Wyniki wyszukiwania - Biblioteka Nauki

1

Forest fires smoke monitoring from Sea-viewing Wide Field-of-view Sensor images

100%

Hassini A. , Dejean S. , Benabadji N. , Hassini N. , Belbachir A. H.

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2008

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tom Vol. 38, nr 4

737-754

EN

A method for detecting forest fires smoke using SeaWiFS (Sea-viewing Wide Field-of View Sensor) images is developed in this paper. The colour masking technique is proposed to extract the maximum fires smoke pixels from the SeaStar/SeaWiFS satellite images by using Fusion by Arithmetic Combination (FAC) of the spectral bands method. Each image used is converted from RGB (Red, Green, Blue) to HIS (Hue, Saturation, Intensity) system. The resulting smoke plumes pixels are obtained visually in the Intensity and Saturation images. Then the values of intensity and saturation are analyzed to be potentially applied in other images. In this research, we applied our detecting forest fires smoke algorithm in seven different scenes, and in a variety of conditions, including different regions of the planet, and different dates. Next, Smoke Pixel Reference Ratio (SPRR) was used to test the proposed method. We found that the method can detect maximum pixels of smoke plumes in spite of some limitations.

2

Remote sensing and sounding of the atmospheric boundary layer

100%

Sorbjan Z. , Stacewicz T.

Acta Geophysica

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2012

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tom Vol. 60, no. 5

1259-1260

3

Inversion of Remote Sensing Data Using Multiple Ratios of Spectral Radiation Intensities and Neural Networks

100%

Cięszczyk S.

Acta Physica Polonica A

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2017

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tom 131

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nr 6

1454-1459

EN

The article presents a method for determining the content and temperature on the basis of spectra from remote measurements. The technique uses measurements of a high resolution radiation spectrum that allows the visibility of the individual rotational lines of gases such as CO₂, used here in the range of 2470-2495 cm¯¹. At the same time a new algorithm is applied of pre-processing the spectrum, involving the use of multiple ratios of intensity at several wavenumbers as input to an inverse model based on neural networks. Due to it, the dimensionality of the input can significantly be reduced. Additionally, the data interpreted do not have to be measured in units of spectral radiance. Thus only the calibration of the sensitivity of the spectrometer at various wavelengths is required. The neural models were constructed on the basis of data from the simulation. The proposed method works with a uniform layer of radiating gas for determining the temperature and CO₂ content. For a non-uniform layer it is possible to determine the line-of-sight temperature profile and average gas content. The method can be extended to different spectral ranges and to other gases present in substantial quantities in the exhaust gases of various processes.

4

Quantum yield of photosynthesis in the Baltic : a new mathematical expression for remote sensing applications

100%

Woźniak B. , Ficek D. , Ostrowska M. , Majchrowski R. , Dera J.

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2007

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tom No. 49 (4)

527-542

EN

Statistical relationships between the quantum yield of photosynthesis ? and selected environmental factors in the Baltic have been established on the basis of a large quantity of empirical data. The model formula is the product of the theoretical maximum quantum yield [formula]. To a sufficiently good approximation, each of these factors fi appears to be dependent on one or at most two environmental factors, such as temperature, underwater irradiance, surface concentration of chlorophyll a, absorption properties of phytoplankton and optical depth. These dependences have been determined for Baltic Case 2 waters. The quantum yield ?, calculated from known values of these environmental factors, is then applicable in the model algorithm for the remote sensing of Baltic primary production. The statistical error of the approximate quantum yields [Fi} is 62%.

5

Remote sensing of vertical phytoplankton pigment distributions in the Baltic: new mathematical expressions. Part 3: Nonphotosynthetic pigment absorption factor

100%

Woźniak B. , Majchrowski R. , Ostrowska M. , Ficek D. , Kunicka J. , Dera J.

