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1

Daily radiation budget of the Baltic Sea surface from satellite data

Zapadka T., Krężel A., Paszkutab M., Darecki M.

Polish Maritime Research

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2015

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nr 3

50--56

EN

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.

2

Latitudinal pattern of abundance and composition of ciliate communities in the surface waters of the Atlantic Ocean

Rychert K., Nawacka B., Majchrowski R., Zapadka T.

Oceanological and Hydrobiological Studies

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2014

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Vol. 43, No. 4

4436--441

EN

Abundance, biomass, and taxonomic composition of the ciliate community were studied in the surface waters along a transect between 50°S 61°W and 48°N 5°W (Atlantic Ocean, March-April 2011). The abundance of heterotrophic ciliates was low in the equatorial zone (280–320 cells l−1, 0.11–0.12 μg C l−1), but it increased toward both the northern and southern temperate zones with the maximum abundance observed at 44°S (2667 cells l−1, 0.82 μg C l−1). This pattern resembles the global distribution of oceanic primary production, which is low at lower latitudes and high in temperate zones. In temperate zones ciliate abundance peaks during spring and fall. Thus, because the present study was carried out during spring in the northern hemisphere and austral fall in the southern hemisphere, the ciliate abundance at higher latitudes was additionally elevated. Functionally autotrophic Mesodinium rubrum was only observed in the northern hemisphere and tropical waters. Its maximum abundance was observed at 48°N (1080 cells l−1, 1.14 μg C l−1). The most frequently observed ciliates were oligotrichs and choreotrichs. Other important ciliates were haptorids (including M. rubrum) and hypotrichs.

3

Inherent optical properties and remote sensing reflectance of Pomeranian lakes (Poland)

Ficek D., Meler J., Zapadka T., Woźniak B., Dera J.

Oceanologia

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2012

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No. 54 (4)

611-630

EN

This paper describes the results of comprehensive empirical studies of the inherent optical properties (IOPs), the remote sensing reflectance Rrs(λ) and the contents of the principal optically active components (OAC) i.e. coloured dissolved organic matter (CDOM), suspended particulate matter (SPM) and chlorophyll a, in the waters of 15 lakes in Polish Pomerania in 2007-2010. It presents numerous spectra of the total absorption a(λ) and scattering b(λ = bp(λ) of light in the visible band (400-700 nm) for surface waters, and separately, spectra of absorption by CDOM aCDOM(λ) and spectra of the mass-specific coefficients of absorption ap*(SPM)(λ) and scattering bp*(SPM)(λ) by SPM. The properties of these lake waters are highly diverse, but all of them can be classified as Case 2 waters (according to the optical classification by Morel & Prieur 1977) and they all have a relatively high OAC content. The lakes were conventionally divided into three types: Type I lakes have the lowest OAC concentrations (chlorophyll concentration Ca = (8.76 š 7.4) mg m-3 and CDOM absorption coefficients aCDOM(440) = (0.57 š 0.22) m-1 (i.e. mean and standard deviation), and optical properties (including spectra of Rrs(?) resembling those of Baltic waters. Type II waters have exceptionally high contents of CDOM (aCDOM(440) = (15.37 š 1.54) m-1), and hence appear brown in daylight and have very low reflectances Rrs(?) (of the order of 0.001 sr-1). Type III waters are highly eutrophic and contain large amounts of suspended matter, including phytoplankton ((CSPM = (47.0 š 39.4) g m-3, Ca = (86.6 š 61.5) mg m-3; aCDOM(440) = (2.77 š 0.86) m-1). Hence the reflectances Rrs(?) of these type of waters are on average one order of magnitude higher than those of the other natural waters, reaching maximum values of 0.03 sr-1 in ? bands 560-580 nm and 690-720 nm (see Ficek et al. 2011). The article provides a number of empirical formulas approximating the relationships between the properties of these lake waters.

4

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

Woźniak B., Bradtke K., Darecki M., Dera J., Dudzińska-Nowak J., Dzierzbicka-Głowacka L., Ficek D., Furmańczyk K., Kowalewski M., Krężel A., Majchrowski R., Ostrowska M., Paszkuta M., Stoń-Egiert J., Stramska M., Zapadka T.

