Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 21

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Inherent optical properties and particulate matter distribution in summer season in waters of Hornsund and Kongsfjorden, Spitsbergen

100%
Sagan S., Darecki M.
Oceanologia
|
2018
|
tom 60
|
nr 1
Two Spitsbergen fjords, Hornsund and Kongsfjorden, are known for being under different hydrological regimes. The first is cold, separated from warm Atlantic water by East Spitsbergen Current, while Kongsfjorden is frequently penetrated by relatively warm Atlantic water. On the other hand, both are under strong influence of water discharge from glaciers and land freshwater input. During the period of observation in both fjords a dominant water mass was Surface Water, which originates mainly from glacial melt. The presence of suspended matter introduced with melt water in Surface Water is reflected by highest values of light attenuation and absorption coefficients recorded in areas close to glacier both in Hornsund and Kongsfjorden. In Hornsund the maximum light attenuation coefficient cpg(555) was 5.817 m−1 and coefficient of light absorption by particles ap(676) = 0.10 m−1. In Kongsfjorden the corresponding values were 26.5 m−1 and 0.223 m−1. In Kongsfjorden suspended matter of the size class 20–200 μm dominated over fractions smaller than 20 μm while in Hornsund dominating size fraction was 2–20 μm. The results provide an evidence of considerable range of variability of the optical properties mainly due to glacial and riverine runoff. The scale of variability of particulate matter in Kongsfjorden is bigger than in Hornsund. Most of the variability in Hornsund can be attributed to glaciers discharge and a presence of particles of mineral origin, while in Kongsfjorden the organic and mineral particles contribute almost equally to defining the optical properties of water.
2

The aerosol optical thickness over the Baltic Sea

100%
Kusmierczyk-Michulec J., Darecki M.
Oceanologia
|
1996
|
tom 38
|
nr 4
3

Derivation of remote sensing reflectance of Baltic waters from above-surface measurements

100%
Olszewski J., Darecki M.
Oceanologia
|
1999
|
tom 41
|
nr 1
4
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Report on the development of the Vistula River plume in the coastal waters of the Gulf of Gdańsk during the May 2010 flood

81%
Zajaczkowski M., Darecki M., Szczucinski W.
Oceanologia
|
2010
|
tom 52
|
nr 2
311-317
The hydrological conditions, suspended matter concentrations and vertical par- ticulate matter flux were measured as the River Vistula flood wave (maximum discharge) was flowing into the southern part of the Gulf of Gdańsk on 26 May 2010. Extending offshore for several tens of kilometres, the river plume was well stratified, with the upper layer flowing away from the shore and the near-bottom water coastwards.
5
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Relationships between inherent optical properties in the Baltic Sea for application to the underwater imaging problem

81%
Levin I., Darecki M., Sagan S., Radomyslskaya T.
Oceanologia
|
2013
|
tom 55
|
nr 1
6

Daily radiation budget of the Baltic Sea surface from satellite data

81%
Zapadka T., Krezel A., Paszkuta M., Darecki M.
Polish Maritime Research
|
2015
|
tom 22
|
nr 3
Recently developed system for assessment of radiation budget for the Baltic Sea has been presented and verified. The system utilizes data from various sources: satellite, model and in situ measurements. It has been developed within the SatBałtyk project (Satellite Monitoring of the Baltic Sea Environment - www.satbaltyk.eu) where the energy radiation budget is one of the key element. The SatBałtyk system generates daily maps of the all components of radiation budget on every day basis. We show the scheme of making daily maps, applied algorithms and empirical data collection within the system. An empirical verification of the system has been carried out based on empirical data collected on the oil rig placed on the Baltic Sea. This verification concerned all the components of the surface radiation budget. The average daily NET products are estimated with statistical error ca. 13 Wm-2. The biggest absolute statistical error is for LWd component and equals 14 Wm-2. The relative error in relation to the average annual values for whole Baltic is the biggest for SWu and reaches 25%. All estimated components have correlation coefficient above 0.91
7
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Laboratory measurements of remote sensing reflectance of selected phytoplankton species from the Baltic Sea

