirk Ayers, J. [AS and M, Inc., Hampton, VA (United States); Mannstein, H. [DLR Inst. fuer Physik der Atmosphaere, Oberpfaffenhofen, Wessling (Germany)

    2005-08-01

    An increase of air traffic over the North Pacific during the last 30 years has been accompanied by an increase in cirrus coverage. To help alleviate the uncertainty in the contribution of air traffic to the cirrus increase, an analysis of linear contrail coverage over the region has been initiated using afternoon NOAA-16 AVHRR data taken during 4 months in 2002 and 2003. Manual evaluation of the automated contrail detection method revealed that it misclassified, on average, 32% of the pixels as contrails and missed 15% of the contrail pixels. After correction for detection errors, the contrail coverage over the domain between 25 and 55 N and between 120 and 150 W varied from a minimum of 0.37% in February to a maximum of 0.56% in May, respectively. The annual mean coverage, after correcting for the diurnal cycle of air traffic, is 0.31%, a value very close to earlier theoretical estimates for the region. Contrail optical depths for the 4 months average 0.24 resulting in a mean unit contrail longwave radiative forcing of 14.2 Wm{sup -2}. The contrail optical depths are twice the mean value expected from theoretical estimates. (orig.)

  5. Ammonia and nitrite oxidation in the Eastern Tropical North Pacific

    Science.gov (United States)

    Peng, Xuefeng; Fuchsman, Clara A.; Jayakumar, Amal; Oleynik, Sergey; Martens-Habbena, Willm; Devol, Allan H.; Ward, Bess B.

    2015-12-01

    Nitrification plays a key role in the marine nitrogen (N) cycle, including in oceanic oxygen minimum zones (OMZs), which are hot spots for denitrification and anaerobic ammonia oxidation (anammox). Recent evidence suggests that nitrification links the source (remineralized organic matter) and sink (denitrification and anammox) of fixed N directly in the steep oxycline in the OMZs. We performed shipboard incubations with 15N tracers to characterize the depth distribution of nitrification in the Eastern Tropical North Pacific (ETNP). Additional experiments were conducted to investigate photoinhibition. Allylthiourea (ATU) was used to distinguish the contribution of archaeal and bacterial ammonia oxidation. The abundance of archaeal and β-proteobacterial ammonia monooxygenase gene subunit A (amoA) was determined by quantitative polymerase chain reaction. The rates of ammonia and nitrite oxidation showed distinct subsurface maxima, with the latter slightly deeper than the former. The ammonia oxidation maximum coincided with the primary nitrite concentration maximum, archaeal amoA gene maximum, and the subsurface nitrous oxide maximum. Negligible rates of ammonia oxidation were found at anoxic depths, where high rates of nitrite oxidation were measured. Archaeal amoA gene abundance was generally 1 to 2 orders of magnitude higher than bacterial amoA gene abundance, and inhibition of ammonia-oxidizing bacteria with 10 μM ATU did not affect ammonia oxidation rates, indicating the dominance of archaea in ammonia oxidation. These results depict highly dynamic activities of ammonia and nitrite oxidation in the oxycline of the ETNP OMZ.

  6. 78 FR 25060 - North Pacific Fishery Management Council (NPFMC); Public Meetings

    Science.gov (United States)

    2013-04-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE... Atmospheric Administration (NOAA), Commerce. ACTION: Notice of a public meeting. SUMMARY: The North Pacific... mobile devices!) 1. Go to...

  7. Climate Prediction Center (CPC) Monthly Pacific North American Teleconnection Pattern Index

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monthly tabulated index of the Pacific/ North American teleconnection pattern. The data spans the period 1950 to present. The index is derived from a rotated...

  8. AFSC/NMML: North Pacific Right Whale Photo-ID Catalog

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The eastern population of the North Pacific right whale (Eubalaena japonica) is the most endangered stock of whales in the world, with recent abundance estimates...

  9. AFSC/NMML: North Pacific Right Whale Vessel Surveys in the Southeastern Bering Sea, 2007 - 2011

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The North Pacific right whale (NPRW) was heavily hunted between the 17th and the 20th centuries. Protection was supposedly afforded by international treaties in the...

  10. Historical Eastern North Pacific Tropical Cyclone Tracks, 1949-2004 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This Historical Eastern North Pacific Tropical Cyclone Tracks file contains the six-hourly (0000, 0600, 1200, 1800 UTC) center locations and intensities for all...

  11. 76 FR 66274 - North Pacific Fishery Management Council (NPFMC); Public Meetings

    Science.gov (United States)

    2011-10-26

    ... Fishery Management Council's (Council) Gulf of Alaska (GOA) and Bering Sea/Aleutian Islands (BS/AI... (GOA Plan Team) and Traynor Room (BS/AI Plan Team), Seattle, WA. Council address: North Pacific...

  12. Eelgrass (Zostera marina) Microsatellite DNA Data; Pacific Coast of North America, 2000-2009

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set contains genetic information collected from eelgrass (Zostera marina) populations along the Pacific coast of North America from Alaska to Baha...

  13. 78 FR 34347 - Endangered and Threatened Species; Recovery Plan for the North Pacific Right Whale

    Science.gov (United States)

    2013-06-07

    ... Plan for the North Pacific Right Whale AGENCY: National Marine Fisheries Service, National Oceanic and... Pacific right whale (Eubalaena japonica). ADDRESSES: Electronic copies of the Final Recovery Plan are... recovery. The Northern right whale (Eubalaena glacialis) has been listed as ``endangered'' under...

  14. Change in surface latent heat flux and its association with tropical cyclone genesis in the western North Pacific

    Science.gov (United States)

    Zhou, Lian-Tong; Chen, Guosen; Wu, Renguang

    2015-01-01

    The present study investigates the influence of June through November (JJASON) thermal state of the western North Pacific warm pool on surface latent heat flux and their association with tropical cyclone (TC) genesis by using 25 level water temperature data with European Centre for Medium-Range Weather Forecasts (ECWMF) operational ocean analysis (ORA-S3), the monthly mean fluxes from Objectively Analyzed Air-sea Fluxes (OAFlux) Project, and the tropical cyclone data from the International Best Track Archive for Climate Stewardship (IBTrACS). It is found that positive (negative) latent heat flux anomalies over the western North Pacific are associated with warm (cold) state of the warm pool. The analysis suggests that the change in sea-air humidity difference has a direct contribution to surface latent heat flux anomalies over the western Pacific in warm state years of the warm pool. However, the change in surface wind speed is the main cause of surface latent heat flux anomalies over central tropical Pacific. In cold state years, change in the sea-air humidity difference has a direct contribution to surface latent heat flux anomalies over the western Pacific and central and eastern tropical Pacific, and the change in surface wind speed appears not to be a cause of identified surface latent heat flux anomalies. Moreover, the results show that the sea-air humidity difference contributes to tropical cyclone genesis in warm state years, but in cold state years, tropical cyclone genesis occurs mainly in regions of sea-air humidity difference decrease and surface wind speed increase.

  15. Estimating historical eastern North Pacific blue whale catches using spatial calling patterns.

    Directory of Open Access Journals (Sweden)

    Cole C Monnahan

    Full Text Available Blue whales (Balaenoptera musculus were exploited extensively around the world and remain endangered. In the North Pacific their population structure is unclear and current status unknown, with the exception of a well-studied eastern North Pacific (ENP population. Despite existing abundance estimates for the ENP population, it is difficult to estimate pre-exploitation abundance levels and gauge their recovery because historical catches of the ENP population are difficult to separate from catches of other populations in the North Pacific. We collated previously unreported Soviet catches and combined these with known catches to form the most current estimates of North Pacific blue whale catches. We split these conflated catches using recorded acoustic calls from throughout the North Pacific, the knowledge that the ENP population produces a different call than blue whales in the western North Pacific (WNP. The catches were split by estimating spatiotemporal occurrence of blue whales with generalized additive models fitted to acoustic call patterns, which predict the probability a catch belonged to the ENP population based on the proportion of calls of each population recorded by latitude, longitude, and month. When applied to the conflated historical catches, which totaled 9,773, we estimate that ENP blue whale catches totaled 3,411 (95% range 2,593 to 4,114 from 1905-1971, and amounted to 35% (95% range 27% to 42% of all catches in the North Pacific. Thus most catches in the North Pacific were for WNP blue whales, totaling 6,362 (95% range 5,659 to 7,180. The uncertainty in the acoustic data influence the results substantially more than uncertainty in catch locations and dates, but the results are fairly insensitive to the ecological assumptions made in the analysis. The results of this study provide information for future studies investigating the recovery of these populations and the impact of continuing and future sources of anthropogenic

  16. Estimating historical eastern North Pacific blue whale catches using spatial calling patterns.

    Science.gov (United States)

    Monnahan, Cole C; Branch, Trevor A; Stafford, Kathleen M; Ivashchenko, Yulia V; Oleson, Erin M

    2014-01-01

    Blue whales (Balaenoptera musculus) were exploited extensively around the world and remain endangered. In the North Pacific their population structure is unclear and current status unknown, with the exception of a well-studied eastern North Pacific (ENP) population. Despite existing abundance estimates for the ENP population, it is difficult to estimate pre-exploitation abundance levels and gauge their recovery because historical catches of the ENP population are difficult to separate from catches of other populations in the North Pacific. We collated previously unreported Soviet catches and combined these with known catches to form the most current estimates of North Pacific blue whale catches. We split these conflated catches using recorded acoustic calls from throughout the North Pacific, the knowledge that the ENP population produces a different call than blue whales in the western North Pacific (WNP). The catches were split by estimating spatiotemporal occurrence of blue whales with generalized additive models fitted to acoustic call patterns, which predict the probability a catch belonged to the ENP population based on the proportion of calls of each population recorded by latitude, longitude, and month. When applied to the conflated historical catches, which totaled 9,773, we estimate that ENP blue whale catches totaled 3,411 (95% range 2,593 to 4,114) from 1905-1971, and amounted to 35% (95% range 27% to 42%) of all catches in the North Pacific. Thus most catches in the North Pacific were for WNP blue whales, totaling 6,362 (95% range 5,659 to 7,180). The uncertainty in the acoustic data influence the results substantially more than uncertainty in catch locations and dates, but the results are fairly insensitive to the ecological assumptions made in the analysis. The results of this study provide information for future studies investigating the recovery of these populations and the impact of continuing and future sources of anthropogenic mortality. PMID

  17. Effects of tropical North Atlantic SST on tropical cyclone genesis in the western North Pacific

    Science.gov (United States)

    Yu, Jinhua; Li, Tim; Tan, Zhemin; Zhu, Zhiwei

    2016-02-01

    The tropical cyclone genesis number (TCGN) in July-October (JASO) over the western North Pacific (WNP) exhibits a robust interannual variation. It shows a longitudinally tri-pole pattern with a high in the eastern WNP and South China Sea (SCS) and a low in the western WNP, which explain 42.2 and 23.4 % of total TCGN variance in the eastern WNP and SCS, respectively. The high-low-high pattern is similar to that derived from a TC genesis potential index (GPI). To understand the cause of the longitudinal distribution of the dominant interannual mode, we examine the contributions of environmental parameters associated with GPI. It is found that relative humidity and relative vorticity are important factors responsible for TC variability in the SCS, while vertical shear and relative vorticity are crucial in determining TC activity in eastern WNP. A simultaneous correlation analysis shows that the WNP TCGN in JASO is significantly negatively correlated (with a correlation coefficient of -0.5) with sea surface temperature anomalies (SSTA) in the tropical North Atlantic (TNA). The longitudinal distribution of TC genesis frequency regressed onto TNA SSTA resembles that regressed upon the WNP TCGN series. The spatial patterns of regressed environmental variables onto the SSTA over the TNA also resemble those onto TCGN in the WNP, that is, an increase of relative humidity in the SCS and a weakening of vertical shear in the eastern WNP are all associated with cold SSTA in the TNA. Further analyses show that the cold SSTA in the TNA induce a negative heating in situ. In response to this negative heating, a low (upper)-level anomalous aniti-cyclonic (cyclonic) flows appear over the subtropical North Atlantic and eastern North Pacific, and to east of the cold SSTA, anomalous low-level westerlies appear in the tropical Indian Ocean. Given pronounced mean westerlies in northern Indian Ocean in boreal summer, the anomalous westerly flows increase local surface wind speed and surface

  18. Interannual Variation of Multiple Tropical Cyclone Events in the Western North Pacific

    Institute of Scientific and Technical Information of China (English)

    GAO Jianyun; Tim LI

    2012-01-01

    The interannual variability of occurrence of multiple tropical cyclone (MTC) events during June-October in the western North Pacific (WNP) was examined for the period 1979-2006.The number of the MTC events ranged from 2 to 9 per year,exhibiting a remarkable year-to-year variation.Seven active and seven inactive MTC years were identified.Compared to the inactive years,tropical cyclone genesis locations extended farther to the east and in the meridional direction during the active MTC years.A composite analysis shows that inactive MTC years were often associated with the El Ni(n)o decaying phase,as warm SST anomalies in the equatorial eastern-central Pacific in the preceding winter transitioned into cold sea surface temperature (SST) anomalies in the concurrent summer.Associated with the SST evolution were suppressed low-level cyclonic vorticity and weakened convection in the WNP monsoon region.In addition to the mean flow difference,significant differences between active and inactive MTC years were also found in the strength of the atmospheric intraseasonal oscillation (ISO).Compared with inactive MTC years,ISO activity was much stronger along the equator and in the WNP region during active MTC years.Both westward- and northward-propagating ISO spectrums strengthened during active MTC years compared to inactive years.The combined mean state and ISO activity changes may set up a favorable environment for the generation of MTC events.

  19. Lowermost mantle anisotropy beneath the north Pacific from differential S-ScS splitting

    Science.gov (United States)

    Wookey, James; Kendall, J.-Michael; Rümpker, Georg

    2005-06-01

    Seismic anisotropy is an important tool for studying the nature, origin and dynamics of the lowermost mantle (D''). We introduce differential S-ScS splitting as a tool for removing the effect of near-source and near-receiver anisotropy to estimate splitting accrued in the D'' region. This is applicable to events recorded at epicentral distances between 60° and 85°. Near-source anisotropy has often been ignored in previous studies of lowermost mantle anisotropy. We apply differential S-ScS splitting to records from Canadian National Seismic Network stations of western Pacific earthquakes; these sample the lowermost mantle beneath the north Pacific. The residual splitting in ScS, which we attribute to D'', shows lag times between 1.0 and 3.9 s. Given the near horizontal ray path of ScS in D'', we interpret the recovered fast directions as the orientation of the fast shear wave in the plane defined by the vertical and transverse directions and observe a clearly non-VTI (transverse isotropy with a vertical axis of symmetry) style of anisotropy. The largest population of results shows an approximately southeasterly dipping symmetry axis which we speculate might be explained by descending palaeoslab material being swept horizontally across the core-mantle boundary towards an upwelling region beneath the central Pacific. Non-VTI symmetry and the many possible contributions to D'' anisotropy from lower-mantle minerals, melt and subducted materials suggest that our understanding of the lowermost mantle could be greatly improved by trying to resolve a more general style of anisotropy.

  20. Seasonal forecasting of intense tropical cyclones over the North Atlantic and the western North Pacific basins

    Science.gov (United States)

    Choi, Woosuk; Ho, Chang-Hoi; Jin, Chun-Sil; Kim, Jinwon; Feng, Song; Park, Doo-Sun R.; Schemm, Jae-Kyung E.

    2016-02-01

    Intense tropical cyclones (TCs) accompanying torrential rain and powerful wind gusts often cause substantial socio-economic losses in the regions around their landfall. This study analyzes intense TCs in the North Atlantic (NA) and the western North Pacific (WNP) basins during the period 1982-2013. Different intensity criteria are used to define intense TCs for these two basins, category 1 and above for NA and category 3 and above for WNP, because the number of TCs in the NA basin is much smaller than that in the WNP basin. Using a fuzzy clustering method, intense TC tracks in the NA and the WNP basins are classified into two and three representative patterns, respectively. On the basis of the clustering results, a track-pattern-based model is then developed for forecasting the seasonal activities of intense TCs in the two basins. Cross-validation of the model skill for 1982-2013 as well as verification of a forecast for the 2014 TC season suggest that our intense TC model is applicable to operational uses.

  1. CRED Simrad em300 multibeam backscatter data from shelf and slope environments at Howland Island, Pacific Remote Island Areas, Central Pacific in netCDF format

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam backscatter imagery extracted from gridded bathymetry of Howland Island, Pacific Remote Island Areas, Central Pacific. These data provide coverage between...

  2. CRED Simrad em300 multibeam backscatter data of Baker Island, Pacific Remote Island Areas, Central Pacific in GeoTIFF format

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam backscatter imagery extracted from gridded bathymetry of the shelf and slope environments of Baker Island, Pacific Island Areas, Central Pacific. These...

  3. CRED Simrad em300 multibeam backscatter data of Johnston Atoll, Pacific Remote Island Areas, Central Pacific in GeoTIFF format

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam backscatter imagery extracted from gridded bathymetry of the shelf and slope environments of Johnston Island, Pacific Island Areas, Central Pacific. These...

  4. CRED Simrad em300 multibeam backscatter data of Jarvis Island, Pacific Remote Island Areas, Central Pacific in GeoTIFF format

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam backscatter imagery extracted from gridded bathymetry of the shelf and slope environments of Jarvis Atoll, Pacific Island Areas, Central Pacific. These...

  5. Fukushima-derived radiocesium in western North Pacific sediment traps

    Directory of Open Access Journals (Sweden)

    M. C. Honda

    2013-02-01

    Full Text Available At two stations in the western North Pacific, K2 in the subarctic gyre and S1 in the subtropical gyre, time-series sediment traps were collecting sinking particles when the Fukushima Daiichi Nuclear Power Plant (FNPP1 accident occurred on 11 March 2011. Radiocesium (134Cs and 137Cs derived from FNPP1 accident was detected in sinking particles collected at 500 m by late March 2011 and at 4810 m by early April 2011 at both stations. The sinking velocity of 134Cs and 137Cs was estimated to be 8 to 36 m day−1 between the surface and 500 m and > 180 m day−1 between 500 m and 4810 m. 137Cs specific activity varied from 0.14 to 0.25 Bq g−1 dry weight. These values are higher than those of surface seawater, suspended particles, and zooplankton collected in April 2011. Although the radiocesium may have been adsorbed onto or incorporated into clay minerals, correlations between 134Cs and lithogenic material were not always significant; therefore, the form of the cesium associated with the sinking particles is still an open question. The total 137Cs flux by late June at K2 and by late July at S1 was 0.5 to 1.7 Bq m−2 at both depths. Compared with 137Cs input to both stations by April 2011, estimated from the surface 137Cs activity and mixed layer depth and by assuming that the observed 137Cs flux was constant throughout the year, the estimated removal rate of 137Cs from the upper layer (residence time in the upper layer was 0.3 to 1.5% (68 to 312 yr. The estimated removal rates and residence times are comparable to previously reported values.

  6. Relationship between the Asian-Pacific oscillation and the tropical cyclone frequency in the western North Pacific

    Institute of Scientific and Technical Information of China (English)

    ZHOU BoTao; CUI Xuan; ZHAO Ping

    2008-01-01

    The relationship between the Asian-Pacific oscillation (APO) and the tropical cyclone frequency over the western North Pacific (WNP) in summer is preliminarily investigated through an analysis of observed data. The result has shown clearly that APO is significantly and positively correlated to the tropical cyclone frequency in the WNP. If APO is above (below) the normal in summer, more (less) tropical cyclones will tend to appear in the WNP. The present study also addresses the large-scale atmospheric general circulation changes underlying the linkage between APO and the WNP tropical cyclone frequency. It follows that a positive phase of summer APO is concurrent with weakened as well as northward and eastward located western Pacific subtropical high (WPSH), low-level convergence and high-level divergence, and reduced vertical zonal wind shear in the WNP, providing favorable environment for the tropical cyclone genesis, and thus more tropical cyclones will come into being, and vice versa.

  7. Relationship between the Asian-Pacific oscillation and the tropical cyclone frequency in the western North Pacific

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The relationship between the Asian-Pacific oscillation (APO) and the tropical cyclone frequency over the western North Pacific (WNP) in summer is preliminarily investigated through an analysis of ob- served data. The result has shown clearly that APO is significantly and positively correlated to the tropical cyclone frequency in the WNP. If APO is above (below) the normal in summer, more (less) tropical cyclones will tend to appear in the WNP. The present study also addresses the large-scale at- mospheric general circulation changes underlying the linkage between APO and the WNP tropical cy- clone frequency. It follows that a positive phase of summer APO is concurrent with weakened as well as northward and eastward located western Pacific subtropical high (WPSH), low-level convergence and high-level divergence, and reduced vertical zonal wind shear in the WNP, providing favorable envi- ronment for the tropical cyclone genesis, and thus more tropical cyclones will come into being, and vice versa.

  8. Climate impacts on the structures of the North Pacific air-sea CO2 flux variability

    Directory of Open Access Journals (Sweden)

    Y. Nojiri

    2011-05-01

    Full Text Available Some dominant spatial and temporal structures of the North Pacific air-sea CO2 fluxes in response to the Pacific Decadal Oscillation (PDO are identified in four data products from four independent sources: an assimilated CO2 flux product, two forward model solutions, and a gridded pCO2 dataset constructed with a neural network approach. The interannual variability of CO2 flux is found to be an order of magnitude weaker compared to the seasonal cycle of CO2 flux in the North Pacific. A statistical approach is employed to quantify the signal-to-noise ratio in the reconstructed dataset to delineate the representativity errors. The dominant variability with a signal-to-noise ratio above one is identified and its correlations with PDO are examined. A tentative four-box structure in the North Pacific air-sea CO2 flux variability linked to PDO emerges in which two positively correlated boxes are oriented in the northwest and southeast directions and contrarily, the negatively correlated boxes are oriented in the northeast and southwest directions. This pattern is verified with the CO2 and pCO2 from four products and its relations to the interannual El Niño-Southern Oscillation (ENSO and lower-frequency PDO are separately identified. A combined EOF analysis between air-sea CO2 flux and key variables representing ocean-atmosphere interactions is carried out to elicit robust oscillations in the North Pacific CO2 flux in response to the PDO. The proposed spatial and temporal structures of the North Pacific CO2 fluxes are insightful since they separate the secular trends of the surface ocean carbon from the interannual variability. The regional characterization of the North Pacific in terms of PDO and CO2 flux variability is also instructive for determining the homogeneous oceanic domains for the Regional Carbon Cycle and Assessment Processes (RECCAP.

  9. 75 FR 20344 - North Pacific Fishery Management Council; Public Meeting

    Science.gov (United States)

    2010-04-19

    ... Management Council's Gulf of Alaska (GOA) and Bering Sea/Aleutian Islands (BSAI) groundfish plan teams will... models to be considered for inclusion in the GOA and BSAI Pacific cod assessments. DATES:...

  10. 75 FR 20566 - North Pacific Fishery Management Council; Public Meeting

    Science.gov (United States)

    2010-04-20

    ... Management Council's Gulf of Alaska (GOA) and Bering Sea/Aleutian Islands (BSAI) groundfish plan teams will... models to be considered for inclusion in the GOA and BSAI Pacific cod assessments. DATES:...

  11. Mesoscale cyclogenesis over the western North Pacific Ocean during TPARC

    OpenAIRE

    Davis, Christopher A.; Sarah C. Jones; Anwender, Doris; Badey, Janina; Scheck, Leonhard

    2013-01-01

    Three cases of mesoscale marine cyclogenesis over the subtropics of the Western Pacific Ocean are investigated. Each case occurred during the THORPEX Pacific Asia Regional Campaign and Tropical Cyclone Structure (TCS-08) field phases in 2008. Each cyclone developed from remnants of disturbances that earlier showed potential for tropical cyclogenesis within the tropics. Two of the cyclones produced gale-force surface winds, and one, designated as a tropical cyclone, resulted in a significant c...

  12. Evaluating the opposing wave interaction hypothesis for the generation of microbaroms in the eastern North Pacific

    Science.gov (United States)

    Walker, Kristoffer T.

    2012-12-01

    Two microphone arrays were deployed in California during 2010 to record microbaroms, quasi-continuous atmospheric pressure oscillations with a period of ˜5 s. In this paper a time-progressive, frequency domain beamforming method is developed and used to analyze microbaroms recorded by these and 10 other infrasonic arrays along the North Pacific rim. Common pelagic microbarom sources that move around the North Pacific are observed during the boreal winter. Summertime North Pacific sources are only observed by western Pacific arrays, presumably a result of weaker microbarom radiation and westward stratospheric winds. A well-defined source is resolved ˜2000 km off the coast of California in January 2011 that moves closer to land over several days. The source locations are corrected for deflection by horizontal winds using acoustic ray trace modeling with range-dependent atmospheric specifications provided by ground-to-space models. The observed source locations do not correlate with anomalies in NOAA Wave Watch 3 (NWW3) model field data. However, application of the opposing wave, microbarom source model of Waxler and Gilbert (2006) to the NWW3 directional wave height spectra output at buoy locations within 1100 km of the western North America coastline predicts microbarom radiation in locations that correlate with observed locations. These results suggest that pelagic North Pacific microbarom radiation detected by infrasonic arrays during the boreal winter could be routinely used to validate NWW3 results in regions with poor sensor coverage.

  13. Age Dependent 3-D Magnetic Modeling of the North Pacific and North Atlantic Oceanic Crust at Intermediate Wavelengths

    Science.gov (United States)

    Yanez, Gonzalo A.; LaBrecque, John L.

    1996-01-01

    Three-dimensional magnetic modeling of the North Atlantic and Northeast pacific is performed at intermediate wavelengths using three models for the acquisition of a natural remanent magnetization. It is shown that a remanent magnetization which is dependent on the rustal age is the dominant source for the intermediate wavelength pattern in both basins.

  14. CCSM3 simulation of pacific multi-decadal climate variability: the role of subpolar North Pacific Ocean

    International Nuclear Information System (INIS)

    Previous analyses of the CCSM3 standard integration have revealed pronounced multidecadal variability in the Pacific climate system. The purpose of the present work is to investigate the physical mechanism underlying the Pacific multidecadal variability (PMV) using specifically designed sensitivity experiments. A novel mechanism is advanced, characterized by a crucial role of the subpolar North Pacific Ocean. The multidecadal signal in ocean temperature and salinity fields is found to originate from the subsurface of the subpolar North Pacific, as result of the wave adjustment to the preceding basin-scale wind curl forcing. The multidecadal signal then ascends to the surface and is amplified through local temperature/salinity convective feedback. Along the southward Oyashio current, the anomaly travels to the Kuroshio Extension (KOE) region and is further intensified through a similar convective feedback in addition to the wind-evaporation-sea surface temperature feedback. The temperature anomaly in the KOE is able to feed back to the large-scale atmospheric circulation, inducing wind curl anomaly over the subpolar region, which in turn generates anomalous oceanic circulation and causes temperature/salinty variability in the subpolar subsurface. Thereby, a closed loop of PMV is established, in the form of a subpolar delayed oscillator

  15. Evaluating the impacts of eastern North Pacific tropical cyclones on North America utilizing remotely-sensed and reanalysis data

    Science.gov (United States)

    Wood, Kimberly M.

    The eastern North Pacific Ocean has the highest density of tropical cyclone genesis events of any tropical basin in the world, and many of these systems form near land before moving westward. However, despite the level of tropical cyclone activity in this basin, and the proximity of the main genesis region to land, tropical cyclone behavior in the eastern North Pacific has been relatively unexplored. When synoptic conditions are favorable, moisture from northward-moving tropical cyclones can be advected into northern Mexico and the southwestern United States, often leading to the development of summertime thunderstorms during the North American monsoon season. An interaction with a mid-latitude trough produces the most rainfall, and the spatial variability of precipitation is greatly affected by the complex topography of the region. Moisture can be advected from a tropical cyclone around the subtropical ridge in place for much of the eastern North Pacific hurricane season and contribute to precipitation. This ridge, when it extends westward over the Pacific Ocean, can also prevent tropical cyclone moisture from impacting the southwestern United States. Northward-moving tropical cyclones often enter an environment with decreasing sea surface temperatures, increasing vertical wind shear, and meridional air temperature and moisture gradients. These key ingredients for extratropical transition are generally present in the eastern North Pacific, but the subtropical ridge prevents many named systems from moving northward, and only 9% of eastern North Pacific tropical cyclones from 1970 to 2011 complete ET according to cyclone phase space. However, over half of the systems that do not complete ET dissipate as cold core cyclones, a structural change that has yet to be explored in other tropical basins. It is difficult to estimate tropical cyclone intensity in a vast ocean area with few direct measurements available. The deviation angle variance technique, an objective

  16. Paleoclimate. Synchronization of North Pacific and Greenland climates preceded abrupt deglacial warming.

    Science.gov (United States)

    Praetorius, Summer K; Mix, Alan C

    2014-07-25

    Some proposed mechanisms for transmission of major climate change events between the North Pacific and North Atlantic predict opposing patterns of variations; others suggest synchronization. Resolving this conflict has implications for regulation of poleward heat transport and global climate change. New multidecadal-resolution foraminiferal oxygen isotope records from the Gulf of Alaska (GOA) reveal sudden shifts between intervals of synchroneity and asynchroneity with the North Greenland Ice Core Project (NGRIP) δ(18)O record over the past 18,000 years. Synchronization of these regions occurred 15,500 to 11,000 years ago, just prior to and throughout the most abrupt climate transitions of the last 20,000 years, suggesting that dynamic coupling of North Pacific and North Atlantic climates may lead to critical transitions in Earth's climate system. PMID:25061208

  17. The relationship of western Pacific monsoon and tropical cyclone activity to North Pacific and North American climate anomalies

    OpenAIRE

    Harr, Patrick A.; Chen, Jeng-Ming; Murphree, Tom

    1992-01-01

    This present study investigates the influence of western Pacific tropical cyclone activity as possible centers of anomalous tropical heating on the large-scale circulation over the Pacific region. The characterization of tropical cyclone activity via an index based on anomalous 700 mb zonal wind is described first. Patterns of anomalous large-scale extratropical circulation anomalies based on composites of similar periods of tropical cyclone activity are then presented, followed by general co...

  18. Rayleigh phase velocities in the upper mantle of the Pacific-North American plate boundary in southern California

    Science.gov (United States)

    Escobar, L.; Weeraratne, D. S.; Kohler, M. D.

    2013-05-01

    The Pacific-North America plate boundary, located in Southern California, presents an opportunity to study a unique tectonic process that has been shaping the plate tectonic setting of the western North American and Mexican Pacific margin since the Miocene. This is one of the few locations where the interaction between a migrating oceanic spreading center and a subduction zone can be studied. The rapid subduction of the Farallon plate outpaced the spreading rate of the East Pacific Rise rift system causing it to be subducted beneath southern California and northern Mexico 30 Ma years ago. The details of microplate capture, reorganization, and lithospheric deformation on both the Pacific and North American side of this boundary is not well understood, but may have important implications for fault activity, stresses, and earthquake hazard analysis both onshore and offshore. We use Rayleigh waves recorded by an array of 34 ocean bottom seismometers deployed offshore southern California for a 12 month duration from August 2010 to 2011. Our array recorded teleseismic earthquakes at distances ranging from 30° to 120° with good signal-to-noise ratios for magnitudes Mw ≥ 5.9. The events exhibit good azimuthal distribution and enable us to solve simultaneously for Rayleigh wave phase velocities and azimuthal anisotropy. Fewer events occur at NE back-azimuths due to the lack of seismicity in central North America. We consider seismic periods between 18 - 90 seconds. The inversion technique considers non-great circle path propagation by representing the arriving wave field as two interfering plane waves. This takes advantage of statistical averaging of a large number of paths that travel offshore southern California and northern Mexico allowing for improved resolution and parameterization of lateral seismic velocity variations at lithospheric and sublithospheric depths. We present phase velocity results for periods sampling mantle structure down to 150 km depth along the

  19. Intrusion of Fukushima-derived radiocaesium into subsurface water due to formation of mode waters in the North Pacific

    Science.gov (United States)

    Kaeriyama, Hideki; Shimizu, Yugo; Setou, Takashi; Kumamoto, Yuichiro; Okazaki, Makoto; Ambe, Daisuke; Ono, Tsuneo

    2016-02-01

    The Fukushima Dai-ichi Nuclear Power Plant accident in March 2011 released radiocaesium (137Cs and 134Cs) into the North Pacific Ocean. Meridional transects of the vertical distribution of radiocaesium in seawater were measured along 147 °E and 155 °E in October-November 2012, 19 months after the accident. These measurements revealed subsurface peaks in radiocaesium concentrations at locations corresponding to two mode waters, Subtropical Mode Water and Central Mode Water. Mode water is a layer of almost vertically homogeneous water found over a large geographical area. Here we show that repeated formation of mode water during the two winter seasons after the Fukushima accident and subsequent outcropping into surface water transported radiocaesium downward and southward to subtropical regions of the North Pacific. The total amount of Fukushima-derived 134Cs within Subtropical Mode Water, decay-corrected to April 2011, was estimated to be 4.2 ± 1.1 PBq in October-November 2012. This amount of 134Cs corresponds to 22-28% of the total amount of 134Cs released to the Pacific Ocean.

  20. 75 FR 55743 - North Pacific Fishery Management Council; Public Meeting

    Science.gov (United States)

    2010-09-14

    ... Annual Catch Limits (ACLs) for crab and scallops; background on Council sector split action and jig fishery for Gulf (GOA) of Alaska Pacific cod fishery management; Board schedule for accepting State regulatory proposals for coordination with pending federal GOA action; ACL requirements and...

  1. 78 FR 4391 - North Pacific Fishery Management Council; Public Meetings

    Science.gov (United States)

    2013-01-22

    ... Collection; Discussion paper on CGOA Trawl Catch Shares; Review and discuss Western GOA issues and discuss...; Initial review of BSAI Flatfish Specifications Flexibility. (T); Initial review of Gulf of Alaska (GOA) Pacific cod sideboards for Freezer Longliners (FFL); Initial review of AFA Vessel Replacement...

  2. 75 FR 70903 - Eastern North Pacific Gray Whale; Notice of Extension of Public Comment Period on Marine Mammal...

    Science.gov (United States)

    2010-11-19

    ... on the petition (75 FR 68756). That Federal Register notice began NMFS' 15-day public comment period... National Oceanic and Atmospheric Administration RIN 0648-XA018 Eastern North Pacific Gray Whale; Notice of... petition to designate the Eastern North Pacific population of gray whales (Eschrichtius robustus) as...

  3. Neutral carbohydrate geochemistry of particulate material in the central equatorial Pacific

    Science.gov (United States)

    Hernes, Peter J.; Hedges, John I.; Peterson, Michael L.; Wakeham, Stuart G.; Lee, Cindy

    Neutral carbohydrate compositions were determined for particulate samples from plankton net tows, shallow floating sediment traps, mid-depth and deep moored sediment traps, and sediment cores collected along a north-south transect in the central equatorial Pacific Ocean during the U.S. JGOFS EqPac program. Total neutral carbohydrate depth profiles and patterns along the transect follow essentially the same trends as bulk and organic carbon (OC) fluxes—attenuating with depth, high near the equator and decreasing poleward. OC-normalized total aldose (TCH 2,O) yields along the transect and with depth do not show any consitent patterns. Relative to a planktonic source, neutral carbohydrate compositions in sediment trap and sediment core samples reflect preferential loss of ribose and storage carbohydrates rich in glucose, and preferential preservation of structural carbohydrates rich in rhamnose, xylose, fucose, and mannose. There is also evidence for an intermediately labile component rich in galactose. It appears that compositional signatures of neutral carbohydrates in sediments are more dependent upon their planktonic source than on any particular diagenetic pathway. Relative to other types of organic matter, neutral carbohydrates are better preserved in calcareous oozes from 12°S to 5°N than in red clays at 9°N based on OC-normalized TCH 2O yields, due to either differing sources or sorption characteristics. Weight per cent glucose generally decreases with increased degradation of organic material in the central equatorial Pacific region. Based on weight per cent glucose, comparisons of samples between Survey I (El Niõn) and Survey II (non-El Niño) indicate that during Survey I, organic material in the epipelagic zone in the northern hemisphere may have undergone more degradation than organic material in the southern hemisphere.

  4. Global Climate network evolves with North Atlantic Oscillation phases: Coupling to Southern Pacific Ocean

    CERN Document Server

    Guez, Oded; Berezin, Yehiel; Wang, Yang; Havlin, Shlomo

    2013-01-01

    We construct a network from climate records of atmospheric temperature at surface level, at different geographical sites in the globe, using reanalysis data from years 1948-2010. We find that the network correlates with the North Atlantic Oscillation (NAO), both locally in the north Atlantic, and through coupling to the southern Pacific Ocean. The existence of tele-connection links between those areas and their stability over time allows us to suggest a possible physical explanation for this phenomenon.

  5. North Central regional environmental characterization report: executive summary - final

    International Nuclear Information System (INIS)

    This Executive Summary of the final North Central Regional Environmental Characterization Report (RECR) is issued primarily for public information purposes and provides a general overview of the report. The complete RECR presents available regional environmental information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Minnesota, Wisconsin, and the Upper Peninsula of Michigan. For each of the States within the North Central Region, information is provided on the environmental disqualifying factors and the environmental regional screening variables to be used in region-to-area screening

  6. Acoustic detections of singing humpback whales (Megaptera novaeangliae) in the eastern North Pacific during their northbound migration.

    Science.gov (United States)

    Norris, T F; McDonald, M; Barlow, J

    1999-07-01

    Numerous (84) acoustic detections of singing humpback whales were made during a spring (08 March-09 June 1997) research cruise to study sperm whales in the central and eastern North Pacific. Over 15,000 km of track-line was surveyed acoustically using a towed hydrophone array. Additionally, 83 sonobuoys were deployed throughout the study area. Detection rates were greatest in late March, near the Hawaiian Islands, and in early April, northeast of the islands. Only one detection was made after April. Detection rates for sonobuoys were unequal in three equally divided longitudinal regions of the study area. Two high density clusters of detections occurred approximately 1200-2000 km northeast of the Hawaiian Islands and were attributed to a large aggregation of migrating animals. The distribution of these detections corroborates findings of previous studies. It is possible that these animals were maintaining acoustic contact during migration. Two unexpected clusters of singing whales were detected approximately 900 to 1000 km west of central and southern California. The location of these detections may indicate a previously undocumented migration route between an offshore breeding area, such as the Revillagigedo Islands, Mexico, and possible feeding areas in the western North Pacific or Bering Sea. PMID:10420640

  7. Statistical Characteristics of Mesoscale Eddies in the North Pacific Derived from Satellite Altimetry

    Directory of Open Access Journals (Sweden)

    Yu-Hsin Cheng

    2014-06-01

    Full Text Available The sea level anomaly data derived from satellite altimetry are analyzed to investigate statistical characteristics of mesoscale eddies in the North Pacific. Eddies are detected by a free-threshold eddy identification algorithm. The results show that the distributions of size, amplitude, propagation speed, and eddy kinetic energy of eddy follow the Rayleigh distribution. The most active regions of eddies are the Kuroshio Extension region, the Subtropical Counter Current zone, and the Northeastern Tropical Pacific region. By contrast, eddies are seldom observed around the center of the eastern part of the North Pacific Subarctic Gyre. The propagation speed and kinetic energy of cyclonic and anticyclonic eddies are almost the same, but anticyclonic eddies possess greater lifespans, sizes, and amplitudes than those of cyclonic eddies. Most eddies in the North Pacific propagate westward except in the Oyashio region. Around the northeastern tropical Pacific and the California currents, cyclonic and anticyclonic eddies propagate westward with slightly equatorward (197° average azimuth relative to east and poleward (165° deflection, respectively. This implies that the background current may play an important role in formation of the eddy pathway patterns.

  8. Comparative Resilience in Five North Pacific Regional Salmon Fisheries

    OpenAIRE

    Courtland L. Smith; Xanthippe Augerot

    2010-01-01

    Over the past century, regional fisheries for Pacific salmon (Oncorhynchus spp.) have been managed primarily for their provisioning function, not for ecological support and cultural significance. We examine the resilience of the regional salmon fisheries of Japan, the Russian Far East, Alaska, British Columbia, and Washington-Oregon-California (WOC) in terms of their provisioning function. Using the three dimensions of the adaptive cycle—capital, connectedness, and resilience—we i...

  9. Hydrogeological mapping of north-central Madagascar using limited data

    OpenAIRE

    Davies, Jeffrey

    2009-01-01

    North-central Madagascar is well endowed with surface-water. Due to soil erosion and pollution, rivers can no longer provide year round clean water supplies. Shallow aquifers are being developed to provide sustainable rural and urban water supplies. A survey of water sources located 2760 boreholes, wells, ponds and springs in the area, but understanding of groundwater occurrence remains poor. The area comprises four hydrogeological zones: the dry Central High Plateau with erosi...

  10. Tectonic implications of post-30 Ma Pacific and North American relative plate motions

    Science.gov (United States)

    Bohannon, R.G.; Parsons, T.

    1995-01-01

    The Pacific plate moved northwest relative to North America since 42 Ma. The rapid half rate of Pacific-Farallon spreading allowed the ridge to approach the continent at about 29 Ma. Extinct spreading ridges that occur offshore along 65% of the margin document that fragments of the subducted Farallon slab became captured by the Pacific plate and assumed its motion proper to the actual subduction of the spreading ridge. This plate-capture process can be used to explain much of the post-29 Ma Cordilleran North America extension, strike slip, and the inland jump of oceanic spreading in the Gulf of California. Much of the post-29 Ma continental tectonism is the result of the strong traction imposed on the deep part of the continental crust by the gently inclined slab of subducted oceanic lithosphere as it moved to the northwest relative to the overlying continent. -from Authors

  11. Relationships between the North Pacific Oscillation and the typhoon/hurricane frequencies

    Institute of Scientific and Technical Information of China (English)

    WANG; HuiJun; SUN; JianQi; FAN; Ke

    2007-01-01

    Relationships between the North Pacific Oscillation (NPO) and the typhoon as well as hurricane frequencies are documented. The correlation between NPO index in June-July-August-September and the annual typhoon number in the western North Pacific is 0.37 for the period of 1949―1998. The NPO is correlated with the annual hurricane number in the tropical Atlantic at - 0.28 for the same period. The variability of NPO is found to be concurrent with the changes of the magnitude of vertical zonal wind shear, sea-level pressure patterns, as well as the sea surface temperature, which are physically associated with the typhoons and hurricanes genesis. The NPO associated atmospheric circulation variability is analyzed to explain how NPO is linked with variability of the tropical atmospheric circulation in the western Pacific and the tropical Atlantic, via the atmospheric teleconnection.

  12. Relationship between the Antarctic oscillation in the western North Pacific typhoon frequency

    Institute of Scientific and Technical Information of China (English)

    WANG HuiJun; FAN Ke

    2007-01-01

    Relationship between the Antarctic oscillation (AAO) and the western North Pacific typhoon number (WNPTN) in the interannual variability is examined in this research. The WNPTN is correlated with the AAO in June-July-August-September (JJAS) in 1949-1998 at -0.48 for the detrended time series, statistically significant at 99% level. The tropical atmospheric circulation as well as the sea surface temperature variability over the western Pacific associated with AAO has been analyzed. It follows that a positive phase of JJAS AAO corresponds to the larger magnitude of the vertical zonal wind shear, the anomalous low-lever anti-cyclonic circulation and anomalous high-level cyclonic circulation, and lower sea surface temperature in the major typhoon genesis region in the western North Pacific, thus providing unfavorable environment for the typhoon genesis, and vice versa.

  13. Pollution transport across the Pacific and its impact on North America

    International Nuclear Information System (INIS)

    Full text: We present a study about the transport of pollution across the Pacific and how this long-range transport impacts the atmospheric composition over North America both on a regional and a local scale. Our focus is on spring 2006 when the NASA INTEX-B campaign (Intercontinental Chemical Transport Experiment) took place. The extensive set of aircraft and ground based field observations form the basis for the analysis together with satellite observations from the MOPITT and MODIS instruments and model simulations with the global MOZART-4 model and the regional WRF-Chem model. Model tracers are used to examine the contributions of different regions to pollution levels over the Pacific and to estimate the ozone production from anthropogenic NOx sources in Asia to ozone loadings over the Pacific and North America. We acknowledge the INTEX-B team for providing the measurements. (author)

  14. Evolution of biogeography in the 21st Century - Development of a North Pacific Nonindigenous Species Database

    Science.gov (United States)

    Aquatic invasive species are one of the major ecological threats to the ecological integrity of estuarine and near-coastal waters. However, lack of systematic inventories of nonindigenous species across the North Pacific countries limits our ability to assess how the extent of i...

  15. Possible relationship between East Asian summer monsoon and western North Pacific tropical cyclone genesis frequency

    Science.gov (United States)

    Choi, Ki-Seon; Cha, Yumi; Kim, Hae-Dong; Kang, Sung-Dae

    2016-04-01

    In the present study, the fact that strong positive correlations have existed between East Asian summer monsoons (EASMs) and western North Pacific tropical cyclone (TC) genesis frequency over the last 37 years was found. To figure out the cause of these correlations, 7 years (positive East Asian summer monsoon index (EASMI) phase) that have the highest values and 7 years (negative EASMI phase) that have the lowest values in the normalized EASM index were selected and the differences in averages between the two phases were analyzed. In the positive EASMI phase, TCs mainly occurred in the northwestern waters of the tropical and subtropical western North Pacific and showed a tendency to move from the far eastern waters of the Philippines, pass the East China Sea, and move northward toward Korea and Japan. On the 500 hPa streamline, whereas anomalous anticyclones developed in the East Asia middle-latitude region, anomalous cyclones developed in the tropical and subtropical western North Pacific. Therefore, in this phase, whereas EASMs were weakened, western North Pacific summer monsoons (WNPSMs) were strengthened so that some more TCs could occur. In addition, in the case of the East China Sea and the southern waters of Japan located between the two anomalous pressure systems, TCs could move some more toward the East Asia middle-latitude region in this phase. According to an analysis of the 850 hPa relative vorticity, negative anomalies were strengthened in the East Asia middle-latitude region while positive anomalies were strengthened in the region south to 25 N. Therefore, in the positive EASMI phase, whereas EASMs were weakened, WNPSMs were strengthened so that some more TCs could occur. According to an analysis of the 850 and 200 hPa horizontal divergence, whereas anomalous downward flows were strengthened in the East Asia middle-latitude region, anomalous upward flows were strengthened in the tropical and subtropical western North Pacific. According to an analysis

  16. Nitrogen cycling in the secondary nitrite maximum of the eastern tropical North Pacific off Costa Rica

    Science.gov (United States)

    Buchwald, Carolyn; Santoro, Alyson E.; Stanley, Rachel H. R.; Casciotti, Karen L.

    2015-12-01

    Nitrite is a central intermediate in the marine nitrogen cycle and represents a critical juncture where nitrogen can be reduced to the less bioavailable N2 gas or oxidized to nitrate and retained in a more bioavailable form. We present an analysis of rates of microbial nitrogen transformations in the oxygen deficient zone (ODZ) within the eastern tropical North Pacific Ocean (ETNP). We determined rates using a novel one-dimensional model using the distribution of nitrite and nitrate concentrations, along with their natural abundance nitrogen (N) and oxygen (O) isotope profiles. We predict rate profiles for nitrate reduction, nitrite reduction, and nitrite oxidation throughout the ODZ, as well as the contributions of anammox to nitrite reduction and nitrite oxidation. Nitrate reduction occurs at a maximum rate of 25 nM d-1 at the top of the ODZ, at the same depth as the maximum rate of nitrite reduction, 15 nM d-1. Nitrite oxidation occurs at maximum rates of 10 nM d-1 above the secondary nitrite maximum, but also in the secondary nitrite maximum, within the ODZ. Anammox contributes to nitrite oxidation within the ODZ but cannot account for all of it. Nitrite oxidation within the ODZ that is not through anammox is also supported by microbial gene abundance profiles. Our results suggest the presence of nitrite oxidation within the ETNP ODZ, with implications for the distribution and physiology of marine nitrite-oxidizing bacteria, and for total nitrogen loss in the largest marine ODZ.

  17. Two new species of the bee genus Peponapis, with a key to the North and Central American species (Hymenoptera: Apidae: Eucerini)

    OpenAIRE

    Ricardo Ayala; Terry Griswold

    2012-01-01

    Two new species of squash bees, Peponapis pacifica Ayala and Griswold sp. n. and P. parkeri Griswold and Ayala sp. n., are described and illustrated. Peponapis pacifica is oligolectic on flowers of Schizocarpum longisepalum (Cucurbitaceae) endemic to Mexico, where it is found in the tropical dry forest along the Pacific Coast, between Sonora and Chiapas and in the Balsas River basin; and P. parkeri is known only from the Pacific slope of Costa Rica. A key for the North and Central American sp...

  18. A revised estimate of Pacific-North America motion and implications for Western North America plate boundary zone tectonics

    Science.gov (United States)

    Demets, Charles; Gordon, Richard G.; Stein, Seth; Argus, Donald F.

    1987-01-01

    Marine magnetic profiles from the Gulf of Californa are studied in order to revise the estimate of Pacific-North America motion. It is found that since 3 Ma spreading has averaged 48 mm/yr, consistent with a new global plate motion model derived without any data. The present data suggest that strike-slip motion on faults west of the San Andreas is less than previously thought, reducing the San Andreas discrepancy with geodetic, seismological, and other geologic observations.