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2007

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tom No. 49 (4)

513-526

EN

This paper, part 3 of the description of vertical pigment distributions in the Baltic Sea, discusses the mathematical expression enabling the vertical distributions of the non-photosynthetic pigment absorption factor fa to be estimated. The factor fa is directly related to concentrations of the several groups of phytoplankton pigments and describes quantitatively the ratio of the light energy absorbed at given depths by photosynthetic pigments to the light energy absorbed by all the phytoplankton pigments together (photosynthetic and photoprotecting). Knowledge of this factor is highly desirable in the construction of state-of-the-art "light-photosynthesis" models for remote-sensing purposes. The expression enables fa to be estimated with considerable precision on the basis of two surface parameters (available from satellite observations): the total chlorophyll a concentration at the surface Ca(0) and the spectral downward irradiance Ed(?, 0) just below the sea surface. The expression is applicable to Baltic waters from the surface down to an optical depth of ? ? 5. The verification of the model description of fa was based on 400 quasi-empirical values of this factor which were calculated on the basis of empirical values of the following parameters measured at the same depths: Ed(?, z) (or also PAR(z)), apl(?, z), and the concentrations of all the groups of phytoplankton pigments Ca(z) and Cj(z) (where j denotes in turn chl b, chl c, PSC, phyc, PPC). The verification shows that the errors in the values of the non-photosynthetic pigment absorption factor fa estimated using the model developed in this work are small: in practice they do not exceed 4%. Besides the mathematical description of the vertical distribution of fa, this paper also discusses the range of variation of its values measured in the Baltic and its dependence on the trophic index of a basin and depth in the sea. In addition, the similarities and differences in the behaviour of fa in Baltic and oceanic basins are compared.

6

Remote sensing of vertical phytoplankton pigment distributions in the Baltic: new mathematical expressions. Part 1: Total chlorophyll a distribution

100%

Ostrowska M. , Majchrowski R. , Stoń-Egiert J. , Woźniak B. , Ficek D. , Dera J.

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2007

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tom No. 49 (4)

471-489

EN

This article is the first in a series of three describing the modelling of the vertical different photosynthetic and photoprotecting phytoplankton pigments concentration distributions in the Baltic and their interrelations described by the so-called non-photosynthetic pigment factor. The model formulas yielded by this research are an integral part of the algorithms used in the remote sensing of the Baltic ecosystem. Algorithms of this kind have already been developed by our team from data relating mainly to oceanic Case 1 waters (WC1) and have produced good results for these waters. But their application to Baltic waters, i.e., Case 2 waters, was not so successful. On the basis of empirical data for the Baltic Sea, we therefore derived new mathematical expressions for the spatial distribution of Baltic phytoplankton pigments. They are discussed in this series of articles. This first article presents a statistical model for determining the total concentration of chlorophyll, a (i.e., the sum of chlorophylls a+pheo derived spectrophotometrically) at different depths in the Baltic Sea Ca(z) on the basis of its surface concentration Ca(0), which can be determined by remote sensing. This model accounts for the principal features of the vertical distributions of chlorophyll concentrations characteristic of the Baltic Sea. The model's precision was verified empirically: it was found suitable for application in the efficient monitoring of the Baltic Sea. The modified mathematical descriptions of the concentrations of accessory pigments (photosynthetic and photoprotecting) in Baltic phytoplankton and selected relationships between them are given in the other two articles in this series (Majchrowski et al. 2007, Woźniak et al. 2007b, both in this volume).

7

Remote sensing of vertical phytoplankton pigment distributions in the Baltic: new mathematical expressions. Part 2: Accessory pigment distribution

100%

Majchrowski R. , Stoń-Egiert J. , Ostrowska M. , Woźniak B. , Ficek D. , Lednicka B. , Dera J.