Oceanologia

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2011

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No. 53 (4)

925-956

5

SatBałtyk - A Baltic environmental satellite remote sensing system - an ongoing project in Poland. Part 1: Assumptions, scope and operating range

Woźniak B., Bradtke K., Darecki M., Dera J., Dudzińska-Nowak J., Dzierzbicka-Głowacka L., Ficek D., Furmańczyk K., Kowalewski M., Krężel A., Majchrowski R., Ostrowska M., Paszkuta M., Stoń-Egiert J., Stramska M., Zapadka T.

Oceanologia

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2011

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No. 53 (4)

897-924

EN

This article is the first of two papers on the remote sensing methods of monitoring the Baltic ecosystem, developed by a Polish team. The main aim of the five-year SatBałtyk (2010-2014) research project (Satellite Monitoring of the Baltic Sea Environment) is to prepare the technical infrastructure and set in motion operational procedures for the satellite monitoring of the Baltic environment. This system is to characterize on a routine basis the structural and functional properties of this sea on the basis of data supplied by the relevant satellites. The characterization and large-scale dissemination of the following properties of the Baltic is anticipated: 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 water, distributions of algal blooms, the occurrence of upwelling events, and the characteristics of primary organic matter production and photosynthetically released oxygen in the water. It is also intended to develop and, where feasible, to implement satellite techniques for detecting slicks of petroleum derivatives and other compounds, evaluating the state of the sea's ice cover, and forecasting the hazards from current and future storms and providing evidence of their effects in the Baltic coastal zone. The ultimate objective of the project is to implement an operational system for the routine determination and dissemination on the Internet of the above-mentioned features of the Baltic in the form of distribution maps as well as plots, tables and descriptions characterizing the state of the various elements of the Baltic environment. The main sources of input data for this system will be the results of systematic recording by environmental satellites and also special-purpose ones such as TIROS N/NOAA, MSG (currently Meteosat 9), EOS/AQUA and ENVISAT. The final effects of the SatBałtyk project are to be achieved by the end of 2014, i.e. during a period of 60 months. These two papers present the results obtained during the first 15 months of the project. Part 1 of this series of articles contains the assumptions, objectives and a description of the most important stages in the history of our research, which constitute the foundation of the current project. It also discusses the way in which SatBałtyk functions and the scheme of its overall operations system. The second article (Part 2), will discuss some aspects of its practical applicability in the satellite monitoring of the Baltic ecosystem (see Woźniak et al. (2011) in this issue).

6

Remote sensing reflectance of Pomeranian lakes and the Baltic

Ficek D., Zapadka T., Dera J.

Oceanologia

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2011

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No. 53 (4)

959-970

EN

The remote sensing reflectance R_rs, concentrations of chlorophyll a and other pigments C_i, suspended particulate matter concentrations C_SPM and coloured dissolved organic matter absorption coefficient αCDOM(λ) were measured in the euphotic zones of 15 Pomeranian lakes in 2007-2010. On the basis of 235 sets of data points obtained from simultaneous estimates of these quantities, we classified the lake waters into three types. The first one, with the lowest αCDOM(440 nm) (usually between 0.1 and 1.3 m-1 and chlorophyll α concentrations 1.3 < Ca < 33 mg m-3), displays a broad peak on the reflectance spectrum at 560-580 nm and resembles the shape of the remote sensing reflectance spectra usually observed in the Baltic Proper. A set of Rrs spectra from the Baltic Proper is given for comparison. The second lake water type has a very high CDOM absorption coefficient (usually αCDOM(440 nm) > 10 m-1, up to 17.4 m-1 in Lake Pyszne; it has a relatively low reflectance (Rrs < 0.001 sr-1) over the entire spectral range, and two visible reflectance spectra peaks at ca 650 and 690-710 nm. The third type of lake water represents waters with a lower CDOM absorption coefficient (usually αCDOM(440 nm) < 5 m-1) and a high chlorophyll a concentration (usually Ca > 4 mg m-3, up to 336 mg m-3 in Lake Gardno). The remote sensing reflectance spectra in these waters always exhibit three peaks (Rrs > 0.005 sr-1): a broad one at 560-580 nm, a smaller one at ca 650 nm and a well-pronounced one at 690-720 nm. These Rrs(λ) peaks correspond to the relatively low absorption of light by the various optically active components of the lake water and the considerable scattering (over the entire spectral range investigated) due to the high SPM concentrations there. The remote sensing maximum at λ 690-720 nm is higher still as a result of the natural fluorescence of chlorophyll a. Empirical relationships between the spectral reflectance band ratios at selected wavelengths and the various optically active components for these lake waters are also established: for example, the chlorophyll a concentration in surface water layer Ca = 6.432 e4.556X, where X = [max Rrs (695 ≤λ≤720) - Rrs(? = 670)] / max Rrs (695 ? ? ? 720), and the coefficient of determination R^2 = 0.95.