  19. Interannual relationships between the tropical sea surface temperature and summertime subtropical anticyclone over the western North Pacific

    Science.gov (United States)

    Chung, Pei-Hsuan; Sui, Chung-Hsiung; Li, Tim

    2011-07-01

    The interannual variability of the Western North Pacific Subtropical High (WNPSH) in boreal summer is investigated with the use of the NCEP/NCAR Reanalysis Data. The most significant change of the 500 hPa geopotential height field appears at the western edge of the WNPSH, with dominant 2-3 year and 3-5 year power spectrum peaks. The 2-3 year oscillation of the WNPSH and associated circulation and sea surface temperature (SST) patterns possess a coherent eastward propagating feature, with a warm SST anomaly (SSTA) and anomalous ascending motion migrating from the tropical Indian Ocean in the preceding autumn to the maritime continent in the concurrent summer of a strong WNPSH. A strong WNPSH is characterized by anomalous anticyclonic circulation and maximum subsidence in the western North Pacific (WNP). The anomalous WNPSH circulation has an equivalent barotropic vertical structure and resides in the sinking branch of the local Hadley circulation, triggered by enhanced convection over the maritime continent. A heat budget analysis reveals that the WNPSH is maintained by radiative cooling. The 3-5 year oscillation of the WNPSH exhibits a quasi-stationary feature, with a warm SSTA (anomalous ascending motion) located in the equatorial central eastern Pacific and Indian Ocean and a cold SSTA (anomalous descending motion) located in the western Pacific. The anomaly pattern persists from the preceding winter to the concurrent summer of a high WNPSH. The greatest descent is located to the southeast of the anomalous anticyclone center, where a baroclinic vertical structure is identified. The zonal phase difference and the baroclinic vertical structure suggest that the anomalous anticyclone on this timescale is a Rossby wave response to a negative latent heating associated with the persistent local cold SSTA. ECHAM4 model experiments further confirm that the 2-3 year mode is driven by the SSTA forcing over the maritime continent, while the 3-5 year mode is driven by the

  20. CHARACTERISTICS OF FARMLAND LEASING IN THE NORTH CENTRAL UNITED STATES

    OpenAIRE

    Patterson, Brian; Hanson, Steven D.; Robison, Lindon J.

    1998-01-01

    Leasing behavior differs across the North Central United States. Survey data is used to characterize leasing activity in the region. Data is collected on the amount of leased farmland, amount of cash and share leased land, and common output share levels. Factors influencing leasing and arrangements are also identified.

  1. World and experiences of AIDS orphans in north central Namibia

    NARCIS (Netherlands)

    Brug, van der M.

    2007-01-01

    How do young AIDS orphans deal with the loss of their parents and their changed circumstances? This thesis discusses the social environment, experiences and perceptions of fourteen orphans in north central Namibia. The author followed the children for five months from September 2003 until March 2004

  2. A Study of Transport and Impact Strength of Fukushima Nuclear Pollutants in the North Pacific Surface

    Institute of Scientific and Technical Information of China (English)

    FU Hongli; LI Wei; ZHANG Xuefeng; HAN Guijun; WANG Xidong; WU Xinrong; ZHANG Lianxin

    2014-01-01

    Based on the statistics of surface drifter data of 1979-2011 and the simulation of nuclear pollutant particulate move-ments simulated using high quality ocean reanalysis surface current dataset, the transport pathways and impact strength of Fuku-shima nuclear pollutants in the North Pacific have been estimated. The particulates are used to increase the sampling size and en-hance the representativeness of statistical results. The trajectories of the drifters and particulates are first examined to identify typical drifting pathways. The results show that there are three types of transport paths for nuclear pollutants at the surface: 1) most pollutant particles move eastward and are carried by the Kuroshio and Kuroshio-extension currents and reach the east side of the North Pacific after about 3.2-3.9 years;2) some particles travel with the subtropical circulation branch and reach the east coast of China after about 1.6 years according to one drifter trajectory and about 3.6 years according to particulate trajectories;3) a little of them travel with local, small scale circulations and reach the east coast of China after about 1.3-1.8 years. Based on the par-ticulates, the impact strength of nuclear pollutants at these time scales can be estimated according to the temporal variations of relative concentration combined with the radioactive decay rate. For example, Cesium-137, carried by the strong North Pacific current, mainly accumulates in the eastern North Pacific and its impact strength is 4%of the initial level at the originating Fuku-shima area after 4 years. Due to local eddies, Cesium-137 in the western North Pacific is 1%of the initial pollutant level after 1.5 years and continuously increases to 3%after 4 years. The vertical movement of radioactive pollutants is not taken into account in the present study, and the estimation accuracy would be improved by considering three-dimensional flows.

  3. Mesoscale cyclogenesis over the western north Pacific Ocean during TPARC

    Directory of Open Access Journals (Sweden)

    Christopher A. Davis

    2013-01-01

    Full Text Available Three cases of mesoscale marine cyclogenesis over the subtropics of the Western Pacific Ocean are investigated. Each case occurred during the THORPEX Pacific Asia Regional Campaign and Tropical Cyclone Structure (TCS-08 field phases in 2008. Each cyclone developed from remnants of disturbances that earlier showed potential for tropical cyclogenesis within the tropics. Two of the cyclones produced gale-force surface winds, and one, designated as a tropical cyclone, resulted in a significant coastal storm over eastern Japan. Development was initiated by a burst of organized mesoscale convection that consolidated and intensified the surface cyclonic circulation over a period of 12–24 h. Upper-tropospheric potential vorticity anomalies modulated the vertical wind shear that, in turn, influenced the periods of cyclone intensification and weakening. Weak baroclinicity associated with vertical shear was also deemed important in organizing mesoscale ascent and the convection outbreaks. The remnant tropical disturbances contributed exceptional water vapour content to higher latitudes that led to strong diabatic heating, and the tropical remnants contributed vorticity that was the seed of the development in the subtropics. Predictability of these events more than three days in advance appears to be minimal.

  4. Comparative Resilience in Five North Pacific Regional Salmon Fisheries

    Directory of Open Access Journals (Sweden)

    Courtland L. Smith

    2010-06-01

    Full Text Available Over the past century, regional fisheries for Pacific salmon (Oncorhynchus spp. have been managed primarily for their provisioning function, not for ecological support and cultural significance. We examine the resilience of the regional salmon fisheries of Japan, the Russian Far East, Alaska, British Columbia, and Washington-Oregon-California (WOC in terms of their provisioning function. Using the three dimensions of the adaptive cycle—capital, connectedness, and resilience—we infer the resilience of the five fisheries based on a qualitative assessment of capital accumulation and connectedness at the regional scale. In our assessment, we evaluate natural capital and connectedness and constructed capital and connectedness. The Russian Far East fishery is the most resilient, followed by Alaska, British Columbia, Japan, and WOC. Adaptive capacity in the fisheries is contingent upon high levels of natural capital and connectedness and moderate levels of constructed capital and connectedness. Cross-scale interactions and global market demand are significant factors in reduced resilience. Greater attention to ecological functioning and cultural signification has the potential to increase resilience in Pacific salmon ecosystems.

  5. Intensified impact of northern tropical Atlantic SST on tropical cyclogenesis frequency over the western North Pacific after the late 1980s

    Science.gov (United States)

    Cao, Xi; Chen, Shangfeng; Chen, Guanghua; Wu, Renguang

    2016-08-01

    Previous studies suggest that spring SST anomalies over the northern tropical Atlantic (NTA) affect the tropical cyclone (TC) activity over the western North Pacific (WNP) in the following summer and fall. The present study reveals that the connection between spring NTA SST and following summer-fall WNP TC genesis frequency is not stationary. The influence of spring NTA SST on following summer-fall WNP TC genesis frequency is weak and insignificant before, but strong and significant after, the late 1980s. Before the late 1980s, the NTA SST anomaly-induced SST anomalies in the tropical central Pacific are weak, and the response of atmospheric circulation over the WNP is not strong. As a result, the connection between spring NTA SST and following summer-fall WNP TC genesis frequency is insignificant in the former period. In contrast, after the late 1980s, NTA SST anomalies induce pronounced tropical central Pacific SST anomalies through an Atlantic-Pacific teleconnection. Tropical central Pacific SST anomalies further induce favorable conditions for WNP TC genesis, including vertical motion, mid-level relative humidity, and vertical zonal wind shear. Hence, the connection between NTA SST and WNP TC genesis frequency is significant in the recent period. Further analysis shows that the interdecadal change in the connection between spring NTA SST and following summer-fall WNP TC genesis frequency may be related to the climatological SST change over the NTA region.

  6. Observation-based estimate of the Fukushima radionuclide in the North Pacific

    Science.gov (United States)

    Yoshida, Sachiko; Jayne, Steven; Macdonald, Alison; Buesseler, Ken; Rypina, Irina

    2014-05-01

    Contaminated waters from Fukushima nuclear power plant (FNPP) were discharged directly into the North Pacific Ocean in March 2011. Coastal current system in this region and time scale of the water exchange with the open ocean is not well understood, however both observational evidence and numerical model simulation results indicate relatively rapid advection of contaminants eastward into the highly energetic mixed water region in the confluence of the Kuroshio and Oyashio. Surface drifters deployed near the FNPP in early summer 2011 show trajectories crossing the North Pacific generally following the large scale ocean circulation after one year. Previously obtained cesium (Cs) samples from multiple cruises near FNPP and off shore region between 2011 and 2013 are collected and evaluated to diagnose the propagating Cs signal crossing North Pacific Ocean. In this presentation, we use radionuclides of Fukushima origin as a tracer to understand the North Pacific circulation and mixing process after two years of release. Large numbers of the observation are repeatedly took place near shore where Cs shows still relatively higher about 10-30 Bq/m3 in 2013. Temperature-salinity (T-S) properties for the available hydrographic data indicate that the majority of the samples were obtained in the region where the water is highly influenced by the warm-salty Kuroshio origin water. Depth profiles of 35N section in March-May 2013 cruise of the U.S. Climate Variability and Predictability and Carbon (CLIVAR) repeat Hydrography sections are examined to track the radionuclide penetration into the subsurface ocean and the subduction pathways along isopycnal surfaces. Available large drifter datasets that accumulated over decades of field work can guide us in estimating the spread of these radionuclides. By applying an innovative statistical analysis to the drifter data, we investigate the spreading of radionuclides in the Pacific Ocean over 5-year time scales.

  7. Pacific Decadal Variability and Central Pacific Warming El Niño in a Changing Climate

    Energy Technology Data Exchange (ETDEWEB)

    Di Lorenzo, Emanuele

    2015-02-27

    This research aimed at understanding the dynamics controlling decadal variability in the Pacific Ocean and its interactions with global-scale climate change. The first goal was to assess how the dynamics and statistics of the El Niño Southern Oscillation and the modes of Pacific decadal variability are represented in global climate models used in the IPCC. The second goal was to quantify how decadal dynamics are projected to change under continued greenhouse forcing, and determine their significance in the context of paleo-proxy reconstruction of long-term climate.

  8. Population structure of nuclear and mitochondrial DNA variation among humpback whales in the North Pacific.

    Science.gov (United States)

    Baker, C S; Medrano-Gonzalez, L; Calambokidis, J; Perry, A; Pichler, F; Rosenbaum, H; Straley, J M; Urban-Ramirez, J; Yamaguchi, M; von Ziegesar, O

    1998-06-01

    The population structure of variation in a nuclear actin intron and the control region of mitochondrial DNA is described for humpback whales from eight regions in the North Pacific Ocean: central California, Baja Peninsula, nearshore Mexico (Bahia Banderas), offshore Mexico (Socorro Island), southeastern Alaska, central Alaska (Prince Williams Sound), Hawaii and Japan (Ogasawara Islands). Primary mtDNA haplotypes and intron alleles were identified using selected restriction fragment length polymorphisms of target sequences amplified by the polymerase chain reaction (PCR-RFLP). There was little evidence of heterogeneity in the frequencies of mtDNA haplotypes or actin intron alleles due to the year or sex composition of the sample. However, frequencies of four mtDNA haplotypes showed marked regional differences in their distributions (phi ST = 0.277; P < 0.001; n = 205 individuals) while the two alleles showed significant, but less marked, regional differences (phi ST = 0.033; P < 0.013; n = 400 chromosomes). An hierarchical analysis of variance in frequencies of haplotypes and alleles supported the grouping of six regions into a central and eastern stock with further partitioning of variance among regions within stocks for haplotypes but not for alleles. Based on available genetic and demographic evidence, the southeastern Alaska and central California feeding grounds were selected for additional analyses of nuclear differentiation using allelic variation at four microsatellite loci. All four loci showed significant differences in allele frequencies (overall FST = 0.043; P < 0.001; average n = 139 chromosomes per locus), indicating at least partial reproductive isolation between the two regions as well as the segregation of mtDNA lineages. Although the two feeding grounds were not panmictic for nuclear or mitochondrial loci, estimates of long-term migration rates suggested that male-mediated gene flow was several-fold greater than female gene flow. These results

  9. 75 FR 13084 - North Pacific Fishery Management Council; Public Meetings

    Science.gov (United States)

    2010-03-18

    ... Species Committee; Final action on Groundfish ACL requirements. 5. Gulf of Alaska (GOA) Rockfish Program: Initial review of analysis for Central GOA limited access rockfish program. 6. Bering Sea Crab.... Miscellaneous Groundfish Issues: Initial review of analysis for controlling Gulf of Alaska (GOA) Tanner...

  10. Distant Influence of Kuroshio Eddies on North Pacific Weather Patterns?

    Science.gov (United States)

    Ma, Xiaohui; Chang, Ping; Saravanan, R.; Montuoro, Raffaele; Hsieh, Jen-Shan; Wu, Dexing; Lin, Xiaopei; Wu, Lixin; Jing, Zhao

    2015-12-01

    High-resolution satellite measurements of surface winds and sea-surface temperature (SST) reveal strong coupling between meso-scale ocean eddies and near-surface atmospheric flow over eddy-rich oceanic regions, such as the Kuroshio and Gulf Stream, highlighting the importance of meso-scale oceanic features in forcing the atmospheric planetary boundary layer (PBL). Here, we present high-resolution regional climate modeling results, supported by observational analyses, demonstrating that meso-scale SST variability, largely confined in the Kuroshio-Oyashio confluence region (KOCR), can further exert a significant distant influence on winter rainfall variability along the U.S. Northern Pacific coast. The presence of meso-scale SST anomalies enhances the diabatic conversion of latent heat energy to transient eddy energy, intensifying winter cyclogenesis via moist baroclinic instability, which in turn leads to an equivalent barotropic downstream anticyclone anomaly with reduced rainfall. The finding points to the potential of improving forecasts of extratropical winter cyclones and storm systems and projections of their response to future climate change, which are known to have major social and economic impacts, by improving the representation of ocean eddy-atmosphere interaction in forecast and climate models.

  11. North pacific right whale surveys conducted in the Bering Sea and North Pacific Ocean by Alaska Fisheries Science Center, National Marine Mammal Laboratory from 2007-08-01 to 2011-09-10 (NCEI Accession 0133935)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The North Pacific right whale (NPRW) was heavily hunted between the 17th and the 20th centuries. Protection was supposedly afforded by international treaties in the...

  12. Centennial changes in North Pacific anoxia linked to tropical trade winds

    Science.gov (United States)

    Deutsch, Curtis; Berelson, William; Thunell, Robert; Weber, Thomas; Tems, Caitlin; McManus, James; Crusius, John; Ito, Taka; Baumgartner, Timothy; Ferreira, Vicente; Mey, Jacob; van Geen, Alexander

    2014-01-01

    Climate warming is expected to reduce oxygen (O2) supply to the ocean and expand its oxygen minimum zones (OMZs). We reconstructed variations in the extent of North Pacific anoxia since 1850 using a geochemical proxy for denitrification (δ15N) from multiple sediment cores. Increasing δ15N since ~1990 records an expansion of anoxia, consistent with observed O2 trends. However, this was preceded by a longer declining δ15N trend that implies that the anoxic zone was shrinking for most of the 20th century. Both periods can be explained by changes in winds over the tropical Pacific that drive upwelling, biological productivity, and O2 demand within the OMZ. If equatorial Pacific winds resume their predicted weakening trend, the ocean’s largest anoxic zone will contract despite a global O2 decline.

  13. Hindcast of 137Cs in the North Pacific Ocean from 1945 to 2013 by eddy-resolving ROMS

    Science.gov (United States)

    Tsubono, Takaki; Misumi, Kazuhiro; Tsumune, Daisuke; Aoyama, Michio; Hirose, Katsumi

    2014-05-01

    We conducted the hindcast of 137Cs activity in the North Pacific Ocean from 1945 to 2013, before and after the Fukushima Dai-ichi Nuclear Power Plant (1F NPP) accident. We used the Regional Ocean Model System (ROMS) with high resolution (1/12°-1/4° in horizontal, 45 levels in vertical), of which domain was the North Pacific Ocean. This model employed the CORE normal year forcing data for a driving forcing and the 50 years averaged SODA data for boundary conditions. The reconstructed global fallout due to atmospheric nuclear weapons' tests and Chernobyl accident was employed for atmospheric input flux of 137Cs from 1945 to 2013. After the accident, the atmospheric deposition and direct release of 137Cs from 1F NPP were also employed for input condition. Five ensemble calculations of 137Cs activity were conducted by moving the start period of the input flux for one year. The simulated vertical distributions of 137Cs activity along 165°E represented the overall patterns of the observed 137Cs activity before (in 2002) and after (in 2012) the accident, in particular the high activity core of the 137Cs around North Pacific Subtropical Mode Water and Central Mode Water, indicating that this model can represent the subduction process and formation of the Mode Waters. The simulated 137Cs activity in the surface ranged from 0.75 to 2.Bq m-3 in the north of Kuroshio Extension in 2011 before the accident. The main body of high 137Cs activity water from 1F NPP was transported in the northern part of Kuroshio Extension after the accident. In Sep. 2012, 18 months after the accident, the main body of high 137Cs activity water (≥ 10 Bq m-3) was located at around 40°N, 150°E-160°W. The water over 10 Bq m-3 of 137Cs activity was not detected in surface layer, but in the layer of σθ=25.8-26.2 at two small areas (44°N, 180°W-165°W and 48°N, 160°W-140°W). This model simulation suggests that the main body of high 137Cs activity water from 1F NPP has never reached the

  14. Data-driven prediction strategies for low-frequency patterns of North Pacific climate variability

    CERN Document Server

    Comeau, Darin; Giannakis, Dimitrios; Majda, Andrew J

    2015-01-01

    The North Pacific exhibits patterns of low-frequency variability on the intra-annual to decadal time scales, which manifest themselves in both model data and the observational record, and prediction of such low-frequency modes of variability is of great interest to the community. While parametric models, such as stationary and non-stationary autoregressive models, possibly including external factors, may perform well in a data-fitting setting, they may perform poorly in a prediction setting. Ensemble analog forecasting, which relies on the historical record to provide estimates of the future based on past trajectories of those states similar to the initial state of interest, provides a promising, nonparametric approach to forecasting that makes no assumptions on the underlying dynamics or its statistics. We apply such forecasting to low-frequency modes of variability for the North Pacific sea surface temperature and sea ice concentration fields extracted through Nonlinear Laplacian Spectral Analysis. We find ...

  15. Interannual variability and future projection of summertime ocean wave heights in the western North Pacific

    Directory of Open Access Journals (Sweden)

    W. Sasaki

    2006-10-01

    Full Text Available A 70-yr (from 1985–1995 to 2055–2065 change of decadal mean summertime extreme significant wave heights (SWH in the western North Pacific under CO2-induced global warming condition is projected. For this purpose, possible atmospheric fields under future global warming are derived from 10-yr time-slice experiments using a T106 AGCM. The future changes of SWH are assessed by an empirical approach, where possible changes of SWH are estimated using a linear regression model which shows an empirical relationship between SWH anomalies and an eastward shift of the monsoon trough. It is projected that SWH increases by up to ~0.4 m over a wide area of the western North Pacific.

  16. Relationships between ENSO and East Asian-western North Pacific monsoon: observations versus 18 CMIP5 models

    Science.gov (United States)

    Wu, B.

    2014-12-01

    The relationships between ENSO and the East Asian-western North Pacific monsoon during ENSO mature winter and decaying summer are studied by examining the pre-industrial control runs of 18 global climate models (GCMs) that participated in the phase five of the Coupled Model Intercomparison Project (CMIP5). In the observation, the tropical western North Pacific (WNP) is dominated by an anomalous anticyclone (cyclone) during El Niño (La Niña) mature winter, referred to as WNPAC (WNPC). WNPAC is asymmetric with WNPC. Multi-model assessments support the idea that the asymmetry results from the combined effects of the asymmetric remote forcing from the equatorial central-eastern Pacific and the asymmetric local sea surface temperature (SST) anomalies. It has been proposed that the asymmetric circulation anomalies over the tropical WNP have a contribution to the asymmetric decaying rates between El Niño and La Niña. The mechanism works in the CMIP5 models. Those models that can (cannot) simulate the asymmetry between WNPAC and WNPC tend to reproduce ENSO with asymmetric (symmetric) decaying rates. In the observation, WNPAC maintains throughout El Niño decaying summer. The maintenance of WNPAC primarily relies on the local forcing of underlying cold SST anomalies in the early summer, remaining from preceding winter and spring, whereas to remote forcing from the tropical Indian Ocean in the late summer. The two mechanisms are reproduced by the multi-model ensemble mean. The scatter diagrams for the CMIP5 models demonstrate that the response of WNPAC to the remote forcing from the tropical Indian Ocean intensifies from June to July, concurring with the establishment of the climatological WNP monsoon trough.

  17. Characteristics of tropical cyclone genesis in the western North Pacific during the developing and decaying phases of two types of El Niño

    Science.gov (United States)

    Chung, Pei-Hsuan; Li, Tim

    2014-05-01

    During the developing phase of central Pacific El Nino (CPEN), more frequent TC genesis over the northwest quadrant of the western North Pacific (WNP) is attributed to the horizontal shift of environmental vorticity field. Such a northwestward shift resembles the La Niña composite, even though factors that cause the shift differ (in the La Niña case the relative humidity effect is crucial). Greater reduction of TC frequency over WNP happened during the decaying phase of eastern Pacific El Nino (EPEN) than CPEN, due to the difference of the anomalous Philippine Sea anticyclone strength. The TC genesis exhibits an upward (downward) trend over the northern (southern) part of the WNP, which is linked to SST and associated circulation changes through local and remote effects.

  18. ENSO and Western North Pacific tropical cyclone activity simulated in a CGCM

    Energy Technology Data Exchange (ETDEWEB)

    Iizuka, Satoshi; Matsuura, Tomonori [National Research Institute for Earth Science and Disaster Prevention, Tsukuba, Ibaraki (Japan)

    2008-06-15

    A high-resolution (T213) coupled ocean-atmosphere general circulation model (CGCM) has been used to examine the relationship between El Nino/Southern Oscillation (ENSO) and tropical cyclone (TC) activity over the western North Pacific (WNP). The model simulates ENSO-like events similar to those observed, though the amplitude of the simulated Nino34 sea surface temperature (SST) anomaly is twice as large as observed. In El Nino (La Nina) years, the annual number of model TCs in the southeast quadrant of the WNP increases (decreases), while it decreases (increases) in the northwest quadrant. In spite of the significant difference in the mean genesis location of model TCs between El Nino and La Nina years, however, there is no significant simultaneous correlation between the annual number of model TCs over the entire WNP and model Nino34 SST anomalies. The annual number of model TCs, however, tends to decrease in the years following El Nino, relating to the development of anticyclonic circulation around the Philippine Sea in response to the SST anomalies in the central and eastern equatorial Pacific. Furthermore, it seems that the number of model TCs tends to increase in the years before El Nino. It is also shown that the number of TCs moving into the East Asia is fewer in October of El Nino years than La Nina years, related to the anomalous southward shift of mid-latitude westerlies, though no impact of ENSO on TC tracks is found in other months. It is found that model TCs have longer lifetimes due to the southeastward shift of mean TC genesis location in El Nino years than in La Nina years. As the result of longer fetch of TCs over warm SST, model TCs appear to be more intense in El Nino years. These relationships between ENSO and TC activity in the WNP are in good agreement with observational evidence, suggesting that a finer-resolution CGCM may become a powerful tool for understanding interannual variability of TC activity. (orig.)

  19. Pelagic Ostracods of the Genera Halocypris and Felia (Subfamily Halocypridinae) from the North Pacific

    OpenAIRE

    Chavtur, Vladimir G.; STOVBUN, GALINA G.

    2008-01-01

    Morphology of Halocypris inflata (Dana, 1853), H. pelagica Claus, 1890, Felia cornuta (Müller, 1906) and F. bicornis (Müller, 1906) is examined with North Pacific materials and compared with previous records. Complete synonymy and corrected distribution were given for these species. Halocypris angustifrontalis, new species is described in detail. It differs from known species of this genus by its very large size and the structure of the coxal segment of the mandible. Keys to all species of bo...

  20. Millennial-scale variability in denitrification and phosphorus burial in the Eastern Tropical North Pacific

    OpenAIRE

    Francavilla, Stephen A.

    2009-01-01

    The remarkable synchrony between changes in temperature recorded in Greenland ice cores and variations in N isotope records from sedimentary cores recovered from the Arabian Sea and the Eastern Tropical North Pacific (ETNP) has provided evidence for teleconnections between changes in marine denitrification in the tropics and climate variations in the northern high latitudes. Changes in tropical denitrification have been attributed to changes in productivity, changes in the source of intermedi...

  1. Tempo-spatial patterns of bacterial community composition in the western North Pacific Ocean

    OpenAIRE

    Kataoka, Takafumi; Hodoki, Yoshikuni; Suzuki, Koji; Saito, Hiroaki; Higashi, Seigo

    2009-01-01

    In the western North Pacific, where subarctic Oyashio waters encounter subtropical Kuroshio waters, phylotype composition of heterotrophic bacteria was estimated by denaturing gradient gel electrophoresis (DGGE) of PCR-amplified bacterial 16S ribosomal DNA. Total bacterial abundance was also measured by flow cytometry. The study area was divided into four water masses: coastal, Oyashio, Kuroshio, and the Kuroshio-Oyashio transition. Abundances of heterotrophic bacteria in the Oyashio, Kuroshi...

  2. Sequential megafaunal collapse in the North Pacific Ocean: An ongoing legacy of industrial whaling?

    OpenAIRE

    Springer, A. M.; Estes, J. A.; van Vliet, G. B.; T. M. Williams; Doak, D F; Danner, E. M.; Forney, K. A.; Pfister, B.

    2003-01-01

    Populations of seals, sea lions, and sea otters have sequentially collapsed over large areas of the northern North Pacific Ocean and southern Bering Sea during the last several decades. A bottom-up nutritional limitation mechanism induced by physical oceanographic change or competition with fisheries was long thought to be largely responsible for these declines. The current weight of evidence is more consistent with top-down forcing. Increased predation by killer whales probably drove the sea...

  3. Contrasting Marine Carbon Monoxide Budget in the North Pacific and the Amundsen Sea

    Science.gov (United States)

    Kwon, Young Shin; Siek Rhee, Tae

    2016-04-01

    Carbon monoxide (CO) is a trace gas that affects the global climate indirectly by participating in the atmospheric chemistry. Although in many studies it is estimated to be produced fast in the surface ocean from the photolysis of chromophoric dissolved organic carbon (CDOM), also it decreases considerably by the microbial oxidation and the vertical mixing in water column. Therefore, the strength of oceanic source to the atmosphere is not so considerable. To investigate how the CO budget in the mixed layer governs the CO emission from sea to air, we conducted the underway measurements of CO, the dark incubation experiments, and the measurements of CDOM absorbance during two expeditions in the Amundsen Sea and the North Pacific in summer season of 2012. Dark incubation experiments revealed that microbial consumption rate in the North Pacific was 2.7 nM d‑1whilst 1.2 nM d‑1 in the Amundsen Sea, which is ca. 2.3 times smaller. However, CO production rate was as much as about 40 times higher in the North Pacific (1 nM d‑1) due mainly to sea-ice albedo in the Amundsen Sea. It seems that this different CO budget between the two regions causes different amplitude of diurnal variation of dissolved CO. That is, compared to the Amundsen Sea, CO is produced faster in daytime and removed faster all day in the North Pacific where the sinusoidal amplitude of CO is larger. In both regions, ˜97% of CO is estimated to be consumed by microbes, and sea-to-air flux density calculated from the underway measurements was insignificant in terms of the total atmospheric reservoir. Our observations indicate that the source strength of the ocean was evenly weak regardless of the scale of CO budget in the ocean. That is, marine biota can be thought as a main control of CO in the atmosphere, the important trace gas for the global climate change.

  4. Impact of tropical Pacific variability on the mean North Atlantic thermohaline circulation

    OpenAIRE

    Semenov, Vladimir; Latif, Mojib

    2006-01-01

    A series of 500 years long coupled general circulation model simulations has been performed, in which the sea surface temperatures (SSTs) in different tropical oceans have been prescribed from climatology. A statistically significant reduction by about one Sverdrup of the meridional overturning circulation (MOC) in the North Atlantic was found when the tropical Pacific SSTs do not vary interannually. Anomalously low salinities originating in the tropical Atlantic due to increased precipitatio...

  5. AFSC/RACE/GAP/Conrath: Notes on the Reproductive Biology of Female Salmon Sharks in the Eastern North Pacific Ocean

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Little information has previously been published on the reproductive biology of the salmon shark in the Eastern North Pacific ocean. This data set incorporates...

  6. New predictors and a new prediction model for the typhoon frequency over western North Pacific

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, the impacts of the atmospheric circulation during boreal winter-spring on the western North Pacific (WNP) typhoon frequency (WNPTF) are studied. Several new factors in winter-spring influencing the typhoon frequency were identified, including the sea ice cover in the North Pacific and the North Pacific oscillation. Based on these results, the multi-linear regression was applied to establishing a new forecast model for the typhoon frequency by using the datasets of 1965―1999. The forecast model shows a high correlation coefficient (0.79) between the model simulated and the actual typhoon frequencies in the period of 1965―1999. The forecast model also exhibits reasonable hindcasts for the typhoon frequencies for the years 2000―2006. Therefore, this work demonstrates that the new predictors are significant for the prediction of the interannual variability of the WNPTF, which could be potentially used in the operational seasonal forecast of the typhoon frequency in the WNP to get a more physically based operational prediction model and higher forecast skill.

  7. The Moisture Structure of ISO in Western North Pacific Revealed by AIRS

    Institute of Scientific and Technical Information of China (English)

    TAO Li; FU Xiouhua; WANG Bin

    2009-01-01

    Using the humidity profiles from the Atmospheric Infrared Sounder (AIRS) dataset, rainfall from the Tropical Rainfall Measuring Mission (TRMM) Global Precipitation Index (GPI), and surface winds from QuickSCAT (QSCAT) as well as SST from the Advanced Microwave Scanning Radiometer for NASA's Earth Observing System (AMSR_E), we analyzed the structure of summer intraseasonal oscillation (ISO) over the western North Pacific region in 2003-2004. We find that the signal of 20-90-day oscillations in the western North Pacific originates from the equatorial Indian Ocean, and propagates eastward to Philippine Sea and then moves northwestward to South China. The AIRS humidity data reveal that the boundary-layer moisture leads the mid-troposphere moisture during the ISO propagation. The positive SST anomaly may play an important role to moistening the boundary-layer, which preconditions the ISO propagation. Therefore, the intraseasonal SST anomaly could positively feed back to the atmosphere through moistening the boundary-layer, destabilizing the troposphere, and contributing to the northwestward propagation of the ISO in western North Pacific. On the other hand, the salient feature that the boundary-layer moisture anomaly leads mid-troposphere moisture does not exist in ECMWF/TOGA analysis.

  8. Toward a Multi-Decadal Climatology of North Pacific Polar Lows Employing Dynamical Downscaling

    Directory of Open Access Journals (Sweden)

    Fei Chen

    2012-01-01

    Full Text Available The North Pacific is an area where sub-synoptic Polar Lows frequently form during the cold season, especially over the Bering Sea, Gulf of Alaska and Japan Sea. So far, a multi-decadal climatology of such Polar Lows based on individual cases has not been assembled. Here, we consider dynamical downscaling method for realistically constructing the formation and life cycles of such lows over the past 6 decades without exploiting sub-synoptic information in initial fields. To do so, a regional climate model is conditioned by large-scale information of NCEP re-analyses. We test the approach by examining its skill in simulating ten known cases of North Pacific Polar Lows. Three of these are discussed in some detail. The signatures of all storms emerge in the simulations with additional sub-synoptic details. The tracks of the simulated Polar Lows closely follow the tracks derived from satellite imagery. We conclude that the suggested method is suitable for constructing multi-decade climatologies, including trends and variability, of Polar Lows in the North Pacific by dynamically downscaling NCEP re-analyses.

  9. Phenology of particle size distributions and primary productivity in the North Pacific subtropical gyre (Station ALOHA)

    Science.gov (United States)

    White, Angelicque E.; Letelier, Ricardo M.; Whitmire, Amanda L.; Barone, Benedetto; Bidigare, Robert R.; Church, Matthew J.; Karl, David M.

    2015-11-01

    The particle size distribution (PSD) is a critical aspect of the oceanic ecosystem. Local variability in the PSD can be indicative of shifts in microbial community structure and reveal patterns in cell growth and loss. The PSD also plays a central role in particle export by influencing settling speed. Satellite-based models of primary productivity (PP) often rely on aspects of photophysiology that are directly related to community size structure. In an effort to better understand how variability in particle size relates to PP in an oligotrophic ecosystem, we collected laser diffraction-based depth profiles of the PSD and pigment-based classifications of phytoplankton functional types (PFTs) on an approximately monthly basis at the Hawaii Ocean Time-series Station ALOHA, in the North Pacific subtropical gyre. We found a relatively stable PSD in the upper water column. However, clear seasonality is apparent in the vertical distribution of distinct particle size classes. Neither laser diffraction-based estimations of relative particle size nor pigment-based PFTs was found to be significantly related to the rate of 14C-based PP in the light-saturated upper euphotic zone. This finding indicates that satellite retrievals of particle size, based on particle scattering or ocean color would not improve parameterizations of present-day bio-optical PP models for this region. However, at depths of 100-125 m where irradiance exerts strong control on PP, we do observe a significant linear relationship between PP and the estimated carbon content of 2-20 μm particles.

  10. Reexamination of tropical cyclone heat potential in the western North Pacific

    Science.gov (United States)

    Wada, Akiyoshi

    2016-06-01

    Tropical cyclone heat potential (TCHP), a measure of the oceanic heat content from the surface to the 26°C isotherm depth, has been widely used for tropical cyclone (TC) forecasting and climatological studies. This study reexamines TCHP and the relation to TCs in the western North Pacific in view of the importance of the oceanic reference isothermal depth. Original TCHP is not applicable around the Kuroshio and Kuroshio Extension regions because the value is zero where sea surface temperature is below 26°C. Therefore, this study proposes an improved version of TCHP as new TCHP under relatively weak baroclinic conditions in the atmospheric environment during the TC season from July to November. The alternative oceanic reference isothermal temperature (TRef24) used to calculate new TCHP is determined based on 2 m dew point temperature or 24°C when it is lower than 24°C. We examine the relationship between TCHPs and changes in best track central pressures during the previous 6 h from 2002 to 2012. Relatively high new TCHP is associated with deep oceanic isotherm depth and the decrease in TRef24 around the Kuroshio region from September to November. Case studies for Typhoons Maemi (2003), Songda (2004), and Roke (2011) reveal that TCs could intensify/redevelop around the Ryukyu Islands over warm eddies revealed by high new TCHP, where original TCHP is relatively low. The results indicate that new TCHP can be a metric for TC intensification caused by wind-induced surface heat exchange processes associated with atmospheric temperature and moisture near the surface and upper ocean stratification.

  11. Physical and underway data collected aboard the ROGER REVELLE during cruise AMAT02RR in the North Pacific Ocean and South Pacific Ocean from 2005-09-03 to 2006-03-03 (NCEI Accession 0155592)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0155592 includes physical and underway data collected aboard the ROGER REVELLE during cruise AMAT02RR in the North Pacific Ocean and South Pacific...

  12. Physical and underway data collected aboard the MELVILLE during cruise MV1007 in the North Pacific Ocean and South Pacific Ocean from 2010-05-17 to 2010-06-16 (NODC Accession 0089615)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089615 includes physical and underway data collected aboard the MELVILLE during cruise MV1007 in the North Pacific Ocean and South Pacific Ocean...

  13. Physical and underway data collected aboard the ATLANTIS during cruise AT15-63 in the North Pacific Ocean and South Pacific Ocean from 2010-03-15 to 2010-04-14 (NODC Accession 0103918)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0103918 includes physical and underway data collected aboard the ATLANTIS during cruise AT15-63 in the North Pacific Ocean and South Pacific Ocean...

  14. Physical and underway data collected aboard the ATLANTIS during cruise AT15-43 in the North Pacific Ocean and South Pacific Ocean from 2009-01-09 to 2009-02-16 (NODC Accession 0103873)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0103873 includes physical and underway data collected aboard the ATLANTIS during cruise AT15-43 in the North Pacific Ocean and South Pacific Ocean...

  15. Chemical, optical and other data collected aboard the MELVILLE during cruise MV1105 in the North Pacific Ocean and South Pacific Ocean from 2011-04-29 to 2011-05-28 (NODC Accession 0116958)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0116958 includes chemical, optical and other data collected aboard the MELVILLE during cruise MV1105 in the North Pacific Ocean and South Pacific...

  16. Examining the Relationship Between the Pacific / North American Teleconnection Pattern and the Great Plains Low-Level Jet

    Science.gov (United States)

    Harding, K. J.; Snyder, P. K.

    2014-12-01

    The Pacific / North American (PNA) teleconnection pattern is a prominent low frequency mode of variability in the Northern Hemisphere that is most pronounced in the boreal winter. However, the PNA can exert significant daily to weekly variability and influence weather patterns over the Midwest during the spring and summer months. In this study, we use the NCEP-NCAR Reanalysis to demonstrate the link between the PNA teleconnection pattern and the Great Plains Low-Level Jet (GPLLJ). The negative phase of the PNA, which is associated with lower heights over the Great Plains and ridging in the Southeast U.S., enhances the GPLLJ by increasing the pressure gradient within the GPLLJ on daily to monthly timescales. We show that strong GPLLJ events predominantly occur when the PNA index is negative. Strong GPLLJ events with a very negative PNA index (increase the duration of GPLLJ events. As a result, strong GPLLJ events associated with a very negative PNA index contribute to a greater number of heavy precipitation events over the North Central U.S. by enhancing the meridional transport of moisture into the Upper Midwest and driving greater moisture convergence north of the GPLLJ maximum over extended periods. A significant majority of the greatest 5-day North Central precipitation events in the Climate Prediction Center Daily Precipitation dataset occur when the PNA index is negative, with most strong precipitation events having a very negative PNA. The PNA is typically the most negative 1-4 days in advance of heavy precipitation events. This finding may help improve short- to medium-range predictability of Upper Midwest heavy rainfall events.

  17. Relative importance of tropical SST anomalies in maintaining the Western North Pacific anomalous anticyclone during El Niño to La Niña transition years

    Science.gov (United States)

    Chen, Zesheng; Wen, Zhiping; Wu, Renguang; Lin, Xiaobin; Wang, Jiabao

    2016-02-01

    This study investigates the relative importance of tropical Indian Ocean warming (IOW) and equatorial central to eastern Pacific cooling (EPC) in sustaining an anomalous Western North Pacific anticyclone (WNPAC) during the transition from an El Niño in the preceding winter to a La Niña in the subsequent summer through a suite of numerical experiments. The numerical results indicate that the WNPAC is maintained by a combined effect of IOW and EPC during the La Niña developing years. The contribution of IOW in maintaining the WNPAC sustains from spring to early summer, but appears to weaken after that as IOW decays. The role of IOW is via an eastward-propagating Kelvin wave induced Ekman divergence mechanism. The decay of IOW is because of reduction in downward solar radiation associated with above normal precipitation in situ. As the cooling develops over central to eastern Pacific from spring to summer, EPC starts to contribute to the maintenance of the WNPAC during summer through stimulating a Rossby wave response to its northwest. In this study, we have identified that the cooling over the central to eastern Pacific plays an important role in sustaining the WNPAC during La Niña developing summers. This finding may help improve the prediction of the East Asian summer monsoon, which is closely associated with the WNPAC.

  18. CRED Reson 8101 multibeam backscatter data of Palmyra Atoll, Pacific Remote Island Areas, Central Pacific with 1 meter resolution in GeoTIFF format

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam backscatter imagery extracted from gridded bathymetry of the lagoon, shelf, and slope environments of Palmyra Atoll, Pacific Island Areas, Central...

  19. Magnetostratigraphic correlation of the Upper Cretaceous System in the North Pacific

    Science.gov (United States)

    Kodama, K.

    2003-06-01

    Magnetostratigraphic data for Upper Cretaceous sedimentary strata in widely separated regions of the North Pacific, including Japan, Far East Russia and western North America, are reviewed in terms of calibration to the geomagnetic polarity time scale and regional correlation. A series of normal and reversed polarity zones are recognized in the Upper Cretaceous strata in Shikoku and Hokkaido, Japan, and South Sakhalin, Far East Russia. Combined magnetostratigraphic and biostratigraphic correlation has assigned these zones to the Late Cretaceous geomagnetic polarity chrons including C31r through C33r and the Cretaceous long normal interval. Corresponding geomagnetic reversals have been documented from the Upper Cretaceous successions of the Western Interior of North America, in combination with high-resolution ammonite biostratigraphy and radiometric age dates. Biostratigraphy of the Great Valley Sequence in California is also well-defined, but there is only one reversed interval that can be correlated with polarity chron C33r. The most complete record of polarity reversals in South Sakhalin would provide an integrated reference scheme which can be of significant use not only to correlate dissimilar faunal assemblages of disparate regions in the North Pacific, but also to contribute to a global definition of Upper Cretaceous stage boundaries.

  20. 78 FR 58240 - International Fisheries; Western and Central Pacific Fisheries for Highly Migratory Species...

    Science.gov (United States)

    2013-09-23

    ... Act) to establish a catch limit of 3,763 metric tons (mt) of bigeye tuna (Thunnus obesus) for vessels...; Western and Central Pacific Fisheries for Highly Migratory Species; Bigeye Tuna Catch Limit in Longline... of 3,763 mt is reached in 2013 or 2014, retaining, transshipping, or landing bigeye tuna caught...

  1. 76 FR 74747 - Western and Central Pacific Fisheries for Highly Migratory Species; 2011 Bigeye Tuna Longline...

    Science.gov (United States)

    2011-12-01

    ... tons (mt) of bigeye tuna (Thunnus obesus) for calendar year 2011 (74 FR 63999, December 7, 2009, and... Fisheries for Highly Migratory Species; 2011 Bigeye Tuna Longline Fishery Closure AGENCY: National Marine.... pelagic longline fishery for bigeye tuna in the western and central Pacific Ocean as a result of...

  2. 76 FR 82180 - International Fisheries; Western and Central Pacific Fisheries for Highly Migratory Species...

    Science.gov (United States)

    2011-12-30

    ... part on the findings by the WCPFC that the stock of bigeye tuna (Thunnus obesus) in the WCPO was... seine gear may not discard at sea within the Convention Area any bigeye tuna (Thunnus obesus), yellowfin...; Western and Central Pacific Fisheries for Highly Migratory Species; Fishing Restrictions for Bigeye...

  3. 77 FR 8759 - International Fisheries; Western and Central Pacific Fisheries for Highly Migratory Species...

    Science.gov (United States)

    2012-02-15

    ... vessels to retain all catch of bigeye tuna (Thunnus obesus), yellowfin tuna (Thunnus albacares), and... Measure for Bigeye and Yellowfin Tuna in the Western and Central Pacific Ocean,'' for FAD prohibition..., bigeye tuna, albacore, skipjack tuna, swordfish, shark, other; and (6) an indication of whether...

  4. 77 FR 51709 - International Fisheries; Western and Central Pacific Fisheries for Highly Migratory Species...

    Science.gov (United States)

    2012-08-27

    ... rule establishes a catch limit of 3,763 metric tons (mt) of bigeye tuna (Thunnus obesus) for vessels in... final rule to implement the longline bigeye tuna ] elements of CMM 2008-01 (74 FR 63999). The rule...; Western and Central Pacific Fisheries for Highly Migratory Species; Bigeye Tuna Catch Limit in...

  5. Anthropogenic 129I in the North Pacific, Bering and Chukchi Seas, and Arctic Ocean in 2012-2013

    Science.gov (United States)

    Nagai, H.; Hasegawa, A.; Yamagata, T.; Kumamoto, Y.; Nishino, S.; Matsuzaki, H.

    2015-10-01

    Most of anthropogenic 129I in marine environment are due to discharge from the nuclear fuel reprocessing facilities at Sellafield (U.K.) and La Hague (France) for past few decades. The discharge raised 129I concentration in seawaters in the North Atlantic and Arctic Oceans to more than 109 atoms L-1, which is two orders of magnitude higher than that in other region. Recently, in March 2011, a large quantity of 129I was released into the western North Pacific due to the Fukushima Daiichi Nuclear Power Plant (F1NPP) accident. To evaluate the influence of these events, we have measured 129I concentration in seawaters in the northern North Pacific Ocean, Bering and Chukchi Seas, and Arctic Ocean in 2012-2013. The 129I concentrations were 1.0-1.8 × 107 atoms L-1 in the surface waters in the vicinity of 47°N 150°E-130°W North Pacific Ocean, Bering Sea, and Chukchi Sea (<74°N), which are equal to or lower than the 129I concentration level in surface water in the North Pacific Ocean before the F1NPP accident. The vertical profiles in the North Pacific were almost same as that observed in the western North Pacific before the F1NPP accident. The 129I distribution in seawater in the North Pacific to the Chukchi Sea revealed no significant increase of 129I concentration caused by the F1NPP accident. The 129I concentrations were 13-14 × 107 atoms L-1 in surface waters and 80 × 107 atoms L-1 at depths of 300 and 800 m in the Arctic Ocean.

  6. Interannual and decadal variability and trends in upper ocean temperatures in the North Pacific Ocean

    International Nuclear Information System (INIS)

    Temperature profiles from the surface to 400 m deployed over the North Pacific Ocean for the 45 years from 1950--1994 are mapped onto a coarse grid each month, allowing trends in the upper ocean temperature to be estimated. Only temperature profiles distributed from 20 degree N-60 degree N are used, these subjected to rigorous scientific quality control. Two parameters are chosen to be representative of the upper ocean thermal structure; i.e., sea surface temperature (SST) and heat storage over the upper 400 m (HS400). Mapping of SST and HS400 is conducted monthly, with optimal interpolation utilizing a priori estimates of the covariance structure of the anomalous fields determined by White. This yields a time sequence of 540 monthly maps for each parameter over this 45-year period. Examining these time sequences for decadal variability and trends finds their magnitude and sign to change substantially as a function of geographical location over the North Pacific Ocean. For example, all along the west coast of North America, both SST and HS400 warmed during the past 45 years. But, in the middle of the North Pacific Ocean, both parameters cooled over this period. The average SST and HS400 over the entire domain from 20 degree-60 degree N did not show a trend. Rather, decadal variability dominated the time sequence, with the 1950's colder than normal, the 1960's near normal, the 1970's warmer than normal, the 1980's colder than normal, and the 1990's warmer than normal. This natural decadal variability obscures any possible anthropogenic warming due to increased greenhouse gas concentrations in the atmosphere over this period

  7. Investigating the 'Iron Hypothesis' in the North Pacific: Trans-Pacific Dust and Methanesulfonate (MSA) in the Denali Ice Core, Alaska

    Science.gov (United States)

    Saylor, P. L.; Osterberg, E. C.; Winski, D.; Ferris, D. G.; Koffman, B. G.; Kreutz, K. J.; Wake, C. P.; Campbell, S. W.

    2015-12-01

    Oceanic deposition of Asian-sourced, Iron-rich dust particulate has been linked to enhanced phytoplankton productivity in regions of the Pacific Ocean. High Nutrient Low Chlorophyll (HNLC) ocean regions, such as the North Pacific, are hypothesized to play a significant role in changing atmospheric CO­2 concentrations on glacial-interglacial timescales. Phytoplankton blooms generate methanesulfonate (MSA), an atmospheric oxidation product of dimethylsulfide (DMS) that is readily aerosolized and deposited in nearby glacial ice. In the summer of 2013, an NSF-funded team from Dartmouth College and the Universities of Maine and New Hampshire collected two 1000 year-long parallel ice cores to bedrock from the summit plateau of Mount Hunter in Denali National Park, Alaska (62.940° N, 151.088° W, 3912 m elevation). The Mt. Hunter ice core site is well situated to record changes in trans-Pacific dust flux and MSA emissions in the North Pacific. Here we investigate the history of dust flux to Denali over the last millennium using major and trace element chemistry and microparticle concentration and size distribution data from the Mt. Hunter cores. We evaluate potential controlling mechanisms on Denali dust flux including conditions at Asian dust sources (storminess, wind speed, precipitation), the strength of the Aleutian Low, and large-scale climate modes such as the El Niño-Southern Oscillation and the Pacific Decadal Oscillation. We also evaluate the Mt. Hunter record for relationships between dust flux and MSA concentrations to investigate whether dust fertilization enhanced North Pacific phytoplankton production over the past 1000 years. Future work will create a composite North Pacific dust record using new and existing Mt. Logan ice core records to evaluate these relationships over the entire Holocene.