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2007

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tom No. 49 (4)

491-511

EN

This is the second in a series of articles, the aim of which is to derive mathematical expressions describing the vertical distributions of the concentrations of different groups of phytoplankton pigments; these expressions are necessary in the algorithms for the remote sensing of the marine ecosystem. It presents formulas for the vertical profiles of the following groups of accessory phytoplankton pigments: chlorophylls b, chlorophylls c, phycobilins, photosynthetic carotenoids and photoprotecting carotenoids, all for the uppermost layer of water in the Baltic Sea with an optical depth of ? ? 5. The mathematical expressions for the first four of these five groups of pigments, classified as photosynthetic pigments, enable their concentrations to be estimated at different optical depths in the sea from known surface concentrations of chlorophyll a. The precision of these estimates is characterised by the following relative statistical errors according to logarithmic statistics ?_: approximately 44% for chlorophyll b, approx. 39% for chlorophyll c, approx. 43% for phycobilins and approx. 45% for photosynthetic carotenoids. On the other hand, the mathematical expressions describing the vertical distributions of photoprotecting carotenoid concentrations enable these to be estimated at different depths in the sea also from known surface concentrations of chlorophyll a, but additionally from known values of the irradiance in the PAR spectral range at the sea surface, with a statistical error ?_ of approximately 42%.

8

Calibration free laser-induced breakdown spectroscopy (LIBS) identification of seawater salinity

88%

Tawfik W. , Mohamed Y.

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2007

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tom Vol. 37, nr 1-2

5-19

EN

Laser-induced breakdown spectroscopy (LIBS) has been used as a remote sensing system to analyze seawater samples and to identify their salinities without ordinary calibration curves. The plasma is generated by focusing a pulsed Nd : YAG laser on the seawater surface in air at atmospheric pressure. Such plasma emission spectrum was collected using wide band fused-silica optical fiber of one-meter length connected to a portable Echelle spectrometer (Mechelle 7500 ? Multichannel Instruments, Stockholm, Sweden) with intensified CCD camera. Spectroscopic analysis of plasma evolution of laser produced plasmas has been characterized in terms of their spectra, electron density and electron temperature assuming the local thermodynamic equilibrium (LTE) and optically thin plasma conditions. Three elements Na, Ca and Mg were determined in the obtained spectra to identify the salinity of seawater samples. The electron temperature Te and density Ne were determined using the emission intensity and Stark broadening. The obtained values of Te and Ne for natural seawater sample (salinity 3.753%) are 11580 K ą 0.35% and 3.33×1018 cm?3 ą 14.3%. These values exhibit a significant change only if the matrix changes (i.e., the salinity changes). On the other hand, no significant difference was obtained if Te and Ne were determined using any of the three elements (Na, Ca and Mg) in the same matrix. It is concluded that Te and Ne represent a fingerprint plasma characterization for a given seawater sample and its salinity could be identified using only one element without need to analyze the rest of elements in the seawater matrix. The obtained results indicate that it is possible to improve the exploitation of LIBS in the remote on-line environmental monitoring, by following up only a single element as a marker to identify the seawater matrix composition and salinity without need to analyze that matrix which saves a lot of time and efforts.

9

Review of Soil Moisture and Plant Water Stress Models Based on Satellite Thermal Imagery

88%

Łopatka A. , Miturski T. , Pudełko R. , Kozyra J. , Koza P.

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2016

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tom 49

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nr 1

EN

The paper analyzes the advantages and disadvantages of the most commonly used groups of models of soil moisture and plant water stress based on satellite thermal imagery. We present a simple proof of linking NDTI and CWSI indicators with plants water stress and quantitative justification for the shape of the points cloud on the chart Ts-NDVI.

10

Integration of Aeromagnetic Data and Landsat Imagery for Structural Analysis: A Case Study of Awgu in Enugu State, South-Eastern, Nigeria

88%

Ijeh B. I. , Ohaegbuchu H. E. , Okpetue P. C.

