Three dimensional circulation of water with variable wind in the Caspian Sea

This research is based on a numerical model for forecasting the three-dimensional behavior of (sea) water motion due to the effect of a variable wind velocity. The results obtained are then analyzed and compared with observation. This model is based on the equations that overcome the current and distribution of temperature by applying the method of finite difference with assuming Δx, Δy as constant and Δz, variable. The model is based on the momentum equation, continuity equation and thermodynamic energy equation and tension at the surface and middle layers and bottom stress. The horizontal and vertical eddy viscosity and thermal diffusivity coefficients we used in accordance with that of the Bennet on Outario Lake (1977). Considering the Caspian Sea dimension in numerical model the Coriolis parameter used with β effects and the approximation Boussines have been used. For the program controlling some simple experiment with boundary condition similar to that of the Caspian Sea have been done. For modeling the Caspian Sea the grid of the field was done as follows: At horizontal surface grid size is 10×10km extension and at vertical in 10 layers with varying thickness from surface to bed respectively as: 5, 10, 20, 3, 50, 100, 150, 200, 25, 500 and higher. The data of wind as velocity، direction and temperature of water related to 15th September 1995 at 6،12 and 18 o’clock were obtained from synoptic station at the Caspian Sea shore and the research marine of Haji Alief. The information concerning shore wind was measured and by the method of SPM (shore protection manual) was transferred to far shore winds through interpolation and by use of inverse square distance of position distribution of the wind velocity at the Caspian surface field was obtained. The model has been evaluated according to the reports and observations. Through studying the position of the current in different layers، the velocity in the cross section in the northern، southern and the middle layers، will be discussed. The results reveal the presence of the circulation cells in the three above mentioned areas. The circulation with depth is reduced too. The results obtained through the numerical solution of the temperature equation have been compared with the observation. The temperature change in different layers in cross section illustrates the relative accordance of the model mentioned.

Proceedings of the Second PICES Workshop on the Okhotsk Sea and Adjacent Areas [Nemuro, Japan, November 9-12, 1998]

Table of Contents [pdf, 0.01 Mb] Preface [pdf, 0.01 Mb] Masaaki Aota Long-term tendencies of sea ice concentration and air temperature in the Okhotsk Sea coast of Hokkaido [pdf, 0.05 Mb] Hajime Ito & Miki Yoshioka Geography of the seasonally ice covered seas [pdf, 0.5 Mb] George V. Shevchenko & Victor F. Putov On wind and tide induced sea-ice drift on the northeastern shelf of Sakhalin Island (analysis of radar data) [pdf, 0.96 Mb] Boris S. Dyakov, A.A. Nikitin, L. S. Muktepavel & T.A. Shatilina Variability of the Japan and Okhotsk Seas ice cover depending on geopotential field H500 over the Far-Eastern region [pdf, 0.10 Mb] Aleksandr G. Petrov & Nikolay A. Rykov Intermediate cold layer and ice cover in the Sea of Okhotsk [pdf, 0.37 Mb] Vladimir Ponomarev, Olga Trusenkova, Elena Ustinova & Dmitry Kaplunenko Interannual variations of oceanographic and meteorological characteristics in the Sea of Okhotsk [pdf, 0.16 Mb] George V. Shevchenko & Akie Kato Seasonal and interannual changes of atmospheric pressure, air and water temperature in the area of the Kuril Ridge [pdf, 0.13 Mb] George V. Shevchenko & Vladimir Yu. Saveliev Spatial variability of the wind field in the area of the Kuril Islands [pdf, 0.15 Mb] Alexander L. Figurkin & Igor A. Zhigalov Seasonal variability and specifity of the oceanological conditions in the northern Okhotsk Sea in 1997 [pdf, 1.04 Mb] Igor A. Zhabin Ventilation of the upper portion of the intermediate water in the Okhotsk Sea [pdf, 0.80 Mb] Vladimir A. Luchin & Alexander L. Figurkin Oceanographic conditions over the Kashevarov Bank [pdf, 0.61 Mb] Toshiyuki Awaji, Tomohiro Nakamura, Takaki Hatayama, Kazunori Akimoto & Takatoshi Takizawa Tidal exchange through the Kuril Straits [pdf, 2.01 Mb] Tomohiro Nakamura, Toshiyuki Awaji, Takaki Hatayama, Kazunori Akimoto, Takatoshi Takizawa & Masao Fukasawa Vertical mixing induced by tidally generated internal waves in the Kuril Straits [pdf, 0.83 Mb] Katsuro Katsumata & Ichiro Yasuda Water exchange between the Okhotsk Sea and the North Pacific Ocean estimated by simple models [pdf, 0.97 Mb] Konstantin A. Rogachev Oyashio west path culmination as the consequence of a rapid thermohaline transition in the Pacific Subarctic [pdf, 0.22 Mb] Yasuhiro Kawasaki On the year-to-year change in subarctic water characteristics around the Kuril Islands [pdf, 0.39 Mb] Alexander L. Figurkin & Evgeniy E. Ovsyannikov Influence of oceanological conditions of the West Kamchatka shelf waters on spawning grounds and on pollock egg distribution [pdf, 0.97 Mb] Igor E. Kochergin & Alexander A. Bogdanovsky Transport and turbulence characteristics for the northeastern Sakhalin shelf conditions [pdf, 0.08 Mb] Igor E. Kochergin, Alexander A. Bogdanovsky, Valentina D. Budaeva, Vyacheslav G. Makarov, Vasily F. Mishukov, S.N. Ovsienko, Victor F. Putov, L.A. Reitsema, J.W. Sciallabba, O.O. Sergucheva & P.V. Yarosh Modeling of oil spills for the shelf conditions of northeastern Sakhalin [pdf, 0.32 Mb] Valentina D. Budaeva & Vyacheslav G. Makarov A peculiar water regime of currents in the area of eastern Sakhalin shelf [pdf, 0.66 Mb] Nikolay A. Rykov The oceanographic databases on the Sakhalin shelf [pdf, 0.27 Mb] Akifumi Nakata, Iori Tanaka, Hiroki Yagi, Tomomi Watanabe, Gennady A. Kantakov & Andrew D. Samatov Formation of high-density water (over 26.8 sigma-t) near the La Perouse Strait (the Soya Strait) [pdf, 0.09 Mb] Minoru Odamaki & Kouji Iwamoto Currents and tidal observations by Hydrographic Department of Maritime Safety Agency, off the Okhotsk coast of Hokkaido [pdf, 0.16 Mb] Yasushi Fukamachi, Genta Mizuta, Kay I. Ohshima, Motoyo Itoh, Masaaki Wakatsuchi & Masaaki Aota Mooring measurements off Shiretoko Peninsula, Hokkaido in 1997-1998 [pdf, 0.19 Mb] Mikhail A. Danchenkov, David Aubrey & Stephen C. Riser Oceanographic features of the La Perouse Strait [pdf, 0.91 Mb] Iori Tanaka & Akifumi Nakata Results of direct current measurements in the La Perouse Strait (the Soya Strait), 1995-1998 [pdf, 0.06 Mb] Gennady A. Kantakov & George V. Shevchenko In situ observations of Tsushima and West-Sakhalin currents near La Perouse (Soya) Strait [pdf, 0.79 Mb] Irina Y. Bragina Geographical and biological characteristics of the net zooplankton in the southwestern part of the Sea of Okhotsk during 1987-1996 [pdf, 0.27 Mb] List of corresponding authors [pdf, 0.01 Mb] (Document pdf contains 193 pages)