  8. Iron fertilisation by Asian dust influences North Pacific sardine regime shifts

    Science.gov (United States)

    Qiu, Yongsong

    2015-05-01

    Forcing factors and mechanisms underlying multidecadal variability in the production of the world's major fish stocks are one of the great mysteries of the oceans. The Japanese and California sardine are species that exhibit the regime shifts. It is shown in the present work that during two periods of frequent Asian dust events over the last 100 years, sardines on opposite sides of the Pacific Ocean only flourished under a dust-active regime. The earlier such regime that peaked in the 1930s was strong, and it brought synchronous changes in the two species that were linked to the frequency of Asian dust events. However, there is an apparent mismatch in the rise and fall of abundance between the two species in the current dust-active regime. The massive increase in Japanese sardine stock in the 1970s was related to high levels of ocean precipitation and strong winter mixing, whereas the stock collapse since 1988 has been attributed to diminished winter mixing. High levels of ocean precipitation in the western North Pacific effectively cause wet deposition of Asian dust and enhance Japanese sardine stock, whereas it reduces dust flux that can be transported to the eastern North Pacific, delaying the increase of California sardine stock. Analysis further indicates that productivity of Japanese sardine stock is jointly controlled by wet deposition of Asian dust and winter mixing, which supplies macronutrients from depth. California sardine productivity is inversely related to precipitation in the western North Pacific and is positively affected by precipitation off western North America. This indicates that Asian dust influx dominates productivity of the species because of iron-limited ocean productivity in the California sardine ranges. The analysis suggests that dust regime shifts influence shifts in sardine productivity regimes and that iron input from Asian dust during trans-Pacific transport is directly responsible. It appears that in addition to enhancing

  9. Synchronous seasonal change in fin whale song in the North Pacific.

    Science.gov (United States)

    Oleson, Erin M; Širović, Ana; Bayless, Alexandra R; Hildebrand, John A

    2014-01-01

    Fin whale (Balaenoptera physalus) song consists of down-swept pulses arranged into stereotypic sequences that can be characterized according to the interval between successive pulses. As in blue (B. musculus) and humpback whales (Megaptera novaeangliae), these song sequences may be geographically distinct and may correlate with population boundaries in some regions. We measured inter-pulse intervals of fin whale songs within year-round acoustic datasets collected between 2000 and 2006 in three regions of the eastern North Pacific: Southern California, the Bering Sea, and Hawaii. A distinctive song type that was recorded in all three regions is characterized by singlet and doublet inter-pulse intervals that increase seasonally, then annually reset to the same shorter intervals at the beginning of each season. This song type was recorded in the Bering Sea and off Southern California from September through May and off Hawaii from December through April, with the song interval generally synchronized across all monitoring locations. The broad geographic and seasonal occurrence of this particular fin whale song type may represent a single population broadly distributed throughout the eastern Pacific with no clear seasonal migratory pattern. Previous studies attempting to infer population structure of fin whales in the North Pacific using synchronous individual song samples have been unsuccessful, likely because they did not account for the seasonal lengthening in song intervals observed here. PMID:25521493

  10. Synchronous seasonal change in fin whale song in the North Pacific.

    Directory of Open Access Journals (Sweden)

    Erin M Oleson

    Full Text Available Fin whale (Balaenoptera physalus song consists of down-swept pulses arranged into stereotypic sequences that can be characterized according to the interval between successive pulses. As in blue (B. musculus and humpback whales (Megaptera novaeangliae, these song sequences may be geographically distinct and may correlate with population boundaries in some regions. We measured inter-pulse intervals of fin whale songs within year-round acoustic datasets collected between 2000 and 2006 in three regions of the eastern North Pacific: Southern California, the Bering Sea, and Hawaii. A distinctive song type that was recorded in all three regions is characterized by singlet and doublet inter-pulse intervals that increase seasonally, then annually reset to the same shorter intervals at the beginning of each season. This song type was recorded in the Bering Sea and off Southern California from September through May and off Hawaii from December through April, with the song interval generally synchronized across all monitoring locations. The broad geographic and seasonal occurrence of this particular fin whale song type may represent a single population broadly distributed throughout the eastern Pacific with no clear seasonal migratory pattern. Previous studies attempting to infer population structure of fin whales in the North Pacific using synchronous individual song samples have been unsuccessful, likely because they did not account for the seasonal lengthening in song intervals observed here.

  11. Coralline alga reveals first marine record of subarctic North Pacific climate change

    Science.gov (United States)

    Halfar, J.; Steneck, R.; Schone, B.; Moore, G.W.K.; Joachimski, M.; Kronz, A.; Fietzke, J.; Estes, James

    2007-01-01

    While recent changes in subarctic North Pacific climate had dramatic effects on ecosystems and fishery yields, past climate dynamics and teleconnection patterns are poorly understood due to the absence of century-long high-resolution marine records. We present the first 117-year long annually resolved marine climate history from the western Bering Sea/Aleutian Island region using information contained in the calcitic skeleton of the long-lived crustose coralline red alga Clathromorphum nereostratum, a previously unused climate archive. The skeletal ??18O-time series indicates significant warming and/or freshening of surface waters after the middle of the 20th century. Furthermore, the time series is spatiotemporally correlated with Pacific Decadal Oscillation (PDO) and tropical El Nio??-Southern Oscillation (ENSO) indices. Even though the western Bering Sea/Aleutian Island region is believed to be outside the area of significant marine response to ENSO, we propose that an ENSO signal is transmitted via the Alaskan Stream from the Eastern North Pacific, a region of known ENSO teleconnections. Copyright 2007 by the American Geophysical Union.

  12. Whales, Dolphins, and Porpoises of the Eastern North Pacific and Adjacent Arctic Waters: A Guide to Their Identification.

    Science.gov (United States)

    Leatherwood, Stephen; And Others

    This field guide is designed to permit observers to identify the cetaceans (whales, dolphins, and porpoises) they see in the waters of the eastern North Pacific, including the Gulf of California, Hawaii, and the western Arctic of North America. The animals described are grouped not by scientific relationships but by similarities in appearance in…

  13. Oxygen distribution and aerobic respiration in the north and south eastern tropical Pacific oxygen minimum zones

    DEFF Research Database (Denmark)

    Tiano, Laura; Garcia-Robledo, Emilio; Dalsgaard, Tage;

    2014-01-01

    Highly sensitive STOX O-2 sensors were used for determination of in situ O-2 distribution in the eastern tropical north and south Pacific oxygen minimum zones (ETN/SP OMZs), as well as for laboratory determination of O-2 uptake rates of water masses at various depths within these OMZs. Oxygen was...... generally below the detection limit (few nmol L-1) in the core of both OMZs, suggesting the presence of vast volumes of functionally anoxic waters in the eastern Pacific Ocean. Oxygen was often not detectable in the deep secondary chlorophyll maximum found at some locations, but other secondary maxima...... efficiently at extremely low oxygen concentrations with apparent half-saturation concentrations (K-m values) ranging from about 10 to about 200 nmol L-1. (C) 2014 The Authors. Published by Elsevier Ltd....

  14. The continental margin is a key source of iron to the HNLC North Pacific Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Lam, P.J.; Bishop, J.K.B

    2008-01-15

    Here we show that labile particulate iron and manganese concentrations in the upper 500m of the Western Subarctic Pacific, an iron-limited High Nutrient Low Chlorophyll (HNLC) region, have prominent subsurface maxima between 100-200 m, reaching 3 nM and 600 pM, respectively. The subsurface concentration maxima in particulate Fe are characterized by a more reduced oxidation state, suggesting a source from primary volcagenic minerals such as from the Kuril/Kamchatka margin. The systematics of these profiles suggest a consistently strong lateral advection of labile Mn and Fe from redox-mobilized labile sources at the continental shelf supplemented by a more variable source of Fe from the upper continental slope. This subsurface supply of iron from the continental margin is shallow enough to be accessible to the surface through winter upwelling and vertical mixing, and is likely a key source of bioavailable Fe to the HNLC North Pacific.

  15. Holocene Pacific - North American plate interaction in southern Alaska: implications for the Yakataga seismic gap.

    Science.gov (United States)

    Lahr, J.C.; Plafker, G.

    1980-01-01

    The St. Elias, Alaska, earthquake (magnitude 7.1 MS) on February 28, 1979, occurred along the complex Pacific-North American plate boundary between Yakutat Bay and Prince William Sound, rupturing only a fraction of the seismic gap identified in that region. To aid in evaluating the potential for, and likely site of, a future earthquake occurring in the remainder of the gap, we have formulated a kinematic model of neotectonic deformation in southern Alaska from available geologic and seismic data. In this model the part of the North American plate bordering on the Gulf of Alaska is divided into three subblocks, which are partially coupled to the Pacific plate. On the basis of the model, the gap-filling rupture or ruptures would most likely be along the north-dipping thrust faults of the Pamplona zone between Icy Bay and the eastern end of the Aleutian Trench. If the accumulated strain of 3.8 m postulated for this region were released suddenly in one event involving the remainder of the gap, the result would be an earthquake as large as magnitude 8. -Authors

  16. Ecoregional analysis of nearshore sea-surface temperature in the North Pacific.

    Directory of Open Access Journals (Sweden)

    Meredith C Payne

    Full Text Available The quantification and description of sea surface temperature (SST is critically important because it can influence the distribution, migration, and invasion of marine species; furthermore, SSTs are expected to be affected by climate change. To better understand present temperature regimes, we assembled a 29-year nearshore time series of mean monthly SSTs along the North Pacific coastline using remotely-sensed satellite data collected with the Advanced Very High Resolution Radiometer (AVHRR instrument. We then used the dataset to describe nearshore (<20 km offshore SST patterns of 16 North Pacific ecoregions delineated by the Marine Ecoregions of the World (MEOW hierarchical schema. Annual mean temperature varied from 3.8°C along the Kamchatka ecoregion to 24.8°C in the Cortezian ecoregion. There are smaller annual ranges and less variability in SST in the Northeast Pacific relative to the Northwest Pacific. Within the 16 ecoregions, 31-94% of the variance in SST is explained by the annual cycle, with the annual cycle explaining the least variation in the Northern California ecoregion and the most variation in the Yellow Sea ecoregion. Clustering on mean monthly SSTs of each ecoregion showed a clear break between the ecoregions within the Warm and Cold Temperate provinces of the MEOW schema, though several of the ecoregions contained within the provinces did not show a significant difference in mean seasonal temperature patterns. Comparison of these temperature patterns shared some similarities and differences with previous biogeographic classifications and the Large Marine Ecosystems (LMEs. Finally, we provide a web link to the processed data for use by other researchers.

  17. Lg Coda Variations in North-Central Iran

    Directory of Open Access Journals (Sweden)

    Mojtaba Naghavi

    2012-01-01

    Full Text Available Ground motion records in north-central Iran have been used in order to obtain the Lg coda , using stack spectral ratio method. The lateral variations in 0 and its frequency dependence are estimated in the 0.3–7.0 Hz frequency range which led to =267(±32×0.71(±0.14. The observed variations in quality factor show low values of 0 in western part of the study region where bounded by relatively high values in southern and northern parts. Since the seismicity of the study area is quite shallow the obtained results can be attributed to the upper 30 km of the crust. The Damavand volcano and its surrounding region also exhibit variations in the value of 0 which result in low and intermediate values of 0 in western and eastern parts, respectively. Current seismicity in Damavand is mostly confined to its southwestern part, whereas our results proved to possess low values of 0. In general, most of factor variations can be attributed to the lateral heterogeneity as well as the severity of the crustal velocity gradient, and as expected the north-central Iran is well inferred as a tectonically active region.

  18. Assemblages of phytoplankton pigments along a shipping line through the North Atlantic and tropical Pacific

    Science.gov (United States)

    Dandonneau, Yves; Niang, Awa

    2007-05-01

    A set of phytoplankton pigment measurements collected on eight quarterly transects from France to New Caledonia is analyzed in order to identify the main assemblages of phytoplankton and to relate their occurrence to oceanic conditions. Pigment concentrations are first divided by the sum [monovinyl chlorophyll a plus divinyl chlorophyll a] to remove the effect of biomass, and second are normalized to give an equal weight to all pigments. The resulting 17 pigments × 799 observations matrix is then classified into 10 clusters using neural methodology. Eight out of these 10 clusters have a well marked regional or seasonal character, thus evidencing adapted responses of the phytoplankton communities. The main gradient opposes two clusters with high fucoxanthin and chlorophyll c1+2 in the North Atlantic in January, April and July, to three clusters in the South Pacific Subtropical Gyre with high divinyl chlorophyll a, zeaxanthin and phycoerythrin. One of the clusters in the South Pacific Subtropical Gyre has relatively high zeaxanthin and phycoerythrin contents and dominates in November and February (austral summer), while another with relatively high divinyl chlorophylls a and b dominates in May and August (austral winter). The third one in the South Pacific is characterized by high carotene concentration and its occurrence peaks in February and May. In the equatorial current system, one cluster, rich in chlorophylls b and c1+2, is strictly located in a narrow zone centred at the equator, while another with relatively high violaxanthin concentration is restricted to the high nutrient - low chlorophyll waters in only the southern part of the South Equatorial Current. One cluster with relatively high prasinoxanthin content has a spatial distribution spanning the entire South Equatorial Current. Two clusters have a ubiquitous distribution: one in the equatorial Pacific, the Carribbean Sea and the North Atlantic during summer has pigment concentrations close to the

  19. Structure and dynamics of decadal anomalies in the wintertime midlatitude North Pacific ocean-atmosphere system

    Science.gov (United States)

    Fang, Jiabei; Yang, Xiu-Qun

    2015-12-01

    The structure and dynamics of decadal anomalies in the wintertime midlatitude North Pacific ocean-atmosphere system are examined in this study, using the NCEP/NCAR atmospheric reanalysis, HadISST SST and Simple Ocean Data Assimilation data for 1960-2010. The midlatitude decadal anomalies associated with the Pacific Decadal Oscillation are identified, being characterized by an equivalent barotropic atmospheric low (high) pressure over a cold (warm) oceanic surface. Such a unique configuration of decadal anomalies can be maintained by an unstable ocean-atmosphere interaction mechanism in the midlatitudes, which is hypothesized as follows. Associated with a warm PDO phase, an initial midlatitude surface westerly anomaly accompanied with intensified Aleutian low tends to force a negative SST anomaly by increasing upward surface heat fluxes and driving southward Ekman current anomaly. The SST cooling tends to increase the meridional SST gradient, thus enhancing the subtropical oceanic front. As an adjustment of the atmospheric boundary layer to the enhanced oceanic front, the low-level atmospheric meridional temperature gradient and thus the low-level atmospheric baroclinicity tend to be strengthened, inducing more active transient eddy activities that increase transient eddy vorticity forcing. The vorticity forcing that dominates the total atmospheric forcing tends to produce an equivalent barotropic atmospheric low pressure north of the initial westerly anomaly, intensifying the initial anomalies of the midlatitude surface westerly and Aleutian low. Therefore, it is suggested that the midlatitude ocean-atmosphere interaction can provide a positive feedback mechanism for the development of initial anomaly, in which the oceanic front and the atmospheric transient eddy are the indispensable ingredients. Such a positive ocean-atmosphere feedback mechanism is fundamentally responsible for the observed decadal anomalies in the midlatitude North Pacific ocean

  20. A 290-a record of atmospheric circulation over the North Pacific from a Mt. Logan ice core, Yukon Territory

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Calibrations between sodium (Na+) concentrations from a Mt. Logan ice core and sea level pressure (SLP) series show that Na+ concentrations are closely correlated with the autumn-time (SeptemberOctober-November) Aleutian low (AleuLow). A deepening of the AleuLow strengthens the transport of sea-salt aerosols from the North Pacific to the Mt. Logan region. The Mt. Logan Na+ record is used to develop a 292 a (1688~1979) reconstruction of the AleuLow revealing a dramatic intensification of atmospheric circulation over the North Pacific region since the 20th century. Mean SLP of the AleuLow was about 1 hPa lower during the 20th century than during prior periods. The strongest deepening of the AleuLow appeared in the 1950s. Significant correlations are also found between the Mt. Logan AleuLow proxy series and the Pacific decadal oscillation (PDO) and Pacific circulation (PC) index during the 20th century. Evolutionary spectral analysis of the proxy record shows significant periodicities from 15 to 30 a consistent with PDO fluctuations and the bidecadal oscillation of North Pacific atmosphere-ocean circulation. A period of 11 a in the AleuLow record may be associated with the Schwabe 11-a cycle of sunspot activity. Additional longer ice core records from this region will aid in the efforts to further understand the climatic change over the North Pacific region.

  1. Tropical cyclone-related socio-economic losses in the western North Pacific region

    OpenAIRE

    Welker, Christoph Simon; E. Faust

    2013-01-01

    The western North Pacific (WNP) is the area of the world most frequently affected by tropical cyclones (TCs). However, little is known about the socio-economic impacts of TCs in this region, probably because of the limited relevant loss data. Here, loss data from Munich RE's NatCatSERVICE database is used, a high-quality and widely consulted database of natural disasters. In the country-level loss normalisation technique we apply, the original loss data are normalised to present-day exposure ...

  2. Tropical cyclone-related socio-economic losses in the western North Pacific region

    OpenAIRE

    Welker, Christoph; Faust, Eberhard

    2013-01-01

    The western North Pacific (WNP) is the area of the world most frequently affected by tropical cyclones (TCs). However, little is known about the socio-economic impacts of TCs in this region, probably because of the limited relevant loss data. Here, loss data from Munich RE’s NatCat-SERVICE database is used, a high-quality and widely consulted database of natural disasters. In the country-level loss normalisation technique we apply, the original loss data are normalised to present-day expos...

  3. Interdecadal variability of the tropospheric biennial oscillation in the western North Pacific

    International Nuclear Information System (INIS)

    The observed tropospheric biennial oscillation (TBO) in the western North Pacific (WNP) monsoon region has an interdecadal variability with a period of 40–50 yr. That suggests a weaker effect of the TBO on the East Asia followed by a stronger one. A simple analytic model was designed to investigate the mechanism of the interdecadal variability of the TBO. The results indicated that a local TBO air-sea system not only supports the TBO variability in the WNP monsoon region but also produces an interdecadal variability of the TBO

  4. Harmful algal blooms in the PICES region of the North Pacific

    OpenAIRE

    2002-01-01

    Foreword Background and objectives [pdf, 0.84 MB] Country reviews and status reports Section I. Western North Pacific Japan Yasuwo Fukuyo, Ichiro Imai, Masaaki Kodama and Kyoichi Tamai Red tides and harmful algal blooms in Japan [pdf, 0.7 MB] People's Republic of China Tian Yan, Ming-Jiang Zhou and Jing-Zhong Zou A national report of HABs in China [pdf, 0.24 MB] Republic of Korea Sam Geun Lee, Hak Gyoon Kim, Eon Seob Cho and Chang Kyu Lee Harmful ...

  5. Interdecadal variability of the tropospheric biennial oscillation in the western North Pacific

    Institute of Scientific and Technical Information of China (English)

    Zheng Bin; Lin Ai-Lan; Gu De-Jun; Li Chun-Hui

    2008-01-01

    The observed tropospheric biennial oscillation (TBO) in the western North Pacific (WNP) monsoon region has an interdecadal variability with a period of 40-50 yr.That suggests a weaker effect of the TBO on the East Asia followed by a stronger one.A simple analytic model was designed to investigate the mechanism of the interdecadal variability of the TBO.The results indicated that a local TBO air-sea system not only supports the TBO variability in the WNP monsoon region but also produces an interdecadal variability of the TBO.

  6. Distribution and biology of epipelagic animals in the northern North Pacific Ocean and adjacent seas-I. Fishes and squids in the southern Okhotsk Sea and western North Pacific Ocean off the Kuril Islands in the autumn of 1993

    OpenAIRE

    Nagasawa, Kazuya; Ueno, Yasuhiro; Azuma, Teruo; OGURA, Miki(College of National Rehabilitation Center for the Disabled); Startsev, Alexander V.; Ivanova, Irena M.; Morris, John F. T.

    1996-01-01

    A surface-trawl survey was conducted by the R/V Kaiyo mare in the southern Okhotsk Sea and western North Pacific Ocean off the Kuril Islands in October and November 1993. The distributions and abundances of the species caught are described and discussed. Twenty-four fish species (1 lamprey, 1 shark, and 22 teleosts) and one squid species were identified. Juvenile Pacific salmon (6 species of the genus Oncorhynchus) were the most abundant, followed by myctophids, juvenile arabesque greenling (...

  7. Subtropical Potential Vorticity Intrusion Drives Increasing Tropospheric Ozone over the Tropical Central Pacific

    Science.gov (United States)

    Nath, Debashis; Chen, Wen; Graf, Hans-F.; Lan, Xiaoqing; Gong, Hainan; Nath, Reshmita; Hu, Kaiming; Wang, Lin

    2016-01-01

    Drawn from multiple reanalysis datasets, an increasing trend and westward shift in the number of Potential Vorticity intrusion events over the Pacific are evident. The increased frequency can be linked to a long-term trend in upper tropospheric equatorial westerly wind and subtropical jets during boreal winter to spring. These may be resulting from anomalous warming and cooling over the western Pacific warm pool and the tropical eastern Pacific, respectively. The intrusions brought dry and ozone rich air of stratospheric origin deep into the tropics. In the tropical upper troposphere, interannual ozone variability is mainly related to convection associated with El Niño/Southern Oscillation. Zonal mean stratospheric overturning circulation organizes the transport of ozone rich air poleward and downward to the high and midlatitudes leading there to higher ozone concentration. In addition to these well described mechanisms, we observe a long-term increasing trend in ozone flux over the northern hemispheric outer tropical (10–25°N) central Pacific that results from equatorward transport and downward mixing from the midlatitude upper troposphere and lower stratosphere during PV intrusions. This increase in tropospheric ozone flux over the Pacific Ocean may affect the radiative processes and changes the budget of atmospheric hydroxyl radicals. PMID:26868836

  8. Subtropical Potential Vorticity Intrusion Drives Increasing Tropospheric Ozone over the Tropical Central Pacific

    Science.gov (United States)

    Nath, Debashis; Chen, Wen; Graf, Hans-F.; Lan, Xiaoqing; Gong, Hainan; Nath, Reshmita; Hu, Kaiming; Wang, Lin

    2016-02-01

    Drawn from multiple reanalysis datasets, an increasing trend and westward shift in the number of Potential Vorticity intrusion events over the Pacific are evident. The increased frequency can be linked to a long-term trend in upper tropospheric equatorial westerly wind and subtropical jets during boreal winter to spring. These may be resulting from anomalous warming and cooling over the western Pacific warm pool and the tropical eastern Pacific, respectively. The intrusions brought dry and ozone rich air of stratospheric origin deep into the tropics. In the tropical upper troposphere, interannual ozone variability is mainly related to convection associated with El Niño/Southern Oscillation. Zonal mean stratospheric overturning circulation organizes the transport of ozone rich air poleward and downward to the high and midlatitudes leading there to higher ozone concentration. In addition to these well described mechanisms, we observe a long-term increasing trend in ozone flux over the northern hemispheric outer tropical (10-25°N) central Pacific that results from equatorward transport and downward mixing from the midlatitude upper troposphere and lower stratosphere during PV intrusions. This increase in tropospheric ozone flux over the Pacific Ocean may affect the radiative processes and changes the budget of atmospheric hydroxyl radicals.

  9. The role of tropical Atlantic SST anomalies in modulating western North Pacific tropical cyclone genesis

    Science.gov (United States)

    Huo, Liwei; Guo, Pinwen; Hameed, Saji N.; Jin, Dachao

    2015-04-01

    The connection between north tropical Atlantic (NTA) sea surface temperature (SST) anomalies and tropical cyclone (TC) genesis over the western North Pacific (WNP) and associated physical mechanisms are investigated in this study. We demonstrate a remarkable negative correlation of WNP TC genesis frequency with the (preceding) boreal spring NTA SST anomalies. Our analysis suggests that major factors for TC genesis including distributions of large-scale vorticity and midtropospheric humidity are rendered unfavorable by remote teleconnections while barotropic energy conversion from the large-scale flow is suppressed. As shown in recent studies, the remote teleconnection from the Atlantic is sustained and enhanced throughout the typhoon season through local air-sea interactions. These results suggest that boreal spring NTA SST anomaly could be a new predictor for the seasonal WNP TC activity.

  10. Correlation and migration studies of North Central Sumatra oils

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, R.J. [Chevron Texaco Energy Research Technology Company, Richmond, CA (United States); Heidrick, T.; Mertani, B.; Qivayanti [PT Caltex Pacific Indonesia, Rumbai (Indonesia); Li, M. [Geological Survey of Canada, Calgary (China)

    2002-12-01

    The Central Sumatra Basin (CSB) is a profile petroleum-producing basin and its petroleum systems have been extensively studied. The widely occurring Tertiary lacustrine shale, Brown Shale, has long been recognized as the main source rock for tens of billions of barrels of oil in place. The oils produced from different fields display significant variation in source characteristics that have been attributed to variation in source facies. Despite this generalized recognition of the oil source, the links between major oil accumulations and many possible source kitchens throughout the basin have not been established as detailed oil-source correlation, and oil migration routes are not well defined. For continued exploration in the region, detailed genetic grouping and migration routes of the oils were evaluated through geochemical characterization of numerous oils from various fields in the northern part of Central Sumatra. Biomarker and carbon isotopic data indicate that the oils are quite similar geochemically but form several genetic groups on the basis of subtle but persistent differences in source facies. The groupings appear geographically meaningful and show association of the different oil groups with various troughs. Carbazole distributions show consistency in suggesting differences in relative migration distance among the oils within each genetic group. By combining the oil grouping and carbazole distributions with geological data, models of migration directions and pathways for oils in North Central Sumatra have been constructed. (author)

  11. Fertility and pacification among the Mekranoti of Central Brazil.

    Science.gov (United States)

    Werner, D

    1983-06-01

    Demographic data from 3 different historical periods of the Mekranoti-Kayapo Indians of Central Brazil were used to examine various explanations for historical changes in fertility among this group. The possible effects of warfare on Mekranoti fertility were also examined since warfare has had an important role in many preindustrial societies. The Mekranoti are a group of 285 relatively unacculturated Indians living in a single village in southern Para, Brazil. As in precontact days, their economy is based on slash and burn agriculture, hunting, and fishing. To assess Mekranoti fertility, pregnancy histories collected from all women 15 years or older as of December 1976 were used. In precontact years a woman who survived to age 50 could expect to give birth 6.5 times. During the contact years this average dropped to 5.6 and in the postcontact period it soared to almost 8.5. The drop in Mekranoti fertility from precontact to contact years corresponds with an increase in mortality. The direction of these changes would support a "health" argument about fertility, but the degrees of change do not. Whereas mortality increased markedly after 1955, fertility fell only slightly. The data are not consistent with the view that changes in lactation periods are responsible for fertility changes. The number of uses of contraceptives per reproductive woman year did not not vary much in the different historical periods and certainly could not account for differences in Mekranoti fertility. The data suggest that fertility changes over Mekranoti history may be due in part to sexual abstinence resulting either from postpartum sexual taboos or, more importantly, from a lack of husbands. Sex imbalances resulting from high male mortality in warfare and subsequent disruption of marriages by disease and death left many women without spouses for long periods of time. The findings are consistent with other studies that found lower fertility associated with male absence. The Mekranoti are

  12. Trans-Pacific Transport of Saharan Dust to Western North America: A Case Study

    Science.gov (United States)

    Kendry, Ian G. M.; Strawbridge, Kevin B.; O'Neill, Norman; Macdonald, Anne Marie; Liu, Peter S. K.; Leaitch, W. Richard; Anlauf, Kurt G.; Jaegle, Lyatt; Fairlie, T. Duncan; Westphal, Douglas L.

    2007-01-01

    The first documented case of long range transport of Saharan dust over a pathway spanning Asia and the Pacific to Western North America is described. Crustal material generated by North African dust storms during the period 28 February - 3 March 2005 reached western Canada on 13-14 March 2005 and was observed by lidar and sunphotometer in the Vancouver region and by high altitude aerosol instrumentation at Whistler Peak. Global chemical models (GEOS-CHEM and NRL NAAPS) confirm the transport pathway and suggest source attribution was simplified in this case by the distinct, and somewhat unusual, lack of dust activity over Eurasia (Gobi and Takla Makan deserts) at this time. Over western North America, the dust layer, although subsiding close to the boundary layer, did not appear to contribute to boundary layer particulate matter concentrations. Furthermore, sunphotometer observations (and associated inversion products) suggest that the dust layer had only subtle optical impact (Aerosol Optical Thickness (Tau(sub a500)) and Angstrom exponent (Alpha(sub 440-870) were 0.1 and 1.2 respectively) and was dominated by fine particulate matter (modes in aerodynamic diameter at 0.3 and 2.5microns). High Altitude observations at Whistler BC, confirm the crustal origin of the layer (rich in Ca(++) ions) and the bi-modal size distribution. Although a weak event compared to the Asian Trans-Pacific dust events of 1998 and 2001, this novel case highlights the possibility that Saharan sources may contribute episodically to the aerosol burden in western North America.

  13. Using high resolution multispectral imaging to map Pacific coral reefs in support of UNESCO's World Heritage Central Pacific project

    Science.gov (United States)

    Siciliano, Daria; Olsen, Richard C.

    2007-10-01

    Concerns over worldwide declines in marine resources have prompted the search for innovative solutions for their conservation and management, particularly for coral reef ecosystems. Rapid advances in sensor resolution, coupled with image analysis techniques tailored to the unique optical problems of marine environments have enabled the derivation of detailed benthic habitat maps of coral reef habitats from multispectral satellite imagery. Such maps delineate coral reefs' main ecological communities, and are essential for management of these resources as baseline assessments. UNESCO's World Heritage Central Pacific Project plans to afford protection through World Heritage recognition to a number of islands and atolls in the central Pacific Ocean, including the Phoenix Archipelago in the Republic of Kiribati. Most of these islands however lack natural resource maps needed for the identification of priority areas for inclusion in a marine reserve system. Our project provides assistance to UNESCO's World Heritage Centre and the Kiribati Government by developing benthic and terrestrial habitat maps of the Phoenix Islands from high-resolution multispectral imagery. The approach involves: (i) the analysis of new Quickbird multispectral imagery; and (ii) the use of MARXAN, a simulated annealing algorithm that uses a GIS interface. Analysis of satellite imagery was performed with ENVI®, and includes removal of atmospheric effects using ATCOR (a MODTRAN4 radiative transfer model); de-glinting and water column correction algorithms; and a number of unsupervised and supervised classifiers. Previously collected ground-truth data was used to train classifications. The resulting habitat maps are then used as input to MARXAN. This algorithm ultimately identifies a proportion of each habitat to be set aside for protection, and prioritizes conservation areas. The outputs of this research are being delivered to the UNESCO World Heritage Centre office and the Kiribati Government as

  14. Isotopic fractionation of dissolved nitrate during denitrification in the eastern tropical North Pacific Ocean

    International Nuclear Information System (INIS)

    The isotopic composition (delta15N) of dissolved nitrate was measured at five stations within the oxygen-deficient region of the eastern tropical North Pacific Ocean (ETNP) and at one station 900km northeast of Hawaii which was considered to be representative of all major water masses of the Pacific. At this last station, the delta15N composition of dissolved nitrate decreased systematically from about 0.6% at 400m to approximately 0.5% at 5,000m; these results are consistent with other estimates from the western Pacific. In contrast, vertical profiles of delta15N of dissolved nitrate from the ETNP showed a marked departure from the above observed trend and correlated with losses of nitrate arising from denitrification. Instantaneous fractionation factors (α) were estimated using the one dimensional vertical diffusion-advection model. These results suggest that 14NO3- is consumed 3-4% faster than 15NO3-, significantly larger than fractionations (-1yr-1 for the stations investigated. The above upper limit is probably excessive, but the average maximum for the four stations analyzed is estimated to be 3.5 μg-at NO3-1-1yr-1. These results compare favorably with suitably corrected oxygen utilization rates derived from electron transport activity measurements

  15. On meridional circulation and heat budget of the troposphere over the Equatorial Central Pacific

    OpenAIRE

    Hastenrath, Stefan L.

    2011-01-01

    The existence of an equatorial dry zone in the Central Pacific enclosed between moister belts in both hemispheres is borne out by rainfall measurements and daily ESSA III and ESSA V cloud mosaics. The tropospheric wind regime is studied mainly on the basis of aerological soundings during the Line Islands Experiment (LIE) in spring 1967 and observations of earlier periods. During LIE, upper-tropospheric Westerlies extend continuously across the equator. In the lower layers, Easterlies dominate...

  16. North Central Transmission Line: Guidelines for the environmental impact statement

    International Nuclear Information System (INIS)

    Guidelines that Manitoba Hydro must follow in the preparation of the environmental impact statement on the proposed North Central Transmission Line (TCTL) project are presented. The project consists of a 138 kV transmission line, two 25 kV distribution lines, and related ancillary structures and facilities. The review process must be sensitive to cultural and community needs and must involve those most directly affected, and should be grounded in the impacted northern communities. The review should include a project background, the proposal, a description of the existing natural and socio-economic environment, and must address employment, education and training, impacts on renewable resource harvesting, environmental impacts, social impacts and economic impacts, legal/jurisdictional issues, infrastructure, mitigation and compensation, and environmental monitoring and follow-up. 1 fig., 20 tabs

  17. Summer diatom blooms in the North Pacific subtropical gyre: 2008-2009.

    Directory of Open Access Journals (Sweden)

    Tracy A Villareal

    Full Text Available The summertime North Pacific subtropical gyre has widespread phytoplankton blooms between Hawaii and the subtropical front (∼30°N that appear as chlorophyll (chl increases in satellite ocean color data. Nitrogen-fixing diatom symbioses (diatom-diazotroph associations: DDAs often increase 10(2-10(3 fold in these blooms and contribute to elevated export flux. In 2008 and 2009, two cruises targeted satellite chlorophyll blooms to examine DDA species abundance, chlorophyll concentration, biogenic silica concentration, and hydrography. Generalized observations that DDA blooms occur when the mixed layer depth is 10 µm chl a fraction (∼40-90+% of total chl a. Integrated diatom abundance varied 10-fold over 10 µm size fraction, and increased up to 5-fold in the blooms. The two years differed in the magnitude of the surface chl a increase (2009>2008, the abundance of pennate diatoms within the bloom (2009>2008, and the substantially greater mixed layer depth in 2009. Only the 2009 bloom had sufficient chl a in the >10 µm fraction to produce the observed ocean color chl increase. Blooms had high spatial variability; ocean color images likely average over numerous small events over time and space scales that exceed the individual event scale. Summertime DDA export flux noted at the Hawaii time-series Sta. ALOHA is probably a generalized feature of the eastern N. Pacific north to the subtropical front.

  18. 3-D modelling and analysis of Dst C-responses in the North Pacific Ocean region, revisited

    DEFF Research Database (Denmark)

    Kuvshinov, A.; Utada, H.; Avdeev, D.; Koyama, T.

    2005-01-01

    During the last decade a number of one-dimensional (1-D) conductivity profiles have been constructed for the upper and mid-mantle of the North Pacific Ocean region. These profiles differ significantly, and from our point of view it is still unclear which profile is the best candidate for the upper...... dense grids in modelling, by considering 3-D models which include not only an inhomogeneous surface layer but also inhomogeneous deeper structures. (3) To derive an alternative 1-D upper and mid-mantle section for the North Pacific Ocean by carefully selecting the data for interpretation and by using 3......-responses if the published 1-D sections with conducting uppermost 400 km are considered as the upper and mid-mantle sections. Our 3-D simulations and reinterpretation of the data also confirm the recent finding that the upper and mid-mantle beneath North Pacific Ocean in the depth range down to 400 km is much...

  19. Intensification of North Pacific intermediate water ventilation during the Younger Dryas

    Science.gov (United States)

    Ohkushi, Ken'ichi; Hara, Naoki; Ikehara, Minoru; Uchida, Masao; Ahagon, Naokazu

    2016-04-01

    Modern North Pacific intermediate water (NPIW) is formed in the mixed water region where the Oyashio and Kuroshio currents meet. The source for cooling and freshening of NPIW is intermediate water in the Okhotsk Sea. The Okhotsk intermediate water outflows to the open Pacific, forming the Oyashio intermediate water by mixing with the subarctic gyre water. In the Oyashio region, the intermediate water originating from the Okhotsk Sea flows mainly at depths shallower than 500 m. On the other hand, ventilation of intermediate water in the subarctic Pacific during the deglaciation remains a topic of debate. In this study, foraminiferal δ18O and δ13C signatures were determined in a dated sediment core collected at 777 m water depth to evaluate the intensity and depth distribution of the source of NPIW since the last deglaciation in the Oyashio region. Benthic foraminiferal δ18O increased by 0.3-0.4‰ from the end of the Bølling/Ållerød warm episode to the Younger Dryas cold episode, suggesting intermediate water cooling. Consistent with this trend, benthic δ13C values point to decreased nutrient contents during the cold event. Conversely, benthic δ18O signatures from a nearby core site at a water depth of 1,366 m did not show such cooling. These results suggest that cold intermediate water originating from the north was actively ventilated at depths of at least 700-800 m, and possibly even 1,200 m during the Younger Dryas, implying that NPIW ventilation was thicker and deeper than under modern conditions.

  20. Pacific sleeper shark Somniosus pacificus trophic ecology in the eastern North Pacific Ocean inferred from nitrogen and carbon stable-isotope ratios and diet.

    Science.gov (United States)

    Courtney, D L; Foy, R

    2012-04-01

    Stable-isotope ratios of nitrogen (δ¹⁵N) and lipid-normalized carbon (δ¹³C') were used to examine geographic and ontogenetic variability in the trophic ecology of a high latitude benthopelagic elasmobranch, the Pacific sleeper shark Somniosus pacificus. Mean muscle tissue δ¹³C' values of S. pacificus differed significantly among geographic regions of the eastern North Pacific Ocean. Linear models identified significant ontogenetic and geographic variability in muscle tissue δ¹⁵N values of S. pacificus. The trophic position of S. pacificus in the eastern North Pacific Ocean estimated here from previously published stomach-content data (4·3) was within the range of S. pacificus trophic position predicted from a linear model of S. pacificus muscle tissue δ¹⁵N (3·3-5·7) for fish of the same mean total length (L(T) ; 201·5 cm), but uncertainty in predicted trophic position was very high (95% prediction intervals ranged from 2·9 to 6·4). The relative trophic position of S. pacificus determined here from a literature review of δ¹⁵N by taxa in the eastern North Pacific Ocean was also lower than would be expected based on stomach-content data alone when compared to fishes, squid and filter feeding whales. Stable-isotope analysis revealed wider variability in the feeding ecology of S. pacificus in the eastern North Pacific Ocean than shown by diet data alone, and expanded previous conclusions drawn from analyses of stomach-content data to regional and temporal scales meaningful for fisheries management. PMID:22497395

  1. Variability in the correlation between Asian dust storms and chlorophyll a concentration from the North to Equatorial Pacific.

    Science.gov (United States)

    Tan, Sai-Chun; Yao, Xiaohong; Gao, Hui-Wang; Shi, Guang-Yu; Yue, Xu

    2013-01-01

    A long-term record of Asian dust storms showed seven high-occurrence-frequency centers in China. The intrusion of Asian dust into the downwind seas, including the China seas, the Sea of Japan, the subarctic North Pacific, the North Pacific subtropical gyre, and the western and eastern Equatorial Pacific, has been shown to add nutrients to ocean ecosystems and enhance their biological activities. To explore the relationship between the transported dust from various sources to the six seas and oceanic biological activities with different nutrient conditions, the correlation between monthly chlorophyll a concentration in each sea and monthly dust storm occurrence frequencies reaching the sea during 1997-2007 was examined in this study. No correlations were observed between dust and chlorophyll a concentration in the dust sources and many sea areas, suggesting a link between dust and chlorophyll a concentration in those seas. However, the correlation coefficients were highly variable. In general, the correlation coefficients (0.54-0.63) for the Sea of Japan were highest, except for that between the subarctic Pacific and the Taklimakan Desert, where it was as high as 0.7. For the >50 m China seas and the North Pacific subtropical gyre, the correlation coefficients were in the range 0.32-0.57. The correlation coefficients for the western and eastern Equatorial Pacific were relatively low (dust sources, the transport pathways, the dust deposition, the nutrient conditions of oceans, and the probability of dust storms reaching the seas. PMID:23460892

  2. Assessment of tsunami hazards for the Central American Pacific coast from southern Mexico to northern Peru

    OpenAIRE

    B. Brizuela; Armigliato, A.; S. Tinti

    2014-01-01

    Central America (CA), from Guatemala to Panama, has been struck by at least 52 tsunamis between 1539 and 2013, and in the extended region from Mexico to northern Peru (denoted as ECA, Extended Central America in this paper) the number of recorded tsunamis in the same time span is more than 100, most of which were triggered by earthquakes located in the Middle American Trench that runs parallel to the Pacific coast. The most severe event in the catalogue is the tsunami that o...

  3. Tropical cyclone-related socio-economic losses in the western North Pacific region

    Directory of Open Access Journals (Sweden)

    C. Welker

    2013-01-01

    Full Text Available The western North Pacific (WNP is the area of the world most frequently affected by tropical cyclones (TCs. However, little is known about the socio-economic impacts of TCs in this region, probably because of the limited relevant loss data. Here, loss data from Munich RE's NatCatSERVICE database is used, a high-quality and widely consulted database of natural disasters. In the country-level loss normalisation technique we apply, the original loss data are normalised to present-day exposure levels by using the respective country's nominal gross domestic product at purchasing power parity as a proxy for wealth. The main focus of our study is on the question of whether the decadal-scale TC variability observed in the Northwest Pacific region in recent decades can be shown to manifest itself economically in an associated variability in losses. It is shown that since 1980 the frequency of TC-related loss events in the WNP exhibited, apart from seasonal and interannual variations, interdecadal variability with a period of about 22 yr – driven primarily by corresponding variations of Northwest Pacific TCs. Compared to the long-term mean, the number of loss events was found to be higher (lower by 14% (9% in the positive (negative phase of the decadal-scale WNP TC frequency variability. This was identified for the period 1980–2008 by applying a wavelet analysis technique. It was also possible to demonstrate the same low-frequency variability in normalised direct economic losses from TCs in the WNP region. The identification of possible physical mechanisms responsible for the observed decadal-scale Northwest Pacific TC variability will be the subject of future research, even if suggestions have already been made in earlier studies.

  4. Tropical cyclone-related socio-economic losses in the western North Pacific region

    Science.gov (United States)

    Welker, C.; Faust, E.

    2013-01-01

    The western North Pacific (WNP) is the area of the world most frequently affected by tropical cyclones (TCs). However, little is known about the socio-economic impacts of TCs in this region, probably because of the limited relevant loss data. Here, loss data from Munich RE's NatCatSERVICE database is used, a high-quality and widely consulted database of natural disasters. In the country-level loss normalisation technique we apply, the original loss data are normalised to present-day exposure levels by using the respective country's nominal gross domestic product at purchasing power parity as a proxy for wealth. The main focus of our study is on the question of whether the decadal-scale TC variability observed in the Northwest Pacific region in recent decades can be shown to manifest itself economically in an associated variability in losses. It is shown that since 1980 the frequency of TC-related loss events in the WNP exhibited, apart from seasonal and interannual variations, interdecadal variability with a period of about 22 yr - driven primarily by corresponding variations of Northwest Pacific TCs. Compared to the long-term mean, the number of loss events was found to be higher (lower) by 14% (9%) in the positive (negative) phase of the decadal-scale WNP TC frequency variability. This was identified for the period 1980-2008 by applying a wavelet analysis technique. It was also possible to demonstrate the same low-frequency variability in normalised direct economic losses from TCs in the WNP region. The identification of possible physical mechanisms responsible for the observed decadal-scale Northwest Pacific TC variability will be the subject of future research, even if suggestions have already been made in earlier studies.

  5. North Pacific Mesoscale Coupled Air-Ocean Simulations Compared with Observations

    Energy Technology Data Exchange (ETDEWEB)

    Koracin, Darko; Cerovecki, Ivana; Vellore, Ramesh; Mejia, John; Hatchett, Benjamin; McCord, Travis; McLean, Julie; Dorman, Clive

    2013-04-11

    Executive summary The main objective of the study was to investigate atmospheric and ocean interaction processes in the western Pacific and, in particular, effects of significant ocean heat loss in the Kuroshio and Kuroshio Extension regions on the lower and upper atmosphere. It is yet to be determined how significant are these processes are on climate scales. The understanding of these processes led us also to development of the methodology of coupling the Weather and Research Forecasting model with the Parallel Ocean Program model for western Pacific regional weather and climate simulations. We tested NCAR-developed research software Coupler 7 for coupling of the WRF and POP models and assessed its usability for regional-scale applications. We completed test simulations using the Coupler 7 framework, but implemented a standard WRF model code with options for both one- and two-way mode coupling. This type of coupling will allow us to seamlessly incorporate new WRF updates and versions in the future. We also performed a long-term WRF simulation (15 years) covering the entire North Pacific as well as high-resolution simulations of a case study which included extreme ocean heat losses in the Kuroshio and Kuroshio Extension regions. Since the extreme ocean heat loss occurs during winter cold air outbreaks (CAO), we simulated and analyzed a case study of a severe CAO event in January 2000 in detail. We found that the ocean heat loss induced by CAOs is amplified by additional advection from mesocyclones forming on the southern part of the Japan Sea. Large scale synoptic patterns with anomalously strong anticyclone over Siberia and Mongolia, deep Aleutian Low, and the Pacific subtropical ridge are a crucial setup for the CAO. It was found that the onset of the CAO is related to the breaking of atmospheric Rossby waves and vertical transport of vorticity that facilitates meridional advection. The study also indicates that intrinsic parameterization of the surface fluxes

  6. Influence of climatic warming in the Southem and Northem Hemisphere on the tropical cyclone over the western North Pacific Ocean

    Institute of Scientific and Technical Information of China (English)

    TIAN Rong-xiang; WENG Huan-xin

    2006-01-01

    Based on analyzing the surface air temperature series in the Southern and Northern Hemisphere and the tropical cyclone (TC) over the western North Pacific Ocean, the relationships between climatic warming and the frequency and intensity of tropical cyclone are investigated. The results showed that with the climatic warming in both hemispheres, the frequency of the tropical cyclone over the western North Pacific Ocean reduces and its intensity weakens simultaneously. A possible explanation might be that the cold air invasion from the Southern Hemisphere weakens due to global warming.

  7. Bundled slaty cleavage in laminated argillite, north-central minnesota

    Science.gov (United States)

    Southwick, D.L.

    1987-01-01

    Exceptional bundled slaty cleavage (defined herein) has been found in drill cores of laminated, folded, weakly metamorphosed argillite at several localities in the early Proterozoic Animikie basin of north-central Minnesota. The cleavage domains are more closely spaced within the cleavage bundles than outside them, the mean tectosilicate grain size of siltstone layers, measured normal to cleavage, is less in the cleavage bundles than outside them, and the cleavage bundles are enriched in opaque phases and phyllosilicates relative to extra-bundle segments. These facts suggest that pressure solution was a major factor in bundle development. If it is assumed that opaque phases have been conserved during pressure solution, the modal differences in composition between intra-bundle and extra-bundle segments of beds provide a means for estimating bulk material shortening normal to cleavage. Argillite samples from the central part of the Animikie basin have been shortened a minimum of about 22%, as estimated by this method. These estimates are similar to the shortening values derived from other strain markers in other rock types interbedded with the argillite, and are also consistent with the regional pattern of deformation. ?? 1987.

  8. Temperature, salinity, and nutrients data from CTD, MBT, and bottle casts in the Arctic, North Atlantic and North Pacific Oceans from the SACKVILLE and other platforms from 1928-05-12 to 1998-11-03 (NODC Accession 0000448)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — CTD, MBT, bottle and other data were collected in the Arctic, North Atlantic, and North Pacific Oceans from the SACKVILLE and other platforms from 12 May 1928 to 03...

  9. Temperature, salinity, and nutrients data from bottle, CTD, and XBT casts in the Arctic, North Atlantic, and North Pacific Oceans from the ANTON DOHRN and other platforms from 02 July 1916 to 28 January 1999 (NODC Accession 0000677)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bottle, CTD, and XBT data were collected in the Arctic, North Atlantic, and North Pacific Oceans from the ANTON DOHRN and other vessels from 02 July 1916 to 28...

  10. Temperature profile data from XBT and BT casts in the North/South Pacific Ocean and North/South Atlantic Ocean from the NOAA Ship RESEARCHER and other platforms from 02 April 1987 to 24 November 1987 (NODC Accession 8800007)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile data were collected using XBT and BT casts from the NOAA Ship RESEARCHER and other platforms in the North/South Pacific Ocean and North/South...

  11. Temperature, salinity, and nutrients data from bottle, CTD, and XBT casts from the JOHN P. TULLY and other vessels in the North Atlantic and North Pacific Oceans from 03 August 1959 to 01 July 2001 (NODC Accession 0000664)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bottle, CTD, and XBT data were collected in the North Atlantic and North Pacific Oceans from the John P. Tully and other vessels from 03 August 1959 to 01 July...

  12. Distributions of dissolved organic and inorganic carbon and radiocarbon in the eastern North Pacific continental margin

    Science.gov (United States)

    Bauer, James E.; Druffel, Ellen R. M.; Wolgast, David M.; Griffin, Sheila; Masiello, Caroline A.

    Temporal variations in the natural radiocarbon ( 14C) signatures of dissolved organic and inorganic carbon (DOC and DIC, respectively) in seawater have been studied previously (Druffel, E.R.M., Bauer, J.E., Williams, P.M., Griffin, S., Wolgast, D.M., 1996. Seasonal variability of radiocarbon in particulate organic carbon in the northeast Pacific. J. Geophys. Res. 101, 20 543-20 552; Bauer, J.E., Druffel, E.R.M., Williams, P.M., Wolgast, D.M., Griffin, S., 1998. Temporal variability in dissolved organic carbon and radiocarbon in the eastern North Pacific Ocean. J. Geophys. Res. 103, 2867-2882) at a long-term time-series station (Sta. M: 32°N, 123W) in the eastern North Pacific located at the eastern edge of the North Pacific abyssal plain. In June 1995 a transect was made from Sta. M inshore to approximately 500 m depth in order to evaluate the distributions of 14C in DOC and DIC from the abyssal plain to the upper continental slope. Concentrations and Δ 14C values of DOC in mixed layer waters (25 and 85 m) decreased toward the upper slope. In deeper waters, concentrations and Δ 14C values were in general similar at all three sites. Differences in DOC concentrations and Δ 14C-DOC between Sta. M and the rise and upper slope sites were explained in part by the mixing of DOC and Δ 14C along constant density ( σt) surfaces. However, specific deviations from conservative behavior due to mixing were observed for Δ 14C-DOC at mesopelagic (˜700 m) and near-bottom (˜3600- 3900 m) depths of the continental rise. Comparable findings are reported for DIC, where σt-normalized concentrations and Δ 14C values in Sta. M, rise and upper slope waters were similar, with the exception of slight increases in concentrations and Δ 14C values in near-bottom waters of the rise. These observations indicate that both DOC and DIC in continental rise and slope surface waters of the eastern North Pacific Ocean margin are comprised of a component of actively upwelled material derived

  13. Transport process of Pu isotope in marginal seas of the western North Pacific Ocean

    International Nuclear Information System (INIS)

    Significant quantities of Pu isotopes have been released into the marine environment as the result of atmospheric nuclear weapons testing. Most radionuclides globally dispersed in atmospheric nuclear weapons testing were released into the environment during the 1950's and 1960's. In the western North Pacific Ocean, the principal source can be further distinguished as two distinct sources of Pu: close-in tropospheric fallout from nuclear weapons testing at the Pacific Proving Grounds (PPG) in the Marshall Islands and global stratospheric fallout. Since the 240Pu/239Pu atom ratio is characteristic for the Pu emission source, information on Pu isotopic signature is very useful to better understand the transport process in the oceans and to identify the sources of Pu. The mean atom ratio of 240Pu/239Pu from the global stratospheric fallout is 0.180 ±0.014 based on soil sample data, whereas that from close-in tropospheric fallout from the PPG is 0.33 - 0.36. The 240Pu/239Pu atom ratios in seawater samples collected in marginal seas of the western North Pacific Ocean will provide important and useful data for understanding the process controlling Pu transport and for distinguishing future Pu sources. The objectives of this study were to measure the 239+240Pu concentrations and 240Pu/239Pu atom ratios in seawater from the Sea of Okhotsk, Japan Sea, South China Sea and Sulu Sea and to discuss the transport process of Pu. Large-volume seawater samples (250 L each) were collected from the surface to the bottom in marginal seas of the western North Pacific Ocean with acoustically triggered quadruple PVC sampling bottles during the R/V Hakuho-Maru cruise. The 239Pu and 240Pu concentrations and 240Pu/239Pu atom ratios were measured with a double-focusing SF-ICP-MS, which was equipped with a guard electrode to eliminate secondary discharge in the plasma and to enhance overall sensitivity. In the Sea of Okhotsk, the 239+240Pu concentration was 2.8 mBq m-3 in the surface water

  14. Pu isotopes in the western North Pacific Ocean before the accident at Fukushima Dai-ichi Nuclear Power Station

    Science.gov (United States)

    Yamada, M.; Zheng, J.; Aono, T.