World News of Natural Sciences

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2018

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tom 18

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nr 2

79-105

EN

In this study, digital format data comprising of aeromagnetic and remotely sensed (Landsat ETM+7) data were used for structural interpretation of the Awgu area (predominantly underlain by sedimentary rocks) in Enugu State, southeastern part of Nigeria. Aeromagnetic data were analyzed using the Oasis Montaj 7.5 software and interpretation was carried out by applying the vertical and horizontal gradients, analytical signal, reduction to pole, tilt depth, as well as Euler deconvolution. The total magnetic intensity map shows a magnetic signature ranging from -39nT to 129nT. The 3D Euler solution of the study area has a structural index of 1.0 with dyke/fault as the shape of the inferred geological structure. In the Landsat ETM+7 satellite data used, band 5 was found as the most suitable in (automatic) delineation. The automatic lineament extraction process was carried out utilizing the line module of PCI Geomatica (2015 version). The essence of analysis and interpretation of the Landsat ETM+7 was to determine the lineament trends and density across the area. Rockworks 16 version software was used to generate the rose diagrams. As a result of the work, the aeromagnetic and Landsat lineament maps of the study area were summarized using rose diagrams. This revealed NE-SW as the major trend with some secondary trends NW-SE, E-W and N-S directions. However, the NE-SW trend reflects the younger tectonic events, because the younger events are more pronounced and tend to obliterate the older events. In a comparison of the aeromagnetic and Landsat lineament extraction of the study area in terms of number of lineaments, directions and total length of lineaments, the Landsat imagery were found to be better than the number, directions and total length of the aeromagnetic data.

11

Demonstration of a new indicator for studying upwelling in the northern South China Sea

88%

Lin L. , Wang Y.-S. , Sun C.-C. , Li N. , Wang H. , Mitchell B. G. , Wu M.-L. , Song H. , Wu J.-F.

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2011

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tom No. 53 (2)

605-622

EN

In order to demonstrate that silicate 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 silicate (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.

12

Studies of aerosols advected to coastal areas with the use of remote techniques

88%

Zieliński T. , Petelski T. , Makuch P. , Strzałkowska A. , Ponczkowska A. , Markowicz K. , Chourdakis G. , Georgoussis G. , Kratzer S.

Acta Geophysica

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2012

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tom Vol. 60, no. 5

1359-1385

EN

This paper presents the results of the studies of aerosol optical properties measured using lidars and sun photometers. We describe two case studies of the combined measurements made in two coastal zones in Crete in 2006 and in Rozewie on the Baltic Sea in 2009. The combination of lidar and sun photometer measurements provides comprehensive information on both the total aerosol optical thickness in the entire atmosphere as well as the vertical structure of aerosol optical properties. Combination of such information with air mass back-trajectories and data collected at stations located on the route of air masses provides complete picture of the aerosol variations in the study area both vertically and horizontally. We show that such combined studies are especially important in the coastal areas where depending on air mass advection directions and altitudes the influence of fine or coarse mode (in this case possibly sea-salt) particles on the vertical structure of aerosol optical properties is an important issue to consider.

13

Analysis of Spatial Development in and Around the City of Isparta through Remote Sensing and Geographic Information Systems

88%

Temurçin K. , Uluşar G.

Prace Komisji Geografii Przemysłu Polskiego Towarzystwa Geograficznego

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2013

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tom 22

120-132

EN

Remote Sensing is a method of examination used in the study of resources on earth without any physical contact. It is a method by which the characteristics of the land below are recorded from space and sky. Determining the characteristics of natural and cultural resources of earth, sustainable exploitation of these resources in the most effective ways and continuous monitoring of the changes in these resources are fundamental to being a developed country. For a sustainable land use and urbanization, data about the unstable natural environment must be collected and monitored at regular intervals, and in order to do these, Remote Sensing (RS) and Geographical Information Systems (GIS) are employed. Images obtained through RS method can be analyzed for the accurate use of the data available. This study seeks to determine the spatial development in and around the city of Isparta through digital imaging processing techniques on different satellite images which belong to different years. Images from satellites ASTER and LANDSAT; information on the quarters in Isparta and the city plan and ERDAS IMAGINE 9.1 program were used in the study. The spatial development of the city of Isparta was studied on the basis of the satellite images obtained in the years 1987, 2000 and 2010 and this study was integrated into GIS. Having analyzed how much change occurred and which way it trended, important information was collected which will be used as source for future studies to be carried out on Isparta. It was observed that while residential areas increased, amount of forested land, and agricultural areas decreased during the periods studied.

