Temat: Statistical analysis - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Statistical analysis of Mediterranean coastal storms
Autorzy:: Martzikos, N.T.
Prinos, P.E.
Memos, C.D.
Tsoukala, V.K.
Powiązania:: https://bibliotekanauki.pl/articles/2079010.pdf
Data publikacji:: 2021
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: Mediterranean Sea
storm
extreme event
coastal zone
statistical analysis
Opis:: Coastal storms as extreme hydrometeorological events have severe impacts on the coasts and consequently affect the coastal communities, attracting considerable research interest nowadays. Attempting to understand the risk of these extreme events, a coastal storm analysis is accomplished by studying the parameters which define a coastal storm and their properties, such as the wave height, the wave period, the duration, the calm period, and the storm energy. The frequency of occurrence of coastal storms, the thresholds of storm parameters and the way they are interrelating with each other draw a rough outline of wave climate during coastal storm events for a specific location. This information is valuable afterwards for the design of coastal structures and the coastal zone management. In this work, buoy datasets from 30 locations in the Mediterranean Sea are analysed for describing coastal storm activity. A sample of 4008 coastal storms is identified. Each location faces around 10—14 coastal storms per year, with most of them to occur in winter months and their characteristics to be sitedependent. Their average duration is lower than 30 hours, and 25% of them are consecutive events which hit the same location in less than a day. Furthermore, the wave period and the main direction present no remarkable fluctuations during a coastal storm. With this analysis, a deeper understanding of coastal storm severity is pursued, gaining knowledge about their past activity, in order to be prepared in the future and to protect the coastal areas.
Źródło:: Oceanologia; 2021, 63, 1; 133-148
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Multivariate statistical analysis of water quality and phytoplankton characteristics in Daya Bay, China, from 1999 to 2002
Autorzy:: Wang, Y.S.
Lou, Z.P.
Sun, C.C.
Wu, M.L.
Han, S.H.
Powiązania:: https://bibliotekanauki.pl/articles/48049.pdf
Data publikacji:: 2006
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: South China Sea
water quality
China
phytoplankton
Daya Bay
multivariate statistical analysis
Opis:: This study analyzed seasonal physicochemical and phytoplankton data collected at 12 marine monitoring stations in Daya Bay from 1999 to 2002. Cluster analysis based on water quality and phytoplankton parameters measured at the 12 stations could be grouped into three clusters: cluster I – stations S1,S2 , S7 and S11 in the southern part and the north-eastern part of Daya Bay; cluster II – stations S5, S6,S9 ,S1 0 and S12 in the central and north-eastern parts of Daya Bay; cluster III – stations S3,S 4 and S8 in the cage culture areas in the south-western part of Daya Bay and in the north-western part of the Bay near Aotou harbor. Bivariate correlations between phytoplankton density and the major physical and nutrient factors were calculated for all stations. Factor analysis shows that there were high positive loadings of pH,T IN and the ratio of TIN to PO4-P in the three clusters, which indicates that all the stations in the three clusters were primarily grouped according to their respective nutrient conditions.
Źródło:: Oceanologia; 2006, 48, 2
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Validation and statistical analysis of the group for high resolution sea surface temperature data in the Arabian Gulf
Autorzy:: Nesterov, O.
Temimi, M.
Fonseca, R.
Nelli, N.R.
Addad, Y.
Bosc, E.
Abida, R.
Powiązania:: https://bibliotekanauki.pl/articles/2078874.pdf
Data publikacji:: 2021
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: validation
statistical analysis
sea surface temperature
annual variability
seasonal variability
Arabian Gulf
Oman Sea
Opis:: The combined effect of climate change and steadily increasing seawater demand for industrial and domestic purposes in the Arabian Gulf region has a significant impact on the ecosystem in this region. Additionally, this effect may reduce the efficiency and increase the operating costs of industrial facilities that utilize seawater for cooling and other purposes. In this context, it is important to know various statistical characteristics of the sea surface temperature (SST) and their trends, in addition to the mean climatological characteristics. The analysis conducted in this study utilized a 17-year Group for High Resolution Sea Surface Temperature Level 4 dataset of 0.01 × 0.01° spatial resolution. First, the dataset was compared against a 2-year seawater temperature measurements at the ten offshore buoys in the relatively shallow coastal waters of the United Arab Emirates between Ras Ghumais and Dubai, which showed a reasonably good agreement between the two datasets, with the estimated root mean square deviations ranging from 0.5 to 0.9°C. Subsequently, several statistical SST characteristics were calculated. The trend analysis showed not only positive tendencies in the mean SSTs of up to 0.08°C/year in the northern Gulf, but also the trends in the annual percentile exceedances, particularly the 95th percentiles (near-maximum SSTs), which increased by approximately 0.07°C/year in the western United Arab Emirates and eastern Qatar waters. On the contrary, the 5th percentiles (near-minimum SSTs) decreased by up to 0.1°C/year, especially in the waters around Bahrain, Qatar, and the western United Arab Emirates. These results indicate that extreme hot and cold SST events in the Gulf are becoming more frequent and more extreme than before.