    2011-12-01

    Anthropogenic radionuclides such as Pu-239 (half-life: 24100 yr), Pu-240 (half-life: 6560 yr) and Pu-241 (half-life: 14.325 yr) mainly have been released into the environment as the result of atmospheric nuclear weapons testing. In the North Pacific Ocean, two distinct sources of Pu isotopes can be identified; i.e., the global stratospheric fallout and close-in tropospheric fallout from nuclear weapons testing at the Pacific Proving Grounds in the Marshall Islands. The atom ratio of Pu-240/Pu-239 is a powerful fingerprint to identify the sources of Pu in the ocean. The Pu-240/Pu-239 atom ratios in seawater and marine sediment samples collected in the western North Pacific before the accident at Fukushima Dai-ichi Nuclear Power Station will provide useful background data for understanding the process controlling Pu transport and for distinguishing future Pu sources. The atom ratios of Pu-240/Pu-239 in water columns from the Yamato and Tsushima Basins in the Japan Sea were significantly higher than the mean global fallout ratio of 0.18; however, there were no temporal variation of atom ratios during the period from 1984 to 1993 in the Japan Sea. The total Pu-239+240 inventories in the whole water columns were approximately doubled during the period from 1984 to 1993 in the two basins. The atom ratio of Pu-240/Pu-239 in surface water from Sagami Bay, western North Pacific Ocean, was 0.224 and showed no notable variation from the surface to the bottom with the mean atom ratio being 0.234. The atom ratios for the Pacific coast, near the Rokkasho nuclear fuel reprocessing plant, were approximately the same as the 0.224 ratio obtained from Sagami Bay, western North Pacific margin. The atom ratios in the surficial sediments from Sagami Bay ranged from 0.229 to 0.247. The mean atom ratio in the sediment columns in the East China Sea ranged from 0.248 for the Changjiang estuary to 0.268 for the shelf edge. The observed atom ratios were significantly higher than the mean

  15. Interdecadal modulation on the relationship between ENSO and typhoon activity during the late season in the western North Pacific

    Science.gov (United States)

    Zhao, Haikun; Wang, Chunzai

    2016-07-01

    The present study identifies an interdecadal modulation of the Pacific decadal oscillation (PDO) on the relationship between El Niño-Southern oscillation (ENSO) and typhoon activity during the late season (October-December) in the western North Pacific. The PDO is uncorrelated with ENSO during the warm phase of 1979-1997, while the PDO is positively correlated with ENSO during the cold phase of 1998-2012. Further analyses show that the warm phase is associated with the reduced ENSO-typhoon activity relationship and more typhoons, whereas the cold phase is corresponded to the enhanced ENSO-typhoon activity relationship and fewer typhoons. These variations are mainly manifested by a significant difference of typhoon activity in the southeastern part of the western North Pacific. Moreover, the change of ENSO-typhoon relationship is largely due to changes in large-scale environmental conditions especially from low-level vorticity and vertical wind shear between the two phases, which are related to the changes in tropical Indo-Pacific sea surface temperature. The study implies that the phase of the PDO should be taken into account when ENSO is used as a predictor for predicting typhoon activity in the western North Pacific.

  16. Variability in the correlation between Asian dust storms and chlorophyll a concentration from the North to Equatorial Pacific.

    Directory of Open Access Journals (Sweden)

    Sai-Chun Tan

    Full Text Available A long-term record of Asian dust storms showed seven high-occurrence-frequency centers in China. The intrusion of Asian dust into the downwind seas, including the China seas, the Sea of Japan, the subarctic North Pacific, the North Pacific subtropical gyre, and the western and eastern Equatorial Pacific, has been shown to add nutrients to ocean ecosystems and enhance their biological activities. To explore the relationship between the transported dust from various sources to the six seas and oceanic biological activities with different nutrient conditions, the correlation between monthly chlorophyll a concentration in each sea and monthly dust storm occurrence frequencies reaching the sea during 1997-2007 was examined in this study. No correlations were observed between dust and chlorophyll a concentration in the 50 m China seas and the North Pacific subtropical gyre, the correlation coefficients were in the range 0.32-0.57. The correlation coefficients for the western and eastern Equatorial Pacific were relatively low (<0.36. These correlation coefficients were further interpreted in terms of the geographical distributions of dust sources, the transport pathways, the dust deposition, the nutrient conditions of oceans, and the probability of dust storms reaching the seas.

  17. Dynamical-statistical seasonal prediction for western North Pacific typhoons based on APCC multi-models

    Science.gov (United States)

    Kim, Ok-Yeon; Kim, Hye-Mi; Lee, Myong-In; Min, Young-Mi

    2016-03-01

    This study aims at predicting the seasonal number of typhoons (TY) over the western North Pacific with an Asia-Pacific Climate Center (APCC) multi-model ensemble (MME)-based dynamical-statistical hybrid model. The hybrid model uses the statistical relationship between the number of TY during the typhoon season (July-October) and the large-scale key predictors forecasted by APCC MME for the same season. The cross validation result from the MME hybrid model demonstrates high prediction skill, with a correlation of 0.67 between the hindcasts and observation for 1982-2008. The cross validation from the hybrid model with individual models participating in MME indicates that there is no single model which consistently outperforms the other models in predicting typhoon number. Although the forecast skill of MME is not always the highest compared to that of each individual model, the skill of MME presents rather higher averaged correlations and small variance of correlations. Given large set of ensemble members from multi-models, a relative operating characteristic score reveals an 82 % (above-) and 78 % (below-normal) improvement for the probabilistic prediction of the number of TY. It implies that there is 82 % (78 %) probability that the forecasts can successfully discriminate between above normal (below-normal) from other years. The forecast skill of the hybrid model for the past 7 years (2002-2008) is more skillful than the forecast from the Tropical Storm Risk consortium. Using large set of ensemble members from multi-models, the APCC MME could provide useful deterministic and probabilistic seasonal typhoon forecasts to the end-users in particular, the residents of tropical cyclone-prone areas in the Asia-Pacific region.

  18. The developmental biogeography of hawksbill sea turtles in the North Pacific.

    Science.gov (United States)

    Van Houtan, Kyle S; Francke, Devon L; Alessi, Sarah; Jones, T Todd; Martin, Summer L; Kurpita, Lauren; King, Cheryl S; Baird, Robin W

    2016-04-01

    High seas oceanic ecosystems are considered important habitat for juvenile sea turtles, yet much remains cryptic about this important life-history period. Recent progress on climate and fishery impacts in these so-called lost years is promising, but the developmental biogeography of hawksbill sea turtles (Eretmochelys imbricata) has not been widely described in the Pacific Ocean. This knowledge gap limits the effectiveness of conservation management for this globally endangered species. We address this with 30 years of stranding observations, 20 years of bycatch records, and recent simulations of natal dispersal trajectories in the Hawaiian Archipelago. We synthesize the analyses of these data in the context of direct empirical observations, anecdotal sightings, and historical commercial harvests from the insular Pacific. We find hawksbills 0-4 years of age, measuring 8-34 cm straight carapace length, are found predominantly in the coastal pelagic waters of Hawaii. Unlike other species, we find no direct evidence of a prolonged presence in oceanic habitats, yet satellite tracks of passive drifters (simulating natal dispersal) and our small sample sizes suggest that an oceanic phase for hawksbills cannot be dismissed. Importantly, despite over 600 million hooks deployed and nearly 6000 turtle interactions, longline fisheries have never recorded a single hawksbill take. We address whether the patterns we observe are due to population size and gear selectivity. Although most sea turtle species demonstrate clear patterns of oceanic development, hawksbills in the North Pacific may by contrast occupy a variety of ecosystems including coastal pelagic waters and shallow reefs in remote atolls. This focuses attention on hazards in these ecosystems - entanglement and ingestion of marine debris - and perhaps away from longline bycatch and decadal climate regimes that affect sea turtle development in oceanic regions. PMID:27110350

  19. Millennial-scale plankton regime shifts in the subtropical North Pacific Ocean

    Science.gov (United States)

    McMahon, Kelton W.; McCarthy, Matthew D.; Sherwood, Owen A.; Larsen, Thomas; Guilderson, Thomas P.

    2015-12-01

    Climate change is predicted to alter marine phytoplankton communities and affect productivity, biogeochemistry, and the efficacy of the biological pump. We reconstructed high-resolution records of changing plankton community composition in the North Pacific Ocean over the past millennium. Amino acid-specific δ13C records preserved in long-lived deep-sea corals revealed three major plankton regimes corresponding to Northern Hemisphere climate periods. Non-dinitrogen-fixing cyanobacteria dominated during the Medieval Climate Anomaly (950-1250 Common Era) before giving way to a new regime in which eukaryotic microalgae contributed nearly half of all export production during the Little Ice Age (~1400-1850 Common Era). The third regime, unprecedented in the past millennium, began in the industrial era and is characterized by increasing production by dinitrogen-fixing cyanobacteria. This picoplankton community shift may provide a negative feedback to rising atmospheric carbon dioxide concentrations.

  20. Enhancement of phytoplankton chlorophyll by submesoscale frontal dynamics in the North Pacific Subtropical Gyre

    Science.gov (United States)

    Liu, Xiao; Levine, Naomi M.

    2016-02-01

    Subtropical gyres contribute significantly to global ocean productivity. As the climate warms, the strength of these gyres as a biological carbon pump is predicted to diminish due to increased stratification and depleted surface nutrients. We present results suggesting that the impact of submesoscale physics on phytoplankton in the oligotrophic ocean is substantial and may either compensate or exacerbate future changes in carbon cycling. A new statistical tool was developed to quantify surface patchiness from sea surface temperatures. Chlorophyll concentrations in the North Pacific Subtropical Gyre were shown to be enhanced by submesoscale frontal dynamics with an average increase of 38% (maximum of 83%) during late winter. The magnitude of this enhancement is comparable to the observed decline in chlorophyll due to a warming of ~1.1°C. These results highlight the need for an improved understanding of fine-scale physical variability in order to predict the response of marine ecosystems to projected climate changes.

  1. Geotechnical properties of sediments from North Pacific and Northern Bermuda Rise

    International Nuclear Information System (INIS)

    Studies of geotechnical properties for the Sub-seabed Disposal Program have been oriented toward sediment characterization related to effectiveness as a containment media and determination of detailed engineering behavior. Consolidation tests of the deeper samples in the North Pacific clays indicate that the sediment column is normally consolidated. The in-situ coefficient of permeability (k) within the cored depth of 25 meters is relatively constant at 10-7 cm/sec. Consolidated undrained (CIU) triaxial tests indicate stress-strain properties characteristic of saturated clays with effective angles of friction of 350 for smectite and 310 for illite. These results are being used in computer modeling efforts. Some general geotechnical property data from the Bermuda Rise are also discussed

  2. Effects of monsoon trough interannual variation on tropical cyclogenesis over the western North Pacific

    Science.gov (United States)

    Cao, Xi; Li, Tim; Peng, Melinda; Chen, Wen; Chen, Guanghua

    2014-06-01

    The western North Pacific monsoon trough (MT) exhibits marked interannual variation (IAV) associated with El Niño-Southern Oscillation forcing. The role of MT IAV in tropical cyclone (TC) development was investigated using the Advanced Research Weather Research and Forecasting model placed on a beta plane. It was found that MT IAV has a great influence on vortex development. In strong years, the MT provides more favorable environmental conditions—primarily through enhanced low-level vorticity, convergence and midlevel moisture—for TC formation and vice versa in weak years. Sensitivity experiments that separated the dynamic and thermodynamic (moisture) factors from strong MT IAV showed that the thermodynamic impact associated with MT IAV is comparable to the dynamic impact.

  3. Intermediate-wavelength magnetic anomaly field of the North Pacific and posible source distributions

    Science.gov (United States)

    Labrecque, J. L.; Cande, S. C.; Jarrard, R. D.

    1985-01-01

    A technique that eliminates external field sources and the effects of strike aliasing was used to extract from marine survey data the intermediate wavelength magnetic anomaly field for (B) in the North Pacific. A strong correlation exists between this field and the Magsat field although a directional sensitivity in the Magsat field can be detected. The intermediate wavelength field is correlated to tectonic features. Island arcs appear as positive anomalies of induced origin likely due to variations in crustal thickness. Seamount chains and oceanic plateaus also are manifested by strong anomalies. The primary contribution to many of these anomalies appears to be due to a remanent magnetization. The source parameters for the remainder of these features are presently unidentified ambiguous. Results indicate that the sea surface field is a valuable source of information for secular variation analysis and the resolution of intermediate wavelength source parameters.

  4. The intermediate wavelength magnetic anomaly field of the north Pacific and possible source distributions

    Science.gov (United States)

    Labrecque, J. L.; Cande, S. C.; Jarrard, R. D. (Principal Investigator)

    1983-01-01

    A technique that eliminates external field sources and the effects of strike aliasing was used to extract from marine survey data the intermediate wavelength magnetic anomaly field for (B) in the North Pacific. A strong correlation exists between this field and the MAGSAT field although a directional sensitivity in the MAGSAT field can be detected. The intermediate wavelength field is correlated to tectonic features. Island arcs appear as positive anomalies of induced origin likely due to variations in crustal thickness. Seamount chains and oceanic plateaus also are manifested by strong anomalies. The primary contribution to many of these anomalies appears to be due to a remanent magnetization. The source parameters for the remainder of these features are presently unidentified ambiguous. Results indicate that the sea surface field is a valuable source of information for secular variation analysis and the resolution of intermediate wavelength source parameters.

  5. ECOLOGICAL AND WATER QUALITY CONSEQUENCES OF NUTRIENT ADDITION FOR SALMON RESTORATION IN THE PACIFIC NORTHWEST OF NORTH AMERICA

    Science.gov (United States)

    Salmon runs have declined over the past two centuries in the Pacific Northwest region of North America. Reduced inputs of salmon-derived organic matter and nutrients (SDN) may limit freshwater production and thus establish a negative feedback loop affecting future generations of...

  6. Possible Linkage between Monsoon Trough Variability and Tropical Cyclone Activity over Western North Pacific: Role of Tropical Waves

    Science.gov (United States)

    Wu, Liang; Huang, Ronghui; Wen, Zhiping

    2014-05-01

    The present study investigates the influence of the monsoon trough (MT) on the interannual variability of tropical cyclone (TC) activity over the western North Pacific during July-November for the period 1979-2007. It is shown that the TC activity is closely related to the MT location. During the years when the MT extends eastward (retreats westward), more (less) TCs form within the southeastern quadrant of the western North Pacific. Such a relationship can be explained by the changes in tropical waves, such as mixed Rossby-gravity (MRG) waves and (tropical depression) TD-type disturbances, associated with the movement of the MT. An eastward extension of the MT coincides with enhanced TD-MRG type disturbances and a clear MRG-to-TD transition over the southeast quadrant of the western North Pacific. Such a transition is unclear during the years when the MT retreats westward. These waves associated with the eastern extension of the MT are favorable for TC genesis, while those associated with the westward retreat of the MT are not. Diagnosis of the barotropic energy conversion indicates that both the rotational and divergent components of the background flow change associated with MT are responsible for energy conversion from the mean flow to the TD-MRG perturbations. This is an important reason for the linkage between MT variability and TC genesis over the western North Pacific.

  7. Decadal changes in tropical cyclone activity over the western North Pacific in the late 1990s

    Science.gov (United States)

    He, Haozhe; Yang, Jing; Gong, Daoyi; Mao, Rui; Wang, Yuqing; Gao, Miaoni

    2015-12-01

    A pronounced decadal change in tropical cyclone (TC) activity over the western North Pacific (WNP) in the late 1990s was identified. Based on a comparison of the two epochs that occurred before and after the late 1990s, the TC genesis number exhibited an evident decrease over the southern WNP (S-WNP: 5°-20°N, 105°-170°E) and an increase over the northern WNP (N-WNP: 20°-25°N, 115°-155°E), which partly corresponded to a significant northward migration in the seasonal mean latitudinal location of TC genesis, i.e., from 17.2°N to 18.7°N. After the late 1990s, the northwestward-moving track became the most dominant track mode, accompanied by the weakening of both the westward-moving track and the northeastward-recurving track. Meanwhile, the TC occurrence frequency (TCF) experienced evident increases over southeastern China and the Okinawa islands, while prominent decreases occurred over the South China Sea, the Philippine Sea, Japan and east of Japan. Changes in the TCF were determined by TC genesis changes, TC track shifts and variations in regional TC durations, which were all ascribed to the decadal change in tropical Indo-Pacific sea surface temperature. The full picture on the decadal changes in the WNP TC activity revealed in this study may provide useful guidance for regional TC seasonal forecasts and future projections.

  8. Effects of South China Sea/western North Pacific summer monsoon on tropospheric biennial oscillation (TBO)

    Institute of Scientific and Technical Information of China (English)

    Zheng Bin; Gu De-Jun; Lin Ai-Lan; Li Chun-Hui

    2007-01-01

    Severed theories have been developed to explain tropical biennial oscillation (TBO), as an air-sea interactive system to impact Asian and global weather and climate, and some models have been established to produce a TBO. A simple 5-box model, with almost all the key processes associated with TBO, can produce a TBO by including air-sea interactions in the monsoon regions. Despite that, the South China Sea/western North Pacific summer monsoon (SCS/WNPSM), a very important monsoon subsystem, is neglected. In this paper, based on the dynamical framework of 5-box model, the term of SCS/WNPSM has been added and a 6-box model has been developed. Comparing the difference of TBO sensibilities with several key parameters, air-sea coupling coefficient α, SST-thermocline feedback coefficient γ and wind-evaporation feedback coefficient λ, between the modified model and original model, TBO is more sensible to the parameters in the new model. The results imply that the eastern Pacific and local wind-evaporation play more important roles in the TBO when including SCS/WNPSM.

  9. Observed eastward progression of the Fukushima 134Cs signal across the North Pacific

    Science.gov (United States)

    Yoshida, Sachiko; Macdonald, Alison M.; Jayne, Steven R.; Rypina, Irina I.; Buesseler, Ken O.

    2015-09-01

    Radionuclide samples taken as part of hydrographic surveys at 30°N in the North Pacific reveal that the easternmost edge of Fukushima-derived 134Cs observed at 174.3°W in 2012 had progressed eastward across the basin to 160.6°W by 2013. The 2013 30°N observations indicate surface 134Cs concentrations of 3-5 Bq/m3 between 160°E and 160°W, slightly lower concentrations west of 160°E and no detectable signal east of 160.6°W. Profile samples show 134Cs penetration to 500 m west of 180° with shoaling penetration depth toward to the east. The near-uniform vertical distribution of 137Cs between 152°W and 121.3°W in the top 500 m is indicative of trace amounts of radionuclides remaining from weapons testing. The physical processes responsible for the deep 134Cs penetration in the western Pacific appear to be related to distinct water mass subduction pathways; however, the timing and rapidity of deep penetration over the broad scales observed has yet to be clarified.

  10. Wind-driven circulation in the subarctic north Pacific using altimeter data

    Indian Academy of Sciences (India)

    Osamu Isoguchi; Hiroshi Kawamura

    2002-09-01

    Time-dependent wind-driven circulation in the subarctic north Pacific is investigated by using Topex/Poseidon (T/P) altimeter data and European Centre for Medium-Range Weather Forecasts (ECMWF) wind data for about 6 years. The first empirical orthogonal function (EOF) of the T/P- derived sea level anomaly (SLA) without the variation related to the steric height change (SLA1) and the first EOF of the ECMWF-based wind stress curl fields represent basin-sized south-north oscillations and their time series agree well with a correlation of 0.49. They appear to express the spin-up and spin-down of the subarctic gyre. The third EOF of SLA (SLA3) and the second EOF of the wind stress curl are also related to the variation of the subarctic gyre. Though the correlation of their time series is 0.27, drastic changes in early winter coincide well. The two EOF pairs can be considered to mean that the SLA variation followed by the latitudinal migration of the Aleutian low is separated into two standing oscillation patterns, that is, the sea level variation combined with SLA1 and SLA3 expresses seasonal variations of the wind-driven circulation of the subarctic gyre. The interannual SLAs constructed by subtracting the SLA1 and SLA3 components clearly show trans-pacific westward propagation even in the high-latitudes. The time series of SLA1 is in agreement with that of in situ SLAs measured with the tide gauge at Petropavlovsk (53-01N, 158-38E), which implies the possibility to monitor the subarctic circulation using tide gauge data.

  11. Seven-day intensity and intensity spread predictions for western North Pacific tropical cyclones

    Science.gov (United States)

    Tsai, Hsiao-Chung; Elsberry, Russell L.

    2015-11-01

    Our weighted-analog intensity (WANI) technique for predicting western North Pacific tropical cyclone intensity and with intensity spread guidance has been extended from five days to seven days. A perfect-prog approach that utilizes the Joint Typhoon Warning Center (JTWC) best-tracks is adopted and the 10 best historical track analogs are selected from the 1945-2009 JTWC best-track file. A development sample from the 2000-2009 seasons is used to develop an intensity bias correction and an intensity spread calibration. Tests with an independent sample from the 2010-2014 seasons demonstrate that the intensity mean absolute errors and the correlation coefficients of the WANI forecast intensities with the verifying intensities essentially remain constant in the five-day to seven-day forecast interval. After calibration of the raw intensity spreads among the 10 historical analogs each 12 h, the uncertainty estimates about the WANI intensity forecasts also do not increase during the five-day to seven-day forecast intervals. The conclusion is that the seven-day WANI will provide intensity and intensity spread predictions of western North Pacific tropical cyclones with a similar performance as our five-day WANI technique. Examples of the performance for this seven-day WANI for westward-moving and northwestward-moving cyclones that make landfall, or for recurving storms that begin decay after rrecurvature over the ocean, demonstrate the value of constraining the intensities at the end of the WANI forecast. Less satisfactory WANI forecasts occur for rapid intensification, rapid decay, and for cyclones with extended periods of non-intensification.

  12. Arabian Peninsula-North Pacific Oscillation and its association with the Asian summer monsoon

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Using correlation and EOF analyses on sea level pressure from 57-year NCEP-NCAR reanalysis data, the Arabian Peninsula-North Pacific Oscillation (APNPO) is identified. The APNPO reflects the co-variability between the North Pacific high and South Asian summer monsoon low. This teleconnec- tion pattern is closely related to the Asian summer monsoon. On interannual timescale, it co-varies with both the East Asian summer monsoon (EASM) and South Asian summer monsoon (SASM); on decadal timescale, it co-varies with the EASM: both exhibit two abrupt climate changes in the middle 1960s and the late 1970s respectively. The possible physical process for the connections between the APNPO and Asian summer monsoon is then explored by analyzing the APNPO-related atmospheric circulations. The results show that with a strong APNPO, the Somali Jet, SASM flow, EASM flow, and South Asian high are all enhanced, and an anomalous anticyclone is produced at the upper level over northeast China via a zonal wave train. Meanwhile, the moisture transportation to the Asian monsoon regions is also strengthened in a strong APNPO year, leading to a strong moisture convergence over India and northern China. All these changes of circulations and moisture conditions finally result in an anoma- lous Asian summer monsoon and monsoon rainfall over India and northern China. In addition, the APNPO has a good persistence from spring to summer. The spring APNPO is also significantly corre- lated with Asian summer monsoon variability. The spring APNPO might therefore provide valuable in- formation for the prediction of Asian summer monsoon.

  13. Resource manager information needs regarding hydrologic regime shifts for the North Pacific Landscape Conservation

    Science.gov (United States)

    Woodward, Andrea; Jenni, Karen

    2014-01-01

    Landscape Conservation Cooperatives (LCCs) are a network of 22 public-private partnerships, defined by ecoregion, that share and provide science to ensure the sustainability of land, water, wildlife, and cultural resources in North America. LCCs were established by the U.S. Department of the Interior (DOI) in recognition of the fact that response to climate change must be coordinated on a landscape-level basis because important resources, ecosystem processes, and resource management challenges extend beyond most of the boundaries considered in current natural resource management. The North Pacific LCC (NPLCC) covers the range of the Pacific coastal temperate rainforest, including an area of 528,360 km2 spanning 22 degrees of latitude from the Kenai Peninsula, Alaska, to Bodega Bay, California. The coverage area includes parts of four States, two Canadian provinces, and more than 100 Tribes and First Nation language groups. It extends from alpine areas at the crest of coastal mountains across subalpine, montane, and lowland forests to the nearshore marine environment. This wide range of latitudes and elevation zones; terrestrial, freshwater, and marine habitats; and complex jurisdictional boundaries hosts a diversity of natural resources and their corresponding management issues are equally diverse. As evidenced by the Science and Traditional Ecological Knowledge (S-TEK) Strategy guiding principles, identifying and responding to the needs of resource managers is key to the success of the NPLCC. To help achieve this goal of the NPLCC, the U.S. Geological Survey (USGS) has organized several workshops with resource managers and resource scientists to identify management information needs relevant to the priority topics identified in the S-TEK Strategy. Here, we detail the results from a first workshop to address the effects of changes in hydrologic regime on rivers, streams, and riparian corridors. The workshop focused on a subset of the full NPLCC geography and was

  14. Parasitism of Dasineura oxycoccana (Diptera: Cecidomyiidae) in North Central Florida.

    Science.gov (United States)

    Roubos, Craig R; Liburd, Oscar E

    2013-06-01

    Blueberry gall midge, Dasineura oxycoccana (Johnson), is a key pest of blueberries in Florida. As a larva, this insect feeds in developing flower and leaf buds. Management of D. oxycoccana relies principally on chemical insecticides; however, efficacy is limited because D. oxycoccana is sheltered within the plant during most of its life cycle. Natural enemies, particularly parasitoids, may play an important role in regulating D. oxycoccana populations. To determine the seasonal dynamics and parasitism rates of eulophid and platygastrid wasps parasitizing D. oxycoccana larvae, we sampled D. oxycoccana larvae by collecting infested blueberry leaf buds from a minimally-managed farm in north central Florida. Midge larvae were examined under a microscope to determine parasitism status of host instars. Parasitism rates ranged from 25 to 40% over the 3-yr study. Percent parasitization was significantly higher in third instars than first or second instars. Midge larvae in the centers of leaf buds were significantly less likely to be parasitized than larvae in outer layers of leaf buds. Thirty-seven percent of midge larvae had been parasitized multiple times, suggesting these parasitoids do not discriminate between parasitized and unparasitized hosts. Implications for pesticide use in relation to the conservation of natural enemies and management of D. oxycoccana populations are discussed. PMID:23726050

  15. North Central Regional geologic characterization report. Volume 1. Final report

    International Nuclear Information System (INIS)

    This report presents available geologic information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Minnesota, Wisconsin, and the Upper Peninsula of Michigan. For each of the states within the North Central Region, information is provided on the geologic disqualifying factor and the geologic regional screening variables to be used in region-to-area screening. The geologic factor and variables include deep mines and quarries, rock mass extent, post-emplacement faulting, suspected Quaternary faulting, seismicity, rock and mineral resources, major groundwater discharge zones, groundwater resources, state of stress, thickness of rock mass, and thickness of overburden. Information is presented on age, areal extent, shape, composition, texture, degree and type of alteration, thickness, and structural features associated with each rock body or complex. Regional seismic and tectonic information is presented, including patterns of earthquake occurrence, earthquake magnitudes, horizontal ground accelerations, and vertical crustal movements. Also included are discussions of the rock and mineral deposits or mines located within or near crystalline rock bodies; groundwater resources and regional hydrology; postulated changes in climate and the associated effects; and landforms, surface processes, and surficial materials on or near the rock bodies. A discussion is also presented of the relationship between the US Department of Energy Siting Guidelines (10 CFR 960) and the geologic disqualifying factor and regional screening variables to be used in the region-to-area screening process. 43 figs., 15 tabs

  16. Revised draft: North Central Regional geologic characterization report. Volume 1

    International Nuclear Information System (INIS)

    This report presents available geologic information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Minnesota, Wisconsin, and the Upper Peninsula of Michigan. For each of the states within the North Central Region, information is provided on the disqualifying factor and the screening variables to be used in region-to-area screening. These factors and variables include hydrologically significant natural resources, rock mass extent, post-emplacement faulting, suspected Quaternary faulting, seismicity, rock and mineral resources, major groundwater discharge zones, water resources, groundwater salinity, and state of stress. Information is presented on age, areal extent, shape, thickness of overburden, composition, texture, degree and type of alteration, and structural features associated with each rock body or complex. Regional seismic and tectonic information is presented, including patterns of earthquake occurrence, earthquake magnitudes, horizontal ground accelerations, and vertical crustal movements. Also included are discussions of the rock and mineral deposits or mines located within or near crystalline rock bodies; groundwater resources and regional hydrology; postulated changes in climate and the associated effects; and landforms, surface processes, and surficial materials on or near the subject rock bodies. A discussion of the relationship between the DOE Siting Guidelines and the geologic disqualifying factor and regional screening variables to be used in the region-to-area screening process is also presented

  17. Revised draft: North Central Regional environmental characterization report. Volume 1

    International Nuclear Information System (INIS)

    This report presents available environmental information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Minnesota, Wisconsin, and the Upper Peninsula of Michigan. For each of the states within the North Central Region, information is provided on those environmental disqualifying factors and regional screening variables to be used in region-to-area screening. These environmental factors and variables include existing and proposed federal protected lands, proximity to federal protected lands, existing state protected lands, proximity to state protected lands, population density and distribution, proximity to highly populated areas, national and state forest lands, state wildlife lands, designated critical habitats for threatened and endangered species, surface water bodies, and wetlands. In addition, supplementary descriptive information providing a general characterization of the region is presented, as is information on environmental parameters that may be of use at later phases of screening. Also included is a discussion of the relationship between the DOE Siting Guidelines and those environmental disqualifying factors and regional screening variables to be used in the region-to-area screening process

  18. North Central Regional environmental characterization report. Volume 1. Final report

    International Nuclear Information System (INIS)

    This report presents available environmental information pertinent to siting a repository for high-level nuclear waste in crystalline rock in Minnesota, Wisconsin, and the Upper Peninsula of Michigan. For each of the states within the North Central Region, information is provided on those environmental disqualifying factors and regional screening variables to be used in region-to-area screening. These environmental factors and variables include existing and proposed Federal-protected lands, proximity to Federal-protected lands, components of national forest lands, existing state-protected lands, proximity to state-protected lands, population density and distribution, proximity to highly populated areas or to 1-mile square areas with 1000 or more persons, national and state forest lands, designated critical habitats for threatened and endangered spcies, surface water bodies, and wetlands. In addition, supplementary descriptive information providing a general characterization of the region is presented, as is information on environmental parameters that will be of use at later phases of screening. Also included is a discussion of the relationship between the US Department of Energy Siting Guidelines (10CFR 960) and those environmental disqualifying factors and regional screening variables to be used in the region-to-area screening process

  19. Response to state comments on the revised draft North Central Regional characterization reports for the Crystalline Repository Project

    International Nuclear Information System (INIS)

    The purpose of this document is to respond to the comments received from the states of the North Central Region on the revised draft North Central Regional Characterization Reports (RCRs). The responses in this document indicate the manner in which the suggestions or comments received have been considered in modifying the revised draft North Central RCRs. Both general comments related to the overall Crystalline Repository Project (CRP) and comments on specific sections of the RCRs are addressed. This document responds to North Central State comments on both the revised draft North Central Regional Geologic Characterization Report (RGCR) and the revised draft North Central Regional Environmental Characterization Report (RECR)

  20. Distribution, sources and risk assessment of polychlorinated biphenyls in soils from the Midway Atoll, North Pacific Ocean.

    Science.gov (United States)

    Ge, Jing; Woodward, Lee Ann; Li, Qing X; Wang, Jun

    2013-01-01

    Concentrations of 28 polychlorinated biphenyls (PCBs) were assessed in soils from the Midway Atoll in the central North Pacific Ocean. The analytical procedure involved the application of accelerated solvent extraction (ASE) and gas chromatography coupled with ion trap mass spectrometric detection (GC/ITMS) for identification and quantification. Among the 28 PCB congeners studied, 26 of them, except CB195 and CB209, were detected in the analyzed samples at different frequencies. The total concentrations of 28 indicator PCBs (ΣPCBs) ranged from 2.6 to 148.8 ng g⁻¹ with an average value of 50.7 ng g⁻¹ and median of 39.5 ng g⁻¹. Sources and congeners' pattern of PCB were investigated in the soil of Midway Atoll. The principal component analysis indicated that the compositions of PCBs in most of the soil samples were similar. The total concentrations of PCBs were used to assess the cancer risk probabilities in humans via ingestion, dermal contact and inhalation of soil particles. Very low cancer risk was found in all soil samples caused by ΣPCBs. PMID:23951182

  1. Maximum wind radius estimated by the 50 kt radius: improvement of storm surge forecasting over the Western North Pacific

    Science.gov (United States)

    Takagi, H.; Wu, W.

    2015-10-01

    Even though the maximum wind radius (Rmax) is an important parameter in determining the intensity and size of tropical cyclones, it has been overlooked in previous storm surge studies. This research reviewed the existing estimation methods of Rmax based on the central pressure or maximum wind speed. These over or underestimated Rmax because of the substantial variety of the data, though an average radius could be moderately estimated. Alternatively, we proposed an Rmax estimation method based on the radius of the 50 knot wind (R50). The data obtained during the passage of strong typhoons by a meteorological station network in the Japanese archipelago enabled us to derive the following formula, Rmax = 0.23R50. Although this new method substantially improved the estimation of Rmax compared to the existing models, an estimation error was unavoidable because of fundamental uncertainties regarding the typhoon's structure or insufficient number of available typhoon data. In fact, a numerical simulation from 2013 Typhoon Haiyan demonstrated a substantial difference in the storm surge height for different Rmax. Therefore, the variability of Rmax should be taken into account in storm surge simulations, independently of the model used, to minimize the risk of over or underestimation of storm surges. The proposed method is expected to increase the reliability of storm surge prediction and contribute to disaster risk management, particularly in the Western North Pacific, including countries such as Japan, China, Taiwan, Philippines, and Vietnam.

  2. A Geodetic Strain Rate Model for the Pacific-North American Plate Boundary, western United States

    Science.gov (United States)

    Kreemer, C.; Hammond, W. C.; Blewitt, G.; Holland, A. A.; Bennett, R. A.

    2012-04-01

    We present a model of crustal strain rates derived from GPS measurements of horizontal station velocities in the Pacific-North American plate boundary in the western United States. The model reflects a best estimate of present-day deformation from the San Andreas fault system in the west to the Basin and Range province in the east. Of the total 2,846 GPS velocities used in the model, 1,197 are derived by ourselves, and 1,649 are taken from (mostly) published results. The velocities derived by ourselves (the "UNR solution") are estimated from GPS position time-series of continuous and semi-continuous stations for which data are publicly available. We estimated ITRF2005 positions from 2002-2011.5 using JPL's GIPSY-OASIS II software with ambiguity resolution applied using our custom Ambizap software. Only stations with time-series that span at least 2.25 years are considered. We removed from the time-series continental-scale common-mode errors using a spatially-varying filtering technique. Velocity uncertainties (typically 0.1-0.3 mm/yr) assume that the time-series contain flicker plus white noise. We used a subset of stations on the stable parts of the Pacific and North American plates to estimate the Pacific-North American pole of rotation. This pole is applied as a boundary condition to the model and the North American - ITRF2005 pole is used to rotate our velocities into a North America fixed reference frame. We do not include parts of the time-series that show curvature due to post-seismic deformation after major earthquakes and we also exclude stations whose time-series display a significant unexplained non-linearity or that are near volcanic centers. Transient effects longer than the observation period (i.e., slow viscoelastic relaxation) are left in the data. We added to the UNR solution velocities from 12 other studies. The velocities are transformed onto the UNR solution's reference frame by estimating and applying a translation and rotation that minimizes

  3. Skill of western North Pacific tropical cyclone intensity forecast guidance relative to Weighted-Analog technique

    Science.gov (United States)

    Tsai, Hsiao-Chung; Elsberry, Russell L.

    2016-06-01

    The accuracy of the western North Pacific tropical cyclone intensity forecast guidance products available at the Joint Typhoon Warning Center (JTWC) is evaluated relative to a new skill metric called Weighted Analog Intensity Pacific (WAIP) that includes knowledge of the JTWC official track forecast and the current intensity, which is information that is available at the time the intensity forecast is generated. An intensity consensus technique called S5XX that includes statistical-dynamic intensity forecasts plus other dynamic and thermodynamic prediction techniques has statistically significant smaller errors than WAIP at 24 h and 48 h and has similar accuracy through 120 h. While the track consensus CONW is a critical input to the JTWC official track forecast, it has no skill relative to WAIP as an intensity forecast. Three regional numerical models also have no skill relative to WAIP, and especially at forecast intervals beyond 72 h because their mean absolute errors are statistically significantly larger than for WAIP. Furthermore, these regional models have statistically significant positive or negative intensity biases relative to the verifying intensities. However, an experimental consensus technique called CMES that includes these three regional models has small accuracy relative to WAIP in the 24 h to 72 h forecast intervals. Geographical-based comparisons of the intensity guidance products with the WAIP indicate almost all of the products are more accurate than WAIP over the South China Sea region. The statistical-dynamic consensus technique S5XX does have skill through 72 h for landfalling situations along the coasts of China and Southeast Asia. At 120 h, the WAIP has superior performance over the guidance products over most areas of the western North Pacific, but again the S5XX is more accurate than WAIP for landfalling tropical cyclones on the Philippine Islands, Southeast Asia, South China, and northeastern Japan. This information will be useful to

  4. Distribution, source and chemical speciation of phosphorus in surface sediments of the central Pacific Ocean

    Science.gov (United States)

    Ni, Jianyu; Lin, Peng; Zhen, Yang; Yao, Xuying; Guo, Laodong

    2015-11-01

    The abundance of five forms of phosphorus (P) in surface sediments from the central Pacific Ocean (4.5-15ºN, 154-143ºW) was determined using a sequential extraction procedure (SEDEX) to examine the distribution and source of different P species. Total P (TP) concentrations ranged from 13.2 to 119 μmol-P/g with an average of 48.6±27.4 μmol-P/g. Within the TP pool, total inorganic P (TIP) concentrations varied from 11.1 to 121 μmol-P/g, while total organic P (TOP) concentrations ranged from undetectable to 4.8 μmol-P/g. Inorganic P was generally the predominant form in surface sediments, comprising on average up to 93% of sedimentary TP, leaving <16% as TOP. Among the five P species, the authigenic or CaCO3-bound P and detrital P were the two major P species (comprising on average 43.4±13.5% and 45.7±14.8% of TP, respectively), followed by the refractory organic P, representing 6.7±2.4% of TP. Fe-bound P accounted for 3.3±1.3% of TP, and exchangeable or adsorbed P made up less than 1% of TP. The spatial distribution of different sedimentary P species showed that higher concentrations of detrital P and Fe-bound P were both found at around 11°N, suggesting similar sources for these two P species. Much of the detrital P was derived from atmospheric sources in the study area, where heavy rainfall in the intertropical convergence zone between 3°N and 11°N has been widely reported. Compared with other marine environments, the central Pacific Ocean had relatively higher detrital P, but lower abundance of adsorbed-P and Fe-bound P. These unquine results suggested that most of the labile P could have been released into the water column during its settling from the surface to the seafloor, or that atmospheric inputs of refractory P were an important source for sedimentary P, accounting for an average of 63% of the TP, in the central Pacific Ocean. High proportions of authigenic P in deep-sea sediments, on the other hand, implied that oceanic sediments are an

  5. Two new species of the bee genus Peponapis, with a key to the North and Central American species (Hymenoptera: Apidae: Eucerini) Dos especies nuevas de abejas del género Peponapis, con una clave para las especies de América del Norte y Central (Hymenoptera: Apidae: Eucerini)

    OpenAIRE

    Ricardo Ayala; Terry Griswold

    2012-01-01

    Two new species of squash bees, Peponapis pacifica Ayala and Griswold sp. n. and P. parkeri Griswold and Ayala sp. n., are described and illustrated. Peponapis pacifica is oligolectic on flowers of Schizocarpum longisepalum (Cucurbitaceae) endemic to Mexico, where it is found in the tropical dry forest along the Pacific Coast, between Sonora and Chiapas and in the Balsas River basin; and P. parkeri is known only from the Pacific slope of Costa Rica. A key for the North and Central American sp...

  6. Climate variation and prediction of rapid intensification in tropical cyclones in the western North Pacific

    Science.gov (United States)

    Wang, B.; Zhou, X.

    2008-02-01

    One of the greatest challenges in tropical weather forecasting is the rapid intensification (RI) of the tropical cyclone (TC), during which its one-minute maximum sustained wind speed increases at least 30 knots per 24 hours. Here we identify and elucidate the climatic conditions that are critical to the frequency and location of the RI on annual, intraseasonal, and interannual time scales. Whereas RI and formation share common environmental preferences, we found that the percentage of TCs with RI varies annually and from year to year. In August, only 30% of TC actually experiences RI, in contrast to the annual maximum of 47% in November. The proportion of RI in July September is higher during El Niño years (53%) than the corresponding one in the La Niña years (37%). Three climate factors may contribute to the increase in the proportion of RI: the southward shift in the monthly or seasonal mean location of the TC formation, the increase in the low-level westerly meridional shear vorticity, and the decrease in northerly vertical shear. When the mean latitude of TC formation increases, the mixed-layer heat content decreases while TC’s inertial stability increases; both are more detrimental to the RI than to TC formation because the RI requires large amount of latent heat energy being extracted efficiently from the ocean mixed layer and requires accelerated low-level radial inflow that carries latent heat reaching the inner core region. We further demonstrate that the RI frequency in the Philippine Sea and South China Sea can be predicted 10 to 30 days in advance based on the convective anomalies in the equatorial western Pacific (5° S 5° N, 130° 150° E) on intraseasonal time scale. The Niño 3.4 SSTA in June is a potential predictor for the peak TC season (July September) RI activity in the southeast quadrant of the western North Pacific (0 20° N, 140 180° E). The RI is an essential characteristic of category 4 and 5 hurricanes and super typhoons because

  7. Stable isotope signatures of seasonal precipitation on the Pacific coast of central Panama.

    Science.gov (United States)

    Kern, Zoltán; Harmon, Russell S; Fórizs, István

    2016-01-01

    As calculated from data archived in the IAEA-WMO Global Network of Isotopes in Precipitation programme, the amount-weighted local meteoric water line for the Pacific coast of central Panama is: δ(2)H = 7.63(±0.08) × δ(18)O + 6.51(±0.49). Amount-weighted mean isotopic values were regressed against the sea surface temperature (SST) fields of the adjacent tropical oceans. A negative correlation of precipitation isotope composition with Caribbean SSTs is observed only for the early wet season (May-June), whilst the mid-summer dry period is characterized by positive correlation with eastern Pacific SSTs, similar to the late wet season (October-November). The negative response of May-June rainfall isotopic composition to Caribbean SSTs is explained by a SST-mediated change in stratiform rain fraction from organized convective systems proximal to the Inter Tropical Convergence Zone (ITCZ). The positive correlation for the rest of the wet season, when the organized convective zone of ITCZ and its attached stratiform belt are distant from the Pacific coast of Panama, is interpreted as simple evaporative temperature effect on isotopic fractionation. PMID:25761056

  8. Assimilation of Satellite Altimetry into a Western North Pacific Operational Model

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An ocean data assimilation system, COMPASS-K (the Comprehensive Ocean Modeling, Prediction, Analysis and Synthesis System in the Kuroshio-region), has been developed at the Meteorological Research Institute (MRI). The purposes of the development are understanding ocean variability in the Kuroshio re gion as a local response to a global climate change with assimilated four-dimensional data sets, develop ment of an operational system in the Japan Meteorological Agency, and for the GODAE (Global Ocean Data Assimilation Experiment) project. The model is an eddy permitting version of an MRI-OGCM. Space-time decorrelation scales of ocean variability are estimated with TOPEX/POSEIDON (T/P) altimeter data. Subsurface temperature and salinity fields are projected from the T / P altimeter data with a statistical correlation method and are assim ilated into the model with a time-retrospective nudging scheme. Seasonal variation in the western North Pacific is investigated. Realistic space-time distribution of the physical quantities, the path of Kuroshio and its separation from Honshu are captured well. The Kuroshio volume transport is well reproduced in a reanalysis experiment of 1993. Preliminary predictability experi ments are done in February and March, 1994. Predictability diagram shows the time scale of the predictability for temperature field is about 17 days in the Kuroshio south of Japan. This time scale is smal ler than that in the North Atlantic.

  9. Maximum wind radius estimated by the 50 kt radius: improvement of storm surge forecasting over the western North Pacific

    Science.gov (United States)

    Takagi, Hiroshi; Wu, Wenjie

    2016-03-01

    Even though the maximum wind radius (Rmax) is an important parameter in determining the intensity and size of tropical cyclones, it has been overlooked in previous storm surge studies. This study reviews the existing estimation methods for Rmax based on central pressure or maximum wind speed. These over- or underestimate Rmax because of substantial variations in the data, although an average radius can be estimated with moderate accuracy. As an alternative, we propose an Rmax estimation method based on the radius of the 50 kt wind (R50). Data obtained by a meteorological station network in the Japanese archipelago during the passage of strong typhoons, together with the JMA typhoon best track data for 1990-2013, enabled us to derive the following simple equation, Rmax = 0.23 R50. Application to a recent strong typhoon, the 2015 Typhoon Goni, confirms that the equation provides a good estimation of Rmax, particularly when the central pressure became considerably low. Although this new method substantially improves the estimation of Rmax compared to the existing models, estimation errors are unavoidable because of fundamental uncertainties regarding the typhoon's structure or insufficient number of available typhoon data. In fact, a numerical simulation for the 2013 Typhoon Haiyan as well as 2015 Typhoon Goni demonstrates a substantial difference in the storm surge height for different Rmax. Therefore, the variability of Rmax should be taken into account in storm surge simulations (e.g., Rmax = 0.15 R50-0.35 R50), independently of the model used, to minimize the risk of over- or underestimating storm surges. The proposed method is expected to increase the predictability of major storm surges and to contribute to disaster risk management, particularly in the western North Pacific, including countries such as Japan, China, Taiwan, the Philippines, and Vietnam.

  10. Convergent evolution of ecomorphological adaptations in geographically isolated Bay gobies (Teleostei: Gobionellidae) of the temperate North Pacific.

    Science.gov (United States)

    Ellingson, Ryan A; Swift, Camm C; Findley, Lloyd T; Jacobs, David K

    2014-01-01

    North Pacific Bay gobies (Teleostei: Gobioidei: Gobionellidae) inhabit bays, beaches, coastal lagoons, and estuaries of temperate Asia and North America, but are absent from the boreal northernmost Pacific. Previously, morphological characters conventionally subdivided the clade into two groups - an elongate-bodied, infaunal-inhabiting "Astrabe" group, and a deeper-bodied, non-infaunal "Chasmichthys" group - each with a disjunct East-West (amphi-) Pacific distribution. Here we use mitochondrial and multi-locus nuclear DNA sequence data to show that several morphological characters previously used to delimit these two groups have in fact arisen independently on both sides of the Pacific, revealing convergence of ecologically adaptive characters within a geographically divided clade. Basal divergence of the resultant tree coincides with a dramatic global cooling event at the Eocene/Oligocene transition, without evidence of subsequent trans-Pacific migration. A novel approach to partitioning sequence data by relative rate, as opposed to traditional gene/codon position partitioning, was used to help distinguish phylogenetic signal from noise on a per-site basis. Resulting improvements in topology and nodal support, along with decreased computational effort, suggest that this partitioning strategy may be useful for future studies in phylogenetics and phylogenomics. PMID:24148989

  11. Persistent millennial-scale climate variability in the eastern tropical North Pacific over the last two glacial cycles

    Science.gov (United States)

    Arellano-Torres, Elsa; Ganeshram, Raja S.; Pichevin, Laetitia E.; Salas-de-Leon, David Alberto

    2015-06-01

    High-resolution sediment records from the eastern tropical North Pacific (ETNP) spanning the last ~240 ka B.P. were studied to document the nature of millennial-scale climatic events in the tropical Pacific and to investigate teleconnection mechanisms. We present organic carbon (%OC) and diffuse spectral reflectivity records as indicative of upwelling and productivity changes off NW Mexico over the middle to late Pleistocene. The new productivity records document the persistence of abrupt millennial-scale changes over the last two glacial cycles. Detailed spectral and wavelet time series analyses show the predominance of longer climatic cycles (2-6 ka) during the last and the penultimate glacial periods. The persistence of millennial variability during the penultimate glacial, in absence of large ice rafted debris events in the North Atlantic, suggests that freshwater input through ice sheet dynamics is not essential for millennial-scale climate variability. Given the worldwide emerging picture of remarkable similar millennial-scale records over long time periods, we suggest that the pacing of this climate variability may represent a natural resonance in the climate system, amplified by a tightly coupled oceanic and atmospheric teleconnection processes. We present a schematic scenario of millennial-scale climate change depicting the role of the tropical Pacific in this global teleconnection system by linking productivity and upwelling changes in the ETNP with shifts in the position of the Intertropical Convergence Zone and the strength of the subtropical North Pacific High.