14

High accuracy Land Use Land Cover (LULC) maps for detecting agricultural drought effects in rainfed agro-ecosystems in central Mexico

88%

Sierra-Soler A. , Adamowski J. , Qi Z. , Saadat H. , Pingale S. , Sierra-Soler A. , Adamowski J. , Qi Z. , Saadat H. , Pingale S.

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nr 26

15

Optimizing statistical classification accuracy of satellite remotely sensed imagery for supporting fast flood hydrological analysis

88%

Alexakis D. , Agapiou A. , Hadjimitsis D. , Retalis A.

Acta Geophysica

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2012

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tom Vol. 60, no. 3

959-984

EN

The aim of this study is to improve classification results of multispectral satellite imagery for supporting flood risk assessment analysis in a catchment area in Cyprus. For this purpose, precipitation and ground spectroradiometric data have been collected and analyzed with innovative statistical analysis methods. Samples of regolith and construction material were in situ collected and examined in the spectroscopy laboratory for their spectral response under consecutive different conditions of humidity. Moreover, reflectance values were extracted from the same targets using Landsat TM/ETM+ images, for drought and humid time periods, using archived meteorological data. The comparison of the results showed that spectral responses for all the specimens were less correlated in cases of substantial humidity, both in laboratory and satellite images. These results were validated with the application of different classification algorithms (ISODATA, maximum likelihood, object based, maximum entropy) to satellite images acquired during time period when precipitation phenomena had been recorded.

16

Cyfrowa fotogrametria i teledetekcja w Polsce

88%

Jachimski J. , Mierzwa W. , Mularz S. , Pyka K.

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1999

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tom T. 1

11-36

PL

Tradycje fotogrametryczne sięgają w Polsce okresu pierwszej wojny światowej. Doświadczenia badawcze i technologiczne dotyczące metod fotogrametrii analogowej i analitycznej oraz fotointerpretacji zaowocowały łatwością przejścia do metod cyfrowych w ostatniej dekadzie bieżącego stulecia. Przejście to było tym łatwiejsze, że wiele cyfrowych rozwiązań technologicznych powstawało, w wyniku badań prowadzonych w Polsce, równolegle do rozwiązań światowych. Należą do nich opracowanie: cyfrowego autografu VSD oraz programu do wytwarzania cyfrowych ortofotogramów ze zdjęć lotniczych. Do pionierskich fotogrametrycznych zastosowań komercyjnych pakietów należy zaliczyć ortofotomapy cyfrowe, szczególnie te, które opracowano dla terenu Krakowa i Warszawy, przy wykorzystaniu równocześnie obrazów lotniczych i satelitarnych. Metody cyfrowe przyspieszyły też rozwój specjalnych opracowań fotogrametrii bliskiego zasięgu; szczególnie dokumentacji obiektów zabytkowych. Również teledetekcja lotnicza i satelitarna, cyfrowa ze swej natury, ma znaczne osiągnięcia: zastosowanie termowizji do badania termicznego zanieczyszczenia rzek, lub badanie warunków mikroklimatycznych w aglomeracjach miejsko-przemysłowych, badanie stanów powodziowych rzek szacowania plonów i zbiorów pasz z trwałych użytków zielonych oraz szacowanie wilgotności gruntu na podstawie zobrazowań satelitarnych. Do niewątpliwych osiągnięć należy też opracowanie cyfrowej mapy użytkowania ziemi w Polsce, cyfrowej satelitarnej fotomapy Polski i wydanie atlasu zdjęć satelitarnych Polski. Teledetekcja naziemna (termowizja) ma osiągnięcia w badaniu stanu zwałowisk lub obiektów przemysłowych i w badaniu strat ciepła w budynkach mieszkalnych. Klamrą spinającą różne zastosowania fotogrametrii i teledetekcji są systemy informacji przestrzennej o środowisku, które znajdują zastosowanie nie tylko jako nośnik półproduktów i produktów końcowych opracowań zdalnych, ale służą również do przeprowadzania coraz bardziej złożonych analiz. Dzięki upowszechnianiu się systemów GIS, geoinformatyka staje się w Polsce metodą uniwersalnego wykorzystywania kompleksowej informacji o środowisku, gromadzonej przez różnych specjalistów, w znacznym stopniu metodami fotogrametrii i teledetekcji.