Źródło:: Oceanologia; 2021, 63, 4; 497-515
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Satellite estimates of the long-term trend in phytoplankton size classes in the coastal waters of North-Western Bay of Bengal
Autorzy:: Miranda, J.
Lotliker, A.A.
Baliareingh, S.K.
Jena, A.K.
Samanta, A.
Sahu, K.C.
Kumar, T.S.
Powiązania:: https://bibliotekanauki.pl/articles/2079007.pdf
Data publikacji:: 2021
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: phytoplankton
size class
coastal water
long-term variability
satellite data
statistical analysis
Bengal Bay
Opis:: The study presents long-term variability in satellite retrieved phytoplankton size classes (PSC) at two coastal sites, off Gopalpur and Visakhapatnam, in the north-western Bay of Bengal. The abundance-based models by Brewin et al. (2010) (B10) and Sahay et al. (2017) (S17), for retrieval of PSC (micro, nano, and picophytoplankton), from satellite data, were validated. Both the models performed well in the retrieval of nano and microphytoplankton. However, B10 performed poorly in retrieving picophytoplankton. The statistical analysis indicated better performance of the S17 model and hence was applied to Moderate Resolution Imaging Spectroradiometer onboard Aqua satellite (MODISA) data to understand the temporal (at monthly climatology) and spatial variability (from nearshore to offshore). The spatial distribution indicated nearshore dominance of micro and offshore dominance of picophytoplankton. In nearshore waters off Gopalpur, microphytoplankton dominated throughout the year except for months of south-west monsoon (June and July) where the dominance of picophytoplankton was observed. All PSC exhibited similar distribution at an annual scale with a primary peak during pre-monsoon (March and April) and a secondary peak during post-monsoon (September— November). However, microphytoplankton concentration during post-monsoon was higher off Gopalpur in comparison to Visakhapatnam. The higher microphytoplankton concentration during pre-monsoon was attributed to recurrent phytoplankton blooms. Whereas, post-monsoon increment could be attributed to enhanced phytoplankton growth by availing nutrients sourced from monsoonal precipitation induced terrigenous influx. The outcome of the present study recommends the use of the S17 model for satellite retrieval of PSC from the north-western Bay of Bengal.
Źródło:: Oceanologia; 2021, 63, 1; 40-50
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Demonstration of a new indicator for studying upwelling in the Northern South China Sea
Autorzy:: Lin, L.
Wang, Y.-S.
Sun, C.-C.
Li, N.
Wang, H.
Mitchell, B.G.
Wu, M.-L.
Song, H.
Wu, J.-F.
Powiązania:: https://bibliotekanauki.pl/articles/48889.pdf
Data publikacji:: 2011
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: China Sea
cluster analysis
multivariate statistical analysis
principal component analysis
remote sensing
satellite monitoring
sea surface temperature
silicate
spatial distribution
upwelling
Opis:: In order to demonstrate that silicate (SiO3-Si) can be used as an indicator to study upwelling in the northern South China Sea, hierarchical cluster analysis (CA) and principle component analysis (PCA) were applied to analyse the metrics of the data consisting of 14 physical-chemical-biological parameters at 32 stations. CA categorized the 32 stations into two groups (low and high nutrient groups). PCA was applied to identify five Principal Components (PCs) explaining 78.65% of the total variance of the original data. PCA found important factors that can describe nutrient sources in estuarine, upwelling, and non-upwelling areas. PC4, representing the upwelling source, is strongly correlated to SiO3-Si. The spatial distribution of silicate from the surface to 200 m depth clearly showed the upwelling regions, which is also supported by satellite observations of sea surface temperature.
Źródło:: Oceanologia; 2011, 53, 2
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: A statistical approach to coastal upwelling in the Baltic Sea based on the analysis of satellite data for 1990–2009
Autorzy:: Lehmann, A.
Myrberg, K.
Hoflich, K.