  12. Active Pacific North America Plate boundary tectonics as evidenced by seismicity in the oceanic lithosphere offshore Baja California, Mexico

    Science.gov (United States)

    Hauksson, Egill; Kanamori, Hiroo; Stock, Joann; Cormier, Marie-Helene; Legg, Mark

    2014-03-01

    Pacific Ocean crust west of southwest North America was formed by Cenozoic seafloor spreading between the large Pacific Plate and smaller microplates. The eastern limit of this seafloor, the continent-ocean boundary, is the fossil trench along which the microplates subducted and were mostly destroyed in Miocene time. The Pacific-North America Plate boundary motion today is concentrated on continental fault systems well to the east, and this region of oceanic crust is generally thought to be within the rigid Pacific Plate. Yet, the 2012 December 14 Mw 6.3 earthquake that occurred about 275 km west of Ensenada, Baja California, Mexico, is evidence for continued tectonism in this oceanic part of the Pacific Plate. The preferred main shock centroid depth of 20 km was located close to the bottom of the seismogenic thickness of the young oceanic lithosphere. The focal mechanism, derived from both teleseismic P-wave inversion and W-phase analysis of the main shock waveforms, and the 12 aftershocks of M ˜3-4 are consistent with normal faulting on northeast striking nodal planes, which align with surface mapped extensional tectonic trends such as volcanic features in the region. Previous Global Positioning System (GPS) measurements on offshore islands in the California Continental Borderland had detected some distributed Pacific and North America relative plate motion strain that could extend into the epicentral region. The release of this lithospheric strain along existing zones of weakness is a more likely cause of this seismicity than current thermal contraction of the oceanic lithosphere or volcanism. The main shock caused weak to moderate ground shaking in the coastal zones of southern California, USA, and Baja California, Mexico, but the tsunami was negligible.

  13. Neogene north American-Caribbean plate boundary across Northern Central America: Offset along the polochic fault

    Science.gov (United States)

    Burkart, Burke

    1983-12-01

    The Polochic fault was a segment of the North American-Caribbean plate boundary across Central America in the Neogene. Its 130 km of left slip was previously determined by matching structures and stratigraphie outcrop patterns of northwest and central Guatemala across the fault. Additional support for the model and the youthfulness of the recorded offset comes from an essentially perfect match of major geomorphic features across the fault. A reconstruction process which eliminates 123 km of left slip brings together rivers and drainage divides that existed before the Polochic became active. With the reconstruction carried across the isthmus on an east-west fault the regional structural geology assumes the coherent pattern of a continuous orogenic belt whose geometry is compatible with the model of collisional tectonics centered on the Motagua "suture zone". Confined within this belt, narrowed to some 60 km by the reconstruction, lie the major Laramide thrusts, folds and tectonically emplaced serpentinites of Guatemala. Crystalline rocks of Guatemala re-join the Chiapas Massif and Paleozoic sedimentary rocks, exposed in the core of an almost-continuous anticlinorium, extend from southern Chiapas to Lake Izabal. The Polochic does not bend in eastern Guatemala but continues eastward to the Motagua fault where it dies. Westward drift of the northern block resulted in rifting which extended from eastern Guatemala into the Caribbean along the Cayman trough. The Honduras depression may represent an element of a triple junction along with the Polochic and Izabal-Cayman rift. The Polochic continues westward into the Pacific Ocean and offsets the Middle America trench. The Polochic has offset the Miocene volcanic belt of northern Central America, confirming the previous estimate of a Neogene time of movement. About 300 km of relative east-west Neogene displacement has been recorded on the Mid-Cayman rise, only 130 km of which can be accounted for across the Polochic. It is

  14. Assessment of tsunami hazards for the Central American Pacific coast from southern Mexico to northern Peru

    Science.gov (United States)

    Brizuela, B.; Armigliato, A.; Tinti, S.

    2014-07-01

    Central America (CA), from Guatemala to Panama, has been struck by at least 52 tsunamis between 1539 and 2013, and in the extended region from Mexico to northern Peru (denoted as ECA, Extended Central America in this paper) the number of recorded tsunamis in the same time span is more than 100, most of which were triggered by earthquakes located in the Middle American Trench that runs parallel to the Pacific coast. The most severe event in the catalogue is the tsunami that occurred on 2 September 1992 off Nicaragua, with run-up measured in the range of 5-10 m in several places along the Nicaraguan coast. The aim of this paper is to assess the tsunami hazard on the Pacific coast of this extended region, and to this purpose a hybrid probabilistic-deterministic analysis is performed, that is adequate for tsunamis generated by earthquakes. More specifically, the probabilistic approach is used to compute the Gutenberg-Richter coefficients of the main seismic tsunamigenic zones of the area and to estimate the annual rate of occurrence of tsunamigenic earthquakes and their corresponding return period. The output of the probabilistic part of the method is taken as input by the deterministic part, which is applied to calculate the tsunami run-up distribution along the coast.

  15. Shark tooth weapons from the 19th Century reflect shifting baselines in Central Pacific predator assemblies.

    Directory of Open Access Journals (Sweden)

    Joshua Drew

    Full Text Available The reefs surrounding the Gilbert Islands (Republic of Kiribati, Central Pacific, like many throughout the world, have undergone a period of rapid and intensive environmental perturbation over the past 100 years. A byproduct of this perturbation has been a reduction of the number of shark species present in their waters, even though sharks play an important in the economy and culture of the Gilbertese. Here we examine how shark communities changed over time periods that predate the written record in order to understand the magnitude of ecosystem changes in the Central Pacific. Using a novel data source, the shark tooth weapons of the Gilbertese Islanders housed in natural history museums, we show that two species of shark, the Spot-tail (Carcharhinus sorrah and the Dusky (C. obscurus, were present in the islands during the last half of the 19(th century but not reported in any historical literature or contemporary ichthyological surveys of the region. Given the importance of these species to the ecology of the Gilbert Island reefs and to the culture of the Gilbertese people, documenting these shifts in baseline fauna represents an important step toward restoring the vivid splendor of both ecological and cultural diversity.

  16. Shark tooth weapons from the 19th Century reflect shifting baselines in Central Pacific predator assemblies.

    Science.gov (United States)

    Drew, Joshua; Philipp, Christopher; Westneat, Mark W

    2013-01-01

    The reefs surrounding the Gilbert Islands (Republic of Kiribati, Central Pacific), like many throughout the world, have undergone a period of rapid and intensive environmental perturbation over the past 100 years. A byproduct of this perturbation has been a reduction of the number of shark species present in their waters, even though sharks play an important in the economy and culture of the Gilbertese. Here we examine how shark communities changed over time periods that predate the written record in order to understand the magnitude of ecosystem changes in the Central Pacific. Using a novel data source, the shark tooth weapons of the Gilbertese Islanders housed in natural history museums, we show that two species of shark, the Spot-tail (Carcharhinus sorrah) and the Dusky (C. obscurus), were present in the islands during the last half of the 19(th) century but not reported in any historical literature or contemporary ichthyological surveys of the region. Given the importance of these species to the ecology of the Gilbert Island reefs and to the culture of the Gilbertese people, documenting these shifts in baseline fauna represents an important step toward restoring the vivid splendor of both ecological and cultural diversity. PMID:23573214

  17. Scarlet Macaw, Ara macao, (Psittaciformes: Psittacidae) diet in Central Pacific Costa Rica.

    Science.gov (United States)

    Vaughan, Christopher; Nemeth, Nicole; Marineros, Leonel

    2006-09-01

    From 1993 to 1997, we observed Scarlet Macaw (Ara macao) feeding behavior in Central Pacific Costa Rica. Feeding data acquired in this study were not collected systematically, but opportunistically whenever macaws were observed feeding. To supplement feeding observations, we conducted interviews with local residents. Scarlet Macaws fed on seeds, fruits, leaves, flowers and/or bark of 43 plant species. Various plant parts eaten by macaws from several tree species contain secondary compounds toxic to humans, and additional species included in their diet are nonnative, introduced for agricultural purposes. Important macaw feeding tree species are Ceiba pentandra, Schizolobium parahybum, and Hura crepitans; these species are also crucial to this macaw population because of nest cavities they provide. The results of this study contribute to the conservation of Scarlet Macaws in Central Pacific Costa Rica through promoting protection of individual trees, and through local elementary school reforestation programs focusing on tree species that macaws use for feeding and/or nesting. Scarlet Macaw conservation is extremely important, as numerous population pressures have caused significant declines in macaw numbers in Costa Rica. PMID:18491633

  18. 240Pu/239Pu atom ratios in seawater from the western North Pacific and its marginal sea

    International Nuclear Information System (INIS)

    Full text: The atom ratio of 240Pu/239Pu is known to be a useful tracer to identify the sources of plutonium in the ocean. The objectives of this study are to measure the 239+240Pu activities and 240Pu/239Pu atom ratios in seawater from the western North Pacific and its marginal sea and to discuss the transport processes of plutonium. The 240Pu/239Pu atom ratios were measured with sector-field ICPMS. The atom ratios were significantly higher than the mean global fallout ratio. These high atom ratios proved the existence of close-in fallout plutonium originating from the Pacific proving grounds. (author)

  19. Pressure, temperature, and salinity collected by CTDs from ships in the North Pacific and South Pacific Oceans from 6/30/1999 to 12/14/1999 (NODC Accession 0000003)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and pressure data were collected using CTD casts in the North/South Pacific Ocean from NOAA Ship RONALD H. BROWN AND NOAA Ship KA'IMIMOANA from...

  20. Physical and underway data collected aboard the ROGER REVELLE during cruise RR0914 in the North Pacific Ocean, Philippine Sea and South Pacific Ocean from 2009-11-05 to 2009-11-14 (NODC Accession 0089672)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089672 includes physical and underway data collected aboard the ROGER REVELLE during cruise RR0914 in the North Pacific Ocean, Philippine Sea and...

  1. Chemical, optical and other data collected aboard the MELVILLE during cruise MV1014 in the North Pacific Ocean and South Pacific Ocean from 2010-10-19 to 2010-11-14 (NODC Accession 0089659)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0089659 includes chemical, optical, physical and underway data collected aboard the MELVILLE during cruise MV1014 in the North Pacific Ocean and...

  2. Physical and underway data collected aboard the Marcus G. Langseth during cruise MGL1208 in the North Pacific Ocean and South Pacific Ocean from 2012-04-30 to 2012-05-26 (NODC Accession 0104335)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC accession 0104335 includes physical and underway data collected aboard the Marcus G. Langseth during cruise MGL1208 in the North Pacific Ocean and South...

  3. Physical, profile and underway data collected aboard the ROGER REVELLE during cruise RR1214 in the North Pacific Ocean and South Pacific Ocean from 2012-11-05 to 2012-11-16 (NCEI Accession 0129852)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0129852 includes physical, profile and underway data collected aboard the ROGER REVELLE during cruise RR1214 in the North Pacific Ocean and South...

  4. Physical, profile and underway data collected aboard the ROGER REVELLE during cruise RR1213 in the North Pacific Ocean and South Pacific Ocean from 2012-10-04 to 2012-11-05 (NCEI Accession 0129851)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0129851 includes physical, profile and underway data collected aboard the ROGER REVELLE during cruise RR1213 in the North Pacific Ocean and South...

  5. Mercury sources, distribution, and bioavailability in the North Pacific Ocean: Insights from data and models

    Science.gov (United States)

    Sunderland, E.M.; Krabbenhoft, D.P.; Moreau, J.W.; Strode, S.A.; Landing, W.M.

    2009-01-01

    Fish harvested from the Pacific Ocean are a major contributor to human methylmercury (MeHg) exposure. Limited oceanic mercury (Hg) data, particularly MeHg, has confounded our understanding of linkages between sources, methylation sites, and concentrations in marine food webs. Here we present methylated (MeHg and dimethylmercury (Me2Hg)) and total Hg concentrations from 16 hydrographie stations in the eastern North Pacific Ocean. We use these data in combination with information from previous cruises and coupled atmospheric-oceanic modeling results to better understand controls on Hg concentrations, distribution, and bioavailability. Total Hg concentrations (average 1.14 ?? 0.38 pM) are elevated relative to previous cruises. Modeling results agree with observed increases and suggest that at present atmospheric Hg deposition rates, basin-wide Hg concentrations will double relative to circa 1995 by 2050. Methylated Hg accounts for up to 29% of the total Hg in subsurface waters (average 260 ??114 fM). We observed lower ambient methylated Hg concentrations in the euphotic zone and older, deeper water masses, which likely result from decay of MeHg and Me2Hg when net production is not occurring. We found a significant, positive linear relationship between methylated Hg concentrations and rates of organic carbon remineralization (r2 = 0.66, p < 0.001). These results provide evidence for the importance of particulate organic carbon (POC) transport and remineralization on the production and distribution of methylated Hg species in marine waters. Specifically, settling POC provides a source of inorganic Hg(II) to microbially active subsurface waters and can also provide a substrate for microbial activity facilitating water column methylation. Copyright 2009 by the American Geophysical Union.

  6. Variability of tropical cyclone in high frequent occurrence regions over the western North Pacific

    Science.gov (United States)

    Yang, Yuxing; Huang, Fei; Wang, Faming

    2014-06-01

    In this study, three high frequent occurrence regions of tropical cyclones (TCs), i.e., the northern South China Sea (the region S), the south Philippine Sea (the region P) and the region east of Taiwan Island (the region E), are defined with frequency of TC's occurrence at each grid for a 45-year period (1965-2009), where the frequency of occurrence (FO) of TCs is triple the mean value of the whole western North Pacific. Over the region S, there are decreasing trends in the FO of TCs, the number of TCs' tracks going though this region and the number of TCs' genesis in this region. Over the region P, the FO and tracks demonstrate decadal variation with periods of 10-12 year, while over the region E, a significant 4-5 years' oscillation appears in both FO and tracks. It is demonstrated that the differences of TCs' variation in these three different regions are mainly caused by the variation of the Western Pacific Subtropical High (WPSH) at different time scales. The westward shift of WPSH is responsible for the northwesterly anomaly over the region S which inhibits westward TC movement into the region S. On the decadal timescale, the WPSH stretches northwestward because of the anomalous anticyclone over the northwestern part of the region P, and steers more TCs reaching the region P in the greater FO years of the region P. The retreating of the WPSH on the interannual time scale is the main reason for the FO's oscillation over the region E.

  7. Proterozoic-Cambrian detrital zircon and monazite ages from the Anakie lnlier, central Queensland: Grenville and Pacific-Gondwana signatures

    International Nuclear Information System (INIS)

    The Anakie Metamorphic Group is a complexly deformed, dominantly metasedimentary succession in central Queensland. Metamorphic cooling is constrained to ca 500 Ma by previously published K-Ar ages. Detrital-zircon SHRIMP U-Pb ages from three samples of greenschist facies quartz-rich psammites (Bathampton Metamorphics), west of Clermont, are predominantly in the age range 1300-1000Ma (65-75%). They show that a Grenville-aged orogenic belt must have existed in northeastern Australia, which is consistent with the discovery of a potential Grenville source farther north. The youngest detrital zircons in these samples are ca 580 Ma, indicating that deposition may have been as old as latest Neoproterozoic. Two samples have been analysed from amphibolite facies pelitic schist from the western part of the inlier (Wynyard Metamorphics). One sample contains detrital monazite with two age components of ca 580-570 Ma and ca 540 Ma. The other sample only has detrital zircons with the youngest component between 510Ma and 700Ma (Pacific-Gondwana component), which is consistent with a Middle Cambrian age for these rocks. These zircons were probably derived from igneous activity associated with rifting events along the Gondwanan passive margin. These constraints confirm correlation of the Anakie Metamorphic Group with latest Neoproterozoic - Cambrian units in the Adelaide Fold Belt of South Australia and the Wonominta Block of western New South Wales. Copyright (2001) Geological Society of Australia

  8. Possible influence of western North Pacific monsoon on TC activity in mid-latitudes of East Asia

    Science.gov (United States)

    Choi, Ki-Seon; Cha, Yumi; Kim, Hae-Dong; Kang, Sung-Dae

    2016-01-01

    This study analyzed the correlation between tropical cyclone (TC) frequency and the Western North Pacific monsoon index (WNPMI), which have both been influential in East Asia's mid-latitude regions during the summer season over the past 37 years (1977-2013). A high positive correlation existed between these two variables, which was not reduced even if El Niño-Southern Oscillation (ENSO) years were excluded. To determine the cause of this positive correlation, the highest (positive WNPMI phase) and lowest WNPMIs (negative WNPMI phase) during a nine-year period were selected to analyze the mean difference between them, excluding ENSO years. In the positive WNPMI phase, TCs were mainly generated in the eastern seas of the tropical and subtropical western North Pacific, passing through the East China Sea and moving northward toward Korea and Japan. In the negative phase, TCs were mainly generated in the western seas of the tropical and subtropical western North Pacific, passing through the South China Sea and moving westward toward China's southern regions. Therefore, TC intensity in the positive phase was stronger due to the acquisition of sufficient energy from the sea while moving a long distance up to East Asia's mid-latitude. Additionally, TCs occurred more in the positive phase. Regarding the difference of the two phases between the 850 and 500-hPa streamlines, anomalous cyclones were strengthened in the tropical and subtropical western North Pacific, whereas anomalous anticyclones were strengthened in East Asia's mid-latitude regions. Due to these two anomalous pressure systems, anomalous southeasterlies developed in East Asia's mid-latitude regions, which played a role in the anomalous steering flows that moved TCs into these regions. Furthermore, due to the anomalous cyclones that developed in the tropical and subtropical western North Pacific, more TCs could be generated in the positive phase. Both the lower and upper tropospheric layers had warm anomalies

  9. Influence of hydrography of Central Mexican Pacific in the spatial variation of inorganic nutrients during 2010

    Science.gov (United States)

    Olivos-Ortiz, A.; Gaviño-Rodríguez, J. H.; Quijano-Scheggia, S.; Pelayo-Martinez, G.; Torres-Orozco, E.; Calva-Chavez, M.

    2014-12-01

    The Mexican Central Pacific (MCP) is considered an oligotrophic area that holds important populations of different species with ecological and economic importance like marine mammals, billfish and tunas. Hydrographic mechanisms are responsible to interplay with the biogeochemical cycles of nutrients to support primary productivity for these food webs. It is argued that seasonal upwelling of bottom waters rich in nutrients generates distributed in patches of high-productivity, which are also linked to topographic continental forcing. The goal of this study is determine the presence of water masses, depth of the mixed layer, temperature, salinity, patterns of geostrophic currents and their influence on the spatiotemporal variability of inorganic nutrients. For that pupose, three oceanographic cruises were conducted in January, May-June, and October of 2010 off the coast of the MCP. Each campaign consisted of 15 stations in five perpendicular transects with stations at 2, 50 and 100 nm offshore. At each station samples were taken to determine the concentration of NO3-+ NO2-, NH4+, PO43- and SiO2 at 0, 10, 25, 50, 75, 100, 150 and 200 m depth. CTD casts were made up to 500m to obtain profiles of salinity, temperature, water masses, and identify geostrophic currents (direction and intensity). Identified water masses were: Pacific Tropical Surface Water (PTSW), Pacific Equatorial Surface Water (PESW), Equatorial Pacific Water (EPW), California Current Water (CCW), Subtropical Subsurface Water (STSsW), and Pacific Intermediate Water (PIT); these water masses were present in all three seasons being more clear the presence of CCW during autumn and PTSW in winter. The interaction between coastal topography, geostrophic circulation, and the depth of the mixed layer (55m oceanic part in January and 10m coastal area in October) were the factors that determined the location of areas of high concentration of nutrients. The distribution of nutrients was heterogeneous

  10. February 27, 2010 Chilean Tsunami in Pacific and its Arrival to North East Asia

    Science.gov (United States)

    Zaytsev, Andrey; Pelinovsky, EfiM.; Yalciner, Ahmet C.; Ozer, Ceren; Chernov, Anton; Kostenko, Irina; Shevchenko, Georgy

    2010-05-01

    The outskirts of the fault plane broken by the strong earthquake on February 27, 2010 in Chili with a magnitude 8.8 at the 35km depth of 35.909°S, 72.733°W coordinates generated a moderate size tsunami. The initial amplitude of the tsunami source is not so high because of the major area of the plane was at land. The tsunami waves propagated far distances in South and North directions to East Asia and Wet America coasts. The waves are also recorded by several gauges in Pacific during its propagation and arrival to coastal areas. The recorded and observed amplitudes of tsunami waves are important for the potential effects with the threatening amplitudes. The event also showed that a moderate size tsunami can be effective even if it propagates far distances in any ocean or a marginal sea. The far east coasts of Russia at North East Asia (Sakhalin, Kuriles, Kamchatka) are one of the important source (i.e. November 15, 2006, Kuril Island Tsunami) and target (i.e. February, 27, 2010 Chilean tsunami) areas of the Pacific tsunamis. Many efforts have been spent for establishment of the monitoring system and assessment of tsunamis and development of the mitigation strategies against tsunamis and other hazards in the region. Development of the computer technologies provided the advances in data collection, transfer, and processing. Furthermore it also contributed new developments in computational tools and made the computer modeling to be an efficient tool in tsunami warning systems. In this study the tsunami numerical model NAMI DANCE Nested version is used. NAMI-DANCE solves Nonlinear form of Long Wave (Shallow water) equations (with or without dispersion) using finite difference model in nested grid domains from the source to target areas in multiprocessor hardware environment. It is applied to 2010 Chilean tsunami and its propagation and coastal behavior at far distances near Sakhalin, Kuril and Kamchatka coasts. The main tide gauge records used in this study are from

  11. Anthropogenic warming has decreased water supply in North Central Texas

    Science.gov (United States)

    Brikowski, T. H.

    2015-12-01

    North Central Texas, including Dallas-Ft. Worth, the 4th largest metropolitan area in the U.S., has been in a state of drought for most of this 21st Century. Seven million residents there depend almost exclusively on surface water resources, and net water storage declined precipitously until record rainfall in early 2015. Part of the decline in water availability can be attributed to reduced runoff, where despite slightly above normal precipitation, natural basin runoff has declined almost 20% since its peak in the mid-1990's. These changes have coincided with 0.85oC warming above the historical 20th Century mean. Prevalent Vertisol (cracking) soils in the region make runoff especially sensitive to climate variations, and make it difficult to apply traditional hydrologic models to investigate climate-runoff links. Non-parametric (empirical) runoff elasticity methods circumvent these limitations, and are applied here, focusing on the Upper Trinity River basin (UTB). Diagrammatic assessment of UTB temperature-precipitation (T-Pr) runoff elasticity indicates persistent warming greatly increases the risk of reduced runoff, based on historical experience. Evaluation of individual parameter elasticity indicates dry periods since 2000 have primarily been T-driven, in contrast to the Pr-driven 1951-6 drought of record. Observed decline in runoff during 2000-2010 is entirely attributable to increased T. Additional runoff declines from 2011-14 were driven by reduced Pr, augmenting the T-driven reductions. These T effects are most prominent to the west, and decline to minimal extent just east of the UTB. The observed warming can be related to anthropogenic CO2 increase with >95% certainty based on comparison of CMIP5 climate model results for the UTB with and without CO2 forcing. UTB runoff fraction of Pr decreased after 1980 with >97.5% certainty. These results strongly indicate that 21st Century 20% decline in runoff from previous century norms is largely attributable to

  12. Seasonal variation of the upper ocean responding to surface heating in the North Pacific

    Science.gov (United States)

    Lee, Eunjeong; Noh, Yign; Qiu, Bo; Yeh, Sang-Wook

    2015-08-01

    Seasonal variations of the upper ocean, such as mixed layer depth (MLD) and sea surface temperature (SST), responding to the atmospheric forcing in the North Pacific (10°N-50°N), are investigated by analyzing the Argo and NCEP/NCAR reanalysis 1 data. The OAFlux data are also used for comparison. During the early heating period in the high-latitude ocean north of 30°N, where a seasonal thermocline is formed above the deep mixed layer under strong surface heating, the MLD h is found to be scaled as h∝>(Lλ>)1/2, where L is the Monin-Obukhov length scale and λ is the Ekman length scale. On the other hand, in the low-latitude ocean south of 30°N, where the preexisting MLD is shallow and surface heating is weak, h is found to be scaled by λ. It is found that a large amount of heat flux across the MLD occurs, especially in the high-latitude ocean during the late heating period, in which h is small. It suggests the contribution by turbulent mixing across the MLD in addition to radiation penetration, and the eddy diffusivity in the high-latitude ocean is estimated as Kv ˜ 10-4-10-3 m2 s-1. The heat budget of the mixed layer reveals that the contribution from the ocean heat transport is much smaller than the surface heat flux in the high-latitude ocean except in the Kuroshio region, but it is sometimes comparable in the low-latitude ocean.

  13. 226Ra evidence for the ecosystem shift over the past 40 years in the North Pacific Subtropical Gyre

    Institute of Scientific and Technical Information of China (English)

    YANG JunHong; CHEN Min; QIU YuSheng; LI YanPing; MA Qiang; L(U) E; ZHANG Run; HUANG YiPu

    2007-01-01

    Surface seawater was collected for 226Ra measurement in the North Pacific Subtropical Gyre from July to October, 1999 and October to December, 2003. Combined with the historical data reported for this sea area, a declined trend of surface 226Ra concentrations was observed since 1960s, indicating the ecosystem shift in response to global warming. On one side, the enhanced stratification of the upper water column resulting from global warming reduced the 226Ra input from the depth, on the other, the temporal increase of biological production resulting from the climate-related ecosystem structure change strengthened the 226Ra removal from the surface ocean. Both the physical and biological processes resulted in the decrease of surface 226Ra concentrations in the North Pacific Subtropical Gyre. The temporal trend of surface 226Ra concentrations was consistent with the trends of chlorophyll a, silicate, phosphate and primary production previously reported. This study provided 226Ra evidence for the ecosystem shift under global change.

  14. Nineteenth-century Ship-based Catches of Gray Whales, Eschrichtius robustus, in the Eastern North Pacific

    OpenAIRE

    Reeves, Randall R.; Smith, Tim D.; Lund, Judith N.; Lebo, Susan A.; Josephson , Elizabeth A.

    2010-01-01

    The 19th century commercial ship-based fishery for gray whales, Eschrichtius robustus, in the eastern North Pacific began in 1846 and continued until the mid 1870’s in southern areas and the 1880’s in the north. Henderson identified three periods in the southern part of the fishery: Initial, 1846–1854; Bonanza, 1855–1865; and Declining, 1866–1874. The largest catches were made by “lagoon whaling” in or immediately outside the whale population’s main wintering areas in Mexico—Magdalena Bay, Sc...

  15. Distribution and air-sea exchange of organochlorine pesticides in the North Pacific and the Arctic

    Science.gov (United States)

    Cai, Minghong; Ma, Yuxin; Xie, Zhiyong; Zhong, Guangcai; MöLler, Axel; Yang, Haizhen; Sturm, Renate; He, Jianfeng; Ebinghaus, Ralf; Meng, Xiang-Zhou

    2012-03-01

    Surface seawater and boundary layer air samples were collected on the icebreaker Xuelong (Snow Dragon) during the Fourth Chinese Arctic Research Expedition (CHINARE2010) cruise in the North Pacific and Arctic Oceans during 2010. Samples were analyzed for organochlorine pesticides (OCPs), including three isomers of hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), and two isomers of heptachlor epoxide. The gaseous total HCH (ΣHCHs) concentrations were approximately four times lower (average 12.0 pg m-3) than those measured during CHINARE2008 (average 51.4 pg m-3), but were comparable to those measured during CHINARE2003 (average 13.4 pg m-3) in the same study area. These changes are consistent with the evident retreat of sea ice coverage from 2003 to 2008 and increase of sea ice coverage from 2008 to 2009 and 2010. Gaseous β-HCH concentrations in the atmosphere were typically below the method detection limit, consistent with the expectation that ocean currents provide the main transport pathway for β-HCH into the Arctic. The concentrations of all dissolved HCH isomers in seawater increase with increasing latitude, and levels of dissolved HCB also increase (from 5.7 to 7.1 pg L-1) at high latitudes (above 73°N). These results illustrate the role of cold condensation processes in the transport of OCPs. The observed air-sea gas exchange gradients in the Arctic Ocean mainly favored net deposition of OCPs, with the exception of those for β-HCH, which favored volatilization.

  16. Behavior of 137Cs concentrations in the North Pacific in an ocean general circulation model

    Science.gov (United States)

    Tsumune, Daisuke; Aoyama, Michio; Hirose, Katsumi

    2003-08-01

    We have carried out a first simulation of the spatial distributions and the temporal variations of 137Cs concentrations in the North Pacific in off line calculations by using archived output of an ocean general circulation model (OGCM) developed by the National Center of Atmospheric Research (NCAR). Artificial radionuclides including 137Cs are introduced into ocean surface due to global fallout originating from the large-scale atmospheric nuclear weapons tests in 1961-1962. The distribution of radioactive deposition used as forcing for this simulation is estimated from global precipitation data and observed values of annual deposition of radionuclides at the Meteorological Research Institute (MRI) in Japan. 137Cs originating from global fallout have been transported into the ocean interior by advection and diffusion, and the 137Cs concentrations reduced by radioactive decay. We assess the skill of the model calculations by comparing simulated values of 137Cs in seawater with the observed values included in the database compiled by MRI because 137Cs is one of the most useful tracers regarding water motion in the ocean. The vertical and horizontal distributions of the calculated 137Cs concentrations were in good agreement with those of the observed 137Cs concentrations, except in the deep layer.

  17. Occurrence and diversity of mesophilic Shewanella strains isolated from the North-West Pacific Ocean.

    Science.gov (United States)

    Ivanova, Elena P; Sawabe, Tomoo; Zhukova, Natalia V; Gorshkova, Nataliya M; Nedashkovskaya, Olga I; Hayashi, Karin; Frolova, Galina M; Sergeev, Alexander F; Pavel, Konstantin G; Mikhailov, Valery V; Nicolau, Dan V

    2003-06-01

    Although bacteria of the genus Shewanella belong to one of the readily cultivable groups of "Gammaproteobacteria", little is known about the occurrence and abundance of these microorganisms in the marine ecosystem. Studies revealed that of 654 isolates obtained from marine invertebrates (ophiuroid Amphiopholis kochii, sipuncula Phascolosoma japonicum, and holothurian Apostichopus japonicus, Cucumaria japonica), seawater and sediments of the North-West Pacific Ocean (i.e. the Sea of Japan and Iturup Is, Kurile Islands), 10.7% belonged to the genus Shewanella. The proportion of viable Shewanella species varied from 4% to 20% depending on the source of isolation. From the isolation study, representative strains of different phenotypes (from seventy presumptive Shewanella strains) were selected for detailed characterization using phenotypic, chemotaxonomic, and phylogenetic testing. 16S rDNA sequence-based phylogenetic analysis confirmed the results of tentative identification and placed the majority of these strains within only a few species of the genus Shewanella with 98-99% of 16S rDNA sequences identity mainly with S. japonica and S. colwelliana, suggesting that the strains studied might belong to these species. Numerically dominant strains of S. japonica were metabolically active and produced proteinases (gelatinases, caseinases), lipases, amylases, agarases, and alginases. Shewanella strains studied demonstrated weak antimicrobial and antifungal activities that might be an indication of their passive role in the colonization on living and non-living surfaces. PMID:12866857

  18. Photic zone changes in the north-west Pacific Ocean from MIS 4–5e

    Directory of Open Access Journals (Sweden)

    G. E. A. Swann

    2015-01-01

    Full Text Available In comparison to other sectors of the marine system, the palaeoceanography of the subarctic North Pacific Ocean is poorly constrained. New diatom isotope records of δ13C, δ18O, δ30Si (δ13Cdiatom, δ18Odiatom, and δ30Sidiatom are presented alongside existing geochemical and isotope records to document changes in photic zone conditions, including nutrient supply and the efficiency of the soft-tissue biological pump, between Marine Isotope Stage (MIS 4 and MIS 5e. Peaks in opal productivity in MIS 5b/c and MIS 5e are both associated with the breakdown of the regional halocline stratification and increased nutrient supply to the photic zone. Whereas the MIS 5e peak is associated with low rates of nutrient utilisation, the MIS 5b/c peak is associated with significantly higher rates of nutrient utilisation. Both peaks, together with other smaller increases in productivity in MIS 4 and 5a, culminate with a significant increase in freshwater input which strengthens/re-establishes the halocline and limits further upwelling of sub-surface waters to the photic zone. Whilst δ30Sidiatom and previously published records of diatom δ15N (δ15Ndiatom (Brunelle et al., 2007, 2010 show similar trends until the latter half of MIS 5a, the records become anti-correlated after this juncture and into MIS 4, suggesting a possible change in photic zone state such as may occur with a shift to iron or silicon limitation.

  19. Ecogenomic sensor reveals controls on N2-fixing microorganisms in the North Pacific Ocean.

    Science.gov (United States)

    Robidart, Julie C; Church, Matthew J; Ryan, John P; Ascani, François; Wilson, Samuel T; Bombar, Deniz; Marin, Roman; Richards, Kelvin J; Karl, David M; Scholin, Christopher A; Zehr, Jonathan P

    2014-06-01

    Nitrogen-fixing microorganisms (diazotrophs) are keystone species that reduce atmospheric dinitrogen (N2) gas to fixed nitrogen (N), thereby accounting for much of N-based new production annually in the oligotrophic North Pacific. However, current approaches to study N2 fixation provide relatively limited spatiotemporal sampling resolution; hence, little is known about the ecological controls on these microorganisms or the scales over which they change. In the present study, we used a drifting robotic gene sensor to obtain high-resolution data on the distributions and abundances of N2-fixing populations over small spatiotemporal scales. The resulting measurements demonstrate that concentrations of N2 fixers can be highly variable, changing in abundance by nearly three orders of magnitude in less than 2 days and 30 km. Concurrent shipboard measurements and long-term time-series sampling uncovered a striking and previously unrecognized correlation between phosphate, which is undergoing long-term change in the region, and N2-fixing cyanobacterial abundances. These results underscore the value of high-resolution sampling and its applications for modeling the effects of global change. PMID:24477197

  20. Study of thunderstorm activity connection with weather system structures over the North-Western Pacific Ocean

    Science.gov (United States)

    Permyakov, M. S.; Cherneva, N. V.; Shevtsov, B. M.; Potalova, E. Yu.; Holzworth, Robert

    2014-11-01

    Applying the data of VLF direction finder receiving station of IKIR FEB RAS, included into the World Wide Lightning Location Network (WWLLN), the paper investigates the relations of field characteristics of recorded lightning discharges in the north-western part of the Pacific ocean with field characteristics of weather formation meteorological elements, evaluated according to the data of Earth remote sounding from satellites. On the example of separate tropical cyclones (TC) for 2012-2013, the relation of lightning discharge frequency and density with spatial distribution of driving wind whirl is shown. TC structure evolution is traced in cloudiness fields, driving wind whirl, and lightning discharge distribution. This publication is based on work supported by a grant from the U.S. Civilian Research and Development Foundation (RUG1-7084-PA-13) with funding from the United States Department of State. The opinions, findings and conclusions stated herein are those of the authors and do not necessarily reflect those of CRDF Global or the United States Department of State.

  1. Sequential megafaunal collapse in the North Pacific Ocean: An ongoing legacy of industrial whaling?

    Science.gov (United States)

    Springer, A.M.; Estes, J.A.; Van Vliet, G. B.; Williams, T.M.; Doak, D.F.; Danner, E.M.; Forney, K.A.; Pfister, B.

    2003-01-01

    Populations of seals, sea lions, and sea otters have sequentially collapsed over large areas of the northern North Pacific Ocean and southern Bering Sea during the last several decades. A bottom-up nutritional limitation mechanism induced by physical oceanographic change or competition with fisheries was long thought to be largely responsible for these declines. The current weight of evidence is more consistent with top-down forcing. Increased predation by killer whales probably drove the sea otter collapse and may have been responsible for the earlier pinniped declines as well. We propose that decimation of the great whales by post-World War II industrial whaling caused the great whales' foremost natural predators, killer whales, to begin feeding more intensively on the smaller marine mammals, thus "fishing-down" this element of the marine food web. The timing of these events, information on the abundance, diet, and foraging behavior of both predators and prey, and feasibility analyses based on demographic and energetic modeling are all consistent with this hypothesis.

  2. Radiative forcing due to dust aerosol over east Asia-north Pacific region during spring,2001

    Institute of Scientific and Technical Information of China (English)

    WANG Hong; SHI Guangyu; Aoki Teruo; WANG Biao; ZHAO Tianliang

    2004-01-01

    An optical model accounting for the East Asian dust is proposed as a result of theory calculation and composition analysis of the aerosol samples collected in China desert during the international project, "Studies on the Origin and Transport of Aeolian Dust and its Effects on Climate (ADEC)". Study indicates that dust aerosols emitting from China deserts have smaller imaginary parts of refractive indices, therefore absorb less and scatter more solar radiation than the most dust optical models published so far. Furthermore, the forward fraction of scattering is less and the backscattering is stronger than those of the other models. The seasonal averaged radiative forcing in spring, 2001 over east Asia-north Pacific region is simulated employing the new dust optical model. The net forcing at the top of atmosphere (TOA) is estimated as -0.943 W·m-2 for regional and seasonal mean, with shortwave and longwave contributions of -1.700 and 0.759 W·m-2, respectively. The surface net forcing is calculated to be -5.445 W·m-2, and made up of shortwave component of -6.250 W·m-2 and longwave component of +0.759 W·m-2. The distributions of TOA and surface net forcing over this region are also analyzed in this study.

  3. Fast and Slow Responses of the North Pacific Mode Water and Subtropical Countercurrent to Global Warming

    Institute of Scientific and Technical Information of China (English)

    XU Lixiao; XIE Shang-Ping; LIU Qinyu

    2013-01-01

    Six coupled general circulation models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) are employed for examining the full evolution of the North Pacific mode water and Subtropical Countercurrent (STCC) under global warming over 400 years following the Representative Concentration Pathways (RCP) 4.5.The mode water and STCC first show a sharp weakening trend when the radiative forcing increases,but then reverse to a slow strengthening trend of smaller magnitude after the radiative forcing is stablized.As the radiative forcing increases during the 21 st century,the ocean warming is surface-intensified and decreases with depth,strengthening the upper ocean's stratification and becoming unfavorable for the mode water formation.Moving southward in the subtropical gyre,the shrinking mode water decelerates the STCC to the south.After the radiative forcing is stabilized in the 2070s,the subsequent warming is greater at the subsurface than at the sea surface,destabilizing the upper ocean and becoming favorable for the mode water formation.As a result,the mode water and STCC recover gradually after the radiative forcing is stabilized.

  4. Age and growth of albacore Thunnus alalunga in the North Pacific Ocean.

    Science.gov (United States)

    Chen, K-S; Shimose, T; Tanabe, T; Chen, C-Y; Hsu, C-C

    2012-05-01

    The age and growth of North Pacific albacore Thunnus alalunga were investigated using obliquely sectioned sagittal otoliths from samples of 126 females and 148 males. Otolith edge analysis indicated that the identified annulus in a sagittal otolith is primarily formed during the period from September to February. The assessments of the fish age at first annulus formation indicated that the first annulus represents an age of <1 year. This study presents an age estimate (0·75 years) for the formation of the first annulus. The oldest fish ages observed in this study were 10 years for females and 14 years for males. The von Bertalanffy growth parameters of females estimated were L(∞) = 103·5 cm in fork length (L(F) ), K = 0·340 year(-1) and t(0) = -0·53 years, and the parameters of males were L(∞) = 114·0 cm, K = 0·253 year(-1) and t(0) = -1·01 years. Sexual size dimorphism between males and females seemed to occur after reaching sexual maturity. The coefficients of the power function for expressing the L(F) -mass relationship obtained from sex-pooled data were a = 2·964 × 10(-5) and b = 2·928. PMID:22551185

  5. Decadal change of Tropical Cyclone Activity over western North Pacific around late-1990s

    Science.gov (United States)

    He, H.; Yang, J.; Mao, R.; Wang, Y.; Gong, D.

    2014-12-01

    A pronounced decadal change of tropical cyclone (TC) activity was identified over western North Pacific (WNP) around late-1990s. After late-1990s, the WNP total TC genesis number exhibited an evident decrease, particularly over southern WNP region (S-WNP: 5oN-20oN), which was mainly caused by reduced vorticity and descending anomalies. We also detected a significant northward migration of TC genesis from 17.2°N to 18.7°N. The above TC genesis change is attributed to the weakening of monsoon trough and local Hadley cell that is associated with sea surface temperature climate shift around the late-1990s. In terms of three prevailing TC tracks changes, the northwestward-moving track (II) became the most dominant prevailing track mode while the westward-moving track (I) became weaker, and the northeastward-recurving track (III) had a westward shift. The track shifts primarily resulted from the large-scale steering flows change, which also had played a vital role in the modulation of TC regional duration. Thus, the subtropical East Asia tended to have a higher risk of encountering TC while the Southern China had a lower risk. Additionally, a visual reduction was seen in both number and proportion of typhoons reaching categories 1 and 2, and a remarkable poleward migration was also recognized in the average latitudes where TCs have achieved their lifetime-maximum intensity.

  6. Simulations of tropical cyclogenesis associated with different monsoon trough patterns over the western North Pacific

    Science.gov (United States)

    Cao, Xi; Chen, Guanghua; Li, Tim; Ren, Fumin

    2016-01-01

    The numerical simulations of tropical cyclone (TC) genesis during the strong and weak monsoon trough (MT) years, in which meteorological fields are composited, are conducted using advanced research weather research and forecasting model. The simulation results show that both tropical disturbances tend to form in the east of the western North Pacific (WNP) near 160°-170°E during the strong and weak MT years. During the strong MT years, there is a faster formation rate of TC. The eastward-extending MT gradually evolves into a closed monsoon gyre over the WNP during the early stage. The following rapid development of TC can be attributed to the enhanced lower-level southwesterly flows induced by the cross-equatorial currents, enhanced easterly winds, and weak vertical wind shear, which provide a favorable environment for TC genesis. The strengthened large-scale circulation spawns abundant convective updrafts resulting in the aggregation of cyclonic vorticity. In contrast, during the weak MT years, the westward-retreated MT gradually evolves into expansive easterly winds over the WNP. Two episodes of convective updrafts are triggered with a longer interval, and thus lead to a slower TC genesis compared with that during the strong MT years.

  7. Climatological features of WRF-simulated tropical cyclones over the western North Pacific

    Science.gov (United States)

    Kim, Dasol; Jin, Chun-Sil; Ho, Chang-Hoi; Kim, Jinwon; Kim, Joo-Hong

    2014-11-01

    Tropical cyclones (TCs) over the western North Pacific (WNP) are simulated for the 29 TC seasons of July-October from 1982 to 2010 using the regional Weather Research and Forecasting (WRF) model nested within global WRF model simulations. Averaged over the entire 29-year period, the nested global-regional WRF has reasonably simulated the climatology of key TC features such as the location/frequency of genesis and tracks. The dynamical and thermal structures of the simulated TCs are weaker than observations owing to the coarse spatial resolution of the regional WRF (50 km × 50 km). TC frequencies are somewhat underestimated over the East China Sea but are substantially overestimated over the South China Sea and the Philippine Sea with neighboring oceans between 10°N and 15°N. Categorization of the simulated TCs into six clusters based on the observed TC clusters and the associated large-scale circulation show that the nested simulation depicts the observed TC characteristics well except for two clusters associated with TCs traveling from the Philippine Sea to the East China Sea. Errors in the simulated TC genesis and tracks are mostly related to these two clusters. In the simulation, the monsoon confluent zone over the Philippine Sea is too strong, and the mid-latitude jet stream expands farther south than that in the observations. Overall results from this study suggest that the nested global-regional WRF can be useful for studying the TC climatology over the WNP.

  8. Effect of horizontal grid resolution on simulations of the subtropical mode water in the North Pacific

    Science.gov (United States)

    Lee, Ho Jin; Yeop Kim, Sang; Lee, Kyung Eun

    2016-04-01

    We investigate how the Subtopical Mode Water (STMW) can be simulated differently in the North Pacific using a global Ocean General Circulation Model (OGCM) with non-eddying and eddy permitting resolution. The OGCM used in this study is the MOM version 4.1 and has a total of 50 levels along the vertical direction with enhanced resolution near the surface. The CORE version 2 (normal year forcing) data derived from the air-sea flux climatology averaged over 60 years (1948‑2007) are used to calculate heat, salt and momentum fluxes with a bulk formula at the sea surface. The sea surface salinity is restored to the climatological monthly mean surface salinity of the Polar Science Center Hydrographic Climatology on a 60-day timescale, to make up the fresh water flux at the sea surface. Two models that have horizontal resolutions of 1° and 1/4 °, respectively, are integrated during 50 years. The inter-annual variation of the STMW volume was well reproduced with the eddy-permitting grid resolution although the model was forced by a climatological atmospheric forcing. The annual formation and erosion volume of STMW varies by 7% and 9% of the mean volume, respectively.

  9. Gooseneck barnacles (Lepas spp. ingest microplastic debris in the North Pacific Subtropical Gyre

    Directory of Open Access Journals (Sweden)

    Miriam C. Goldstein

    2013-10-01

    Full Text Available Substantial quantities of small plastic particles, termed “microplastic,” have been found in many areas of the world ocean, and have accumulated in particularly high densities on the surface of the subtropical gyres. While plastic debris has been documented on the surface of the North Pacific Subtropical Gyre (NPSG since the early 1970s, the ecological implications remain poorly understood. Organisms associated with floating objects, termed the “rafting assemblage,” are an important component of the NPSG ecosystem. These objects are often dominated by abundant and fast-growing gooseneck barnacles (Lepas spp., which predate on plankton and larval fishes at the sea surface. To assess the potential effects of microplastic on the rafting community, we examined the gastrointestinal tracts of 385 barnacles collected from the NPSG for evidence of plastic ingestion. We found that 33.5% of the barnacles had plastic particles present in their gastrointestinal tract, ranging from one plastic particle to a maximum of 30 particles. Particle ingestion was positively correlated to capitulum length, and no blockage of the stomach or intestines was observed. The majority of ingested plastic was polyethylene, with polypropylene and polystyrene also present. Our results suggest that barnacle ingestion of microplastic is relatively common, with unknown trophic impacts on the rafting community and the NPSG ecosystem.

  10. Seasonal variations in planktonic foraminiferal flux and oxygen isotopic composition in the western North Pacific : Implications for paleoceanographic reconstruction

    OpenAIRE

    Sagawa, Takuya; Kuroyanagi, Azumi; Irino, Tomohisa; Kuwae, Michinobu; Kawahata, Hodaka

    2013-01-01

    The oxygen isotopic composition (delta O-18) of planktonic foraminiferal shells in seafloor sediment provides information on past surface oceanography. Knowledge of seasonal and depth habitat, as well as the delta O-18 disequilibrium (vital effect), is essential to constrain the interpretation of sedimentary delta O-18. Here, we present a 1-year time series of planktonic foraminiferal shell fluxes and delta(18)Ofrom a sediment trap moored in the northwestern margin of the North Pacific. The v...

  11. Whales, dolphins, and porpoises of the eastern North Pacific and adjacent Arctic waters: a guide to their identification

    OpenAIRE

    Leatherwood, Stephen; Randall R Reeves; Perrin, William F; William E Evans; Hobbs, Larry

    1982-01-01

    This is an identification guide for cetaceans (whales, dolphins, and porpoises), that was designed to assist laymen in identifying cetaceans encountered in eastern North Pacific and Arctic waters. It was intended for use by ongoing cetacean observer programs. This is a revision of an earlier guide with the same title published in 1972 by the Naval Undersa Center and the National Marine Fisheries Service. It includes sections on identifying cetaceans at sea as well as stranded animals on sh...

  12. Assessing water resources adaptive capacity to climate change impacts in the Pacific Northwest Region of North America

    OpenAIRE

    Hamlet, A F

    2010-01-01

    Climate change impacts in Pacific Northwest Region of North America (PNW) are projected to include increasing temperatures and changes in the seasonality of precipitation (increasing precipitation in winter, decreasing precipitation in summer). Changes in precipitation are also spatially varying, with the northwestern parts of the region generally experiencing greater increases in cool season precipitation than the southeastern parts. These changes in climate are projected to cause loss of sn...

  13. Assessing water resources adaptive capacity to climate change impacts in the Pacific Northwest Region of North America

    OpenAIRE

    Hamlet, A F

    2011-01-01

    Climate change impacts in Pacific Northwest Region of North America (PNW) are projected to include increasing temperatures and changes in the seasonality of precipitation (increasing precipitation in winter, decreasing precipitation in summer). Changes in precipitation are also spatially varying, with the northwestern parts of the region generally experiencing greater increases in cool season precipitation than the southeastern parts. These changes in climate are projected to cause loss of sn...

  14. Evaluating the opposing-wave interaction hypothesis for the generation of microbaroms in the eastern North Pacific

    Science.gov (United States)

    Walker, K. T.

    2012-12-01

    Two microphone arrays were deployed in California during 2010 to record microbaroms, quasi-continuous atmospheric pressure oscillations with a period of ~5 s. Here I present a time-progressive, frequency-domain beamforming method and analyze microbaroms recorded from November 2010 through December 2011 by these and ten other infrasonic arrays along the North Pacific rim. Common pelagic microbarom sources that move around the north Pacific are observed during the boreal winter. Summertime microbarom sources are only observed by western Pacific arrays, presumably a result of weaker microbarom radiation and westward stratospheric winds. A well-defined source is resolved ~2000 km off the coast of California in January 2011 that moves closer to land over several days. This source location is corrected for deflection by horizontal winds using acoustic ray-trace modeling with range-dependent atmospheric specifications provided by ground-to-space (G2S) models. The source locations do not correlate with anomalies in NOAA Wave Watch 3 (NWW3) model field data. However, I apply the opposing-wave, microbarom source model of Waxler and Gilbert (2006) to the NWW3 directional wave height spectra output at buoy locations within ~1000 km of the western North America coastline and show that the spatial locations of the predicted microbarom source correlate well with the location of the observed microbaroms ~500 km off the coast. These results suggest that pelagic North Pacific microbarom radiation detected by infrasonic arrays during the boreal winter could be routinely used to validate NWW3 results in regions with poor sensor coverage.