Vertical transport and exchange of materials in the upper waters of the oceans (VERTEX): introduction to the program, hydrographic conditions and major component fluxes during VERTEX I

This paper introduces VERTEX, a multi-disciplinary research program dealing with various aspects of particle transport in the upper, high-energy layers (0-2000 m) of the ocean. Background information is presented on hydrography, biological composition of trapped particulates, and major component fluxes observed on a cruise off central California (VERTEX I). Organic C fluxes measured with two trap systems are compared with several other estimates taken from the literature. The intent of this overview paper is to provide a common setting in an economical manner, and avoid undue repetition of background and ancillary information in subsequent publications. (PDF is 43 pages).

The distribution of cirripeds and gastropods on plain vertical rock surfaces in the upper intertidal and splash zones

This is a student paper done for a University of California Berkeley Zoology class. Since UCB didn't have its own marine lab at the time, it rented space at Hopkins Marine Station where this work was done. Cadet Hand earned his Ph.D. from Berkeley and went on to become Director of the Bodega Marine Laboratory. Donald Putnam Abbott also earned his Ph.D. from Berkeley and later became a Stanford professor at Hopkins Marine Station. (PDF contains 26 pages)

Effects of shear on eggs and larvae of striped bass, morone saxatilis, and white perch, M. americana

Shear stress, generated by water movement, can kill fish eggs and larvae by causing rotation or deformation. Through the use of an experimental apparatus, a series of shear (as dynes/cm2)-mortality equations for fixed time exposures were generated for striped bass and white perch eggs and larvae. Exposure of striped bass eggs to a shear level of 350 dynes/cm2 kills 36% of the eggs in 1 min; 69% in 2 min, and 88% in 4 min; exposure of larvae to 350 dynes/cm2 kills 9.3% in 1 min, 30.0% in 2 min, and 68.1% in 4 min. A shear level of 350 dynes/cm2 kills 38% of the white perch eggs in 1 min, 41% in 2 min, 89% in 5 min, 96% in 10 min, and 98% in 20 min. A shear level of 350 dynes/cm2 applied to white perch larvae destroys 38% of the larvae in 1 min, 52% in 2 min, and 75% in 4 min. Results are experimentally used in conjunction with the determination of shear levels in the Chesapeake and Delaware Canal and ship movement for the estimation of fish egg and larval mortalities in the field.