Powiązania:: https://bibliotekanauki.pl/articles/49090.pdf
Data publikacji:: 2012
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: Baltic Sea
coastal upwelling
sea surface temperature
statistical analysis
numerical model
1990-2009 period
meteorological data
satellite data
Opis:: A statistical analysis of Baltic Sea upwelling has been carried out to cover, for the first time, the entire sea area for the period 1990–2009. Weekly composite SST maps based on NOAA/AVHRR satellite data were used to evaluate the location and frequency of upwelling. The results obtained were analysed and compared with earlier studies with excellent agreement. Our study enables the most intense upwelling areas in the entire Baltic Sea to be evaluated. According to the analysis of 443 SST maps, the most common upwelling regions are found off the Swedish south and east coasts (frequency 10–25%), the Swedish coast of the Bothnian Bay (16%), the southern tip of Gotland (up to 15%), and the Finnish coast of the Gulf of Finland (up to 15%). Pronounced upwelling also occurs off the Estonian coast and the Baltic east coast (up to 15%), the Polish coast and the west coast of Rugen (10–15%); otherwise the upwelling frequency was between 5 and 10%. Additionally, simulated SST distributions derived from a Baltic Sea numerical model were analysed for the same period. Furthermore, at specific positions close to the coastline, surface winds based on the SMHI meteorological data base were analysed for the same 20-year period. Wind components parallel to the coast were discriminated into favourable and unfavourable winds forcing upwelling. The obtained frequencies of upwelling-favourable winds fit very well the observed upwelling frequencies derived from satellite SST maps. A positive trend of upwelling frequencies along the Swedish east coast and the Finnish coast of the Gulf of Finland was calculated for the period 1990–2009.
Źródło:: Oceanologia; 2012, 54, 3
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Megascale rhythmic shoreline forms on a beach with multiple bars
Autorzy:: Pruszak, Z.
Rozynski, G.
Szmytkiewicz, P.
Powiązania:: https://bibliotekanauki.pl/articles/47943.pdf
Data publikacji:: 2008
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: bar
beach
shoreline form
shoreline configuration
wavelength
Baltic Sea
rhythmic form
nearshore zone
Baltic coast
statistical analysis
multibar profile
Opis:: The study, carried out in 2003 and 2006 at the Lubiatowo Coastal Research Station (Poland), located on the non-tidal southern Baltic coast (tidal range < 0.06 m), focused on larger rhythmic forms (mega-cusps) with wavelengths in the interval 500 m > Lc > 20 m. Statistical analyses of detailed shoreline configurations were performed mostly with the Discrete Wavelet Transform method (DWT). The beach is composed of fine sand with grain diameter D50 ≈ 0.22 mm, which produces 4 longshore sandbars and a gently sloping seabed with β = 0.015. The analysis confirms the key role of bars in hydro- and morphodynamic surf zone processes. The hypothesis was therefore set up that, in a surf zone with multiple bars, the bars and mega-scale shoreline rhythmic forms form one integrated physical system; experimental evidence to substantiate this hypothesis was also sought. In such a system not only do self-regulation processes include swash zone phenomena, they also incorporate processes in offshore surf zone locations. The longshore dimensions of large cusps are thus related to the distances between periodically active large bed forms (bars). The spatial dimension of bar system activity (number of active bars) depends, at a given time scale, on the associated hydrodynamic conditions. It was assumed that such a time scale could include either the development and duration of a storm, or a period of stable, yet distinct waves, capable of remodelling the beach configuration. The indentation to wavelength ratio of mega-cusps for the studied non-tidal dissipative environment may be one order of magnitude greater than for mesotidal, reflective beaches.
Źródło:: Oceanologia; 2008, 50, 2; 183-203
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Influence of underwater light fields on pigment characteristics in the Baltic Sea – results of statistical analysis
Autorzy:: Ston-Egiert, J.
Majchrowski, R.
Darecki, M.
Kosakowska, A.
Ostrowska, M.
Powiązania:: https://bibliotekanauki.pl/articles/48040.pdf
Data publikacji:: 2012
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: pigment
phytoplankton
underwater irradiance
statistical analysis
Baltic Sea
light intensity
spectral distribution
water
chlorophyll
carotenoid
high performance liquid chromatography
photosynthetic carotenoid
Źródło:: Oceanologia; 2012, 54, 1
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Influence of density stratification on effluent plume dynamics
Autorzy:: Loncar, G.
Paklar, G.B.
Janekovic, I.