  15. Changes in Tropical Cyclone Number in the Western North Pacific in a Warming Environment as Implied by Classical Thermodynamics

    OpenAIRE

    Xiaogang Zhou; Chongjian Liu; Ying Liu; Hui Xu; Xiuming Wang

    2011-01-01

    Observational analyses show that the equatorial trough in the western North Pacific (WNP) is a well-known origin for tropical cyclones (TC) which have tended to weaken in intensity and decrease in number during the last several decades under global warming. A scientific problem then arises as to why higher sea surface temperatures (SSTs), one of the necessary conditions for typhoon genesis, can cause a weakened equatorial trough and a decreased TC number. In this paper, the WNP is taken as an...

  16. Observations of heterogeneous reactions between Asian pollution and mineral dust over the Eastern North Pacific during INTEX-B

    OpenAIRE

    C. S. McNaughton; A. D. Clarke; V. Kapustin; Shinozuka, Y.; S. G. Howell; Anderson, B. E.; E. Winstead; Dibb, J.; E. Scheuer; Cohen, R. C.; Wooldridge, P.; Perring, A.; L. G. Huey; Kim, S.; Jimenez, J. L.

    2009-01-01

    In-situ airborne measurements of trace gases, aerosol size distributions, chemistry and optical properties were conducted over Mexico and the Eastern North Pacific during MILAGRO and INTEX-B. Heterogeneous reactions between secondary aerosol precursor gases and mineral dust lead to sequestration of sulfur, nitrogen and chlorine in the supermicrometer particulate size range.

    Simultaneous measurements of aerosol size distributions and weak-acid soluble calcium result in an ...

  17. Shallow-water zoantharians (Cnidaria, Hexacorallia from the Central Indo-Pacific

    Directory of Open Access Journals (Sweden)

    James Reimer

    2014-10-01

    Full Text Available Despite the Central Indo-Pacific (CIP and the Indonesian Archipelago being a well-known region of coral reef biodiversity, particularly in the ‘Coral Triangle’, little published information is available on its zoantharians (Cnidaria: Hexacorallia: Zoantharia. In order to provide a basis for future research on the Indo-Pacific zoantharian fauna and facilitate comparisons between more well-studied regions such as Japan and the Great Barrier Reef, this report deals with CIP zoantharian specimens in the Naturalis collection in Leiden, the Netherlands; 106 specimens were placed into 24 morpho-species and were supplemented with 88 in situ photographic records from Indonesia, the Philippines, and Papua New Guinea. At least nine morpho-species are likely to be undescribed species, indicating that the region needs more research in order to properly understand zoantharian diversity within the CIP. The Naturalis’ zoantharian specimens are listed by species, as well as all relevant collection information, and in situ images are provided to aid in future studies on zoantharians in the CIP.

  18. Current direction, temperature, and conductivity data from moored current meter casts in the North Pacific Ocean from 29 April 1981 - 02 December 1981 (NODC Accession 8300030)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current direction, temperature, and conductivity data were collected using moored current meter casts in the North Pacific Ocean from April 29, 1981 to December 2,...

  19. Salinity and sigma-t data from moored current meter and CTD casts in the North Pacific Ocean from 26 August 1979 - 07 June 1982 (NODC Accession 8200146)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Salinity and sigma-t data were collected using moored current meter and CTD casts in the North Pacific Ocean from August 26, 1979 to June 7, 1982. Data were...

  20. Physical and underway data collected aboard the NEW HORIZON during cruise NH1313 in the North Pacific Ocean on 2013-06-04 (NCEI Accession 0132108)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0132108 includes physical and underway data collected aboard the NEW HORIZON during cruise NH1313 in the North Pacific Ocean on 2013-06-04. These...

  1. Carbon dioxide, temperature, salinity, and atmospheric pressure from surface underway survey in the North Pacific from January 1998 to January 2004 (NODC Accession 0045502)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sea surface pCO2, sea surface temperature, sea surface salinity, and atmospheric pressure measurements collected in the North Pacific as part of the NOAA Office of...

  2. Current meter and temperature profile data from current meter and buoy casts in the North Pacific Ocean from 01 October 1997 to 31 August 1998 (NODC Accession 9800144)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter and temperature profile data were collected using current meter and buoy casts in the North Pacific Ocean from 01 October 1997 to 31 August 1998. Data...

  3. Physical and underway data collected aboard the NEW HORIZON during cruise NH1302 in the North Pacific Ocean on 2013-03-05 (NCEI Accession 0132103)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0132103 includes physical and underway data collected aboard the NEW HORIZON during cruise NH1302 in the North Pacific Ocean on 2013-03-05. These...

  4. Chemical and temperature profile data from CTD casts in the East China Sea, Sea of Japan, and North Pacific Ocean (NODC Accession 9700022)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Chemical and temperature profile data were collected from CTD casts in the East China Sea, Sea of Japan, and North Pacific Ocean. Data were submitted by the Japan...

  5. Plankton data collected using net casts from the FRANCISCO DE ULLOA in the North Pacific Ocean from 15 July 1998 to 30 July 1998 (NODC Accession 0000911)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Plankton data were collected using net casts in the North Pacific Ocean from FRANCISCO DE ULLOA. Data were collected from 15 July 1998 to 30 July 1998. Data were...

  6. Zooplankton data collected using net casts from the FRANCISCO DE ULLOA in the North Pacific Ocean from 01 January 1999 to 31 January 1999 (NODC Accession 0000912)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Zooplankton data were collected using net casts in the North Pacific Ocean from FRANCISCO DE ULLOA. Data were collected from 01 January 1999 to 31 January 1999....

  7. Physical and underway data collected aboard the NEW HORIZON during cruise NH1502 in the North Pacific Ocean on 2015-02-18 (NCEI Accession 0145830)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0145830 includes physical and underway data collected aboard the NEW HORIZON during cruise NH1502 in the North Pacific Ocean on 2015-02-18. These...

  8. Physical, nutrients, and other data from CTD and bottle casts from the North Pacific Ocean from 19 February 1991 to 31 December 2000 (NODC Accession 0000472)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical, nutrients, and other data were collected from CTD and bottle casts from the North Pacific Ocean from 19 February 1991 to 31 December 2000. Parameters...

  9. Temperature, salinity, and oxygen profiles from bottle casts from the North Pacific Ocean from 29 September 1987 to 22 November 1987 (NODC Accession 0000433)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bottle and other data were collected from the North Pacific Ocean from 29 September 1987 to 22 November 1987. Data were collected by the Ukrainian Scientific Centre...

  10. NOAA marine environmental buoy data from the National Data Buoy Center in the Gulf of Alaska, Gulf of Mexico, Bering Sea, North Atlantic Ocean, North Pacific Ocean, Coastal Waters of SE Alaska, Coastal Waters of Western U.S., Great Lakes, North American Coastline-North, and North American Coastline-South from 2002-10-01 to 2002-10-31 (NODC Accession 0000400)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pressure, temperature, and other data were collected from fixed platforms in the Gulf of Alaska, Gulf of Mexico, Bering Sea, North Atlantic Ocean, North Pacific...

  11. An Assessment of Multi-model Simulations on the Variability of Western North Pacific Tropical Cyclones and Its Association with ENSO

    Science.gov (United States)

    Han, Rongqing; Wang, Hui; Hu, Zeng-Zhen; Kumar, Arun; Li, Weijing; Long, Lindsey N.; Schemm, Jae-Kyung E.; Peng, Peitao; Wang, Wanqiu; Si, Dong; Jia, Xiaolong; Zhao, Ming; Vecchi, Gabriel A.; Larow, Timothy E.; Lim, Young-Kwon; Schubert, Siegfried D.; Camargo, Suzana J.; Henderson, Naomi; Jonas, Jeffrey A.; Walsh, Kevin J. E.

    2016-04-01

    An assessment on the simulations of interannual variability of tropical cyclones (TCs) over the western North Pacific (WNP) and association with El Niño-Southern Oscillation (ENSO), as well as a subsequent diagnosis for possible causes of the model biases generated from simulating the large scale climate conditions, are documented in the paper. The model experiments are carried out by the Hurricane Work Group under the U.S. Climate Variability and Predictability Research Program (CLIVAR) using five global climate models (GCMs) with a total of 16 ensemble members forced by the observed sea surface temperature, and spanning 28-yr period from 1982 to 2009. The results show GISS and GFDL model ensemble means best simulate the interannual variability of TCs and the multi-model ensemble mean (MME) follows. Also, the MME has the closest climate mean annual number of WNP TCs and the smallest root-mean-square error to the observation. Most GCMs can simulate the interannual variability of WNP TCs well, with stronger TC activities during two types of El Niño, namely eastern Pacific (EP) and central Pacific (CP) El Niño, and weaker activity during La Niña. However, none of models captures the differences in TC activity between EP and CP El Niño as shown in observations, which may be due to the bias of the circulations in models in response to the westward shift of tropical heating associated with CP El Niño. In addition, a general unrealistic scene exists in model simulations with the underestimated intensities of the convection anomaly over the maritime continent in the western tropical Pacific during each ENSO phase of whatever warm or cold, which may be the important source of biases in simulating WNP TC associated with the ENSO events.

  12. Response of Mode Water and Subtropical Countercurrent to Greenhouse Gas and Aerosol Forcing in the North Pacific

    Institute of Scientific and Technical Information of China (English)

    WANG Liyi; LIU Qinyu; XU Lixiao; XIE Shang-Ping

    2013-01-01

    The response of the North Pacific Subtropical Mode Water and Subtropical Countercurrent (STCC) to changes in greenhouse gas (GHG) and aerosol is investigated based on the 20th-century historical and single-forcing simulations with the Geophysical Fluid Dynamics Laboratory Climate Model version 3 (GFDL CM3).The aerosol effect causes sea surface temperature (SST)to decrease in the mid-latitude North Pacific,especially in the Kuroshio Extension region,during the past five decades (1950-2005),and this cooling effect exceeds the warming effect by the GHG increase.The STCC response to the GHG and aerosol forcing are opposite.In the GHG (aerosol) forcing run,the STCC decelerates (accelerates) due to the decreased (increased) mode waters in the North Pacific,resulting from a weaker (stronger) front in the mixed layer depth and decreased (increased) subduction in the mode water formation region.The aerosol effect on the SST,mode waters and STCC more than offsets the GHG effect.The response of SST in a zonal band around 40°N and the STCC to the combined forcing in the historical simulation is similar to the response to the aerosol forcing.

  13. Relationship of regional PM2.5 variations in east Asia and climate variability in the North Pacific

    Science.gov (United States)

    So, J.; Yeh, S. W.; Kim, M.; Park, R.

    2014-12-01

    Recent studies have suggested that the Short Lived Climate Pollutants (SLCPs) such as Sulfate aerosols, Black carbon, Seasalt play a role to influence the weather and climate variability by changing radiative forcings. Therefore, it is useful to examine the relationship between atmospheric variability and SLCPs. Particularly, the concentration of Particle Matter 2.5 (PM2.5) is significant in east Asia, which is mostly due to a rapid industrialization. It is known that both the atmospheric circulation and cloud variability is closely associated with the variations of PM2.5 in east Asia are associated with major atmospheric variables for 1986-2010 using the GEOS-Chem model and the observational datasets. The composite analysis reveals that the high and low concentration year of PM2.5 in east Asia is differently associated with the spatial pattern of atmospheric anomalies over the North Pacific. In addition, the changes in the PM2.5 concentration in east Asia may lead the changes in the amount of high and low cloud in the downstream region of the North Pacific. This indicates that the PM2.5 variations in east Asia may significantly influence the weather and climate variability in the North Pacific by modulating the cloud amount and atmospheric circulation, which is largely consistent with some previous studies.

  14. Pre-bomb marine reservoir ages in the western north Pacific: Preliminary result on Kyoto University collection

    International Nuclear Information System (INIS)

    The calibration of radiocarbon dates on marine materials involves a global marine calibration with regional corrections. The marine reservoir ages in the Western North Pacific have not been discussed, while it is quite important to determine the timing of palaeo-environmental changes as well as archaeological interpretation around this region. The lack of adequate collection of the pre-bomb shell from western north Pacific was the biggest problem. Recently we had a chance to examine specimens from an old shell collection stored in Kyoto University, including shell specimens from Japan, Korea, Taiwan and the Micronesia of 1920s and 1930s. We explored the possibility for usage of specimen without clear evidence of live collection by measuring 30 apparent radiocarbon ages of pre-bomb mollusk shells from 18 sites in Western North Pacific. The preliminary results showed several discrepancies with previously reported results and with each other. We have to carefully select the shell specimen that has biological signs such as articulating fulcrum. In order to exploit this big resource of pre-bomb shell collection, the new technique to distinguish fossils from live collected samples should be developed by using chemical and physical methods

  15. The annual cycle of gross primary production, net community production, and export efficiency across the North Pacific Ocean

    Science.gov (United States)

    Palevsky, Hilary I.; Quay, Paul D.; Lockwood, Deirdre E.; Nicholson, David P.

    2016-02-01

    We measured triple oxygen isotopes and oxygen/argon dissolved gas ratios as nonincubation-based geochemical tracers of gross oxygen production (GOP) and net community production (NCP) on 16 container ship transects across the North Pacific from 2008 to 2012. We estimate rates and efficiency of biological carbon export throughout the full annual cycle across the North Pacific basin (35°N-50°N, 142°E-125°W) by constructing mixed layer budgets that account for physical and biological influences on these tracers. During the productive season from spring to fall, GOP and NCP are highest in the Kuroshio region west of 170°E and decrease eastward across the basin. However, deep winter mixed layers (>200 m) west of 160°W ventilate ~40-90% of this seasonally exported carbon, while only ~10% of seasonally exported carbon east of 160°W is ventilated in winter where mixed layers are stations are consistent with our regional productivity rate estimates in the eastern but not western North Pacific. These results highlight the need to estimate productivity rates over broad spatial areas and throughout the full annual cycle including during winter ventilation in order to accurately estimate the rate and efficiency of carbon sequestration via the ocean's biological pump.

  16. A Statistical Model of Tropical Cyclone Tracks in the Western North Pacific with ENSO-Dependent Cyclogenesis

    Science.gov (United States)

    Yonekura, Emmi; Hall, Timothy M.

    2011-01-01

    A new statistical model for western North Pacific Ocean tropical cyclone genesis and tracks is developed and applied to estimate regionally resolved tropical cyclone landfall rates along the coasts of the Asian mainland, Japan, and the Philippines. The model is constructed on International Best Track Archive for Climate Stewardship (IBTrACS) 1945-2007 historical data for the western North Pacific. The model is evaluated in several ways, including comparing the stochastic spread in simulated landfall rates with historic landfall rates. Although certain biases have been detected, overall the model performs well on the diagnostic tests, for example, reproducing well the geographic distribution of landfall rates. Western North Pacific cyclogenesis is influenced by El Nino-Southern Oscillation (ENSO). This dependence is incorporated in the model s genesis component to project the ENSO-genesis dependence onto landfall rates. There is a pronounced shift southeastward in cyclogenesis and a small but significant reduction in basinwide annual counts with increasing ENSO index value. On almost all regions of coast, landfall rates are significantly higher in a negative ENSO state (La Nina).

  17. Molecular phylogeny of Babesia poelea from brown boobies (Sula leucogaster) from Johnston Atoll, Central Pacific

    Science.gov (United States)

    Yabsley, Michael J.; Work, Thierry M.; Rameyer, Robert A.

    2006-01-01

    The phylogenetic relationship of avian Babesia with other piroplasms remains unclear, mainly because of a lack of objective criteria such as molecular phylogenetics. In this study, our objective was to sequence the entire 18S, ITS-1, 5.8S, and ITS-2 regions of the rRNA gene and partial β-tubulin gene of B. poelea, first described from brown boobies (Sula leucogaster) from the central Pacific, and compare them to those of other piroplasms. Phylogenetic analyses of the entire 18S rRNA gene sequence revealed that B. poelea belonged to the clade of piroplasms previously detected in humans, domestic dogs, and wild ungulates in the western United States. The entire ITS-1, 5.8S, ITS-2, and partial β-tubulin gene sequence shared conserved regions with previously described Babesia and Theileria species. The intron of the β-tubulin gene was 45 bp. This is the first molecular characterization of an avian piroplasm.

  18. USGS research on geohazards of the North Pacific: past, present, and future

    Science.gov (United States)

    McNutt, M. K.; Eichelberger, J. C.

    2012-12-01

    The disastrous earthquakes and tsunamis of Sumatra in 2004 and Tohoku in 2011 have driven re-examination of where and how such events occur. Particular focus is on the North Pacific. Of the top 30 earthquakes recorded instrumentally worldwide, 50% occurred along the line of subduction from the Kuril Islands to the southern Alaska mainland. This region has seen monstrous volcanic eruptions (Katmai-Novarupta, 1912), destructive tsunamis (Severo-Kurilsk, 1952), and one of Earth's largest instrumentally-recorded earthquakes (M9.2 Alaska, 1964). Only the modest populations in these frontier towns half a century ago kept losses to a minimum. Impact of any natural disaster to population, vital infrastructure, and sea and air transportation would be magnified today. While USGS had a presence in Alaska for more than a century, the great Alaska earthquake of 1964 ushered in the first understanding of the area's risks. This was the first mega-thrust earthquake properly interpreted as such, and led to re-examination of the 1960 Chilean event. All modern conceptions of mega-thrust earthquakes and tsunamis derive some heritage from USGS research following the 1964 event. The discovery of oil in the Alaska Arctic prompted building a pipeline from the north slope of Alaska to the ice-free port of Valdez. The USGS identified risks from crossing permafrost and active faults. Accurate characterization of these hazards informed innovative designs that kept the pipeline from rupturing due to ground instability or during the M7.9 Denali earthquake of 2002. As a large state with few roads, air travel is common in Alaska. The frequent ash eruptions of volcanoes in the populous Cook Inlet basin became a serious issue, highlighted by the near-crash of a large passenger jet in 1989. In response, the USGS and its partners developed and deployed efficient seismic networks on remote volcanoes and initiated regular satellite surveillance for early warning of ash eruptions. Close collaboration

  19. Contribution of cephalopod prey to the diet of large pelagic fish predators in the central North Atlantic Ocean

    Science.gov (United States)

    Logan, John M.; Toppin, Rebecca; Smith, Sean; Galuardi, Benjamin; Porter, Julie; Lutcavage, Molly

    2013-10-01

    Trophic studies documenting the importance of cephalopod prey for large pelagic fish predators have been performed recently for open ocean ecosystems in the Pacific and Indian oceans, but similar data for the central North Atlantic Ocean have been lacking. A series of longline sampling cruises targeting large pelagic fish species was undertaken in the central North Atlantic Ocean in 2001-2002, and stomach samples were analyzed from a variety of tuna, shark, and billfish species to help fill this data gap. Stomach samples were collected from nine species (n=170 non-empty stomachs), with the majority of stomachs from Atlantic swordfish (Xiphias gladius; n=69), yellowfin tuna (Thunnus albacares; n=31), and albacore tuna (Thunnus alalunga; n=28). Ommastrephid squids were the most ubiquitous prey group across predator species and sampling years. Secondary cephalopod prey included octopods, histioteuthids, and architeuthids. Mesopelagic fishes and Sargassum-associated fishes were also identified as important prey. Diet composition varied spatially and prey size increased with predator size for swordfish and yellowfin tuna. Our results support findings in other ocean basins that demonstrate the importance of squid to large pelagic fishes and highlight the need for more research on their ecological and biophysical dynamics.

  20. Phylogeography of amphi-boreal fish: tracing the history of the Pacific herring Clupea pallasii in North-East European seas

    OpenAIRE

    Laakkonen, Hanna M; Lajus, Dmitry L.; Strelkov, Petr; Väinölä, Risto

    2013-01-01

    Background The relationships between North Atlantic and North Pacific faunas through times have been controlled by the variation of hydrographic circumstances in the intervening Arctic Ocean and Bering Strait. We address the history of trans-Arctic connections in a clade of amphi-boreal pelagic fishes using genealogical information from mitochondrial DNA sequence data. The Pacific and Atlantic herrings (Clupea pallasii and C. harengus) have basically vicarious distributions in the two oceans ...

  1. Southern Ocean influence on the eastern tropical North Pacific's intermediate-depth circulation during the Last Glacial Maximum

    Science.gov (United States)

    Carriquiry, José D.; Sanchez, Alberto; Leduc, Guillaume

    2015-08-01

    The oxygen and carbon isotopic compositions of benthic foraminiferal tests were measured on sedimentary sequences retrieved on the Magdalena Margin, off southern Baja California, Mexico. We reconstruct the hydrographic changes along the water column that occurred in the northeastern tropical Pacific since the Last Glacial Maximum (LGM) and compare those changes to the ones that occurred in the northwest Pacific (NWP, i.e., off Japan and Russia), in the northeast Pacific along the Californian Margin, as well as in the southeast Pacific (off Chile). The foraminiferal δ18O depth profiles across the North and southeast Pacific show similar trends between the LGM and the Holocene, indicating that changes in the oceanographic conditions between ~400 and 2000 m depth were very similar. Changes in the isotopic composition of dissolved inorganic carbon (δ13CDIC) in the Baja California Margin since the Last Glacial Maximum were reconstructed using the δ13C of shallow endobenthic foraminifers U. peregrina and the epibenthic Cibicides mckannai. The most striking result is a marked shift toward more positive δ13C values below 1200 m depth in the northeast Pacific (NEP) during the Holocene (relative to the LGM). This observation suggests that a nutrient-rich water mass ventilated the NEP during the LGM. At a basin scale, the δ13C values of NEP waters at intermediate depths were more negative relative to the NWP and southeast Pacific during the LGM, suggesting that the nutrient-rich water column along the NEP (i.e., Baja California Margin) was confined in that area as observed today.

  2. Development of a Seasonal Extratropical Cyclone Activity Outlook for the North Pacific, Bering Sea, and Alaskan Regions

    Science.gov (United States)

    Shippee, N. J.; Atkinson, D. E.; Walsh, J. E.; Partain, J.; Gottschalck, J.; Marra, J. J.

    2013-12-01

    Storm activity (i.e. 'storminess') and associated forecasting skill in the North Pacific, Bering Sea, and Alaska is relatively well understood on a daily to weekly scale, however, two important elements are missing from current capacity. First, there is no way to predict storm activity at the monthly to seasonal time frame. Second, storm activity is characterized in terms that best serve weather specialists, and which are often not very informative for different sectors of the public. Increasing the utility of forecasts for end users requires consultation with these groups, and can include expressing storm activity in terms of, for example, strong-wind return intervals or ship hull strength. These types of forecasts can provide valuable information for use in community planning, resource allocation, or potential risk assessment. A preliminary study of seasonal storminess predictability in the North Pacific and Alaska regions has shown that a key factor related to the annual variation of seasonal storminess is the strength of the Aleutian Low as measured using indices such as the North Pacific Index (NPI) or Aleutian Low Pressure Index (ALPI). Use of Empirical Orthogonal Function (EOF) analysis to identify patterns in storminess variability indicates that the primary mode of annual variation is found to be best explained by the variation in the strength of the Aleutian Low. NPI and the first component of storm activity for the entire region are found to be are highly correlated (R = 0.83). This result is supported by the works of others such as Rodionov et al. (2007), who note the impact of the strength of the Aleutian Low on storm track and speed. Additionally, the phase of the Pacific Decadal Oscillation (PDO), along with NPI, have been shown to be highly correlated with annual variance in the seasonal storminess for the North Pacific and Alaska. Additional skill has been identified when the phase of the Pacific Decadal Oscillation (PDO) is explicitly considered

  3. Post-breeding season distribution of black-footed and Laysan albatrosses satellite-tagged in Alaska: Inter-specific differences in spatial overlap with North Pacific fisheries

    Science.gov (United States)

    Fischer, K.N.; Suryan, R.M.; Roby, D.D.; Balogh, G.R.

    2009-01-01

    We integrated satellite-tracking data from black-footed albatrosses (Phoebastria nigripes; n = 7) and Laysan albatrosses captured in Alaska (Phoebastria immutabilis; n = 18) with data on fishing effort and distribution from commercial fisheries in the North Pacific in order to assess potential risk from bycatch. Albatrosses were satellite-tagged at-sea in the Central Aleutian Islands, Alaska, and tracked during the post-breeding season, July-October 2005 and 2006. In Alaskan waters, fishing effort occurred almost exclusively within continental shelf and slope waters. Potential fishery interaction for black-footed albatrosses, which most often frequented shelf-slope waters, was greatest with sablefish (Anoplopoma fimbria) longline and pot fisheries and with the Pacific halibut (Hippoglossus stenolepsis) longline fishery. In contrast, Laysan albatrosses spent as much time over oceanic waters beyond the continental shelf and slope, thereby overlapping less with fisheries in Alaska than black-footed albatrosses. Regionally, Laysan albatrosses had the greatest potential fishery interaction with the Atka mackerel (Pleurogrammus monopterygius) trawl fishery in the Western Aleutian Islands and the sablefish pot fishery in the Central Aleutian Islands. Black-footed albatrosses ranged further beyond Alaskan waters than Laysan albatrosses, overlapping west coast Canada fisheries and pelagic longline fisheries in the subarctic transition domain; Laysan albatrosses remained north of these pelagic fisheries. Due to inter-specific differences in oceanic distribution and habitat use, the overlap of fisheries with the post-breeding distribution of black-footed albatrosses is greater than that for Laysan albatrosses, highlighting inter-specific differences in potential vulnerability to bycatch and risk of population-level impacts from fisheries. ?? 2008 Elsevier Ltd.

  4. Evaluation of radioactive cesium impact from atmospheric deposition and direct release fluxes into the North Pacific from the Fukushima Daiichi nuclear power plant

    Science.gov (United States)

    Tsubono, Takaki; Misumi, Kazuhiro; Tsumune, Daisuke; Bryan, Frank O.; Hirose, Katsumi; Aoyama, Michio

    2016-09-01

    The North Pacific distribution of 134Cs released from the Fukushima Daiichi nuclear power plant (F1NPP) has been investigated using an eddy-resolving model. We conducted simulations based on two scenarios: (1) an input flux that was a combination of atmospheric deposition and direct release from the F1NPP (combination-flux scenario) and (2) an input flux that took account only of the direct release of 134Cs (single-flux scenario). The combination-flux scenario simulation successfully reproduced the distribution of 134Cs activity observed in the surface layer from April 2011 to January 2014. The results indicate that 134Cs deposited via atmospheric deposition into the Kuroshio-Oyashio Interfrontal Zone and 134Cs directly released from F1NPP were both transported to south of the Subarctic Front around 42°N in June of 2012. The combination-flux scenario suggests that the 134Cs activities observed in the area north of 42°N in 2012 originated from atmospheric deposition and that the 134Cs activity was subducted in Central Mode Water during the winters of 2011 and 2012. We directly compared simulated and observed 134Cs activities in the surface layer at 179 points across a wide area to the east of 155°E from 2011 to 2013 to evaluate the accuracy of the two scenarios. The root-mean-square error and correlation coefficient, R, were 7.3 Bq m-3 and 0.86, respectively, for the combination-flux scenario and 13.8 Bq m-3 and 0.46, respectively, for the single-flux scenario, confirming that reproduction of the 134Cs activity in the North Pacific after the F1NPP accident requires taking both fluxes into consideration. Based on a linear least-squares regression between simulated and observed 134Cs activity, the total 134Cs flux into the North Pacific was estimated at 16.1±1.4 PBq.

  5. A comparative study of Taiwan's short-term medical missions to the South Pacific and Central America

    Directory of Open Access Journals (Sweden)

    Chiu Ya-Wen

    2012-12-01

    Full Text Available Abstract Background Taiwan has been dispatching an increasing number of short-term medical missions (STMMs to its allied nations to provide humanitarian health care; however, overall evaluations to help policy makers strengthen the impact of such missions are lacking. Our primary objective is to identify useful strategies by comparing STMMs to the South Pacific and Central America. Methods The data for the evaluation come from two main sources: the official reports of 46 missions to 11 countries in Central America and 25 missions to 8 countries in the South Pacific, and questionnaires completed by health professionals who had participated in the above missions. In Central America, STMMs were staffed by volunteer health professionals from multiple institutions. In the South Pacific, STMMs were staffed by volunteer health professionals from single institutions. Results In comparison to STMMs to Central America, STMMs to the South Pacific accomplished more educational training for local health providers, including providing heath-care knowledge and skills (p Conclusions Health-care services provided by personnel from multiple institutions are as efficient as those from single institutions. Proficiency in the native language and provision of education for local health-care workers are essential for conducting a successful STMM. Our data provide implications for integrating evidence into the deployment of STMMs.

  6. A review of interaction between neon flying squid ( Ommastrephes bartramii) and oceanographic variability in the North Pacific Ocean

    Science.gov (United States)

    Yu, Wei; Chen, Xinjun; Yi, Qian; Tian, Siquan

    2015-08-01

    The neon flying squid ( Ommastrephes bartramii) is a short-lived opportunistic species widely distributed in subtropical and temperate waters in the North Pacific Ocean. The life cycle of O. bartramii from planktonic eggs to nektonic adults is closely linked to oceanographic conditions. The fluctuations in O. bartramii abundance and distribution tend to increase and widen continuously due to the heavy influences of ocean-climate events on various spatio-temporal scales. In this study, we reviewed the interaction between O. bartramii and oceanography variability in the North Pacific with respect to large-scale climatic-oceanic phenomena including El Niño, La Niña, Kuroshio, Oyashio and Pacific Decadal Oscillation (PDO), as well as regional environmental variables such as sea surface temperature (SST), sea surface height (SSH), sea surface salinity (SSS), chlorophyll-a (Chl- a) concentration, and plankton density. The population dynamics of O. bartramii is mediated mainly by meso- and large-scale climatic-oceanic events ( e.g., Kuroshio and Oyashio Currents) rather than other local environmental conditions ( e.g., SST and Chl- a concentration), because all of the oceanographic influences are imposed on the context of large-scale climate changes ( e.g., PDO). An unstructured-grid finite-volume coastal ocean model coupled with an individual-based model is proposed to simulate relevant physical-biological oceanographic processes for identifying ocean-climate influence and predicting O. bartramii distribution and abundance in the North Pacific. Future research needs to be focused on improving the knowledge about early life history of O. bartramii and evaluating the relationship between marine physical environment and two separate passive drifting life stages of O. bartramii including free-floating eggs and planktonic paralarvae.

  7. What factors are driving summer phytoplankton blooms in the North Pacific Subtropical Gyre?

    Science.gov (United States)

    White, Angelicque E.; Spitz, Yvette H.; Letelier, Ricardo M.

    2007-12-01

    Annually recurrent summer to fall surface blooms of the dinitrogen (N2) fixing genera Trichodesmium and Richelia have a significant impact on biogeochemical cycling in the North Pacific Subtropical Gyre (NPSG). Yet the environmental determinants of these blooms have not been thoroughly resolved. Here, we combine remote sensing of ocean color, sea surface temperature (SST), sea surface height anomalies (SSHa), wind forcing, and integrated irradiance with the vessel-based time series of the Hawaii Ocean Time-series (HOT) program at Station ALOHA (22.75°N, 158.00°W) and mooring data derived from the National Data Buoy Center (NDBC) buoy 51001 (23.42°N, 162.2°W). With these data sets we attempt to constrain the environmental window under which blooms of large cell-sized N2 fixing organisms increase in abundance in NPSG surface waters using phycoerythrin (PE) as a proxy. For identified blooms, our analyses indicate that these events are confined to the months of June-October, SST in the range of 25°-27°C, and mixed layer depths less than 70 m. Neither wind forcing nor SSHa are correlated (directly or time-lagged) with increases in PE concentrations. Furthermore, blooms do not consistently result in increases of in situ or remotely sensed chlorophyll a. Additional higher-resolution data sets of physical forcing, diazotroph abundance, and biochemical properties, sampled on the timescale of bloom development (days-weeks), will be necessary to the environmental conditions supporting annual summer-fall blooms.

  8. Contributions from DMS and ship emissions to CCN observed over the summertime North Pacific

    Directory of Open Access Journals (Sweden)

    L. Phinney

    2009-01-01

    Full Text Available Measurements of cloud condensation nuclei (CCN made over the remote North Pacific Ocean in July 2002 are analysed with concurrent measurements of aerosol number, mass and composition. Overall the CCN are controlled by the sulphate, including one case of particle nucleation and growth resulting from dimethyl sulphide oxidation that enhanced CCN concentrations. Hourly CCN concentrations are correlated with concentrations of sulphate plus methanesulphonic acid (MSA over the entire study period (r2=0.43 and 0.52 for supersaturations of 0.34 and 0.19%, respectively, and are not well correlated with other organics (r2<0.2. One case study reveals elevated mass and number concentrations of ultrafine and fine organic particles due to regional ship emissions, during which organic mass concentrations (see Fig. 2. In Fig. 7c, the 80–90 nm particle concentrations are correlated with CCN values (r2=0.39 and 0.46 for supersaturations of 0.19 and 0.34%, respectively. The evolution of the time series and mass distributions of organics, sulphate and MSA over this timeframe indicate that the regional distribution of small, diffuse ship-sourced organic particles act as condensation sites for sulphur species, resulting in a subsequent increase in number concentrations of CCN. Direct emissions of organic particles may exert a strong control on marine CCN concentrations once diffused into the marine atmosphere by acting as condensation sites for biogenic and anthropogenic sulphur species.

  9. Contributions from DMS and ship emissions to CCN observed over the summertime North Pacific

    Directory of Open Access Journals (Sweden)

    L. Langley

    2010-02-01

    Full Text Available Measurements of cloud condensation nuclei (CCN made over the North Pacific Ocean in July 2002 are analysed with concurrent measurements of aerosol number, mass and composition. Overall the CCN are controlled by the sulphate, including one case that suggests particle nucleation and growth resulting from dimethyl sulphide oxidation that enhanced CCN concentrations. Hourly CCN concentrations are correlated with concentrations of sulphate plus methanesulphonic acid (MSA over the entire study period (r2=0.43 and 0.52 for supersaturations of 0.34% and 0.19%, respectively, and are not well correlated with other organics (r2<0.2. One case study reveals elevated mass and number concentrations of ultrafine and fine organic particles due to regional ship emissions, identified through quadrupole aerosol mass spectrometer (Q-AMS measurements, during which organic mass concentrations are correlated with CCN values (r2=0.39 and 0.46 for supersaturations of 0.19% and 0.34%, respectively. The evolution of the time series and mass distributions of organics, sulphate and MSA over this timeframe indicate that the regional distribution of small, diffuse ship-sourced organic particles act as condensation sites for sulphur species, resulting in a subsequent increase in number concentrations of CCN. We conclude that, where present, direct emissions of anthropogenic organic particles may exert a strong control on marine CCN concentrations once diffused into the marine atmosphere, by acting as condensation sites for biogenic and anthropogenic sulphur species.

  10. Caldera formation and varied eruption styles on North Pacific seamounts: the clastic lithofacies record

    Science.gov (United States)

    Portner, Ryan A.; Clague, Dave A.; Paduan, Jennifer B.

    2014-08-01

    Detailed examination of volcaniclastic and sedimentary rocks collected from the Taney (30 Ma), President Jackson (4 Ma), Vance (3 Ma) and Alarcon (2 Ma) near-ridge seamount chains of the North Pacific reveals seven clastic lithofacies that record various modes of eruption, magma fragmentation, and particle dispersal. Lithofacies are distinguished by differences in lithology, bedding habit, compositional heterogeneity, and relationship to volcanic landforms. Breccia lithofacies were produced through mechanical fragmentation during caldera collapse (polymict) or effusive eruptions onto steep slopes (monomict). Rare globular lapilli mudstone lithofacies contain clasts with morphologies formed by magma-sediment mingling processes (peperite). Seamount summit pyroclastic deposits include proximal lapilli tuff with vesicular pyroclasts, and more distal limu o Pele tuff lithofacies. Much finer-grained hydrothermal mudstone/tuff lithofacies occurs around caldera rims and contains greenschist minerals, hydrothermal clays and basaltic ash that record subsurface phreatomagmatic fragmentation processes. Very fine-grained ash is transported to distal regions by oceanic currents and hydrothermal plumes, and is a component of the regional pelagic sediment budget. Pyroclastic lithofacies only occur on seamount summits suggesting formation during the latter stages of seamount evolution. As a seamount drifts away from an adjacent ridge axis and associated heat source, its magma supply is reduced allowing for magmatic gas buildup and mild explosive eruptions. During this stage, the diminished melt supply under the seamount is unable to fully compensate for extension along the ridge axis and vertical seamount growth. Lateral intrusion into spreading-related structures in this stage causes magma withdrawal and caldera formation. Formation of caldera ring faults also promotes seawater ingress into subseafloor hydrothermal cells, which interact with magma conduits causing phreatomagmatic

  11. Low prevalence of avian influenza virus in shorebirds on the Pacific coast of North America

    Science.gov (United States)

    Iverson, Samuel A.; Takekawa, John Y.; Schwarzbach, Steven; Cardona, Carol J.; Warnock, Nils; Bishop, Mary Anne; Schirato, Greg A.; Paroulek, Sara; Ackerman, Joshua T.; Ip, Hon; Boyce, Walter M.

    2008-01-01

    The emergence of highly pathogenic avian influenza (HPAI) H5N1 has elevated concerns about wild birds as virus hosts; however, little is known about the ecological and epidemiological factors of transmission by shorebirds. Here we summarize results for 2,773 shorebirds that were live-trapped on the Pacific coast of the United States during 2006-2007 and tested for avian influenza virus using real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and virus isolation. As was the case throughout North America, HPAI H5N1 was not detected in shorebirds during this interval. Contrary to other wild bird groups, most notably waterfowl, the prevalence of even low pathogenicity virus among shorebirds in our study areas in California, Washington, and Alaska was extremely low (0.5%). Virus was detected by RT-PCR from four different species, including, Dunlin (Calidris alpina; N = 3), Western Sandpiper (C. mauri; N = 8), Long-billed Dowitcher (Limnodromus scolopaceus; N = 1), and American Avocet (Recurvirostra americana; N = 1), with the detections in the latter three constituting the first published records for these birds. Based on studies in the eastern United States, we expected, but did not detect (H1 = 1.6, P = 0.21) elevated avian influenza prevalence among shorebirds during spring migration. Diagnostic tests, which were designed to evaluate testing and sampling methods, indicated poor functioning of traditional virus isolation methods and no improvement in detection likelihood by collecting oropharyngeal swabs in addition to cloacal swab samples for low pathogenicity viruses (Z1 = 0.7, P = 0.48).

  12. Wind and sunlight shape microbial diversity in surface waters of the North Pacific Subtropical Gyre.

    Science.gov (United States)

    Bryant, Jessica A; Aylward, Frank O; Eppley, John M; Karl, David M; Church, Matthew J; DeLong, Edward F

    2016-06-01

    Few microbial time-series studies have been conducted in open ocean habitats having low seasonal variability such as the North Pacific Subtropical Gyre (NPSG), where surface waters experience comparatively mild seasonal variation. To better describe microbial seasonal variability in this habitat, we analyzed rRNA amplicon and shotgun metagenomic data over two years at the Hawaii Ocean Time-series Station ALOHA. We postulated that this relatively stable habitat might reveal different environmental factors that influence planktonic microbial community diversity than those previously observed in more seasonally dynamic habitats. Unexpectedly, the data showed that microbial diversity at 25 m was positively correlated with average wind speed 3 to 10 days prior to sampling. In addition, microbial community composition at 25 m exhibited significant correlations with solar irradiance. Many bacterial groups whose relative abundances varied with solar radiation corresponded to taxa known to exhibit strong seasonality in other oceanic regions. Network co-correlation analysis of 25 m communities showed seasonal transitions in composition, and distinct successional cohorts of co-occurring phylogenetic groups. Similar network analyses of metagenomic data also indicated distinct seasonality in genes originating from cyanophage, and several bacterial clades including SAR116 and SAR324. At 500 m, microbial community diversity and composition did not vary significantly with any measured environmental parameters. The minimal seasonal variability in the NPSG facilitated detection of more subtle environmental influences, such as episodic wind variation, on surface water microbial diversity. Community composition in NPSG surface waters varied in response to solar irradiance, but less dramatically than reported in other ocean provinces. PMID:26645474

  13. A preliminary study on thermoluminescence characteristics of sediments from the North Pacific

    Institute of Scientific and Technical Information of China (English)

    L(U) Huahua; SHI Xuefa; WU Yonghua; YANG Gang; WEI Jianwei; REN Xiangwen

    2007-01-01

    Thirty-eight surficial deposit samples were collected from the equatorial North Pacific, and the natural thermoluminescence (TL) characteristics of both bulk and clay fraction samples (<2 μm fractions) were studied by the FJ427-A1 automatic TL Dosimeter for the first time. With the measurements of clay mineral composition, element composition by XRD and ICP, the correlations between TL intensity and sedimentary environment proxies were analyzed, such as water depth, ratio of FeO to Fe2O3 contents, LOI, and major clay mineral concentration, and it was found the bulk sample's TL signal was stronger than the clay ones. Usually, increase in the clay components may result in the decrease of TL intensity. From the shape of TL curves, the pelagic sediments can be divided into two groups: the majority group has two glow peaks, in general, the first peak is broad and flat, but the second narrow and sharp; the minority group only has a single peak because the first is absent. The peak centers of TL curves are almost fixed, falling in the temperature sections 230~260 and 390~405 ℃ respectively. Lorentz model packed in the Origin 7.5 was chosen to deal with the TL curves. From the processing results, three parameters (H, C and A), corresponding to the height, center, and kurtosis of TL curve, were obtained to describe the curve characteristics. The correlations between TL curve parameters and sedimentary environment proxies were also calculated. On the basis of the above work, the relationship between TL characteristics and sediment type, mineral composition, sedimentary environment of surface sediments was discussed in the study area, and a conclusion is: sediments from the environment of shallower water, higher organic contents and weaker reductivity have stronger TL signals.

  14. Age and Growth of the Dusky Shark, Carcharhinus obscurus, in the Western North Pacific Ocean

    Directory of Open Access Journals (Sweden)

    Shoou-Jeng Joung

    2015-01-01

    Full Text Available Age and growth of the dusky shark, Carcharhinus obscurus, in the western North Pacific Ocean was estimated based on 434 specimens (213 females and 256 males collected between September 2002 and November 2003 at the Nanfanao fish market, in northeastern Taiwan. Sex-specific relationships between body weight (W and total length (TL were estimated as follows: W = 2.03 _ 10-6TL3.216 (n = 209, p < 0.01 for females and W = 8.01 _ 10-6TL2.957 (n = 294, p < 0.01 for males. The relationship between TL and the vertebral centrum radius (R for both sexes _ data was described using the following equation TL = 14.74 + 20.31R (n = 399, p < 0.01. Growth band pairs (including translucent and opaque bands in precaudal vertebrae were determined to form once annually, based on centrum edge analysis and verified by statistical analysis. The maximum number of growth band pairs was 29 for females and 24 for males. The Robertson growth function best fit the observed length-at-age data. Sex-specific growth equations were not significantly different; thus, the combined growth parameters for both sexes were estimated as: asymptotic length (L∞(L∞ = 369.4 cm TL, b = 0.912, growth coefficient (kR = 0.126 yr-1 (n = 385, p < 0.01. Age at maturity was estimated to be 16.6 yrs for females and 15.5 yrs for males.

  15. Upper-tropospheric environment-tropical cyclone interactions over the western North Pacific: A statistical study

    Science.gov (United States)

    Qian, Yu-Kun; Liang, Chang-Xia; Yuan, Zhuojian; Peng, Shiqiu; Wu, Junjie; Wang, Sihua

    2016-05-01

    Based on 25-year (1987-2011) tropical cyclone (TC) best track data, a statistical study was carried out to investigate the basic features of upper-tropospheric TC-environment interactions over the western North Pacific. Interaction was defined as the absolute value of eddy momentum flux convergence (EFC) exceeding 10 m s-1 d-1. Based on this definition, it was found that 18% of all six-hourly TC samples experienced interaction. Extreme interaction cases showed that EFC can reach ~120 m s-1 d-1 during the extratropical-cyclone (EC) stage, an order of magnitude larger than reported in previous studies. Composite analysis showed that positive interactions are characterized by a double-jet flow pattern, rather than the traditional trough pattern, because it is the jets that bring in large EFC from the upper-level environment to the TC center. The role of the outflow jet is also enhanced by relatively low inertial stability, as compared to the inflow jet. Among several environmental factors, it was found that extremely large EFC is usually accompanied by high inertial stability, low SST and strong vertical wind shear (VWS). Thus, the positive effect of EFC is cancelled by their negative effects. Only those samples during the EC stage, whose intensities were less dependent on VWS and the underlying SST, could survive in extremely large EFC environments, or even re-intensify. For classical TCs (not in the EC stage), it was found that environments with a moderate EFC value generally below ~25 m s-1 d-1 are more favorable for a TC's intensification than those with extremely large EFC.

  16. Attributing Tropical Cyclogenesis to Equatorial Waves in the Western North Pacific

    Science.gov (United States)

    Schreck, Carl J., III; Molinari, John; Mohr, Karen I.

    2009-01-01

    The direct influences of equatorial waves on the genesis of tropical cyclones are evaluated. Tropical cyclogenesis is attributed to an equatorial wave when the filtered rainfall anomaly exceeds a threshold value at the genesis location. For an attribution threshold of 3 mm/day, 51% of warm season western North Pacific tropical cyclones are attributed to tropical depression (TD)-type disturbances, 29% to equatorial Rossby waves, 26% to mixed Rossby-Gravity waves, 23% to Kelvin waves, 13% to the Madden-Julian oscillation (MJO), and 19% are not attributed to any equatorial wave. The fraction of tropical cyclones attributed to TD-type disturbances is consistent with previous findings. Past studies have also demonstrated that the MJO significantly modulates tropical cyclogenesis, but fewer storms are attributed to the MJO than any other wave type. This disparity arises from the difference between attribution and modulation. The MJO produces broad regions of favorable conditions for cyclogenesis, but the MJO alone might not determine when and where a storm will develop within these regions. Tropical cyclones contribute less than 17% of the power in any portion of the equatorial wave spectrum because tropical cyclones are relatively uncommon equatorward of 15deg latitude. In regions where they are active, however, tropical cyclones can contribute more than 20% of the warm season rainfall and up to 50% of the total variance. Tropical cyclone-related anomalies can significantly contaminate wave-filtered precipitation at the location of genesis. To mitigate this effect, the tropical cyclone-related rainfall anomalies were removed before filtering in this study.

  17. Tropical cyclone genesis potential index over the western North Pacific simulated by CMIP5 models

    Science.gov (United States)

    Song, Yajuan; Wang, Lei; Lei, Xiaoyan; Wang, Xidong

    2015-11-01

    Tropical cyclone (TC) genesis over the western North Pacific (WNP) is analyzed using 23 CMIP5 (Coupled Model Intercomparison Project Phase 5) models and reanalysis datasets. The models are evaluated according to TC genesis potential index (GPI). The spatial and temporal variations of the GPI are first calculated using three atmospheric reanalysis datasets (ERA-Interim, NCEP/NCAR Reanalysis-1, and NCEP/DOE Reanalysis-2). Spatial distributions of July-October-mean TC frequency based on the GPI from ERA-interim are more consistent with observed ones derived from IBTrACS global TC data. So, the ERA-interim reanalysis dataset is used to examine the CMIP5 models in terms of reproducing GPI during the period 1982-2005. Although most models possess deficiencies in reproducing the spatial distribution of the GPI, their multimodel ensemble (MME) mean shows a reasonable climatological GPI pattern characterized by a high GPI zone along 20°N in the WNP. There was an upward trend of TC genesis frequency during 1982 to 1998, followed by a downward trend. Both MME results and reanalysis data can represent a robust increasing trend during 1982-1998, but the models cannot simulate the downward trend after 2000. Analysis based on future projection experiments shows that the GPI exhibits no significant change in the first half of the 21st century, and then starts to decrease at the end of the 21st century under the representative concentration pathway (RCP) 2.6 scenario. Under the RCP8.5 scenario, the GPI shows an increasing trend in the vicinity of 20°N, indicating more TCs could possibly be expected over the WNP under future global warming.

  18. Seasonal prediction of typhoon genesis frequency and track patterns in the North West Pacific area

    Science.gov (United States)

    Hyoun, Yoosun; Kang, Kiryong; Shin, Do-Shick

    2014-05-01

    This study is to investigate the performance of the typhoon seasonal predictability using a dynamical model. The check items are the monthly statistics for total number of typhoon genesis in Western North Pacific (WNP) area and possible threat to Korean peninsula among them, and the probability of each categorized track pattern. As the dynamical model the Florida State University/Center for Ocean-Atmospheric Prediction Studies (FSU/COAPS) was used, and it uses five ensemble members including control run are generated using time-lagged methods and the resolution of T126L27 (a Gaussian grid spacing of 0.94º). The model initial conditions are obtained from the National Center for Enviromental Prediction Global Forecast System (NCEP GFS) and the SST from Climate Forecast System with bias correction was used for ocean surface boundary condition. The summer (Jun-Jul-Aug) season prediction is made one month prior to target season. The detection of tropical cyclone used in this system is based on six criteria. First, the isolated vortex type minimum sea level pressure should be below 1008hPa. Second, the maximum wind speed is larger than 17m s-1. Third, the magnitude of the maximum relative vorticity at 850hPa exceeds 3.5x10-5s-1. Fourth, the average temperature difference from the area mean of surrounding region at 300hPa, 500hPa, 700hPa exceeds 2.5K. Fifth, the maximum wind speed at 850hPa is larger than that at 300hPa. Sixth, this identified vortex should last more than two days. These criteria were chosen after close examination from model-observation comparison. In this study, we will focus on performance of the system typhoon frequency and track pattern in the WNP area during 2004-2013.

  19. Growth rates and production of heterotrophic bacteria and phytoplankton in the North Pacific subtropical gyre

    Science.gov (United States)

    Jones, David R.; Karl, David M.; Laws, Edward A.

