Pub Date : 2014-05-27DOI: 10.1109/BALTIC.2014.6887838
H. Seim, S. Lockhart
A cross-shelf moored array, shipboard current profiler observations and glider observations were collected over the first few months of 2012 as part of a study of wintertime phytoplankton blooms off the coast of northern South Carolina, United States. The combined dataset is examined to document the internal wave field in the region inshore of the offshore deflection of the Gulf Stream. Moderate amplitude isopycnal displacements of 10-20 meters are common in glider observations over the slope; much larger displacements were observed when the glider was drawn offshore by the Gulf Stream. Meanders of the Gulf Stream indirectly forced the outer shelf flow through formation of filaments off the meander crests that moved along the upper slope. Several filaments exhibited unusually strong flow and moved equatorward, displacing ambient waters. Moored current meters indicate intermittent internal tides on the upper slope and shelf and a correlation with the external tide. The intermittency of the internal tide may be related to the varying alongshelf flow and varying mass field over the shelf.
{"title":"Connection between internal wave activity and outer shelf and slope circulation during winter 2012 off Long Bay (SE US)","authors":"H. Seim, S. Lockhart","doi":"10.1109/BALTIC.2014.6887838","DOIUrl":"https://doi.org/10.1109/BALTIC.2014.6887838","url":null,"abstract":"A cross-shelf moored array, shipboard current profiler observations and glider observations were collected over the first few months of 2012 as part of a study of wintertime phytoplankton blooms off the coast of northern South Carolina, United States. The combined dataset is examined to document the internal wave field in the region inshore of the offshore deflection of the Gulf Stream. Moderate amplitude isopycnal displacements of 10-20 meters are common in glider observations over the slope; much larger displacements were observed when the glider was drawn offshore by the Gulf Stream. Meanders of the Gulf Stream indirectly forced the outer shelf flow through formation of filaments off the meander crests that moved along the upper slope. Several filaments exhibited unusually strong flow and moved equatorward, displacing ambient waters. Moored current meters indicate intermittent internal tides on the upper slope and shelf and a correlation with the external tide. The intermittency of the internal tide may be related to the varying alongshelf flow and varying mass field over the shelf.","PeriodicalId":435850,"journal":{"name":"2014 IEEE/OES Baltic International Symposium (BALTIC)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115862564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-27DOI: 10.1109/BALTIC.2014.6887884
N. Kolesova, K. Siimon, U. Raudsepp
This paper is based on the analysis of zoobenthic communities from Lahepere Bay of Estonian coastal sea and its region up to Estonian economic zone. The samples were collected on 3.-4. July of 2013 from thirteen stations using Van Veen grab with the opening area of 0.1 m2. From three stations no zoobenthos was found due to oxygen deficit in the near bottom layer. Bottom macrofauna was identified to the species level, abundance and dry biomass was also determined. In deeper areas of the study (57-60 m) only two to four species were found in each sampling station, whereas key species included Macoma balthica, Halicryptus spinulosus and Marenzelleria neglecta. In depth range 43-57 m the species composition consisted of five to seven species, including key species Monoporeia affinis and Bylgides sarsi in addition to previous. Shallower stations (12-34 m) had up to 17 species in one community, key species included bivalves. The results showed that zoobenthic communities were more diverse in the shallow Lahepere Bay with coarse sediment type. The sediment type changed from gravel and sand to mud or clay from the southern part of the Lahepere Bay towards the open sea area. Also the aims of this study, to provide initial physical and zoobenthic data for estimating changes in benthic invertebrate communities after possible anthropogenic impact in the future and to assess ecological quality status of macrozoobenthic communities in the coastal area of the Lahepere Bay region using the ZKI-based Ecological Quality Ratio (EQR), are achieved.