7

Longwave radiation budget at the Baltic Sea surface from satellite and atmospheric model data

Zapadka T., Krężel A., Woźniak B.

Oceanologia

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2008

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No. 50 (2)

147-166

EN

The net longwave radiation flux LW in the Baltic Sea in 2001 has been subjected to spatial and temporal analysis. Maps of the mean monthly LW over the Baltic were drawn using the new semi-empirical formula for the Baltic Sea (Zapadka et al. 2007). The input data for the formula, such as sea surface and air temperatures, and cloud cover, were obtained from the Tiros N/NOAA and METEOSAT 7 satellites and from the UMPL forecast model (see http://meteo.icm.edu.pl). The mean annual LW for 2001 was estimated at 63 W m-2 and compared with available data from other sources. The monthly maps of the net flux LW over the Baltic show that the total values reach a minimum (LW?? ? 50 W m-2) in April, September, October and a maximum (LW = 80 W m-2) in November. The statistical error of daily maps, on which the monthly maps were based, is no more than 18 W m-2.

8

A more accurate formula for calculating the net longwave radiation flux in the Baltic Sea

Zapadka T., Woźniak B., Dera J.

Oceanologia

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2007

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No. 49 (4)

449-470

EN

A new, more accurate formula for calculating the net longwave radiation flux LW ?? has been devised for the Baltic Sea region. To this end, the following sets of simultaneously measured data regarding the longwave radiation of the sea and the atmosphere were used: the temperatures of the sea surface and its contiguous air layer, the water vapour pressure in the air above the water, and the cloud cover. These data were gathered during numerous research cruises in the Baltic in 2000-03 and were supplemented by satellite data from Karlsson (2001) characterising the cloud cover over the whole Baltic. The formula established for LW ?? can be written in the form of three alternative equations, differing with respect to their cloud cover functions: [formula]

9

A simple formula for the net long-wave radiation flux in the southern Baltic Sea

Zapadka T., Woźniak S.B., Woźniak B.

Oceanologia

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2001

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No. 43 (3)

265-277

EN

This paper discusses problems of estimating the net long-wave radiation flux at the sea surface on the basis of easily measurable meteorological quantities (air and sea surface temperatures, near-surface water vapour pressure, cloudiness). Empirical data and existing formulae are compared. Additionally, an improved formula for the southern Baltic region is introduced, with a systematic error of less than 1 W -2 and a statistical error of less than 20 W -2.

10

Preliminary comparison between various models of the long-wave radiation budget of the sea and experimental data from the Baltic Sea [commun.]

Zapadka T., Woźniak S.B.

Oceanologia

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2000

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No. 42 (3)

359-369

EN

This paper discusses existing models of long-wave radiation exchange between the sea surface and the atmosphere, and compares them with experimental data. The latter were based on empirical data collected in the southern Baltic during cruises of r/v `Oceania'. To a greater or lesser extent, all the models were encumbered with significant systematic and statistical errors. The probable reasons for these discrepancies are given.