    1996-10-01

    In field work conducted at 26°N, 155°W, in the North Pacific subtropical gyre, phytoplankton growth rates μp estimated from 14C labeling of chlorophyll a (chl a) averaged approximately one doubling per day in the euphotic zone (0-150 m). Microbial (microalgal plus heterotrophic bacterial) growth rates μm calculated from the incorporation of 3H-adenine into DNA were comparable to or exceeded phytoplankton growth rates at most depths in the euphotic zone. Photosynthetic rates averaged 727 mg C m -2 day -1 Phytoplankton carbon biomass, calculated from 14C labeling of chl a, averaged 7.2 mg m -3 in the euphotic zone. Vertical profiles of particulate DNA and ATP suggested that no more than 15% of particulate DNA was associated with actively growing cells. Heterotrophic bacterial carbon biomass was estimated from a two-year average at station ALOHA (22°45'N, 158°W) of flow cytometric counts of unpigmented, bacteria-size particles which bound DAPI on the assumption that 15% of the particles were actively growing cells and that heterotrophic bacterial cells contained 20 fg C cell -1 The heterotrophic bacterial carbon so calculated averaged 1.1 mg m -3 in the euphotic zone. Heterotrophic bacterial production was estimated to be 164 mg C m -2 day -1 or 23% of the calculated photosynthetic rate. Estimated heterotrophic bacterial growth rates averaged 0.97 day -1 in the euphotic zone and reached 4.7 day - at a depth of 20 m. Most heterotrophic bacterial production occurred in the upper 40 m of the euphotic zone, suggesting that direct excretion by phytoplankton, perhaps due to photorespiration or ultraviolet light effects, was a significant source of dissolved organic carbon for the bacteria.

  20. Central Wind Forecasting Programs in North America by Regional Transmission Organizations and Electric Utilities: Revised Edition

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, J.; Porter, K.

    2011-03-01

    The report and accompanying table addresses the implementation of central wind power forecasting by electric utilities and regional transmission organizations in North America. The first part of the table focuses on electric utilities and regional transmission organizations that have central wind power forecasting in place; the second part focuses on electric utilities and regional transmission organizations that plan to adopt central wind power forecasting in 2010. This is an update of the December 2009 report, NREL/SR-550-46763.

  1. The characteristic differences of tropical cyclones forming over the western North Pacific and the South China Sea

    Institute of Scientific and Technical Information of China (English)

    YUAN Jinnan; WANG Dongxiao; LIU Chunxia; HUANG Jian; HUANG Huijun

    2007-01-01

    The best track dataset of tropical cyclones in the western North Pacific (WNP) and the South China Sea (SCS) from 1977 to 2005 during the satellite era, the NCEP/NCAR reanalysis dataset and the extended reconstructed sea surface temperature dataset are employed in this study. The main climatological characteristics of tropical cyclone formation over the WNP and the SCS are compared. It is found that there is obviously different for the locations of tropical cyclone origins, achieving the lowest central pressure and termination points between over the WNP and over the SCS. The annual number of tropical cyclones forming over the SCS is obviously less than over the WNP, and there is a significant negative correlation with the correlation coefficient being - 0.36 at the 5% significance level between over the WNP and over the SCS. The mean speed of tropical cyclone moving is 6.5 m/s over the WNP and 4.6 m/s over the SCS. The mean lowest central pressure of tropical cyclones is obviously weaker over the SCS than over the WNP. The tropical cyclone days per year, mean total distance and total displacement of tropical cyclone traveled over the WNP are all obviously longer than those over the SCS. Tropical cyclone may intensify to Saffir - Simpson hurricane scale 5 over the WNP, but no tropical cyclone can intensify to Saffir - Simpson hurricane scale 3 over the SCS. The changing ranges of the radii (R15,R16) of the 15.4 m/s winds them and the 25.7 m/s winds over the WNP are obviously wider than those over the SCS,and the median values of the radii over the WNP are also larger than those over the SCS. For the same intensity of tropical cyclones, both radii have larger medians over the WNP than over the SCS. The correlations of annual mean tropical cyclone size parameters between over the WNP and over the SCS are not significant. At the same time, the asymmetric radii of tropical cyclones over the WNP are different from those over the SCS.

  2. Surface-Wind Anomalies in North-Atlantic and North Pacific from SSM/I Observations: Influence on Temperature of Adjoining Land Regions

    Science.gov (United States)

    Otterman, Joseph; Atlas, R.; Ingraham, J.; Ardizzone, J.; Starr, D.; Terry, J.

    1998-01-01

    Surface winds over the oceans are derived from Special Sensor Microwave Imager (SSM/I) measurements, assigning direction by Variational Analysis Method (VAM). Validations by comparison with other measurements indicate highly-satisfactory data quality. Providing global coverage from 1988, the dataset is a convenient source for surface-wind climatology. In this study, the interannual variability of zonal winds is analyzed concentrating on the westerlies in North Atlantic and North Pacific, above 30 N. Interannual differences in the westerlies exceeding 10 m sec (exp -1) are observed over large regions, often accompanied by changes of the same magnitude in the easterlies below 30 N. We concentrate on February/March, since elevated temperatures, by advancing snow-melt, can produce early spring. The extremely strong westerlies in 1997 observed in these months over North Atlantic (and also North Pacific) apparently contributed to large surface-temperature anomalies in western Europe, on the order of +3 C above the climatic monthly average for England and France. At these latitudes strong positive anomalies extended in a ring around the globe. We formulated an Index of South westerlies for the North Atlantic, which can serve as an indicator for day-by-day advection effects into Europe. In comparing 1997 and 1998 with the previous years, we establish significant correlations with the temperature anomalies (one to five days later, depending on the region, and on the season). This variability of the ocean-surface winds and of the temperature anomalies on land may be related to the El Nino/La Nina oscillations. Such large temperature fluctuations over large areas, whatever the cause, can be regarded as noise in attempts to assess long-term trends in global temperature.

  3. [Nesting habitat characterization for Amazona oratrix (Psittaciformes: Psittacidae) in the Central Pacific, Mexico].

    Science.gov (United States)

    Monterrubio-Rico, Tiberio C; Álvarez-Jara, Margarito; Tellez-Garcia, Loreno; Tena-Morelos, Carlos

    2014-09-01

    The nesting requirements of the Yellow-headed Parrot (Amazona oratrix) are poorly understood, despite their broad historical distribution, high demand for pet trade and current endangered status. Information concerning their nesting requirements is required in order to design specific restoration and conser- vation actions. To assess this, we studied their nesting ecology in the Central Pacific, Michoacan, Mexico during a ten year period. The analyzed variables ranged from local scale nest site characteristics such as nesting tree species, dimensions, geographic positions, diet and nesting forest patches structure, to large scale features such as vegetation use and climatic variables associated to the nesting tree distributions by an ecological niche model using Maxent. We also evaluated the parrot tolerance to land management regimes, and compared the Pacific nest trees with 18 nest trees recorded in an intensively managed private ranch in Tamaulipas, Gulf of Mexico. Parrots nested in tall trees with canopy level cavities in 92 nest-trees recorded from 11 tree species. The 72.8% of nesting occurred in trees of Astronium graveolens, and Enterolobium cyclocarpum which qualified as key- stone trees. The forests where the parrots nested, presented a maximum of 54 tree species, 50% of which were identified as food source; besides, these areas also had a high abundance of trees used as food supply. The lowest number of tree species and trees to forage occurred in an active cattle ranch, whereas the highest species rich- ness was observed in areas with natural recovery. The nesting cavity entrance height from above ground of the Pacific nesting trees resulted higher than those found in the Gulf of Mexico. We hypothesize that the differences may be attributed to Parrot behavioral differences adapting to differential poaching pressure and cavity avail- ability. Nesting trees were found in six vegetation types; however the parrots preferred conserved and riparian semi

  4. Carbon dioxide, temperature, salinity and other variables collected via time series monitoring from MOORINGS in the North Pacific Ocean from 2008-11-11 to 2010-09-01 (NODC Accession 0100066)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0100066 includes chemical, physical, time series and underway - surface data collected from MOORINGS in the North Pacific Ocean and South Pacific...

  5. Carbon dioxide, temperature, salinity and other variables collected via time series monitoring from MOORINGS in the North Pacific Ocean from 2010-01-17 to 2011-03-05 (NODC Accession 0100067)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0100067 includes chemical, physical, time series and underway - surface data collected from MOORINGS in the North Pacific Ocean and South Pacific...

  6. Carbon dioxide, temperature, salinity and other variables collected via time series monitoring from MOORINGS in the North Pacific Ocean from 2004-12-19 to 2007-07-30 (NODC Accession 0100073)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0100073 includes chemical, physical, time series and underway - surface data collected from MOORINGS in the North Pacific Ocean and South Pacific...

  7. Carbon dioxide, temperature, salinity and other variables collected via time series monitoring from MOORINGS in the North Pacific Ocean from 2007-02-18 to 2007-10-03 (NODC Accession 0100070)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0100070 includes chemical, physical, time series and underway - surface data collected from MOORINGS in the North Pacific Ocean and South Pacific...

  8. Carbon dioxide, temperature, salinity and other variables collected via time series monitoring from MOORINGS in the North Pacific Ocean from 2005-12-01 to 2008-05-30 (NODC Accession 0100069)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0100069 includes chemical, physical, time series and underway - surface data collected from MOORINGS in the North Pacific Ocean and South Pacific...

  9. Temperature profile and water depth data collected from AMERICAN RESERVIST using BT and XBT casts in the North Pacific Ocean from 20 January 1974 to 29 September 1977 (NODC Accession 8900287)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT casts from the AMERICAN RESERVIST in the North Pacific Ocean and TOGA Area - Pacific Ocean....

  10. Seasonal variation of levoglucosan in aerosols over the western North Pacific and its assessment as a biomass-burning tracer

    Science.gov (United States)

    Mochida, Michihiro; Kawamura, Kimitaka; Fu, Pingqing; Takemura, Toshihiko

    2010-09-01

    Levoglucosan is considered as a useful molecular tracer of biomass-burning aerosols in the atmosphere. To characterize the seasonal variation of its concentrations over the Pacific Ocean and to assess its usefulness as a tracer after long-range transport, we investigated long-term variations of levoglucosan over Chichi-jima in the western North Pacific, from 2001 to 2004. Organic carbon (OC), elemental carbon (EC) and D-glucose were analyzed for comparison. The seasonal variation of levoglucosan concentrations showed a maximum in the winter, which is consistent with the enhanced Asian outflow to the Pacific indicated by backward air-mass trajectories. The concentration levels of levoglucosan estimated from global aerosol model outputs in the winter are, on average, comparable to the observed levels, suggesting that a considerable fraction of levoglucosan did not decompose during long-range transport from the Asian continent by westerly/northwesterly winds. This result is supported by comparable ratios of levoglucosan to EC in Chichi-jima and the East Asian coastal region. Conversely, the measured concentrations of levoglucosan in the summer were significantly lower than the modeled one. This implies a degradation of levoglucosan in the air masses that stagnated over the Pacific, although uncertainties in the model estimate may also be partly responsible for this discrepancy. One possible degradation pathway is oxidation by OH radicals; the contribution of acid-catalyzed reactions needs further investigation.

  11. Phylogeny and genetic diversity of palolo worms (Palola, Eunicidae) from the tropical North Pacific and the Caribbean.

    Science.gov (United States)

    Schulze, Anja

    2006-02-01

    Palolo worms (Palola, Eunicidae) are best known for their annual mass spawnings, or "risings," in the South Pacific. Palola currently contains 14 morphologically similar species, mostly from shallow tropical waters. In this study, 60 specimens of Palola from nine locations in the tropical North Pacific and the Caribbean were sequenced for the two mitochondrial markers cytochrome c oxidase subunit I and 16S ribosomal RNA to infer phylogenetic relationships, genetic diversity, and phylogeography within the taxon. Phylogenetic analysis was performed using Bayesian statistics and parsimony. Vouchers of the same specimens were examined morphologically. Two major clades (A and B) can be distinguished within the monophyletic Palola. A number of individuals in clade B bear rows of ventral eyespots in the posterior body region, typical for swarming P. viridis and probably a synapomorphy for clade B. No morphological synapomorphy was found for clade A. Haplotypes from divergent clades often co-occur in the same location. Some haplotypes are geographically widespread, in one case covering the entire east-west expansion of the tropical Pacific. These results imply that despite the apparent absence of teleplanic larvae in eunicid polychaetes, long-distance dispersal is possible in at least some lineages of Palola. With the first taste of palolo I understood the Samoans' love for it. Certainly it suggested a salty caviar, but with something added, a strong, rich whiff of the mystery and fecundity of the ocean depths. -R. Steinberg. Pacific and Southeast Asian cooking. Time-Life Books, New York, 1970. PMID:16501062

  12. Central Gulf of Alaska Rockfish Permit Program

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The North Pacific Fishery Management Council adopted the Central Gulf of Alaska Rockfish Program (Rockfish Program) on June 14, 2010, to replace the expiring Pilot...

  13. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Coulometer for DIC measurement and other instruments from the MIRAI in the North Pacific Ocean and South Pacific Ocean from 2007-02-16 to 2007-03-26 (NODC Accession 0112269)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112269 includes chemical, discrete sample, physical and profile data collected from MIRAI in the North Pacific Ocean and South Pacific Ocean from...

  14. Dissolved inorganic carbon, pH, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Coulometer for DIC measurement and other instruments from the MIRAI in the North Pacific Ocean and South Pacific Ocean from 2002-12-17 to 2003-02-14 (NODC Accession 0113608)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0113608 includes chemical, discrete sample, physical and profile data collected from MIRAI in the North Pacific Ocean and South Pacific Ocean from...

  15. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from Surface underway, discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from MIRAI in the Bering Sea, North Pacific Ocean and South Pacific Ocean from 2007-10-08 to 2007-12-26 (NODC Accession 0108123)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0108123 includes Surface underway, discrete sample and profile data collected from MIRAI in the Bering Sea, North Pacific Ocean and South Pacific...

  16. Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from time series observations using Bubble type equilibrator for autonomous carbon dioxide (CO2) measurement, Carbon dioxide (CO2) gas analyzer and other instruments from MOORINGS in the North Pacific Ocean and South Pacific Ocean from 2004-05-23 to 2011-09-01 (NODC Accession 0100077)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0100077 includes chemical, physical and time series data collected from MOORINGS in the North Pacific Ocean and South Pacific Ocean from 2004-05-23...

  17. Dissolved inorganic carbon, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Coulometer for DIC measurement and other instruments from the MALCOLM BALDRIDGE in the North Pacific Ocean and South Pacific Ocean from 1990-02-22 to 1990-04-16 (NODC Accession 0000183)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0000183 includes chemical, discrete sample, physical and profile data collected from MALCOLM BALDRIDGE in the North Pacific Ocean and South Pacific...

  18. Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from RONALD H. BROWN in the North Pacific Ocean, South Pacific Ocean and Southern Oceans from 2007-12-15 to 2008-02-23 (NODC Accession 0109903)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0109903 includes discrete sample and profile data collected from RONALD H. BROWN in the North Pacific Ocean, South Pacific Ocean and Southern Oceans...

  19. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the THOMAS WASHINGTON in the North Pacific Ocean and South Pacific Ocean from 1991-08-31 to 1991-10-01 (NODC Accession 0115174)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115174 includes chemical, discrete sample, physical and profile data collected from THOMAS WASHINGTON in the North Pacific Ocean and South Pacific...

  20. Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the DISCOVERER in the North Pacific Ocean and South Pacific Ocean from 1994-01-26 to 1994-04-27 (NODC Accession 0115152)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115152 includes chemical, discrete sample, physical and profile data collected from DISCOVERER in the North Pacific Ocean and South Pacific Ocean...

  1. Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments from the KNORR in the North Pacific Ocean and South Pacific Ocean from 1992-10-06 to 1993-04-13 (NODC Accession 0115156)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0115156 includes chemical, discrete sample, physical and profile data collected from KNORR in the North Pacific Ocean and South Pacific Ocean from...

  2. Dissolved inorganic carbon, pH, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Coulometer for DIC measurement and other instruments from the MIRAI in the North Pacific Ocean and South Pacific Ocean from 2000-12-27 to 2001-02-08 (NODC Accession 0112353)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112353 includes biological, chemical, discrete sample, physical and profile data collected from MIRAI in the North Pacific Ocean and South Pacific...

  3. Dissolved inorganic carbon, pH, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Coulometer for DIC measurement and other instruments from the MIRAI in the North Pacific Ocean and South Pacific Ocean from 1999-11-21 to 1999-12-27 (NODC Accession 0112351)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112351 includes biological, chemical, discrete sample, physical and profile data collected from MIRAI in the North Pacific Ocean and South Pacific...

  4. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from the SOUTHERN SURVEYOR in the North Pacific Ocean and South Pacific Ocean from 2009-02-03 to 2009-03-24 (NODC Accession 0108082)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0108082 includes chemical, discrete sample, physical and profile data collected from SOUTHERN SURVEYOR in the North Pacific Ocean and South Pacific...

  5. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from the MALCOLM BALDRIGE in the North Pacific Ocean and South Pacific Ocean from 1992-02-24 to 1992-05-19 (NODC Accession 0117498)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0117498 includes chemical, discrete sample, physical and profile data collected from MALCOLM BALDRIGE in the North Pacific Ocean and South Pacific...

  6. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and Calcium collected from discrete sample and profile observations using CTD, bottle and other instruments from the MILLER FREEMAN in the North Pacific Ocean and South Pacific Ocean from 1979-04-01 to 1982-06-30 (NODC Accession 0000180)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0000180 includes chemical, discrete sample, physical and profile data collected from MILLER FREEMAN in the North Pacific Ocean and South Pacific...

  7. Inter-annual dynamics of abyssal polychaete communities in the North East Pacific and North East Atlantic—A family-level study

    Science.gov (United States)

    Laguionie-Marchais, C.; Billett, D. S. M.; Paterson, G. L. D.; Ruhl, H. A.; Soto, E. H.; Smith, K. L., Jr.; Thatje, S.

    2013-05-01

    Characterising how deep-sea communities change on contemporary time-scales and understanding underlying ecosystem processes has become important under changing climate and the rise in the exploitation of deep-sea resources. However, little is known about these dynamics and processes. Long-term observations from which inter-annual variations can be detected are scarce in the deep sea. This study examines inter-annual changes in density, family richness and evenness, family and functional group rank abundance distributions of infaunal polychaetes at two abyssal stations in the North East Pacific (Station M, 1991 to 2005) and in the North East Atlantic (Porcupine Abyssal Plain, 1991 to 1999). The two long-term data sets were used to investigate not only if polychaete community structure and composition varied at inter-annual scales in terms of diversity and rank abundance distributions but also if any changes were related to previous observations in megafauna and environmental factors at each locality. The polychaete community structure at each locality was analysed using univariate statistics as well as multivariate ordination techniques based on Bray-Curtis similarity of the yearly family density. Sub-surface deposit feeders, such as Paraonidae, dominated the North East Pacific, whereas surface deposit feeders, such as Cirratulidae, dominated the North East Atlantic. Both stations showed inter-annual variations in density, family evenness and rank abundance distributions. The greatest changes occurred in 1998 in both time series when polychaete densities peaked, and switches in the rank abundance of the most abundant families and functional groups took place. Inter-annual variations in the polychaete community were correlated with a limited number of holothurian species changes, but no correlation was found with particulate organic matter flux or climate indices. Ecological and environmental factors behind the family-level changes remain elusive. Overall, changes in

  8. Interdecadal changes on the seasonal prediction of the western North Pacific summer climate around the late 1970s and early 1990s

    Science.gov (United States)

    Li, Chaofan; Lu, Riyu; Dong, Buwen

    2016-04-01

    Identifying predictability and the corresponding sources for the western North Pacific (WNP) summer climate in the case of non-stationary teleconnections during recent decades benefits for further improvements of long-range prediction on the WNP and East Asian summers. In the past few decades, pronounced increases on the summer sea surface temperature (SST) and associated interannual variability are observed over the tropical Indian Ocean and eastern Pacific around the late 1970s and over the Maritime Continent and western-central Pacific around the early 1990s. These increases are associated with significant enhancements of the interannual variability for the lower-tropospheric wind over the WNP. In this study, we further assess interdecadal changes on the seasonal prediction of the WNP summer anomalies, using May-start retrospective forecasts from the ENSEMBLES multi-model project in the period 1960-2005. It is found that prediction of the WNP summer anomalies exhibits an interdecadal shift with higher prediction skills since the late 1970s, particularly after the early 1990s. Improvements of the prediction skills for SSTs after the late 1970s are mainly found around tropical Indian Ocean and the WNP. The better prediction of the WNP after the late 1970s may arise mainly from the improvement of the SST prediction around the tropical eastern Indian Ocean. The close teleconnections between the tropical eastern Indian Ocean and WNP summer variability work both in the model predictions and observations. After the early 1990s, on the other hand, the improvements are detected mainly around the South China Sea and Philippines for the lower-tropospheric zonal wind and precipitation anomalies, associating with a better description of the SST anomalies around the Maritime Continent. A dipole SST pattern over the Maritime Continent and the central equatorial Pacific Ocean is closely related to the WNP summer anomalies after the early 1990s. This teleconnection mode is quite

  9. Plate tectonic reconstructions and paleogeographic maps of the central and North Atlantic oceans

    OpenAIRE

    Sibuet, Jean-Claude; Rouzo, Stephane; Srivastava, Shiri

    2012-01-01

    We have established a new plate kinematic model of the central and North Atlantic oceans between North America, Africa, Meseta, Iberia, Flemish Cap, and Galicia Bank from Late Triassic to Late Cretaceous to better understand the nature and timing of rifting of Nova Scotia and Morocco conjugate continental margins since Late Triassic. The maps of salt distributions at the Sinemurian-Pliensbachian limit (190 Ma; after salt deposition) and in middle Bajocian (170 Ma) show that an area of the Nov...

  10. Variability in transport processes of Pacific saury Cololabis saira larvae leading to their broad dispersal: Implications for their ecological role in the western North Pacific

    Science.gov (United States)

    Oozeki, Yoshioki; Okunishi, Takeshi; Takasuka, Akinori; Ambe, Daisuke

    2015-11-01

    Transport of Pacific saury Cololabis saira larvae from spawning to nursery grounds was examined based on datasets from larval distribution surveys during winter seasons 1990-2011. In the surveys, a neuston net was towed for 10 min over broad areas off the southern Pacific coast of Japan. Transport trajectories of saury larvae and temperature they experienced were analyzed based on a numerical particle-tracking model from 1993 to 2011 using satellite-based sea surface current and temperature data. Larval growth during the transport was estimated from the relationship of larval growth to environmental factors obtained in a previous study. Results of the particle tracking experiments indicated that a large amount of saury juveniles (knob length, KnL, 40 mm) were transported to an area south of the Kuroshio axis. Only a relatively small amount (14.6%) of the 40 mm KnL stage juveniles were transported in and around the Kuroshio extension, although it has previously been considered important that the juveniles are transported to the area north of the Kuroshio extension. Abundance of juveniles transported to the area north of the Kuroshio extension indicated a positive relationship to the abundance of medium size class saury in the autumn fishing season. Even though a very small part (3.9%) of hatched larvae were transported to this area, recruitment of the saury population depends on this amount of transported hatched larvae. On the other hand, the high juvenile transport rate to the areas south of the Kuroshio axis may suggest a broad dispersal mechanism to ensure that some larvae find a suitable habitat. Subsequently, the importance of saury in the marine ecosystem as a food item for predatory species in the sub-tropical region is discussed.

  11. Late Miocene biogeography and paleoclimatology of the central North Atlantic

    Science.gov (United States)

    Poore, R.Z.

    1981-01-01

    Quantitative analyses of planktonic foraminiferal assemblages from Deep Sea Drilling Project (DSDP) Holes 334 and 410 demonstrate that subpolar and subtropical faunal provinces existed in the North Atlantic during the late Miocene. Climatic oscillations are clearly recorded in Hole 410 by variations in abundance of the Neogloboquadrina subpolar assemblage. These climatic oscillations have a period of about 1 m.y. Higher frequency oscillations with a periodicity of one to several hundred thousand years are evident from about 6.5 to 7.5 m.y. and are probably present throughout the entire late Miocene. A revised age of 7.0 m.y. is proposed for the first occurrence of the calcareous nannofossil Amaurolithus primus (the Amaurolithus datum). ?? 1981.

  12. Drivers of summer oxygen depletion in the central North Sea

    Science.gov (United States)

    Queste, Bastien Y.; Fernand, Liam; Jickells, Timothy D.; Heywood, Karen J.; Hind, Andrew J.

    2016-02-01

    In stratified shelf seas, oxygen depletion beneath the thermocline is a result of a greater rate of biological oxygen demand than the rate of supply of oxygenated water. Suitably equipped gliders are uniquely placed to observe both the supply through the thermocline and the consumption of oxygen in the bottom layers. A Seaglider was deployed in the shallow (≍ 100 m) stratified North Sea in a region of known low oxygen during August 2011 to investigate the processes regulating supply and consumption of dissolved oxygen below the pycnocline. The first deployment of such a device in this area, it provided extremely high-resolution observations, 316 profiles (every 16 min, vertical resolution of 1 m) of conductivity, temperature, and depth (CTD), dissolved oxygen concentrations, backscatter, and fluorescence during a 3-day deployment.The high temporal resolution observations revealed occasional small-scale events (North Sea. However, the glider data show a net oxygen consumption rate of 2.8 ± 0.3 µmol dm-3 day-1, indicating a localized or short-lived (< 200 m or 6 h) increase in oxygen consumption rates. This high rate of oxygen consumption is indicative of an unidentified oxygen sink. We propose that this elevated oxygen consumption is linked to localized depocentres and rapid remineralization of resuspended organic matter.The glider proved to be an excellent tool for monitoring shelf sea processes despite challenges to glider flight posed by high tidal velocities, shallow bathymetry, and very strong density gradients. The direct observation of these processes allows more up to date rates to be used in the development of ecosystem models.

  13. Anomalous chlorofluorocarbons at the bottom of the eastern subtropical North Pacific Ocean

    Science.gov (United States)

    Min, D.; Bullister, J. L.; Fine, R. A.; Mecking, S.; Smethie, W. M., Jr.; Swift, J. H.

    2014-12-01

    Chlorofluorocarbons (CFCs) are man-made compounds which have been widely used as decadal-scale transient tracers for ocean circulation and ventilation processes. These compounds have well-known atmospheric histories and solubilities. Information derived from CFC concentration and ratio measurements in the global ocean allows us to infer the past history of deep water formation and the rates of spreading and mixing processes. These tracers have also been extensively used to compare and calibrate large-scale ocean circulation models and to estimate the oceanic uptake of anthropogenic CO2. During the P02 CLIVAR/CO2 Repeat Hydrography section along 30°N in 2004, low but detectable levels (>0.005 picomole kg-1) of CFCs (esp. CFC-12) were unexpectedly observed in deep waters (>3000-4000m) along an extensive area between Hawaii and California in the subtropical North Pacific Ocean. Near-bottom CFC concentrations tended to be higher toward the California outer continental shelf region (i.e. Southern California Borderland Basins or SCBB). Potential analytical errors or sampling contamination possibilities were carefully checked during the expedition. These anomalous bottom CFC features were observed again in the same region during the P02 revisit cruise in 2013 by an independent group. The presence of CFCs at the levels measured is inconsistent with presently understood rates and pathways of deep ventilation processes in this region. Potential mechanisms for generating these anomalous features will be discussed, including: a) previously unknown deep ventilation processes in this region; b) release of CFCs from sunken ships or other objects; c) spreading of high-CFC content deep waters from the SCBB along the continental slope; d) vertical transport of CFCs by adsorption/uptake by sinking particulates (including particulate organic matter and/or plastic debris) originating in the surface ocean and re-release in the bottom waters. Studies of sediment trap, sediment cores

  14. Latitudinal distributions of organic nitrogen and organic carbon in marine aerosols over the western North Pacific

    Directory of Open Access Journals (Sweden)

    Y. Miyazaki

    2011-04-01

    Full Text Available Marine aerosol samples were collected over the western North Pacific along the latitudinal transect from 44° N to 10° N in late summer 2008 for measurements of organic nitrogen (ON and organic carbon (OC as well as isotopic ratios of total nitrogen (TN and total carbon (TC. Increased concentrations of methanesulfonic acid (MSA and diethylammonium (DEA+ at 40–44° N and subtropical regions (10–20° N together with averaged satellite chlorophyll-a data and 5-day back trajectories suggest a significant influence of marine biological activities on aerosols in these regions. ON exhibited increased concentrations up to 260 ngN m−3 in these marine biologically influenced aerosols. Water-insoluble organic nitrogen (WION was found to be the most abundant nitrogen in the aerosols, accounting for 55 ± 16% of total aerosol nitrogen. In particular, the average WION/ON ratio was as high as 0.93 ± 0.07 at 40–44° N. These results suggest that marine biological sources significantly contributed to ON, a majority of which is composed of water-insoluble fractions in the study region. Analysis of the stable carbon isotopic ratios (δ13C indicated that, on average, marine-derived carbon accounted for ~88 ± 12% of total carbon in the aerosols. In addition, the δ13C showed higher values (from −22 to −20‰ when ON/OC ratios increased from 0.15 to 0.35 in marine biologically influenced aerosols. These results clearly show that organic nitrogen is enriched in organic aerosols originated from an oceanic region with high biological productivity, indicating a preferential transfer of nitrogen-containing organic compounds from the sea surface to the marine atmosphere. Both WION concentrations and WION/water-insoluble organic carbon (WIOC ratios tended to increase with increasing local wind speeds, indicating that sea-to-air emissions of ON via sea spray contribute significantly to the marine organic

  15. Latitudinal distributions of organic nitrogen and organic carbon in marine aerosols over the western North Pacific

    Directory of Open Access Journals (Sweden)

    Y. Miyazaki

    2010-11-01

    Full Text Available Marine aerosol samples were collected over the western North Pacific along the latitudinal transect from 44° N to 10° N in late summer 2008 for measurements of organic nitrogen (ON and organic carbon (OC as well as isotopic ratios of total nitrogen (TN and total carbon (TC. Increased concentrations of methanesulfonic acid (MSA and diethylammonium (DEA+ at 40–44° N and subtropical regions (10–20° N together with averaged satellite chlorophyll a data and 5-day back trajectories suggest a significant influence of marine biological activities on aerosols in these regions. ON exhibited increased concentrations up to 260 ngN m−3 in these marine biologically influenced aerosols. Water-insoluble organic nitrogen (WION was found to be the most abundant nitrogen in the aerosols, accounting for 55 ± 16% of total aerosol nitrogen. In particular, the average WION/ON ratio was as high as 0.93 ± 0.07 at 40–44° N. These results suggest that marine biological sources significantly contributed to ON, a majority of which is composed of water-insoluble fractions in the study region. Analysis of the stable carbon isotopic ratios (δ13C indicated that, on average, marine-derived carbon accounted for ~88 ± 12% of total carbon in the aerosols. In addition, the δ13C increased from −22 to −20‰ when ON/OC ratios increased from 0.15 to 0.35 in marine biologically influenced aerosols. These results clearly show that organic nitrogen is enriched in organic aerosols originated from an oceanic region with high biological productivity, indicating a preferential transfer of nitrogen-containing organic compounds from the sea surface to the marine atmosphere. Both WION concentrations and WION/water-insoluble organic carbon (WIOC ratios showed positive correlations with local wind speeds, suggesting that sea-to-air emissions of ON via sea spray significantly contributes to marine organic aerosols over the

  16. A comparison of mesopelagic mesozooplankton community structure in the subtropical and subarctic North Pacific Ocean

    Science.gov (United States)

    Steinberg, Deborah K.; Cope, Joseph S.; Wilson, Stephanie E.; Kobari, T.

    2008-07-01

    Mesopelagic mesozooplankton communities of an oligotrophic (Hawaii Ocean Time series-HOT station ALOHA) and a mesotrophic (Japanese time-series station K2) environment in the North Pacific Ocean are compared as part of a research program investigating the factors that control the efficiency of particle export to the deep sea (VERtical Transport In the Global Ocean—VERTIGO). We analyzed zooplankton (>350 μm) collected from net tows taken between 0 and 1000 m at each site to investigate the biomass size structure and the abundance of the major taxonomic groups in discrete depth intervals throughout the water column. Biomass of zooplankton at K2 over all depths was approximately an order of a magnitude higher than at ALOHA, with a significantly higher proportion of the biomass at K2 in the larger (>2 mm) size classes. This difference was mostly due to the abundance at K2 of the large calanoid copepods Neocalanus spp. and Eucalanus bungii, which undergo ontogenetic (seasonal) vertical migration. The overall strength of diel vertical migration was higher at K2, with a mean night:day biomass ratio in the upper 150 m of 2.5, vs. a ratio of 1.7 at ALOHA. However, the amplitude of the diel migration (change in weighted mean depth between day and night) was higher at ALOHA for all biomass size classes, perhaps due to deeper light penetration causing deeper migration to avoid visual predators. A number of taxa known to feed on suspended or sinking detritus showed distinct peaks in the mesopelagic zone, which affects particle transport efficiency at both sites. These taxa include calanoid and poecilostomatoid (e.g., Oncaea spp.) copepods, salps, polychaetes, and phaeodarian radiolaria at K2, harpacticoid copepods at ALOHA, and ostracods at both sites. We found distinct layers of carnivores (mainly gelatinous zooplankton) in the mesopelagic at K2 including chaetognaths, hydrozoan medusae, polychaetes, and gymnosome pteropods, and, in the upper mesopelagic zone, of

  17. Marketing Remote Sensing Data for North Pacific Fisheries Development and Management

    Science.gov (United States)

    1995-01-01

    Fish poaching, drug trafficking, ocean dumping, and other illegal activities are important problems on the high seas and in national economic zones. The primary thrust of the EOCAP II project, "Marketing Remote Sensing Data for North Pacific Fisheries Development and Management", was to use space-based sensors to improve the effectiveness of marine monitoring, control, and surveillance (MCS). Our initial objectives were to concentrate on the development of MCS tools using Advanced Very High Resolution Radiometry (AVHRR) and Synthetic Aperture Radar (SAR) data. Although we have successfully completed development of an initial version of our SAR-based monitoring tool (OmniVision), project activity has resulted in a much broader application of space-based assets to marine applications. Based in part on work commenced within EOCAP II, a new company, Ocean and Coastal Environmental Sensing, Inc. (OCENS), has been launched and the development of several new software products outside of the MCS arena initiated. One of those products, SeaStation, is near completion with a Fall, 1995 release date. Equity investment in OCENS now totals $70,000-with an additional amount being sought in the first round of financing. One of the pre-eminent objectives of EOCAP II is to make contributions to the US economy and job growth through the expansion of commercial uses of remotely sensed data. OCENS and the software products it is introducing into marine and coastal zone markets responds to this primary object*e. EOCAP II funding leveraged the market and technical know-how of OCENS founders into smart products that benefit marine and coastal zone users. Although technical difficulties and geopolitical shifts damaged the commercial feasibility of initial project objectives, the flexibility of the EOCAP II program now permits long-term business success. This in no small part stems from the fact that the EOCAP program recognizes the realities of small and start-up businesses and does not

  18. Gross and microscopic morphology of lesions in Cnidaria from Palmyra Atoll, Central Pacific

    Science.gov (United States)

    Williams, Gareth J.; Work, Thierry M.; Aeby, Greta S.; Knapp, Ingrid S.; Davy, Simon K.

    2011-01-01

    We conducted gross and microscopic characterizations of lesions in Cnidaria from Palmyra Atoll, Central Pacific. We found growth anomalies (GA) to be the most commonly encountered lesion. Cases of discoloration and tissue loss were rare. GAs had a focal or multi-focal distribution and were predominantly nodular, exophytic, and umbonate. In scleractinians, the majority of GAs manifested as hyperplasia of the basal body wall (52% of cases), with an associated absence or reduction of polyp structure (mesenteries and filaments, actinopharynx and tentacles), and depletion of zooxanthellae in the gastrodermis of the upper body wall. In the soft corals Sinularia sp. and Lobophytum sp., GAs exclusively manifested as prominent hyperplasia of the coenenchyme with an increased density of solenia. In contrast to scleractinians, soft coral GAs displayed an inflammatory and necrotizing component with marked edema of the mesoglea, accompanied by infiltrates of variably-sized granular amoebocytes. Fungi, algae, sponges, and Crustacea were present in some scleractinian GAs, but absent in soft coral GAs. Fragmentation of tissues was a common finding in Acropora acuminata and Montipora cf. dilatata colonies with tissue loss, although no obvious causative agents were seen. Discoloration in the zoanthid, Palythoa tuberculosa, was found to be the result of necrosis, while in Lobophytum sp. discoloration was the result of zooxanthellar depletion (bleaching). Soft corals with discoloration or tissue loss showed a marked inflammatory response, however no obvious causative organisms were seen. Lesions that appeared similar at the gross level were revealed to be distinct by microscopy, emphasizing the importance of histopathology.

  19. Os isotope dating and growth hiatuses of Co-rich crust from central Pacific

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Up to now, accurate determination of the growth age and hiatuses of the Co-rich crust is still a difficult work, which constrains the researches on the genesis, growth process, controlling factors, regional tectonics, paleo-oceanographic background, etc. of the Co-rich crust. This paper describes our work in determining the initial growth age of the Co-rich crust to be of the late Cretaceous Campanian Stage (about 75-80 Ma), by selecting the Co-rich crust with clear multi-layer structures in a central Pacific seamount for layer-by-layer sample analysis and using a number of chronological methods, such as Co flux dating, dating by correlation with 187Os/188Os evolution curves of seawater, and stratigraphic divi- sion by calcareous nannofossils. We have also discovered growth hiatuses with different time intervals in the early Paleocene, middle Eocene, late Eocene and early-middle Miocene, respectively. These re- sults have provided an important age background for further researches on the Co-rich crust growth process and the paleo-oceanographic environment evolution thereby revealed in the said region.

  20. Physical and chemical effects of ingested plastic debris on short-tailed shearwaters, Puffinus tenuirostris, in the North Pacific Ocean

    OpenAIRE

    Yamashita, Rei; Takada, Hideshige; Fukuwaka, Masa-aki; Watanuki, Yutaka

    2011-01-01

    We investigated the plastics ingested by short-tailed shearwaters, Puffinus tenuirostris, that were accidentally caught during experimental fishing in the North Pacific Ocean in 2003 and 2005. The mean mass of plastics found in the stomach was 0.23 g per bird (n = 99). Plastic mass did not correlate with body weight. Total PCB (sum of 24 congeners) concentrations in the abdominal adipose tissue of 12 birds ranged from 45 to 529 ng/g-lipid. Although total PCBs or higher-chlorinated congeners, ...

  1. Acoustic detection and satellite-tracking leads to discovery of rare concentration of endangered North Pacific right whales

    OpenAIRE

    Wade, Paul; Heide-Jørgensen, Mads Peter; Shelden, Kim; Barlow, Jay; Carretta, James; Durban, John; LeDuc, Rick; Munger, Lisa; Rankin, Shannon; Sauter, Allan; Stinchcomb, Charles

    2006-01-01

    The North Pacific right whale, Eubalaena japonica, is one of the most endangered species of whale in the world. On 10 August 2004, two right whales were located in the Bering Sea using headings to right whale calls provided by directional sonobuoys. A satellite-monitored radio tag attached to one of these whales functioned for 40 days. Over the 40-day period, this whale moved throughout a large part of the southeast Bering Sea shelf, including areas of the outer-shelf where right whales have ...

  2. Effects of the Yakutat terrane collision with North America on the neighboring Pacific plate

    Science.gov (United States)

    Reece, R.; Gulick, S. P.; Christeson, G. L.; Barth, G. A.; van Avendonk, H.

    2011-12-01

    High-resolution bathymetry data show a 30 km N-S trending ridge within the deep-sea Surveyor Fan between the mouths of the Yakutat Sea Valley and Bering Trough in the Gulf of Alaska. The ridge originates in the north, perpendicular to and at the base of the continental slope, coincident with the Transition Fault, the strike-slip boundary between the Yakutat terrane (YAK) and the Pacific plate (PAC). The ridge exhibits greatest relief adjacent to the Transition Fault, and becomes less distinct farther from the shelf edge. Seismic reflection data reveal a sharp basement high beneath the ridge (1.1 sec of relief above "normal" basement in two-way travel time) as well as multiple similarly oriented strike-slip fault segments. The ridge, basement high, and faults are aligned and co-located with an intraplate earthquake swarm on the PAC, which includes four events > 6.5 Mw that occurred from 1987-1992. The swarm is defined by right-lateral strike-slip events, and is collectively called the Gulf of Alaska Shear Zone (GASZ). Based on the extent of historic seismicity, the GASZ extends at least 230 km into the PAC, seemingly ending at the Kodiak-Bowie Seamount Chain. Farther southwest, between the Kodiak-Bowie and Patton-Murray Seamount Chains, there is a large regional bathymetric low with an axis centered along the Aja Fracture Zone, perpendicular to the GASZ and Aleutian Trench. Basement and overlying sediment in the low are irregularly, but pervasively faulted. The GASZ and faulted bathymetric low could represent PAC deformation due to PAC-YAK coupling whereby YAK resistance to subduction is expressed as deformation in the thinner (weaker) PAC crust. The YAK is an allochthonous, basaltic terrane coupled to the PAC that began subducting at a low angle beneath North America (NA) ~25-40 Ma. Due to its 15-25 km thickness, the YAK is resistant to subduction compared to the normal oceanic crust of the PAC. As a result the plates developed differential motion along the

  3. 78 FR 4835 - Endangered and Threatened Species; Recovery Plan for the North Pacific Right Whale

    Science.gov (United States)

    2013-01-23

    ... Pacific Ocean, but the population was dramatically reduced by extensive commercial whaling, now prohibited by the International Whaling Commission. It is estimated that roughly 1,000 individuals remain....

  4. Regional Climate Change Influences Frequency of Frost Damage via Changes in Phenology: Effects of the North Pacific Oscillation (Pacific Decadal Oscillation) on Rocky Mountain Wildflowers

    Science.gov (United States)

    Inouye, D. W.

    2004-12-01

    There is a significant correlation (P = .049) between the state of the North Pacific Oscillation (Pacific Decadal Oscillation) and the amount of winter snowfall at the Rocky Mountain Biological Laboratory (2,800m in the Colorado Rocky Mountains). The 1998 change of this inter-decadal mode of variability of the north Pacific atmosphere system to a dry phase has resulted in decreased snowpack, reversing a trend for increasing snowfall since the previous phase change in 1976. The seasonal timing (phenology) of plant growth and flowering at high altitudes is determined almost entirely by the timing of spring snowmelt, even for species that flower at the end of the season, and the decreased snowpack since 1998 combined with warming air temperatures has resulted in significantly earlier initiation of the growing season and subsequent flowering. Flowering in 2002, for example, was the earliest recorded during my 31-year study, and probably the earliest since at least 1935. Frost (with temperatures as low as -6 or -7ºC) is still likely to occur as late as mid-June, however, and a consequence of the earlier beginning of the growing season is that many species have developed sensitive flower buds or other tissues by mid-June that are likely to be killed by frost. From 1994-1998 the average percentage of flower buds of Helianthella quinquenervis (Asteraceae; aspen sunflower) killed by frost was 26 percent(range 0-81), but since the 1998 NPO phase change a mean of 75 percent of flower buds have been killed (range 0-100; over 90 percent for each of the past four years). The loss of flowers from these frosts has consequences for plant demography (fewer seeds results in fewer seedlings), pollinators (which have fewer floral resources), seed predators (e.g., tephritid flies), and parasitoids (e.g., wasps, which have fewer seed predators to parasitize). A suite of wildflower species whose flowering abundance is positively correlated with the amount of winter snowfall has also

  5. Feeding habits of Dall's porpoises ( Phocoenoides dalli) in the subarctic North Pacific and the Bering Sea basin and the impact of predation on mesopelagic micronekton

    Science.gov (United States)

    Ohizumi, Hiroshi; Kuramochi, Toshiaki; Kubodera, Tsunemi; Yoshioka, Motoi; Miyazaki, Nobuyuki

    2003-05-01

    We investigated the stomach contents of Dall's porpoises collected in pelagic waters spanning most of their range in the North Pacific and the Bering Sea. Analysis revealed the porpoises fed mainly on myctophid fishes in the subarctic North Pacific and on gonatid squids as well as myctophid fishes in the Bering Sea. Most of the prey items were mesopelagic micronekton, primarily fishes and squids that migrate vertically to shallower waters at night. Stomach content was greater during twilight hours, suggesting the porpoises foraged actively on myctophids at night in shallower waters. Stomach contents were strongly characterized by local mesopelagic prey fauna, and prey species selectivity was not apparent. The annual consumption by Dall's porpoises was estimated to be 2.0-2.8 million tons, or 4.7-6.5% of the biomass of mesopelagic fishes in the subarctic North Pacific, and may account for approximately 24-33% of the overall mortality of mesopelagic micronekton, especially myctophids. Myctophids are also common, but less important, prey of other subarctic predators. Dall's porpoises are likely the primary consumers of myctophids in the subarctic North Pacific. Since myctophids are the major component of the mesotrophic level, the trophic relationship between myctophids and Dall's porpoises is thought to be an important pathway of mass and energy in the pelagic food web in the subarctic North Pacific.

  6. Cooling ponds and small rivers in north central United States

    International Nuclear Information System (INIS)

    An attempt is made to review those Commonwealth Edison (Ceco) programs related directly or indirectly to compensation and stock manipulation in fish populations. The direct stocking of sport fish fingerlings for mitigation is one method of stock manipulation. There are, however, two other, less common manipulative approaches to enhancing local fish stocks. First is the use of cooling ponds as off-stream nursery areas for forage and sport species. Second is the use of waste heat to modify habitat temperatures and permit or improve overwintering survival of select species such as gizzard or threadfin shad in north-temperate waters that are naturally too cold to sustain strong populations. This, in turn, will increase the abundance of these species as forage in subsequent years. There are four different Ceco projects which are discussed. These are: Fish releases in Pool 14 of the Mississippi River; Studies of endemic and stock fishes at the Collins and Dresden Cooling Ponds; Fish and water quality monitoring of the Des Plaines and Upper Illinois Rivers; and Proposed walleye, muskellunge and striped bass x white bass hybrid stocking in the Rock River. 7 references

  7. A hypothesis and a case-study projection of an influence of MJO modulation on boreal-summer tropical cyclogenesis in a warmer climate with a global non-hydrostatic model: a transition toward the central Pacific?

    Directory of Open Access Journals (Sweden)

    KAZUYOSHI eOOUCHI

    2014-02-01

    Full Text Available The eastward shift of the enhanced activity of tropical cyclone to the central Pacific is a robust projection result for a future warmer climate, and is shared by most of the state-of-the-art climate models. The shift has been argued to originate from the underlying El-Ñino like sea-surface temperature (SST forcing. This study explores the possibility that the change of the activity of the Madden-Julian Oscillation (MJO can be an additional, if not alternative, contributor to the shift, using the dataset of Yamada et al. (2010 from a global non-hydrostatic 14-km grid mesh time-slice experiment for a boreal-summer case. Within the case-study framework, we develop the hypothesis that an eastward shift of the high-activity area of the MJO, as manifested itself as the significant intra-seasonal modulation of the enhanced precipitation, is associated with the increased tropical cyclogenesis potential over the North central Pacific by regulating cyclonic relative vorticity and vertical shear. In contrast, the North Indian Ocean and maritime continent undergo relatively diminished genesis potential. An implication is that uncertainty in the future tropical cyclogenesis in some part of the Pacific and other ocean basins could be reduced if projection of the MJO and its connection with the underlying SST environment can be better understood and constrained by the improvement of climate models.

  8. Observation of the April 2001 Asian Dust Event by Robotic Carbon Biomass Profiling Floats in the Subarctic North Pacific

    Science.gov (United States)

    Bishop, J. K.; Davis, R. E.

    2001-12-01

    My thesis work (Bishop, 1977) with John was to explore the first aspects of particulate matter biogeochemistry using large volume in-situ filtration sampling. The hardware has evolved from a single sampling device to the 12 unit Multiple Unit Large Volume in-situ Filtration System (MULVFS). These samples have been analyzed for an increasingly 'Edmondian' suite of chemical species. The science question John asked me to address was "How does the chemistry, biology and vertical flux of particulate matter vary in space and time? What are the dominant controlling processes?" The question remains central to the understanding of the biologically driven part of ocean's carbon cycle and still is largely unanswered for most of the world's ocean, especially in the upper ocean from the base of the euphotic zone to kilometer depths. A recent milestone for MULVFS sampling was our first winter-time collection of particles from waters of the subarctic Pacific during Feb. 1996. This kilometer deep profile did establish a benchmark for interpretation of changes in particulate matter abundances in subsurface waters in later seasons. At the same time we found abundant large diatoms and a coccolithophore `bloomlet' in the winter-time surface layer. They had vanished when we revisted the site 9 weeks later. The system had moved much faster than we could follow. The international project Argo will deploy several thousand autonomous profiling floats over the next few years to provide an improved view of the climate state of the ocean. The recent 20-fold plus improvement of rates of ocean to satellite data telemetry permits augmentation of the long-lived Argo-style floats with low-power sensors for carbon system components. As a first step, we have developed a prototype robotic autonomous carbon observer capable of performing high frequency (diurnal) observations of the upper kilometer for seasons to years. The aim is to enable improved exploration of the ocean biological carbon pump

  9. Central Tropical Pacific SST and Salinity Variability over the Little Ice Age

    Science.gov (United States)

    Sayani, H. R.; Cobb, K. M.; Khare, A.; Stone, C.; Grothe, P. R.; Chen, T.; Cheng, H.; Lu, Y.; Edwards, R. L.

    2015-12-01

    Anthropogenic trends are difficult to separate from natural variability in the tropical Pacific, where instrumental data coverage is sparse. Of particular interest are variations of climate in the pre-industrial era, but instrumental data from this time period is virtually nonexistent. Corals allow for the investigation of pre-industrial climate variability, but most living coral colonies rarely span more than a century. Fossil corals provide a valuable archive of climate variability over the past millennia [Cobb et al., 2013] and are best suited to the reconstruction of ENSO. For the reconstruction of mean climate, systematic offsets between proxy records from contemporaneous corals translates to large error bars on the resulting reconstructions [e.g. Felis et al., 2003; Pfeiffer et al., 2009]. By building composite paleoclimate records using multiple corals from the Line Islands (2°N - 6°N, 157°W - 162°W), we quantify mean climate state and climate variability in the central tropical Pacific (CTP) during the Little Ice Age (LIA). We compare paired d18O and Sr/Ca records from Line Island fossil corals to a large collection of modern coral d18O and Sr/Ca records from the same islands to estimate SST and salinity changes from the LIA to the late 20th century. Taken together, Sr/Ca records from three Palmyra Atoll fossil corals spanning 1630-1703CE suggest CTP temperatures may have been 1.7±0.9˚C cooler during much of the 17th century. Reconstructed seawater d18O values are indicative of drier conditions at Palmyra, consistent with a southward shift of the ITCZ during the LIA documented in sediments from the Line Islands [Sachs et al., 2009]. We compare the results from seven LIA-dated fossil corals from nearby Christmas Island (Kiritimati; 2˚N, 157˚W) to the results obtained from Palmyra, enabling us to resolve potential shifts in the meridional gradients of SST and hydrology in this region during the LIA. References:Cobb, K. M., et al. (2013) Science. doi

  10. Sedimentary record of mid-Miocene seismotectonic activity in the Sinop Peninsula, north-central Turkey

    OpenAIRE

    Ayhan ILGAR

    2014-01-01

    The middle Miocene shallow-marine siliciclastic succession in the Sinop Peninsula, north-central Turkey, bears a well-preserved sedimentary record of syndepositional deformation associated with the buried escarpment of an oblique-slip dextral reverse fault and attributed to seismotectonic activity. The deposition occurred in a marginal trough at the edge of a tectonically inverted retroarc foreland basin of the Central Pontides. The synsedimentary deformation involved contemporaneous shorefac...