{"title":"Spatial distribution of macrozoobethos according to environmental conditions in the Lahepere Bay region","authors":"N. Kolesova, K. Siimon, U. Raudsepp","doi":"10.1109/BALTIC.2014.6887884","DOIUrl":"https://doi.org/10.1109/BALTIC.2014.6887884","url":null,"abstract":"This paper is based on the analysis of zoobenthic communities from Lahepere Bay of Estonian coastal sea and its region up to Estonian economic zone. The samples were collected on 3.-4. July of 2013 from thirteen stations using Van Veen grab with the opening area of 0.1 m2. From three stations no zoobenthos was found due to oxygen deficit in the near bottom layer. Bottom macrofauna was identified to the species level, abundance and dry biomass was also determined. In deeper areas of the study (57-60 m) only two to four species were found in each sampling station, whereas key species included Macoma balthica, Halicryptus spinulosus and Marenzelleria neglecta. In depth range 43-57 m the species composition consisted of five to seven species, including key species Monoporeia affinis and Bylgides sarsi in addition to previous. Shallower stations (12-34 m) had up to 17 species in one community, key species included bivalves. The results showed that zoobenthic communities were more diverse in the shallow Lahepere Bay with coarse sediment type. The sediment type changed from gravel and sand to mud or clay from the southern part of the Lahepere Bay towards the open sea area. Also the aims of this study, to provide initial physical and zoobenthic data for estimating changes in benthic invertebrate communities after possible anthropogenic impact in the future and to assess ecological quality status of macrozoobenthic communities in the coastal area of the Lahepere Bay region using the ZKI-based Ecological Quality Ratio (EQR), are achieved.","PeriodicalId":435850,"journal":{"name":"2014 IEEE/OES Baltic International Symposium (BALTIC)","volume":"152 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116903295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-27DOI: 10.1109/BALTIC.2014.6887845
T. Torsvik, J. Kalda
The accurate prediction of currents in the ocean surface layer is of importance for many applications, such as environmental monitoring, offshore commercial operations, and safety of shipping. Numerical models can be used to obtain such predictions, but in most sea areas the availability of current observations remains scarce. We report results of field experiments involving passive surface drifters in the Gulf of Finland, with the purpose to characterize the mesoscale and sub-mesoscale flow dynamics and spreading rate. A total of 51 deployments of surface drifters were made in 2011 and 2013, with duration of drift lasting from 1 to 35 days. The individual tracks produced a velocity distribution with a mean value close to 0.1 m/s, with close resemblance to the Rayleigh distribution. A Lagrangian integral time scale was calculated based on the autocorrelation of the drifter velocity, using three different methods of calculation and splitting the drifter into segments of different duration. The persistency of motion was 7-12 hours on average, with individual trajectories showing persistent motion up to over 20 hours. When inertial oscillations were filtered out from the drifter positions, the average persistency increased to 14-20 hours. Analysis was also made for the relative dispersion of drifter clusters. At small separation scales the speed of drifter separation appears to follow the Richardson's Law, where the relative diffusivity increases as the separation distance to the 1/3 power. However, a transition takes place with separation distances close to 5 km, after which the relative diffusivity decreases with increasing separation distance. These results point to the complexity of the underlying surface current fields, and indicate what scales must be resolved in numerical models in order to obtain reliable predictions for surface currents in the Gulf of Finland.
{"title":"Analysis of surface current properties in the Gulf of Finland using data from surface drifters","authors":"T. Torsvik, J. Kalda","doi":"10.1109/BALTIC.2014.6887845","DOIUrl":"https://doi.org/10.1109/BALTIC.2014.6887845","url":null,"abstract":"The accurate prediction of currents in the ocean surface layer is of importance for many applications, such as environmental monitoring, offshore commercial operations, and safety of shipping. Numerical models can be used to obtain such predictions, but in most sea areas the availability of current observations remains scarce. We report results of field experiments involving passive surface drifters in the Gulf of Finland, with the purpose to characterize the mesoscale and sub-mesoscale flow dynamics and spreading rate. A total of 51 deployments of surface drifters were made in 2011 and 2013, with duration of drift lasting from 1 to 35 days. The individual tracks produced a velocity distribution with a mean value close to 0.1 m/s, with close resemblance to the Rayleigh distribution. A Lagrangian integral time scale was calculated based on the autocorrelation of the drifter velocity, using three different methods of calculation and splitting the drifter into segments of different duration. The persistency of motion was 7-12 hours on average, with individual trajectories showing persistent motion up to over 20 hours. When inertial oscillations were filtered out from the drifter positions, the average persistency increased to 14-20 hours. Analysis was also made for the relative dispersion of drifter clusters. At small separation scales the speed of drifter separation appears to follow the Richardson's Law, where the relative diffusivity increases as the separation distance to the 1/3 power. However, a transition takes place with separation distances close to 5 km, after which the relative diffusivity decreases with increasing separation distance. These results point to the complexity of the underlying surface current fields, and indicate what scales must be resolved in numerical models in order to obtain reliable predictions for surface currents in the Gulf of Finland.","PeriodicalId":435850,"journal":{"name":"2014 IEEE/OES Baltic International Symposium (BALTIC)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121591385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-27DOI: 10.1109/BALTIC.2014.6887828
A. Liibusk, Tarmo Kall, A. Ellmann, T. Kõuts
Different types of tide gauges (TG) are used to monitor sea level dynamics around the Baltic Sea. They are usually connected to national levelling network and several of them are linked into regional networks (e.g. Baltic Operational Oceanographic System). The sea level readings are used for nautical navigation, modelling and forecasting of sea level changes. Long-term and historical sea level series are also useful in studying regional land uplift/subsidence or calibrating satellite altimetry data. Both tasks require precise knowledge of interconnections between height systems of countries surrounding the same sea. Presently, however, six different height reference systems are in official use in the Baltic Sea countries. Even though all these systems are based on mean sea level (MSL) observations averaged over different time-periods, but different reference TG and tidal systems have been adopted for national height systems. The differences of national height systems between the countries around the Baltic Sea can reach up to 20 cm. Overlooking this yields undesirable systematic biases between regional TG data. Additionally, the entire Fennoscandia is affected by apparent land uplift at the velocity rate up to +9 mm/year, primarily due to the viscoelastic response of the solid Earth resulting from the de-glaciation of the Pleistocene ice-sheets. Over a time span this causes notable distortions of height system realisations even within a country. Therefore, the land uplift corrections should be also taken into account in sea level series, which are used for modelling and forecasting of sea level changes. A case study in West-Estonian Archipelago involves a recently developed land uplift model EST2013LU, which is based on four repeated high-precision levelling data from 1933 to 2010. Also connections between levelling network and TG series are analysed. The results reveal that discrepancies due to obsoleteness of the heights in the national height system may cause discrepancies in series of nearby located tide gauges up to 7 cm.