81%
Soja-Wozniak M., Darecki M., Wojtasiewicz B., Bradtke K.
Oceanologia
|
2018
|
tom 60
|
nr 1
Results of unique laboratory measurements of remote sensing reflectance (Rrs) of several phytoplankton species typically occurring in high abundances in the Baltic Sea waters are presented. Reflectance spectra for diatoms: Cyclotella meneghiniana and Skeletonema marinoi and Dolichospermum sp., Nodularia spumigena and sp. were analysed in terms of assessment of their characteristic features and the differences between them. These species contain similar pigments, which results in general similarities of reflectance spectra, i.e. decrease of reflectance magnitude in the blue and red spectrum regions. However, hyper-spectral resolution of optical measurements let us find differences between optical signatures of diatoms and cyanobacteria groups and between species belonging to one group as well. These differences are reflected in location of local maxima and minima in the reflectance spectrum and changes in relative height of characteristic peaks with changes of phytoplankton concentration. Wide ranges of phytoplankton concentrations were analysed in order to show the persistence of Rrs characteristic features. The picoplankton species, Synechococcus sp. show the most distinct optical signature, which let to distinguish separate cluster in hierarchical cluster analysis (HCA). The results can be used to calibrate input data into radiative transfer model, e.g. phase function or to validate modelled Rrs spectra.
8
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Validation of empirical and semi-analytical remote sensing algorithms for estimating absorption by Coloured Dissolved Organic Matter in the Baltic Sea from SeaWiFS and MODIS imagery

81%
Kowalczuk P., Darecki M., Zablocka M., Gorecka I.
Oceanologia
|
2010
|
tom 52
|
nr 2
171-196
An extensive bio-optical data set obtained from field measurements was used to evaluate the performance of an empirical (Kowalczuk et al. 2005) and two semi- analytical algorithms: Carder et al. (1999) and GSM01 (Maritorena et al. 2002) for estimating CDOM absorption in the Baltic Sea. The data set includes coincident measurements of radiometric quantities and absorption coefficients of CDOM made during 43 cruises between 2000 and 2008. In the first stage of the analysis, the accuracy of the empirical algorithm by Kowalczuk et al. (2005) was assessed using in situ measurements of remote sensing reflectance. Validation results improved when matching points located in Gulf of Gdańsk close to the Vistula River mouth were eliminated from the data set. The calculated errors in the estimation of aCDOM(400) in the first phase of the analysis were Bias = −0.02, RMSE = 0.46 and R2 = 0.70. In the second stage, the empirical algorithm was tested on satellite data from SeaWiFS and MODIS imagery. The satellite data were corrected atmospherically with the MUMM algorithm designed for turbid coastal and inland waters and implemented in the SeaDAS software. The results of the best case scenario for estimating the CDOM absorption coefficient aCDOM(400), based on SeaWiFS data, were Bias = −0.02, RMSE = 0.23 and R2 = 0.40. The validation of the Kowalczuk et al. (2005) empirical algorithm applied to MODIS data led to a less accurate estimate of aCDOM(400): Bias = −0.03, RMSE = 0.19 and R2 = 0.29. This assessment of the accuracy of standard semi-analytical algorithms available in the SeaWiFS and MODIS imagery processing software revealed that both algorithms (GSM 01 and Carder) underestimate CDOM absorption in the Baltic Sea with mean systematic and random errors in excess of 70%. The paper presents examples of the application of the Kowalczuk et al. (2005) empirical algorithm for producing maps of the seasonal distribution of aCDOM(400) in the Baltic Sea between 2004 and 2008.
9

In-water remote sensing algorithms for the detection of chlorophyll and yellow substances in the Pomeranian Bay

81%
Olszewski J., Kowalczuk P., Darecki M.
Oceanologia
|
1999
|
tom 41
|
nr 3
10

Spatial and temporal changes in some optical parameters in the southern Baltic

81%
Olszewski J., Sagan S., Darecki M.
Oceanologia
|
1992
|
tom 33
11
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

New simple statistical formulas for estimating surface concentrations of suspended particulate matter (SPM) and particulate organic carbon (POC) from remote-sensing reflectance in the Southern Baltic Sea

71%
Wozniak S. B., Darecki M., Zablocka M., Burska D., Dera J.
Oceanologia
|
2016
|
tom 58
|
nr 3
12
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Influence of underwater light fields on pigment characteristics in the Baltic Sea – results of statistical analysis

71%
Ston-Egiert J., Majchrowski R., Darecki M., Kosakowska A., Ostrowska M.
Oceanologia
|
2012
|
tom 54
|
nr 1
13

Practical applicability and preliminary results of the Baltic environmental satellite remote sensing system (SatBaltyk)