  11. Geographic information system (GIS) compilation of geophysical, geologic, and tectonic data for the Circum-North Pacific

    Science.gov (United States)

    Greninger, Mark L.; Klemperer, Simon L.; Nokleberg, Warren J.

    1999-01-01

    The accompanying directory structure contains a Geographic Information Systems (GIS) compilation of geophysical, geological, and tectonic data for the Circum-North Pacific. This area includes the Russian Far East, Alaska, the Canadian Cordillera, linking continental shelves, and adjacent oceans. This GIS compilation extends from 120?E to 115?W, and from 40?N to 80?N. This area encompasses: (1) to the south, the modern Pacific plate boundary of the Japan-Kuril and Aleutian subduction zones, the Queen Charlotte transform fault, and the Cascadia subduction zone; (2) to the north, the continent-ocean transition from the Eurasian and North American continents to the Arctic Ocean; (3) to the west, the diffuse Eurasian-North American plate boundary, including the probable Okhotsk plate; and (4) to the east, the Alaskan-Canadian Cordilleran fold belt. This compilation should be useful for: (1) studying the Mesozoic and Cenozoic collisional and accretionary tectonics that assembled this continental crust of this region; (2) studying the neotectonics of active and passive plate margins in this region; and (3) constructing and interpreting geophysical, geologic, and tectonic models of the region. Geographic Information Systems (GIS) programs provide powerful tools for managing and analyzing spatial databases. Geological applications include regional tectonics, geophysics, mineral and petroleum exploration, resource management, and land-use planning. This CD-ROM contains thematic layers of spatial data-sets for geology, gravity field, magnetic field, oceanic plates, overlap assemblages, seismology (earthquakes), tectonostratigraphic terranes, topography, and volcanoes. The GIS compilation can be viewed, manipulated, and plotted with commercial software (ArcView and ArcInfo) or through a freeware program (ArcExplorer) that can be downloaded from http://www.esri.com for both Unix and Windows computers using the button below.

  12. Weights, hematology and serum chemistry of free-ranging brown boobies (Sula leucogaster) in Johnston Atoll, Central Pacific

    Science.gov (United States)

    Work, T.M.

    1999-01-01

    Hematologic and serum chemistry values are reported for 105 brown boobies (Sula leucogaster) from Johnston Atoll, Central Pacific. Hematocrit, estimated total plasma solids, total and differential white cell counts, serum glucose, calcium, phosphorus, uric acid, total protein, albumin, globulin, aspartate aminotransferase, and creatinine phosphokinase were analyzed. Hematologic and serum chemistry values varied with age and sex. Values were compared with those of red-footed boobies and other tropical and temperate marine pelecaniforms.

  13. Abyssal fauna of the UK-1 polymetallic nodule exploration claim, Clarion-Clipperton Zone, central Pacific Ocean: Echinodermata

    OpenAIRE

    Glover, Adrian G.; Wiklund,Helena; Rabone, Muriel; Amon, Diva J; Smith, Craig R.; O'Hara,Tim; Mah, Christopher L.; Dahlgren, Thomas G

    2016-01-01

    Abstract We present data from a DNA taxonomy register of the abyssal benthic Echinodermata collected as part of the Abyssal Baseline (ABYSSLINE) environmental survey cruise ‘AB01’ to the UK Seabed Resources Ltd (UKSRL) polymetallic-nodule exploration claim ‘UK-1’ in the eastern Clarion-Clipperton Zone (CCZ), central Pacific Ocean abyssal plain. Morphological and genetic data are presented for 17 species (4 Asteroidea , 4 Crinoidea , 2 Holothuroidea and 7 Ophiuroidea ) identified by a combinat...

  14. Postrelease survival, vertical and horizontal movements, and thermal habitats of five species of pelagic sharks in the central Pacific Ocean

    OpenAIRE

    Musyl, Michael K.; Brill, Richard W; Curran, Daniel S.; Fragoso, Nuno M.; McNaughton, Lianne M.; Nielsen, Anders; Kikkawa, Bert S.; Moyes, Christopher D

    2011-01-01

    From 2001 to 2006, 71 pop-up satellite archival tags (PSATs) were deployed on five species of pelagic shark (blue shark [Prionace glauca]; shortfin mako [Isurus oxyrinchus]; silky shark [Carcharhinus falciformis]; oceanic whitetip shark [C. longimanus]; and bigeye thresher [Alopias superciliosus]) in the central Pacific Ocean to determine species-specific movement patterns and survival rates after release from longline fishing gear. Only a single postrelease mortality could be unequivoc...

  15. Impact of the intraseasonal variability of large-scale circulation over the Western North Pacific on the characteristics of tropical cyclone track

    OpenAIRE

    Chen, T. C.; Wang, Shih-Yu; Yen, M. C.; Clark, A J

    2009-01-01

    The life cycle of the Southeast Asian–western North Pacific monsoon circulation is established by the northward migrations of the monsoon trough and the western Pacific subtropical anticyclone, and is reflected by the intraseasonal variations of mo nsoon westerlies and trad e easterlies in the form of an east–west seesaw oscillation. In this paper, an effort is made to disclose the influence of this monsoon circulation on tropical cyclone tracks during its different ph ases using composite ch...

  16. Analysis and prognosis of tropical cyclone genesis over the western North Pacific on the background of global warming

    Institute of Scientific and Technical Information of China (English)

    LI Yongping; WANG Xiaofeng; YU Runling; QIN Zenghao

    2007-01-01

    As revealed by the observational study, there are more tropical cyclones generated over the western North Pacific from the early 1950s to the early 1970s in the 20th century and less tropical cyclones from the mid-1970s to the present. The decadal change of tropical cyclones activities are closely related to the decadal changes of atmospheric general circulation in the troposphere, which provide favorable or unfavorable conditions for the formation of tropical cyclone. Furthermore, based on the simulation of corresponding atmospheric general circulation from a coupled climate model under the schemes of Intergovernmental Panel on Climate Change (IPCC) special report on emission scenarios (SRES) A2 and B2 emissions scenarios an outlook on the tropical cyclone frequency generated over the western North Pacific in the coming half century is presented. It is indicated that in response to the global climate change the general circulation of atmosphere would become unfavorable for the formation of tropical cyclone as a whole and the frequency of tropical cyclones formation would likely decrease by 5% within the next half century, although more tropical cyclones would appear during a short period in it.

  17. DIGITAL GEOLOGIC MAP OF SHERMAN QUADRANGLE, NORTH CENTRAL TEXAS (CD-ROM)

    Science.gov (United States)

    This compact disc contains digital data sets of the surficial geology and geologic faults for the 1:250,000-scale Sherman quadrangle, North Central Texas, and can be used to make geologic maps, and determine approximate areas and locations of various geologic units. The source d...

  18. Open-Country Poverty in a Relatively Affluent Area - The East North Central States.

    Science.gov (United States)

    Fitzwilliams, Jeanette

    Poverty among open-country households in the East North Central States (11%) was slightly above the incidence found among U.S. whites in general. Incidence of poverty was greatest among the aged, disabled, and small farmers of all ages who made farming their major source of earnings. Of the respondent households in this 1967 survey, 87% had…

  19. Sweet corn growth and yield responses to planting dates of the north central U.S.

    Science.gov (United States)

    Sweet corn is planted over a three-month period in the north central U.S. in order to extend availability for fresh market and processing; however, the extent to which development and growth of sweet corn changes during this period is unreported. Field experiments were conducted in 2006 and 2007 to...

  20. Residual Weeds of Processing Sweet Corn in the North Central Region

    Science.gov (United States)

    Knowledge of weed community structure in vegetable crops of the North Central Region (NCR) is poor. To characterize weed composition of species persisting in sweet corn to harvest, hereafter called residual weeds, 175 sweet corn fields were surveyed in Illinois, Minnesota, and Wisconsin from 2005 to...

  1. Lawn Weeds and Their Control. North Central Regional Extension Publication No. 26.

    Science.gov (United States)

    Purdue Univ., Lafayette, IN. Cooperative Extension Service.

    This publication discusses lawn weed control for the twelve state north central region of the country. Written for use by homeowners, the publication focuses on weed identification and proper herbicide selection and application. Identification of weeds and safe and appropriate herbicide use are emphasized. Forty-six weed and turf plants are…

  2. Climate Variability and Phytoplankton in the Pacific Ocean

    Science.gov (United States)

    Rousseaux, Cecile

    2012-01-01

    The effect of climate variability on phytoplankton communities was assessed for the tropical and sub-tropical Pacific Ocean between 1998 and 2005 using an established biogeochemical assimilation model. The phytoplankton communities exhibited wide range of responses to climate variability, from radical shifts in the Equatorial Pacific, to changes of only a couple of phytoplankton groups in the North Central Pacific, to no significant changes in the South Pacific. In the Equatorial Pacific, climate variability dominated the variability of phytoplankton. Here, nitrate, chlorophyll and all but one of the 4 phytoplankton types (diatoms, cyanobacteria and coccolithophores) were strongly correlated (pclimate variability can play in ocean biology.

  3. Classification of seamount morphology and its evaluating significance of ferromanganese crust in the central Pacific Ocean

    Institute of Scientific and Technical Information of China (English)

    CHU Fengyou; SUN Guosheng; MA Weilin; LI Shoujun; QIAN Xinyan; ZHAO Hongqiao

    2006-01-01

    Using the SeaBeam technology, the morphology of seamount and its relation to the formation of cobalt-rich crust in the central Pacific Ocean were surveyed during the cruise in 2003 for marine mineral resources. The result shows that seamounts can be divided morphologically into the spire seamount and the flat topped seamount. These two types of seamount bear great differences in their landform, lithology and cobalt-rich crust. On the upper portion of the flat topped seamount, the flat top and the sharp escarpments are unfavorable to the growth of crust, and, consequently, the crusts here are mostly laminar or gravelly, their thicknesses generally show great variations, and the consecutive ore body often develops in its deep water region. On the spire topped seamount, however, the flat area is small, and its gradient is constant without large variation from the top to the bottom. This favors the growth of cobalt-rich crust and often leads to consecutive tabular ore body of medium thickness, occurring on the spire topped seamount from the shallow water region to the deep water region. The cobalt-rich crust on the spire topped seamount is much better than that on the flat topped seamount for the crust abundance, crust coverage and number of ore-occurrences within unit area. Furthermore, the crust on the spire topped seamount is rich in cobalt, nickel, manganese elements of high economic value. Because the crust with high quality ore often occurs in the shallow water region on the spire topped seamount, it can be mined and use more easily in the future.

  4. The diverse crustal structure and magmatic evolution of the Manihiki Plateau, central Pacific

    Directory of Open Access Journals (Sweden)

    K. Hochmuth

    2014-07-01

    Full Text Available The Manihiki Plateau is a Large Igneous Province (LIP in the central Pacific. It was emplaced as part of the "Super-LIP" Ontong Java Nui and experienced fragmentation into three sub-plateaus, possibly during the break-up of Ontong Java Nui. The Manihiki Plateau is presumably the centerpiece of this "Super-LIP" and its investigation can therefore decipher the break-up mechanisms as well as the evolution of the plateau after its initial emplacement. By analyzing two seismic refraction/wide-angle reflection profiles crossing the two largest sub-plateaus of the Manihiki Plateau, the High Plateau and the Western Plateaus, we give new insights into their crustal structure and magmatic evolution. The High Plateau shows a crustal structure of 20 km thickness and a seismic P wave velocity distribution, which is comparable to other LIPs. The High Plateau experienced a strong secondary volcanism, which can be seen in relicts of seamount chain volcanism. The Western Plateaus on the other hand show no extensive secondary volcanism and are mainly structured by fault systems and sedimentary basins. A constant decrease in Moho depth (9–17 km is a further indicator of crustal stretching on the Western Plateaus. Those findings lead to the conclusion, that the two sub-plateaus of the Manihiki Plateau experienced a different magmatic and tectonic history. Whereas the High Plateau experienced a secondary volcanism, the Western Plateaus underwent crustal stretching during and after the break-up of Ontong Java Nui. This indicates, that the sub-plateaus of the Manihiki Plateau play an individual part in the break-up history of Ontong Java Nui.

  5. 234Th, 210Pb, 210Po and stable Pb in the central equatorial Pacific: Tracers for particle cycling

    Science.gov (United States)

    Murray, J.W.; Paul, B.; Dunne, J.P.; Chapin, T.

    2005-01-01

    Samples were collected during the 1992 US JGOFS EqPac Survey I and II cruises from 12??N to 12??S at 140??W in the central equatorial Pacific for water column profiles of dissolved, particulate and total 234Th, 210Pb and 210Po and total acid soluble stable Pb and sediment trap fluxes of 234Th, 210Pb and 210Po. Survey I occurred in February/March with moderate El Nino conditions while Survey II was conducted in September/October when there was a well developed cold-tongue. 234Th, 210Pb and 210Po are all particle reactive yet they partition differently between dissolved and particulate phases. Fractionation factors (the ratios of the distribution coefficients) show that the selectivity for suspended and sediment trap particles follows Th>Po>Pb. Scavenging residence times (??) for 234Th, 210Pb and 210Po ranged from 25 to 100 d, 3 to 8 years and 100 to 500 d, respectively. These particle reactive tracers have very different distributions in the water column, which reflect differences in their sources and sinks. The deficiency of 234Th relative to 238U was fairly uniformly distributed meridionally, though deficiencies were higher during Survey II when there was higher new production. Excess 210Pb relative to 226Ra was very asymmetrical with much higher excess values north of the equator. The distributions were similar for Surveys I and II. The deficiency of 210Po relative to 210Pb had a symmetrical distribution about the equator for both Survey I and II but the deficiencies were larger during Survey I when upwelling was smaller. Stable Pb was generally higher at the surface than at 250 m and there was no meridional trend from 12??N to 12??S. A mass balance for 210Pb was used to determine the atmospheric input of 210Pb. The average values for Surveys I and II were 0.12 and 0.32 dpm cm-2 year-1, respectively. There was no general increase in atmospheric input of 210Pb north of the equator but there was a strong maximum at 2-3??N during Survey I coincident with the

  6. Techno-Arrogance and Halfway Technologies: Salmon Hatcheries on the Pacific Coast of North America.

    Science.gov (United States)

    Meffe, Gary K.

    1993-01-01

    Discusses an attempt to recover Pacific salmonid fisheries with hatcheries as an example of a human attitude toward nature that places technological mastery over nature at the forefront of our approach to many environmental problems. Points out how this approach addresses the symptoms but not the causes of the salmon population decline. Suggests…

  7. Investigations of the preferred modes of north Pacific jet variability, their downstream impacts, and tropical and extratropical precursors

    Science.gov (United States)

    Griffin, Kyle S.

    Time extended EOF (TE-EOF) analysis is employed to examine the synoptic-scale evolution of the two leading modes of north Pacific jet stream variability, namely its zonal extension/retraction (TE-EOF 1) and the north/south shift of its exit region (TE-EOF 2). Composite analyses are constructed preceding and following peaks in the principal component associated with each of the two TE-EOFs, providing insight into the preferred evolutions of the north Pacific jet. Jet extension events are associated with an anomalous Gulf of Alaska cyclone, while jet retractions are associated with an anomalous ridge over the Aleutians. Similar but shifted upper level patterns are noted with the corresponding poleward/equatorward shifted jet phases, with the poleward (equatorward) shift of the jet exit region associated with anomalous low-level warmth (cold) over western North America. Such composites also suggest connections between certain phases of these leading modes of jet variability and deep convection in the tropics, a connection that has been challenging to physically diagnose in previous studies. The isentropic pressure depth measures the mass contained within an isentropic layer in a given grid column, enabling the tracking of mass exhausted by deep convection. The gradient of isentropic pressure depth is directly associated with the vertical geostrophic wind shear in that layer and thus provides a means to track the influence of convective mass flux on the evolution of the jet stream. A case study focused on the extreme North American warm episode of March 2012 demonstrates how positive pressure depth anomalies from a strong MJO event impact the jet stream over eastern Asia and drive a portion of the mid-latitude response that leads to the flow amplification and subsequent downstream warmth. This study demonstrates one way by which isentropic pressure depth can diagnose the impacts of tropical deep convection on the mid-latitude circulation. Using TE-EOFs, composites of

  8. Zooplankton abundance, biovolume and size spectra at western boundary currents in the subtropical North Pacific during winter 2012

    Science.gov (United States)

    Dai, Luping; Li, Chaolun; Yang, Guang; Sun, Xiaoxia

    2016-03-01

    Horizontal changes in mesozooplankton abundance, biovolume and size spectra at western boundary currents in the subtropical North Pacific during winter 2012 were evaluated by ZooScan measurement on samples collected by net towing from 23 stations. Zooplankton abundance and biovolume ranged from 35.1 to 456.8 ind. m- 3 and 4.3 to 231.7 mm3 m- 3, respectively. Copepoda were the most dominant species, followed by Chaetognatha and Tunicata. According to the Bray-Curtis cluster analysis based on biovolume of zooplankton size classes of each taxonomic group at intervals of 1 (log2 mm3 ind.- 1) between - 6 and 12 and considering the effect of regional factors, zooplankton communities were classified into four groups, which basically coincided with the geographical patterns of different currents: the North Equatorial Current (NEC), the North Equatorial Counter Current (NECC), the Kuroshio Current (KC), and the Mindanao Eddy (ME), respectively. The largest and lowest biovolumes were observed in the NECC region and the NEC region, respectively, and both were dominated by the 0.3 to 1 mm equivalent spherical diameter (ESD) size class, while the ME region was dominant by the 1 to 2 mm ESD size class. The slopes of the normalized biovolume size spectra for each group were slightly lower than - 1 (range from - 0.85 to - 0.92), which indicates that zooplankton communities in the study area were characterized by low productivity and high energy transfer efficiency.

  9. A seamless, high-resolution digital elevation model (DEM) of the north-central California coast

    Science.gov (United States)

    Foxgrover, Amy C.; Barnard, Patrick L.

    2012-01-01

    A seamless, 2-meter resolution digital elevation model (DEM) of the north-central California coast has been created from the most recent high-resolution bathymetric and topographic datasets available. The DEM extends approximately 150 kilometers along the California coastline, from Half Moon Bay north to Bodega Head. Coverage extends inland to an elevation of +20 meters and offshore to at least the 3 nautical mile limit of state waters. This report describes the procedures of DEM construction, details the input data sources, and provides the DEM for download in both ESRI Arc ASCII and GeoTIFF file formats with accompanying metadata.

  10. Mitigation of Coral Reef Warming Across the Central Pacific by the Equatorial Undercurrent: A Past and Future Divide

    Science.gov (United States)

    Karnauskas, Kristopher B.; Cohen, Anne L.; Gove, Jamison M.

    2016-02-01

    Global climate models (GCMs) predict enhanced warming and nutrient decline across the central tropical Pacific as trade winds weaken with global warming. Concurrent changes in circulation, however, have potential to mitigate these effects for equatorial islands. The implications for densely populated island nations, whose livelihoods depend on ecosystem services, are significant. A unique suite of in situ measurements coupled with state-of-the-art GCM simulations enables us to quantify the mitigation potential of the projected circulation change for three coral reef ecosystems under two future scenarios. Estimated historical trends indicate that over 100% of the large-scale warming to date has been offset locally by changes in circulation, while future simulations predict a warming mitigation effect of only 5-10% depending on the island. The pace and extent to which GCM projections overwhelm historical trends will play a key role in defining the fate of marine ecosystems and island communities across the tropical Pacific.

  11. [Species and size composition of fishes in Barra de Navidad lagoon, Mexican central Pacific].

    Science.gov (United States)

    González-Sansón, Gaspar; Aguilar-Betancourt, Consuelo; Kosonoy-Aceves, Daniel; Lucano-Ramírez, Gabriela; Ruiz-Ramírez, Salvador; Flores-Ortega, Juan Ramón; Hinojosa-Larios, Angel; de Asís Silva-Bátiz, Francisco

    2014-03-01

    State, and it also constitutes the more complete reference on the detailed size composition of a set of dominant species in a coastal lagoon in the central Mexican Pacific. PMID:24912349

  12. Nitrous oxide distribution and its origin in the central and eastern South Pacific Subtropical Gyre

    Directory of Open Access Journals (Sweden)

    J. Charpentier

    2007-05-01

    Full Text Available The biogeochemical mechanism of bacterial N2O production in the ocean has been the subject of many discussions in recent years. New isotopomeric tools can help further knowledge on N2O sources in natural environments. This research shows and compares hydrographic, nitrous oxide concentration, and N2O isotopic and isotopomeric data from three stations across the South Pacific Ocean, from the center of the subtropical oligotrophic gyre (~26° S; 114° W to the upwelling zone along the central Chilean coast (~34° S. Althought AOU/N2O and NO3 trends support the idea that most of N2O source (mainly from intermediate water (200–1000 m come from nitrification, N2O isotopomeric composition (intramolecular distribution of 15N isotopes in N2O reveals an abrupt change in the mechanism of nitrous oxide production, always observed through lower SP (site preference of 15N, at a high – stability layer, where particles could act as microsites and N2O would be produced by nitrifier denitrification (reduction of nitrite to nitrous oxide mediated by primary nitrifiers. There, nitrifier denitrification can account for 40% and 50% (center and east border of the gyre, respectively of the nitrous oxide produced in this specific layer. This process could be associated with the deceleration of sinking organic particles in highly stable layers of the water column. In constrast, coastal upwelling system is characterized by oxygen deficient condition and some N deficit in a eutrophic system. Here, nitrous oxide accumulates up to 480% saturation, and isotopic and isotopomer signal show highly complex nitrous oxide production processes, which presumably reflect both the effect of nitrification and denitrification at low oxygen levels on N2O production, but non N2O consumption by denitrification was observed.

  13. U/Th-dating living and young fossil corals from the central tropical Pacific

    Science.gov (United States)

    Cobb, Kim M.; Charles, Christopher D.; Cheng, Hai; Kastner, Miriam; Edwards, R. Lawrence

    2003-05-01

    This study evaluates the accuracy of U/Th dates for young (reef corals, both living and fossil, and explores strategies for refining those dates. The high precision of the U/Th method (±1-2%) for dating young corals is well-established. Earlier studies have demonstrated the method's accuracy for select samples of known age. However, these studies have focused on typical samples that have extremely low 232Th concentrations (tens of pg/g). Here we study the dating systematics of young corals that have low but significant amounts of 232Th (up to 1000 pg/g), indicating the presence of small fractions of non-radiogenic 230Th (i.e. 230Th not generated by in situ U decay). We report U/Th ages for living and subaerially exposed fossil corals from Palmyra Island, located in the central tropical Pacific, that range from 50 to 700 yr old. The Palmyra corals contain varying amounts of 232Th and small fractions of associated non-radiogenic 230Th. Uncertainty associated with the correction for non-radiogenic 230Th can lead to significant errors in U/Th dates. We have characterized non-radiogenic 230Th/ 232Th values, ( 230Th/ 232Th) nr, as a means of minimizing this source of error. We calculate ( 230Th/ 232Th) nr values ranging from 0 to 2×10 -5 for the Palmyra living corals by comparing measured U/Th dates to absolute dates for the living coral, whose chronology is well-established. For the fossil corals, we employ three different approaches to arrive at ( 230Th/ 232Th) nr estimates. First, we compare measured U/Th dates to absolute dates in samples from a young fossil coral that overlaps the living coral. Next, we use the firm relative dating constraints imposed by five overlapping fossil corals from the 14th-15th centuries to calculate ( 230Th/ 232Th) nr values. Finally, we attempt to anchor the 14th-15th century floating coral chronology to an absolute chronology by correlating the climate signals in the coral records to those in absolutely dated climate proxy records. All

  14. The developmental biogeography of hawksbill sea turtles in the North Pacific

    OpenAIRE

    Van Houtan, Kyle S.; Francke, Devon L.; Alessi, Sarah; Jones, T. Todd; Martin, Summer L.; Kurpita, Lauren; King, Cheryl S.; Baird, Robin W.

    2016-01-01

    Abstract High seas oceanic ecosystems are considered important habitat for juvenile sea turtles, yet much remains cryptic about this important life‐history period. Recent progress on climate and fishery impacts in these so‐called lost years is promising, but the developmental biogeography of hawksbill sea turtles (Eretmochelys imbricata) has not been widely described in the Pacific Ocean. This knowledge gap limits the effectiveness of conservation management for this globally endangered speci...

  15. Anthropogenic processing of dust affects the oxygen content of the North Pacific Ocean

    Science.gov (United States)

    Nenes, Athanasios; Ito, Taka; Johnson, Matthew; Meskhidze, Nicholas; Valett, Jackie; Deutsch, Curtis

    2015-04-01

    Observations from the last several decades show a significant expansion of the tropical Pacific oxygen minimum zone (OMZ). However, the underlying causes remain elusive, as the currently accepted effects of ocean warming and associated solubility decease cannot fully explain the observed oxygen trend. Here we show that anthropogenic pollution can change the pattern of biological productivity and oxygen trends consistent with observations in the tropics and extratropics. These effects are caused by the mobilization of iron in mineral dust by pollutants, where it is transported and deposited to the HNLC regions of the tropical pacific affecting primary productivity and oxygen consumption by bacterial respiration. In this study, it is shown that pollution-mobilized iron deposited to high latitude oceanic environments can profoundly impact subsurface oxygen and the extent of the OMZ through long-range oceanic transport. Together with the intensification of tropical upwelling since the 1990s associated with natural climate variability, our results can explain the expansion of the OMZ in the tropical Pacific in the late twentieth century. Unlike climate variability, however, anthropogenic pollution likely influences the long-term trends in marine biogeochemistry and further alters regional productivity and subsurface oxygen distributions with profound implications for marine habitats and nitrate inventory of the oceans.

  16. Distribution of {delta}{sup 14}C in western North Pacific and tracing carbons of human origin

    Energy Technology Data Exchange (ETDEWEB)

    Aramaki, Takafumi; Mizushima, Toshihiko; Togawa, Orihiko [Japan Atomic Energy Research Inst., Mutsu, Aomori (Japan). Mutsu Establishment; Watanabe, Shuichi; Tsunogai, Shizuo [Hokkaido Univ., Sapporo (Japan); Kuji, Tomoyuki [Japan marine Sience Fundation, Mutsu, Aomori (Japan)

    2001-02-01

    Seawater were collected at six points, 0deg to 48degN around 165degE. Dissolved inorganic carbonates was reduced into graphite. The ratio C-11/C-12 was measured by the accelerator mass analyzer. {sup 14}C concentration was calculated from {delta}{sup 13}C value calculated from the {sup 13}C/{sup 12}C ratio. {sup 14}C resulting from the nuclear weapon test was calculated by comparing estimated {sup 14}C and real {sup 14}C concentration. It was compared with that in 1970s. {sup 14}Cbomb has dissolved into North Pacific Intermediate Water in Arctic latitude, which has moved to Mid-latitude. (A. Yamamoto)

  17. Intraseasonal variability and tropical cyclogenesis in the western North Pacific simulated by a global nonhydrostatic atmospheric model

    Science.gov (United States)

    Nakano, Masuo; Sawada, Masahiro; Nasuno, Tomoe; Satoh, Masaki

    2015-01-01

    successive daily experiments for extended-range (30 day) forecasts are conducted using a global nonhydrostatic atmospheric model without convective parameterization. The model successfully reproduces tropical cyclogenesis (TCG) in six out of eight cases in the western North Pacific in August 2004, up to 2 weeks prior to cyclone formation. Detailed analyses reveal that Typhoon Songda's genesis is related to the eastward extension of the monsoon trough associated with the intraseasonal variability (ISV). The successful simulation of the migration and extension of the monsoon trough leads to a 2 week forecast for Songda's genesis. These findings highlight the need for a model capable of predicting the modulation of large-scale fields by ISV for TCG forecasts and that a global nonhydrostatic cloud-system-resolving model is a promising tool for TCG forecasts.

  18. Projected wave conditions in the Eastern North Pacific under the influence of two CMIP5 climate scenarios

    Science.gov (United States)

    Erikson, L. H.; Hegermiller, C. A.; Barnard, P. L.; Ruggiero, P.; van Ormondt, M.

    2015-12-01

    Hindcast and 21st century winds, simulated by General Circulation Models (GCMs), were used to drive global- and regional-scale spectral wind-wave generation models in the Pacific Ocean Basin to assess future wave conditions along the margins of the North American west coast and Hawaiian Islands. Three-hourly winds simulated by four separate GCMs were used to generate an ensemble of wave conditions for a recent historical time-period (1976-2005) and projections for the mid and latter parts of the 21st century under two radiative forcing scenarios (RCP 4.5 and RCP 8.5), as defined by the fifth phase of the Coupled Model Inter-comparison Project (CMIP5) experiments. Comparisons of results from historical simulations with wave buoy and ERA-Interim wave reanalysis data indicate acceptable model performance of wave heights, periods, and directions, giving credence to generating projections. Mean and extreme wave heights are projected to decrease along much of the North American west coast. Extreme wave heights are projected to decrease south of ∼50°N and increase to the north, whereas extreme wave periods are projected to mostly increase. Incident wave directions associated with extreme wave heights are projected to rotate clockwise at the eastern end of the Aleutian Islands and counterclockwise offshore of Southern California. Local spatial patterns of the changing wave climate are similar under the RCP 4.5 and RCP 8.5 scenarios, but stronger magnitudes of change are projected under RCP 8.5. Findings of this study are similar to previous work using CMIP3 GCMs that indicates decreasing mean and extreme wave conditions in the Eastern North Pacific, but differ from other studies with respect to magnitude and local patterns of change. This study contributes toward a larger ensemble of global and regional climate projections needed to better assess uncertainty of potential future wave climate change, and provides model boundary conditions for assessing the impacts of

  19. Influences of the El Nino Southern Oscillation and the Pacific Decadal Oscillation on the Timing of the North American Spring

    Science.gov (United States)

    McCabe, Gregory J.; Ault, Toby R.; Cook, Benjamin I.; Betancourt, Julio L.; Schwartz, Mark D.

    2012-01-01

    Detrended, modelled first leaf dates for 856 sites across North America for the period 1900-2008 are used to examine how the El Nino Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO) separately and together might influence the timing of spring. Although spring (mean March through April) ENSO and PDO signals are apparent in first leaf dates, the signals are not statistically significant (at a 95% confidence level (p Nino and positive PDO conditions. An analysis of the spatial distributions of first leaf dates for separate and combined ENSO/PDO conditions features a northwest-southeast dipole that is significantly (at p <0.05) different than the distributions for neutral conditions. The nature of the teleconnection between Pacific SST's and first leaf dates is evident in comparable composites for detrended sea level pressure (SLP) in the spring months. During positive ENSO/PDO, there is an anomalous flow of warm air from the southwestern US into the northwestern US and an anomalous northeasterly flow of cold air from polar regions into the eastern and southeastern US. These flow patterns are reversed during negative ENSO/PDO. Although the magnitudes of first leaf date departures are not necessarily significantly related to ENSO and PDO, the spatial patterns of departures are significantly related to ENSO and PDO. These significant relations and the long-lived persistence of SSTs provide a potential tool for forecasting the tendencies for first leaf dates to be early or late.

  20. Connection between the genesis number of tropical cyclones over the western North Pacific and summer rainfall over Northeast Asia

    Science.gov (United States)

    Choi, Ki-Seon; Moon, Il-Ju

    2015-10-01

    Since a tropical cyclone (TC) usually accompanies a large amount of rainfall, it is estimated that average amounts of rainfall in summer increase in Northeast Asia (NA) when the genesis of TC in the western North Pacific (WNP) is frequent. However, the present study found a negative correlation between TC genesis number in summer over the WNP and the amount of summer rainfall over the mid-latitudes of NA from 1980 to 2009. The results of the analysis reveal that in a positive TC genesis phase (years in which TCs occur more frequently than on average), an anomalous cyclone forms over the WNP, which generates anomalous cold and dry northeasterly winds in the mid-latitudes of NA, resulting in reduction of rainfall. In comparison, in a negative TC genesis phase (years in which TCs occur less frequently than on average), a large anomalous anticyclone develops over the western Pacific, which generates anomalous warm and humid southwesterly winds, resulting in increase of rainfall in the same region. The comparisons of the TC tracks between the two phases also reveal that in both phases, the TC passage number is rather low in the mid-latitudes of NA regardless of TC activities over the WNP. This suggests that TC number does not greatly affect the total amount of summer rainfall in NA; instead, a large-scale atmospheric circulation forming favorable (unfavorable) rainfall conditions in the negative (positive) TC genesis phase controls the summer rainfall in that area.

  1. The Structure of Genetic Diversity in Eelgrass (Zostera marina L.) along the North Pacific and Bering Sea Coasts of Alaska

    Science.gov (United States)

    Talbot, Sandra L.; Sage, George K; Rearick, Jolene R.; Fowler, Meg C.; Muñiz-Salazar, Raquel; Baibak, Bethany; Wyllie-Echeverria, Sandy; Cabello-Pasini, Alejandro; Ward, David H.

    2016-01-01

    Eelgrass (Zostera marina) populations occupying coastal waters of Alaska are separated by a peninsula and island archipelago into two Large Marine Ecosystems (LMEs). From populations in both LMEs, we characterize genetic diversity, population structure, and polarity in gene flow using nuclear microsatellite fragment and chloroplast and nuclear sequence data. An inverse relationship between genetic diversity and latitude was observed (heterozygosity: R2 = 0.738, P < 0.001; allelic richness: R2 = 0.327, P = 0.047), as was significant genetic partitioning across most sampling sites (θ = 0.302, P < 0.0001). Variance in allele frequency was significantly partitioned by region only in cases when a population geographically in the Gulf of Alaska LME (Kinzarof Lagoon) was instead included with populations in the Eastern Bering Sea LME (θp = 0.128–0.172; P < 0.003), suggesting gene flow between the two LMEs in this region. Gene flow among locales was rarely symmetrical, with notable exceptions generally following net coastal ocean current direction. Genetic data failed to support recent proposals that multiple Zostera species (i.e. Z. japonica and Z. angustifolia) are codistributed with Z. marina in Alaska. Comparative analyses also failed to support the hypothesis that eelgrass populations in the North Atlantic derived from eelgrass retained in northeastern Pacific Last Glacial Maximum refugia. These data suggest northeastern Pacific populations are derived from populations expanding northward from temperate populations following climate amelioration at the terminus of the last Pleistocene glaciation. PMID:27104836

  2. Surface constraints on the temporal and spatial evolution of the Farallon-Pacific-North America plate boundary

    Science.gov (United States)

    McQuarrie, N.; Oskin, M.

    2009-05-01

    Extension and volcanism are two surface derived data sets used to infer mantle processes back in time. We integrate two new large GIS-based datasets to create palinspastic restorations of extension and volcanism allowing us to readdress the relationship between plate-boundary deformation, intra-plate extension and magmatism in western North America. Using ArcGIS and custom software, we retrodeformed the NAVDat (North American Volcanic Database, navdat.geongrid.org) using the western North America reconstruction of McQuarrie and Wernicke (2005). We compare this data to strain rates calculated over a 50 km-grid forward- deformed from 36 Ma to present. With the deformed grid and palinspastically restored volcanic dataset we quantitatively compare rates of magmatism and deformation and evaluate the age, location, and migration of Cenozoic volcanic arcs. A first order conclusion from this study is that magmatism, throughout the Basin and Range, is primarily driven by plate boundary effects. The plate boundary effects include subduction and rollback of the Farallon plate, creation and expansion of slab windows as the Pacific plate intercepts the North American plate and re-establishment of the ancestral Cascade arc along the eastern margin of the Sierra Nevada at ˜ 15 Ma. Notable exceptions include the Yellowstone hotspot system along the northern boarder of our study area and late-stage (<8 Ma) passive, extension related asthenospheric upwelling that accompanied a thinning lithosphere along the eastern and western margins of the Basin and Range. The palinspastic reconstructions presented here highlight that the classic, high-angle, Basin and Range faulting that comprises most of the physiographic Basin and Range province commenced during a remarkably amagmatic period. These observations largely contradicts the active rifting model where magmatism triggers Basin and Range extension

  3. Wildlife use of existing culverts and bridges in North Central Pennsylvania

    OpenAIRE

    Brudin, Carl O. III

    2003-01-01

    The Pennsylvania Department of Transportation (PENNDOT) District 3-0 initiated a study in North Central Pennsylvania evaluating existing bridges and culverts for use as underpasses by wildlife. This project was a two-phase study to investigate animal passage through existing drainage box culverts, arch culverts and bridges on existing highway systems. The objective of this study was to (1) determine whether wildlife are using existing structures as passageways based on wildlife sign and remot...

  4. Credit Growth in the Middle East, North Africa, and Central Asia Region

    OpenAIRE

    Joe Crowley

    2008-01-01

    Rapid private sector credit growth in the Middle East, North Africa, and Central Asia has been a result of strong economic growth, financial deepening, and banks’ willingness to explore consumer credit markets. Economic growth, the initial ratio of private sector credit to GDP, price volatility, and nonoil exports are found to be significant explanatory variables, while oil exports and spillovers from oil exporting neighbors were not found to have any significance. The credit growth has finan...

  5. Radiological health assessment of natural radioactivity in the vicinity of Obajana cement factory, North Central Nigeria

    OpenAIRE

    Omoniyi Matthew Isinkaye; Jibiri, Nnamdi N.; Adebowale A Olomide

    2015-01-01

    Measurements of activity concentrations of natural radionuclides in and around Obajana cement factory, North Central Nigeria have been carried out in this study to determine the activity levels of natural radionuclides in different environmental matrices in order to assess the radiological health hazards associated with the use of these matrices by the local population. A low-background Pb-shielded gamma spectroscopic counting assembly utilizing NaI (Tl) detector was employed for the measurem...

  6. Imperial Japanese Army Intelligence in North and Central China During the Second Sino-Japanese War

    OpenAIRE

    2014-01-01

    The Japanese today seek to improve their national intelligence apparatus, particularly in relation to human intelligence assets and higher echelon coordination. To be successful, Japan must examine its wartime past in the intelligence field. The Imperial Japanese Army maintained a prolific intelligence presence in North and Central China during the Second World War. Its intelligence apparatus encompassed all aspects of information collection, with considerable overlap between intelligence org...

  7. Strategic Planning for Activation and Operation of the North Central Superpave Center (NCSC): Interim Report

    OpenAIRE

    Olek, J.; McDaniel, Rebecca

    1997-01-01

    The North Central Superpave Center (NCSC) was established to serve the needs of the states and industry in ten states and two Canadian provinces as they implement the Superpave system. Accomplishing this goal requires the cooperation and active support of a number of people and organizations. Organizational and operational issues related to infrastructure, personnel, equipment and finances also needed to be resolved. This project was designed to address those issues, develop a comprehensive s...

  8. Epidemilogical Profile of Speech and Language Disorder in North Central Nigeria

    OpenAIRE

    Aremu, Shuaib K.; Afolabi, Olushola A; Alabi, Biodun S; Elemunkan, Isiah O.

    2011-01-01

    Background: Speech-language pathologists/Otolaryngologists recognize high prevalence of speech and language disorder among children. The aim of the study is to find out the epidemiological profile of speech and language disorder in north central Nigeria. Method: A five year retrospective review of all referral to speech and language therapy unit ENT Department between January 2005 and December 2009. Information retrieved and analysed included bio-data, clinical presentation and diagnosis of t...

  9. Primary infertility associated with schitosoma mansoni: a case report from the Jos plateau, north central Nigeria

    OpenAIRE

    Adisa, J; Egbujo, EM; Yahaya, BA; Echejoh, G

    2012-01-01

    Testicular schistosomiasis caused by Schistosoma mansoni is very rare and more so when associated with primary infertility. A 40 years old man from the Jos Plateau, North Central Nigeria presented with primary infertility after ten years of marriage. Sperm count revealed oligospermia and he also complained of inability to sustain erection. Testicular biopsy revealed several ova of Schistosoma mansoni in the connective tissue of the testes. Cases of infertility in endemic areas especially when...

  10. Assessment of undiscovered oil and gas resources of the Sud Province, north-central Africa

    Science.gov (United States)

    Brownfield, M.E.; Klett, T.R.; Schenk, C.J.; Charpentier, R.R.; Cook, T.A.; Pollastro, R.M.; Tennyson, M.E.

    2011-01-01

    The Sud Province located in north-central Africa recently was assessed for undiscovered, technically recoverable oil, natural gas, and natural gas liquids resources as part of the U.S. Geological Survey's (USGS) World Oil and Gas Assessment. Using a geology-based assessment methodology, the USGS estimated mean volumes of 7.31 billion barrels of oil, 13.42 trillion cubic feet of natural gas, and 353 million barrels of natural gas liquids.

  11. Drinking water and pregnancy outcome in central North Carolina: source, amount, and trihalomethane levels.

    OpenAIRE

    Savitz, D A; Andrews, K W; Pastore, L M

    1995-01-01

    In spite of the recognition of potentially toxic chemicals in chlorinated drinking water, few studies have evaluated reproductive health consequences of such exposure. Using data from a case-control study of miscarriage, preterm delivery, and low birth weight in central North Carolina, we evaluated risk associated with water source, amount, and trihalomethane (THM) concentration. Water source was not related to any of those pregnancy outcomes, but an increasing amount of ingested water was as...

  12. Factors That Affect Tax Compliance among Small and Medium Enterprises (SMEs) in North Central Nigeria

    OpenAIRE

    Ojochogwu Winnie Atawodi; Stephen Aanu Ojeka

    2012-01-01

    Tax is an important stream of revenue for government’s development projects. However, tax compliance amongSMEs is poor. Therefore, this study was conducted using SMEs in Zaria, North-Central Nigeria to evaluate andrank the factors that encourage non-compliance with tax obligation by SMEs. It was found that high tax rates andcomplex filing procedures are the most crucial factors causing non-compliance of SMEs. Other factors likemultiple taxation and lack of proper enlightenment affect tax comp...

  13. Dichothermal layer deepening in relation with halocline depth change associated with northward shrinkage of North Pacific western subarctic gyre in early 2000s

    Science.gov (United States)

    Nagano, Akira; Wakita, Masahide; Watanabe, Shuichi

    2016-02-01

    In the western subarctic North Pacific, a wind-driven cyclonic circulation, called the western subarctic gyre (WSAG), exists. We examined year-to-year changes of the gyre and hydrographic structures, applying the altimetry-based gravest empirical mode (AGEM) method to hydrographic and altimetric sea surface height (SSH) data, and relation to the in situ variation of the temperature minimum layer, i.e., the dichothermal layer, depth at station K2 (47∘ N, 160∘ E). The AGEM-based geostrophic volume transport and the streamfunction of the WSAG in the top 1000-dbar layer show that the gyre changes substantially. From the late 1990s to the mid-2000s, the gyre shrunk northward. Due to the shrinkage, the halocline bottom, which is equivalent to the top of the main pycnocline, deepens at K2 outside the central part of the gyre. The downward displacement of the dichothermal layer at K2 was found to be significantly related to that of the underlying halocline due to the northward shrinkage of the WSAG.

  14. Hydrogeological study and modeling of the Central-North aquifer in Quito

    International Nuclear Information System (INIS)

    The Quito aquifer is composed of two sub-basins: one in the South and the second in the Central- North area. Due to the characteristics of the city, the local water company gave priority to the study of the Central-North sub-basin, where most of the recent studies have been carried out. Since 1991, when the Papallacta project was implemented, EMAAP-Q stopped groundwater extraction from the Quito aquifer, and due to natural recharge, large volumes of groundwater have been recharged, leading to the progressive rising of the water level, up to the surface. The current situation has forced the exploitation of the aquifer as a contribution to the water supply of the Metropolitan District of Quito, with a flow-rate above 800 L·s-1. This pumping will lead to the lowering of the water table, limiting the consequences of the high water levels to the basement of buildings, and at the same time, groundwater will became an strategic alternative of water supply, especially in cases of natural disasters or when surface water systems are not operative. After compilation and evaluation of the hydrological information, the main characteristics of the Quito aquifer, mainly the Central-North sub-basin, were defined after completing a research programme. (author)

  15. The changing climate and human vulnerability in north-central Namibia

    Directory of Open Access Journals (Sweden)

    Margaret N. Angula

    2016-01-01

    Full Text Available North-central Namibia is more vulnerable to effects of climate change and variability. Combined effects of environmental degradation, social vulnerability to poverty and a changing climate will compromise subsistence farming in north-central Namibia (NCN. This will make subsistence and small-scale farmers in the region more vulnerable to projected changes in the climate system. Thus, the aim of this article was to examine factors contributing to subsistence farmers’ vulnerability to impacts of climate change. The article further discusses different aspects of human vulnerability and existing adaptation strategies in response to impacts of climate related disasters experienced over the past three to four decades in NCN. Qualitative and quantitative research approaches and methodology were employed to obtain information from subsistence farmers in north-central Namibia. The sociodemographic characteristics of Ohangwena, Oshana and Omusati Region reveals high levels of unemployment, high adult and elderly population and high dependency on agricultural livelihood system. These indicators help understand levels of household vulnerability. The study concludes that households interviewed revealed low levels of adaptive capacity due to exposure to climate risks and combined effects of social, political and cultural factors. This article provided an understanding that is required to inform the adaptation pathways relevant for NCN.

  16. Glycerol dialkyl glycerol tetraethers and TEX86 index in sinking particles in the western North Pacific

    OpenAIRE

    Yamamoto, Masanobu; Shimamoto, Akifumi; Fukuhara, Tatsuo; Tanaka, Yuichiro; Ishizaka, Joji

    2012-01-01

    Seasonal and depth variation in the flux of glycerol dialkyl glycerol tetraethers (GDGTs) and TEX86 (TEXH86 and TEXL86) values in sinking particles was examined by conducting a 21 month time-series sediment trap experiment at a mooring station (WCT-2, 39°N, 147°E) in the mid-latitude NW Pacific. The aim was to understand the sinking process of GDGTs in the water column and the preservation of the TEX86 signal in the water column and sediment surface. In the shallow trap, the sinking flux of G...

  17. 78 FR 1837 - Nominations for the Western and Central Pacific Fisheries Commission Advisory Committee

    Science.gov (United States)

    2013-01-09

    ... Pacific Fisheries Commission Advisory Committee AGENCY: National Marine Fisheries Service (NMFS), National..., on behalf of the Secretary of Commerce, is seeking nominations for the advisory committee established... committee, to be composed of individuals from groups concerned with the fisheries covered by the Western...

  18. Herbarium specimens reveal the footprint of climate change on flowering trends across north-central North America.

    Science.gov (United States)

    Calinger, Kellen M; Queenborough, Simon; Curtis, Peter S

    2013-08-01

    Shifting flowering phenology with rising temperatures is occurring worldwide, but the rarity of co-occurring long-term observational and temperature records has hindered the evaluation of phenological responsiveness in many species and across large spatial scales. We used herbarium specimens combined with historic temperature data to examine the impact of climate change on flowering trends in 141 species collected across 116,000 km(2) in north-central North America. On average, date of maximum flowering advanced 2.4 days °C(-1), although species-specific responses varied from - 13.5 to + 7.3 days °C(-1). Plant functional types exhibited distinct patterns of phenological responsiveness with significant differences between native and introduced species, among flowering seasons, and between wind- and biotically pollinated species. This study is the first to assess large-scale patterns of phenological responsiveness with broad species representation and is an important step towards understanding current and future impacts of climate change on species performance and biodiversity. PMID:23786499

  19. Effect of biomass burning over the western North Pacific Rim: wintertime maxima of anhydrosugars in ambient aerosols from Okinawa

    Science.gov (United States)

    Zhu, C.; Kawamura, K.; Kunwar, B.

    2015-02-01

    Biomass burning (BB) largely modifies the chemical composition of atmospheric aerosols on the globe. We collected aerosol samples (TSP) at Cape Hedo, on subtropical Okinawa Island, from October 2009 to February 2012 to study anhydrosugars as BB tracers. Levoglucosan was detected as the dominant anhydrosugar followed by its isomers, mannosan and galactosan. We found a clear seasonal trend of levoglucosan and mannosan with winter maxima and summer minima. Positive correlation was found between levoglucosan and nss-K+ (r = 0.38, p agricultural waste burning of maize straw in the North China Plain. Anhydrosugars comprised 0.22% of water-soluble organic carbon (WSOC) and 0.13% of organic carbon (OC). The highest values to WSOC (0.37%) and OC (0.25%) were found in winter, again indicating an important BB contribution to Okinawa aerosols in winter. This study provides useful information to better understand the effect of East Asian biomass burning on the air quality in the western North Pacific Rim.

  20. Species composition and diversity of pelagic fishes based on a longline fishery catch in the North Pacific Ocean

    Institute of Scientific and Technical Information of China (English)

    ZHU Jiangfeng; DAI Xiaojie; CHEN Yong

    2011-01-01

    Evaluation of spatial-temporal variability of species composition and diversity in oceanic ecosystems is not easy because it is usually difficult to obtain sufficient data quantifying such variability.In this study, we examined pelagic species diversity indicators, species richness, Shannon-Wiener index of diversity and Hurlbert's species evenness, for fish assemblages from two areas (north and south) in the North Pacific Ocean (2°-12°N, 178°E-165°W) during May-July 2008. The assemblages were based on data collected by an onboard scientific observer during a commercial longline fishing trip. The species richness and Shannon-Wiener diversity index of fish assemblages in the northern area were slightly higher than those in the southern area, although these differences were not significant (t test,P>0.05). Non-parametric multidimensional scaling and analysis of similarities indicated that there were significant differences in fish assemblages between the two areas (P<0.01).