Powiązania:: https://bibliotekanauki.pl/articles/47653.pdf
Data publikacji:: 2011
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: 3D numerical model
Croatia
density stratification
numerical model
numerical simulation
Rijeka Bay
salinity
sea temperature
statistical analysis
submarine outfall
submarine sewage
Opis:: In this study we modelled sea temperature (T ), salinity (S) and density field dynamics using a 3D numerical model applied to Rijeka Bay (Croatia) in order to explore their effect on effluent plume dynamics in the vicinity of four submarine sewage outfalls when the bora wind (NE direction) is blowing. The vertical density stratification in the area studied is strongly related to the bora wind, which contributes significantly to the lowering of the pycnocline depth through enhanced mixing in the vertical, giving rise to changes in the neutral buoyancy level. The features of near-field plume dynamics were calculated with the use of a separate near-field numerical model, using information on the vertical density distribution previously calculated using a 3D numerical model. The results of the numerical simulations and statistical analysis of the wind data indicate a very low probability of complete water column homogenization and consequent effluent plume rise to the sea surface under the influence of the bora wind during the peak tourist season (May–September).
Źródło:: Oceanologia; 2011, 53, 2
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Analysis of 50-year wind data of the Southern Baltic Sea for modelling coastal morphological evolution – a case study from the Darss-Zingst Peninsula
Autorzy:: Zhang, W.
Harff, J.
Schneider, R.
Powiązania:: https://bibliotekanauki.pl/articles/48896.pdf
Data publikacji:: 2011
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: Baltic Sea
coastal morphological evolution
coastline change
Darss-Zingst Peninsula
modelling
morphodynamic model
sea level
statistical analysis
wind
wind direction
wind speed
Opis:: High-resolution wind series in the southern Baltic Sea for the period of 1958–2007 are analysed to generate representative climate input conditions for a multi-scale morphodynamic model to simulate decadal-to-centennial coastline change. Four seasonal wind classes, each characterized by a predominant distribution of wind direction and speed, are derived from statistical analysis. Further calibration of this statistical description is done by sensitivity studies of the model to generate similar coastline changes of the Darss-Zingst peninsula as the measured data for the last century. The coastline change of this area is then projected for the next 300 years based on four different climate scenarios, through which impacts of accelerated sea level rise and storm frequency on the long-term coastline change are quantified.
Źródło:: Oceanologia; 2011, 53, (1-TI)
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 11.

Tytuł:: The role of the spatial resolution of a three-dimensional hydrodynamic model for marine transport risk assessment
Autorzy:: Andrejev, O.
Soomere, T.
Sokolov, A.
Myrberg, K.
Powiązania:: https://bibliotekanauki.pl/articles/48522.pdf
Data publikacji:: 2011
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:: 2C map
anthropogenic pressure
Baltic Sea
environment risk
environmental management
Finland Gulf
hydrodynamic model
marine transport
maritime spatial planning
OAAS model
pollution
spatial resolution
statistical analysis
three-dimensional hydrodynamic model
Opis:: The paper addresses the sensitivity of a novel method for quantifying the environmental risks associated with the current-driven transport of adverse impacts released from offshore sources (e.g. ship traffic) with respect to the spatial resolution of the underlying hydrodynamic model. The risk is evaluated as the probability of particles released in different sea areas hitting the coast and in terms of the time after which the hit occurs (particle age) on the basis of a statistical analysis of large sets of 10-day long Lagrangian trajectories calculated for 1987–1991 for the Gulf of Finland, the Baltic Sea. The relevant 2D maps are calculated using the OAAS model with spatial resolutions of 2, 1 and 0.5 nautical miles (nm) and with identical initial, boundary and forcing conditions from the Rossby Centre 3D hydrodynamic model (RCO, Swedish Meteorological and Hydrological Institute). The spatially averaged values of the probability and particle age display hardly any dependence on the resolution. They both reach almost identical stationary levels (0.67–0.69 and ca 5.3 days respectively) after a few years of simulations. Also, the spatial distributions of the relevant fields are qualitatively similar for all resolutions. In contrast, the optimum locations for fairways depend substantially on the resolution, whereas the results for the 2 nm model differ considerably from those obtained using finer-resolutionmodels. It is concluded that eddy-permitting models with a grid step exceeding half the local baroclinic Rossby radius are suitable for a quick check of whether or not any potential gain from this method is feasible, whereas higher-resolution simulations with eddy-resolving models are necessary for detailed planning. The asymptotic values of the average probability and particle age are suggested as an indicator of the potential gain from the method in question and also as a new measure of the vulnerability of the nearshore of water bodies to offshore traffic accidents.
Źródło:: Oceanologia; 2011, 53, (1-TI)
0078-3234
Pojawia się w:: Oceanologia
Dostawca treści:: Biblioteka Nauki