著者

CasaretoBeatriz Estela NemotoTakahisa

雑誌

Memoirs of National Institute of Polar Research. Special issue

巻号頁・発行日

vol.40, pp.221-239, 1986-02

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Studies on salps were carried out on the plankton samples collected by R. V. HAKUHO MARU during the KH-83-4 cruise in the Southern Ocean (Australian Sector) as part of the BIOMASS SIBEX I programme. The geographical distribution of salps showed that widely distributed cosmopolitan species such as Salpa fusiformis, Salpa aspera, Thalia democratica and Pegea confoederata reached their southern limit at the Subtropical Convergence. This boundary represents the northern limit for Salpa thompsoni, the most abundant salp of the Southern Ocean. Ihlea racovitzai was limited to the high latitude Antarctic water. Analysis of stratified samplings performed day and night revealed a pattern of diel vertical migration for Salpa thompsoni, Salpa fusiformis and Ihlea magalhanica. Ihlea racovitzai did not show a clear vertical movement between the day time and the night time. The vertical distribution of Ihlea magalhanica and Ihlea racovitzai appeared to extend deeper than the range determined previously. A pattern of vertical stratification in the size composition and stages of maturity for both aggregate and solitary forms of Salpa thompsoni was observed. Moreover, a comparison of the population at different latitudes revealed different compositions.

著者

Gerald Holdsworth

雑誌

Memoirs of National Institute of Polar Research. Special issue

巻号頁・発行日

vol.54, pp.161-168, 2001-03

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Cross correlation between time series of (1) total precipitation for a combined four-station network in northern Japan and of (2) the net snow accumulation determined from an ice core obtained from Mount Logan (60.5°N, 5340m) situated in the Saint Elias Mountains, Yukon, reveals high, statistically significant, cross correlation coefficients of +0.38 for annual data increasing up to +0.71 for seven point smoothing of the two 89 year series. The distance between sites is about 7000km spanning the complete Pacific Ocean between latitudes of about 40°N and 60°N. A review of the extensive literature of oceanology and climatology for the North Pacific Ocean region indicates that a strong coupling exists between the ocean and the atmosphere especially up to and associated with the Polar Front Zone along which major cyclogenesis occurs during most months of the year. Cyclones track generally from west to east with a strong northerly component especially in the eastern (Gulf of Alaska) sector. Examination of these cyclones on GOES satellite images shows that weather systems can transport moisture from mid latitude ocean sources (<40°N) to high on Mount Logan over the top of the warm front zone and high above intervening coastal topography. Thus, the positive correlation between the two time series can be physically justified and qualifies the link as a genuine teleconnection.

著者

Benvenuti Silvano Dall'Antonia Luigi

出版者

国立極地研究所

雑誌

Memoirs of National Institute of Polar Research. Special issue (ISSN:03860744)

巻号頁・発行日

vol.58, pp.110-117, 2004-03

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Our research group has devised and manufactured a data logger, which, glued on the back of a bird, can detect and memorise the direction in which the bird is heading during a flight. Given the birds' constant cruising speed, the memorised data can be used to reconstruct the whole flight path. Subsequent versions of this direction recorder, equipped with new sensors (depth meter and flight sensor), were used to investigate the foraging behaviour of several species of breeding marine birds (Balearic shearwater, Brunnich's guillemot, common guillemot, razorbill, black-legged kittiwake, Audouin's gull, northern gannet, blue-footed booby). The data recorded at different colony sites allowed us to identify the birds' feeding grounds and record the most relevant events occurring in the foraging trips, including the duration of the trips, total flight time, number and duration of the stops where feeding actually occurred, dive profiles and diving behaviour. Differences in the foraging strategies between sexes and between incubating and brooding birds were also investigated.

著者

Takahashi Eiji Watanabe Kentaro Satoh Hiroo

雑誌

Memoirs of National Institute of Polar Research. Special issue

巻号頁・発行日

vol.40, pp.84-95, 1986-02

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Siliceous cysts of 29 different morphological shapes were observed in the sea ice and sea water at the Kita-no-seto Strait, north of Syowa Station, Antarctica. Twenty species of those were newly discovered in the Antarctic waters. Cysts collected were in the size range of 3 to 10μm. They were tentatively classified into four groups based on their morphological characteristics; Sphaerica, Ovoidea, Hemisphaerica, and Tri/quadrihedra. Twelve cysts representative of each group and a cyst of Paraphysomonas imperforata confirmed newly were described. Cysts appeared from March to May, and in December (summer to autumn season) and the species diversity was highest in December with 18 species. Among 29 species, 20 appeared in the sea ice, eight in both sea ice and sea water, and one in sea water only. Main habitat of them seemed to be the brine pockets or channels of the sea ice.

著者

Holdsworth Gerald

出版者

国立極地研究所

雑誌

Memoirs of National Institute of Polar Research. Special issue (ISSN:03860744)

巻号頁・発行日

vol.54, pp.161-168, 2001-03

被引用文献数

1

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Cross correlation between time series of (1) total precipitation for a combined four-station network in northern Japan and of (2) the net snow accumulation determined from an ice core obtained from Mount Logan (60.5°N, 5340m) situated in the Saint Elias Mountains, Yukon, reveals high, statistically significant, cross correlation coefficients of +0.38 for annual data increasing up to +0.71 for seven point smoothing of the two 89 year series. The distance between sites is about 7000km spanning the complete Pacific Ocean between latitudes of about 40°N and 60°N. A review of the extensive literature of oceanology and climatology for the North Pacific Ocean region indicates that a strong coupling exists between the ocean and the atmosphere especially up to and associated with the Polar Front Zone along which major cyclogenesis occurs during most months of the year. Cyclones track generally from west to east with a strong northerly component especially in the eastern (Gulf of Alaska) sector. Examination of these cyclones on GOES satellite images shows that weather systems can transport moisture from mid latitude ocean sources (<40°N) to high on Mount Logan over the top of the warm front zone and high above intervening coastal topography. Thus, the positive correlation between the two time series can be physically justified and qualifies the link as a genuine teleconnection.