Seasonal, horizontal, and vertical distribution of phytoplankton chlorophyll a in the Northeast U.S. Continental Shelf Ecosystem

The broad scale features in the horizontal, vertical, and seasonal distribution of phytoplankton chlorophyll a on the northeast U.S. continental shelf are described based on 57,088 measurements made during 78 oceanographic surveys from 1977 through 1988. Highest mean water column chlorophyll concentration (Chlw,) is usually observed in nearshore areas adjacent to the mouths of the estuaries in the Middle Atlantic Bight (MAB), over the shallow water on Georges Bank, and a small area sampled along the southeast edge of Nantucket Shoals. Lowest Chlw «0.125 ug l-1) is usually restricted to the most seaward stations sampled along the shelf-break and the central deep waters in the Gulf of Maine. There is at least a twofold seasonal variation in phytoplankton biomass in all areas, with highest phytoplankton concentrations (m3) and highest integrated standing stocks (m2) occurring during the winter-spring (WS) bloom, and the lowest during summer, when vertical density stratification is maximal. In most regions, a secondary phytoplankton biomass pulse is evident during convective destratification in fall, usually in October. Fall bloom in some areas of Georges Bank approaches the magnitude of the WS-bloom, but Georges Bank and Middle Atlantic Bight fall blooms are clearly subordinate to WS-blooms. Measurements of chlorophyll in two size-fractions of the phytoplankton, netplankton (>20 um) and nanoplankton «20 um), revealed that the smaller nanoplankton are responsible for most of the phytoplankton biomass on the northeast U.S. shelf. Netplankton tend to be more abundant in nearshore areas of the MAB and shallow water on Georges Bank, where chlorophyll a is usually high; nanoplankton dominate deeper water at the shelf-break and deep water in the Gulf of Maine, where Chlw is usually low. As a general rule, the percent of phytoplankton in the netplankton size-fraction increases with increasing depth below surface and decreases proceeding offshore. There are distinct seasonal and regional patterns in the vertical distribution of chlorophyll a and percent netplankton, as revealed in composite vertical profiles of chlorophyll a constructed for 11 layers of the water column. Subsurface chlorophyll a maxima are ubiquitous during summer in stratified water. Chlorophyll a in the subsurface maximum layer is generally 2-8 times the concentration in the overlying and underlying water and approaches 50 to 75% of the levels observed in surface water during WS-bloom. The distribution of the ratio of the subsurface maximum chlorophyll a to surface chlorophyll a (SSR) during summer parallels the shelfwide pattern for stability, indexed as the difference in density (sigma-t) between 40 m and surface (stability 40. The weakest stability and lowest SSR's are found in shallow tidally-mixed water on Georges Bank; the greatest stability and highest SSR's (8-12:1) are along the mid and outer MAB shelf, over the winter residual water known as the "cold band." On Georges Bank, the distribution of SSR and the stability40 are roughly congruent with the pattern for maximum surface tidal current velocity, with values above 50 cms-1 defining SSR's less than 2:1 and the well-mixed area. Physical factors (bathymetry, vertical mixing by strong tidal currents, and seasonal and regional differences in the intensity and duration of vertical stratification) appear to explain much of the variability in phytoplankton chlorophyll a throughout this ecosystem. (PDF file contains 126 pages.)

Net phytoplankton and zooplankton in the New York Bight, January 1976 to February 1978, with comments on the effects of wind, Gulf Stream eddies, and slope water intrusions

Results are given of monthly net phytoplankton and zooplankton sampling from a 10 m depth in shelf, slope, and Gulf Stream eddy water along a transect running southeastward from Ambrose Light, New York, in 1976, 1977, and early 1978. Plankton abundance and temperature at 10 m and sea surface salinity at each station are listed. The effects of atmospheric forcing and Gulf Stream eddies on plankton distribution and abundance arc discussed. The frequency of Gulf Stream eddy passage through the New York Bight corresponded with the frequency of tropical-subtropical net phytoplankton in the samples. Gulf Stream eddies injected tropical-subtropical zooplankton onto the shelf and removed shelfwater and its entrained zooplankton. Wind-induced offshore Ekman transport corresponded generally with the unusual timing of two net phytoplankton maxima. Midsummer net phytoplankton maxima were recorded following the passage of Hurricane Belle (August 1976) and a cold front (July 1977). Tropical-subtropical zooplankton which had been injected onto the outer shelf by Gulf Stream eddies were moved to the inner shelf by a wind-induced current moving up the Hudson Shelf Valley. (PDF file contains 47 pages.)

Influence of the Azores high on sea level pressure and wind, and on precipitation, in the Eastern Tropical Pacific Ocean

ENGLISH: Intensification of the Azores high pressure cell in mid-year, with concomitant air flow from the Caribbean into the Pacific, is shown to be responsible for a secondary minimum of precipitation observed along the tropical Pacific coast of the Americas, and to have a measurable effect on wind and precipitation several hundred kilometers offshore. SPANISH: La intensificación de la célula de alta presión de las Azores a mediados del año, y la corriente de aire concomitante que entra al Pacífico procedente del Caribe, se demuestra que es la causante de un mínimo secundario de precipitación observado a lo largo de la costa tropical de las Américas en el Pacífico y que tiene un efecto mensurable sobre el viento y la precipitación varios cientos de kilómetros mar afuera. (PDF contains 23 pages.)