71%
Ostrowska M., Darecki M., Krezel A., Ficek D., Furmanczyk K.
Polish Maritime Research
|
2015
|
tom 22
|
nr 3
The SatBałtyk (Satellite Monitoring of the Baltic Sea Environment) project is being realized in Poland by the SatBałtyk Scientific Consortium, specifically appointed for this purpose, which associates four scientific institutions: the Institute of Oceanology PAN in Sopot – coordinator of the project, the University of Gdańsk (Institute of Oceanography), the Pomeranian Academy in Słupsk (Institute of Physics) and the University of Szczecin (Institute of Marine Sciences). The project is aiming to prepare a technical infrastructure and set in motion operational procedures for the satellite monitoring of the Baltic Sea ecosystem. The main sources of input data for this system will be the results of systematic observations by metrological and environmental satellites such as TIROS N/NOAA, MSG (currently Meteosat 10), EOS/AQUA and Sentinel -1, 2, 3 (in the future). The system will deliver on a routine basis the variety of structural and functional properties of this sea, based on data provided by relevant satellites and supported by hydro-biological models. Among them: the solar radiation influx to the sea’s waters in various spectral intervals, energy balances of the short- and long-wave radiation at the Baltic Sea surface and in the upper layers of the atmosphere over the Baltic, sea surface temperature distribution, dynamic states of the water surface, concentrations of chlorophyll a and other phytoplankton pigments in the Baltic waters, spatial distributions of algal blooms, the occurrence of coastal upwelling events, and the characteristics of primary production of organic matter and photosynthetically released oxygen in the water and many others. The structure of the system and preliminary results will be presented
14

The use of satellite data in the operational 3D Coupled Ecosystem Model of the Baltic Sea (3D CEMBS)

71%
Nowicki A., Janecki M., Darecki M., Piotrowski P., Dzierzbicka-Glowacka L.
Polish Maritime Research
|
2016
|
tom 23
|
nr 1
The objective of this paper is to present an automatic monitoring system for the 3D CEMBS model in the operational version. This predictive, eco hydrodynamic model is used as a tool to control the conditions and bio productivity of the Baltic sea environment and to forecast physical and ecological changes in the studied basin. Satellite-measured data assimilation is used to constrain the model and achieve higher accuracy of its results. 3D CEMBS is a version of the Community Earth System Model, adapted for the Baltic Sea. It consists of coupled ocean and ice models, working in active mode together with the ecosystem module. Atmospheric forecast from the UM model (Interdisciplinary Centre for Mathematical and Computational Modelling of the Warsaw University) are used as a forcing fields feed through atmospheric data model. In addition, river inflow of freshwater and nutrient deposition from 71 main rivers is processed by land model. At present, satellite data from AQUA MODIS, processed by the SatBałtyk project Operational System are used for the assimilation of sea surface temperature and chlorophyll a concentration. In the operational mode, 48-hour forecasts are produced at six-hour intervals, providing a wide range of hydrodynamic and biochemical parameters
15

Seasonal changes in selected optical parameters in the Pomeranian Bay in 1996-1997

71%
Kowalczuk P., Sagan S., Olszewski J., Darecki M., Hapter R.
Oceanologia
|
1999
|
tom 41
|
nr 3
16

IO PAS initial model of marine primary production for remote sensing applications

61%
Wozniak B., Dera J., Majchrowski R., Ficek D., Koblentz-Mishke O. J., Darecki M.
Oceanologia
|
1997
|
tom 39
|
nr 4
17
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Algorithms for the remote sensing of the Baltic ecosystem (DESAMBEM). Part 2: Empirical validation

51%
Darecki M., Ficek D., Krezel A., Ostrowska M., Majchrowski R., Wozniak S. B., Bradtke K., Dera J., Wozniak B.
Oceanologia
|
2008
|
tom 50
|
nr 4
509-538
This paper is the second of two articles on the methodology of the remote sensing of the Baltic ecosystem. In Part 1 the authors presented the set of DESAMBEM algorithms for determining the major parameters of this ecosystem on the basis of satellite data (see Woźniak et al. 2008 – this issue). That article discussed in detail the mathematical apparatus of the algorithms. Part 2 presents the effects of the practical application of the algorithms and their validation, the latter based on satellite maps of selected Baltic ecosystem parameters: the distributions of the sea surface temperature (SST), the Photosynthetically Available Radiation (PAR) at the sea surface, the surface concentrations of chlorophyll a and the total primary production of organic matter. Particular emphasis was laid on analysing the precision of estimates of these and other parameters of the Baltic ecosystem, determined by remote sensing methods. The errors in these estimates turned out to be relatively small; hence, the set of DESAMBEM algorithms should in the future be utilised as the foundation for the effective satellite monitoring of the state and functioning of the Baltic ecosystem.
18
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Algorithm for the remote sensing of the Baltic ecosystem (DESAMBEM). Part 1: Mathematical apparatus