著者

Fujii Yoshiyuki Kamiyama Kokichi Shoji Hitoshi Narita Hideki Nishio Fumihiko Kameda Takao Watanabe Okitsugu

雑誌

Memoirs of National Institute of Polar Research. Special issue

巻号頁・発行日

vol.54, pp.209-220, 2001-03

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210-year records of dust concentration, electrical conductivity, acidity (pH), non-sea salt sulfate (nss sulfate) and nitrate concentrations were obtained for an ice core from Site-J, Greenland. The ice core was well dated by counting annual cycles of the δ^<18>O profile and by tuning with time markers established for tritium peaks and the Laki 1783 eruption signal. Dust records in both ice cores from Site-J and Crete suggest that dust storms occurred in 1818,1900,1919,1936 and 1943 over Greenland. Electrical conductivity shows remarkable peaks probably due to volcanic eruptions with VEI larger than 4. The anthropogenic effect on precipitation chemistry started in ca. 1860,40 years earlier than the time previously reported. Nss sulfate increased remarkably, much more than nitrate, because of the rapid increase in solid fossil fuel combustion, but by the early 1970's, the nitrate concentration exceeded the nss sulfate concentration due to the intense increase in liquid fossil fuel combustion since the 1950's. The decrease in sulfate and nitrate concentrations started in the early 1970's. This is attributed to the spread of suppression facilities for anthropogenic pollutants emitted by the combustion of solid and liquid fossil fuels.

著者

Afanasyev Vsevolod

出版者

国立極地研究所

雑誌

Memoirs of National Institute of Polar Research. Special issue (ISSN:03860744)

巻号頁・発行日

vol.58, pp.227-233, 2004-03

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The device has a sensor that periodically measures and records the ambient light level. Following retrieval of the device, the light level records are converted into latitudes and longitudes, which allows the geographic position of the animal to be estimated twice daily. The instrument is also configured to detect and record the history of time spent in water against time spent flying or on land. For seabirds, this can provide time-budget data related to activity and feeding behaviour. Small size, a low profile and robust packaging are crucial for effective deployments on flying birds and diving animals. Long battery life is often essential (e.g. after fledging, juvenile wandering albatrosses Diomedea exulans usually remain at sea for at least five to seven years). Low unit and operation costs are also very desirable, together with simplicity of operation. Dimensions of the instrument are 22x19x12 mm. Weight is 9 g in air and 4 g in water. The device is pressure tested to 800 m depth of water, and can log data for up to eight years. The total cost of components is less than $70. The principles, design specification and circuit description of the device are presented here, together with a representative migration track, obtained during field tests on grey-headed albatrosses Thalassarche chrysostoma, to illustrate performance.

著者

Burney J. Le Boeuf

雑誌

Memoirs of National Institute of Polar Research. Special issue

巻号頁・発行日

vol.58, pp.89-100, 2004-03

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The aim of these studies was to determine local movements of hunting white sharks (Carcharodon carcharias) near a seal rookery and global movements during migration. Seven adults were monitored locally with attached ultrasonic tags that received and telemetered animal position and behavior via an array of three-acoustic-positioning (RAP) buoys moored off Ano Nuevo Island, California. Migratory movements of 6 adults departing this island and nearby Southeast Farallon Island were tracked for 2-6 months with attached pop-up satellite archival tags. Sharks began hunting seals at Ano Nuevo Island in October, spending 40% of the day patrolling the 1 km2 receptive field within 400 m of the island at a depth of 30 m or less. For six weeks, they did not stray far or long from the area, were equally active at night as by day, were non-territorial, and fed infrequently. This nearshore phase at both island rookeries ended abruptly in winter as the sharks moved offshore to a region of the subtropical eastern Pacific half way to Hawaii. An adult male went further, traveling to Hawaii where it remained until migrating back to California, only to repeat the journey the following year. Electronic tagging provides vital information on the hunting and migratory behavior of this apex predator.

著者

Miyoshi Yasunobu/Fujiwara Hitoshi

雑誌

Memoirs of National Institute of Polar Research. Special issue

巻号頁・発行日

vol.59, pp.199-207, 2006-03

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By using a general circulation model, we examine behavior of the migrating semidiurnal tide for solar cycle moderate and geomagnetically quiet conditions. We investigate day-to-day variabilities of the migrating semidiurnal tide in the mesosphere and thermosphere and their relation with the migrating semidiurnal tide generated in the lower atmosphere. The results show that day-to-day variations of the migrating semidiurnal tide are evident from the tropopause to the thermosphere. Fluctuations of the migrating semidiurnal amplitude with periods of 10-12 and 25 days are found at altitudes from 20 to 250km, indicating dynamical coupling between the mesosphere and thermosphere and the lower atmosphere.