EN

The Polish tradition in photogrammetry began in the period of the First World War. Good experiences in the analog and analytical photogrammetry resulted in easy approach to digital methods in the last decade. Introduction of a digital photogrammetry was easy thanks to Polish research experiences and own developments,*) Akademia Górniczo-Hutnicza - Wydział Geodezji Górniczej i Inżynierii Środowiska, Kraków such as digital stereoplotter (VSD), and software for differential rectification of digital images. The pioneering were orthophotomaps, specially those of Cracow and Warsow, produced with the use of combined aerial and satellite images. Digital methods influenced a rapid development of special applications of close range photogrammetry, specially those concerning documentation of historic monuments. Aerial and satellite remote sensing applications have also important achievements: investigation of a thermal water pollution in rivers, investigation of microclimats in the urban and industrial agglomerations, investigation ofthe river flood, evaluation of expected crops harvest and green food for animals, and assessment of ground moisture using satellite imagery. An important achievement it is the digital map of the land use in Poland and an atlas of satellite images of Poland. Terrestrial remote sensing has achievements in evaluation of the state of dumped deposits, or industrial objects, and in assessment of warms loses in the inhabited buildings. Presently, the Spatial Information Systems comprise all the application of photogrammetry and RS, which not only are bearing the half-products and products of evaluation of the image contest, but serve also for noticeably complicated analysis. Thanks to the GIS growing popularity, the geoinformatics in Poland became a method of universal use of complex information about the environment, gathered by various specialists, mostly employing photogrammetric and RS methods.

17

Dobre widoki dla teledetekcji

88%

Przywara J.

|

2006

|

tom nr 3

22-23

18

Zastosowanie termowizji i spektroradiometrii do zdalnego wykrywania skażeń chemicznych

75%

Kastek M. , Madura H. , Orżanowski T. , Sosnowski T.

|

2008

|

tom nr 2

3-6

PL

Zdalna detekcja substancji chemicznych jest ważnym problemem w wielu dziedzinach działalności człowieka. Spektrum zastosowań tego typu urządzeń rozciąga się od monitorowania procesów technologicznych poprzez diagnostykę instalacji przemysłowych i monitoring środowiska naturalnego po zastosowania militarne. W artykule przedstawiono różne metody i urządzenia do zdalnej, pasywnej detekcji skażeń chemicznych. W części teoretycznej przedstawiono analizę możliwości detekcji skażeń chemicznych przez kamerę termowizyjną.

EN

The range of applications in which remote sensing of chemical compounds is used extends from monitoring of technological processes through diagnostics of industrial installation and environmental control up to military applications. The methods and the devices for passive detection of selected gases will be presented. The change of the signal reaching the camera caused by the presence of gas was calculated. The successful detection can be obtained if the absorption (or emission) of a gas cloud, located between object (background) and the camera, causes signal change greater or equal to NETD of the camera.

19

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

75%

Kowalczuk P. , Darecki M. , Zabłocka M. , Górecka I.

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2010

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tom No. 52 (2)

171-196

EN

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.

20

Remote-sensing observations of coastal sub-mesoscale eddies in the south-eastern Baltic

75%

Gurova E. , Chubarenko B.

|

2012

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tom No. 54 (4)

631-654

EN

This paper presents an overview of the sub-mesoscale eddies observed in the coastal zone of the south-eastern Baltic near the shores of the Sambian Peninsula and the Curonian Spit based on CODAR (high-frequency coast-based radar) measurements and analysis of MODIS and ASAR satellite images for the period 30 March 2000-31 December 2011. It was found that when winds are predominantly SW, S or W, a wake eddy of varying size (up to 25 km in diameter) forms off Cape Taran and can cover the area between the shoreline and the 65 m isobath. Its longest lifetime, observed using MODIS images, was 6 days. Another location where coastal sub-mesoscale eddies (up to 10-15 km in diameter) of varying form regularly appear is the coastal slope near the southern and central part of the Curonian Spit.