51%
Wozniak B., Krezel A., Darecki M., Wozniak S. B., Majchrowski R., Ostrowska M., Kozlowski L., Ficek D., Olszewski J., Dera J.
Oceanologia
|
2008
|
tom 50
|
nr 4
451-508
This article is the first of two papers on the remote sensing methods of monitoring the Baltic ecosystem, developed by our team. Earlier, we had produced a series of detailed mathematical models and statistical regularities describing the transport of solar radiation in the atmosphere-sea system, the absorption of this radiation in the water and its utilisation in a variety of processes, most importantly in the photosynthesis occurring in phytoplankton cells, as a source of energy for the functioning of marine ecosystems. The comprehensive DESAMBEM algorithm, presented in this paper, is a synthesis of these models and regularities. This algorithm enables the abiotic properties of the environment as well as the state and the functioning of the Baltic ecosystem to be assessed on the basis of available satellite data. It can be used to determine a good number of these properties: the sea surface temperature, the natural irradiance of the sea surface, the spectral and spatial distributions of solar radiation energy in the water, the surface concentrations and vertical distributions of chlorophyll a and other phytoplankton pigments in this sea, the radiation energy absorbed by phytoplankton, the quantum efficiency of photosynthesis and the primary production of organic matter. On the basis of these directly determined properties, other characteristics of processes taking place in the Baltic ecosystem can be estimated indirectly. Part 1 of this series of articles deals with the detailed mathematical apparatus of the DESAMBEM algorithm. Part 2 will discuss its practical applicability in the satellite monitoring of the sea and will provide an assessment of the accuracy of such remote sensing methods in the monitoring of the Baltic ecosystem (see Darecki et al. 2008 – this issue).
19
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

A study of episodic events in the Baltic Sea – combined in situ and satellite observations

42%
Lysiak-Pastuszak E., Bartoszewicz M., Bradtke K., Darecki M., Drgas N., Kowalczuk P., Krasniewski W., Krezel A., Krzyminski W., Lewandowski L., Mazur-Marzec H., Piliczewski B., Sagan S., Sutryk K., Witek B.
Oceanologia
|
2012
|
tom 54
|
nr 2
A project was developed concerning the operational system of surveillance and the recording of episodic events in the Baltic Sea. In situ information was to be combined with multi-sensory satellite imagery to determine the extent of algal blooms, to track their evolution and that of rapid environmental events like hydrological fronts. The main element of the system was an autonomous Ferry Box module on a ferry operating between Gdynia and Karlskrona, automatically measuring temperature, salinity and chlorophyll a fluorescence. At pre-selected locations, discrete water samples were collected, which were subsequently analysed for their phytoplankton content, and algal hepato- and neurotoxins; they were also used in toxicity tests with Artemia franciscana.
20
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

SatBaltyk – A Baltic environmental satellite remote sensing system – an ongoing project in Poland. Part 2: Practical applicability and preliminary results

42%
Wozniak B., Bradtke K., Darecki M., Dera J., Dudzinska-Nowak J., Dzierzbicka-Glowacka L., Ficek D., Furmanczyk K., Kowalewski M., Krezel A., Majchrowski R., Ostrowska M., Paszkuta M., Ston-Egiert J., Stramska M., Zapadka T.
Oceanologia
|
2011
|
tom 53
|
nr 4
This paper is the second part of the description of the first stage of the SatBałtyk project’s implementation. Part 1 (Woźniak et al. 2011, in this issue) presents the assumptions and objectives of SatBałtyk and describes the most important stages in the history of our research, which is the foundation of this project. It also discusses the operation and general structure of the SatBałtyk system. Part 2 addresses various aspects of the practical applicability of the SatBałtyk Operational System to Baltic ecosystem monitoring. Examples are given of the Baltic’s characteristics estimated using the preliminary versions of the algorithms in this Operational System. At the current stage of research, these algorithms apply mainly to the characteristics of the solar energy influx and the distribution of this energy among the various processes taking place in the atmosphere-sea system, and also to the radiation balance of the sea surface, the irradiance conditions for photosynthesis and the condition of plant communities in the water, sea surface temperature distributions and some other marine phenomena correlated with this temperature. Monitoring results obtained with these preliminary algorithms are exemplified in the form of distribution maps of selected abiotic parameters of the Baltic, as well as structural and functional characteristics of this ecosystem governed by these parameters in the Baltic’s many basins. The maps cover practically the whole area of the Baltic Sea. Also given are results of preliminary inspections of the accuracy of the magnitudes shown on the maps. In actual fact, the errors of these estimates are relatively small. The further practical application of this set of algorithms (to be gradually made more specific) is therefore entirely justified as the basis of the SatBałtyk system for the effective operational monitoring of the state and functioning of Baltic ecosystems. This article also outlines the plans for extending SatBałtyk to include the recording of the effects and hazards caused by current and expected storm events in the Polish coastal zone.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.