{"title":"Correcting tide gauge series due to land uplift and differences between national height systems of the baltic sea countries","authors":"A. Liibusk, Tarmo Kall, A. Ellmann, T. Kõuts","doi":"10.1109/BALTIC.2014.6887828","DOIUrl":"https://doi.org/10.1109/BALTIC.2014.6887828","url":null,"abstract":"Different types of tide gauges (TG) are used to monitor sea level dynamics around the Baltic Sea. They are usually connected to national levelling network and several of them are linked into regional networks (e.g. Baltic Operational Oceanographic System). The sea level readings are used for nautical navigation, modelling and forecasting of sea level changes. Long-term and historical sea level series are also useful in studying regional land uplift/subsidence or calibrating satellite altimetry data. Both tasks require precise knowledge of interconnections between height systems of countries surrounding the same sea. Presently, however, six different height reference systems are in official use in the Baltic Sea countries. Even though all these systems are based on mean sea level (MSL) observations averaged over different time-periods, but different reference TG and tidal systems have been adopted for national height systems. The differences of national height systems between the countries around the Baltic Sea can reach up to 20 cm. Overlooking this yields undesirable systematic biases between regional TG data. Additionally, the entire Fennoscandia is affected by apparent land uplift at the velocity rate up to +9 mm/year, primarily due to the viscoelastic response of the solid Earth resulting from the de-glaciation of the Pleistocene ice-sheets. Over a time span this causes notable distortions of height system realisations even within a country. Therefore, the land uplift corrections should be also taken into account in sea level series, which are used for modelling and forecasting of sea level changes. A case study in West-Estonian Archipelago involves a recently developed land uplift model EST2013LU, which is based on four repeated high-precision levelling data from 1933 to 2010. Also connections between levelling network and TG series are analysed. The results reveal that discrepancies due to obsoleteness of the heights in the national height system may cause discrepancies in series of nearby located tide gauges up to 7 cm.","PeriodicalId":435850,"journal":{"name":"2014 IEEE/OES Baltic International Symposium (BALTIC)","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115578104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-27DOI: 10.1109/BALTIC.2014.6887846
U. Lips, V. Zhurbas, M. Skudra, G. Vali
A regional, 0.5 n.m. and 20 sigma layer grid model of the Gulf of Riga (GoR) was implemented based on the Princeton Ocean Model code with initial conditions and atmospheric forcing taken from HIROMB and HIRLAM output. A basic run that covers an ice-free period of May 1-December 31, 2012, brought the following results: - the mean summertime surface circulation in GoR displays a whole-basin anticyclonic gyre with more intense currents in the western half of the gyre; - two seasonal currents are identified: the Northern Longshore Current (NLC) in the western part of GoR and the Southern Subsurface Longshore Current in the eastern part of GoR; - in the cold season of the year (when seasonal pycnocline is absent), the anticyclonic gyre in GoR is replaced by a cyclonic gyre. The seasonal change in sign of the whole-basin surface circulation in GoR is likely controlled by the NLC, a baroclinic jet-like current formed along the western shore in summer due to the prevalence of southwesterly, upwelling-favored winds, and presence of seasonal stratification that can be approximated as a two-layer vertical structure; this baroclinic jet disappears in winter when the seasonal pycnocline is absent.
{"title":"Features of summertime circulation in the Gulf of Riga (A numerical simulation)","authors":"U. Lips, V. Zhurbas, M. Skudra, G. Vali","doi":"10.1109/BALTIC.2014.6887846","DOIUrl":"https://doi.org/10.1109/BALTIC.2014.6887846","url":null,"abstract":"A regional, 0.5 n.m. and 20 sigma layer grid model of the Gulf of Riga (GoR) was implemented based on the Princeton Ocean Model code with initial conditions and atmospheric forcing taken from HIROMB and HIRLAM output. A basic run that covers an ice-free period of May 1-December 31, 2012, brought the following results: - the mean summertime surface circulation in GoR displays a whole-basin anticyclonic gyre with more intense currents in the western half of the gyre; - two seasonal currents are identified: the Northern Longshore Current (NLC) in the western part of GoR and the Southern Subsurface Longshore Current in the eastern part of GoR; - in the cold season of the year (when seasonal pycnocline is absent), the anticyclonic gyre in GoR is replaced by a cyclonic gyre. The seasonal change in sign of the whole-basin surface circulation in GoR is likely controlled by the NLC, a baroclinic jet-like current formed along the western shore in summer due to the prevalence of southwesterly, upwelling-favored winds, and presence of seasonal stratification that can be approximated as a two-layer vertical structure; this baroclinic jet disappears in winter when the seasonal pycnocline is absent.","PeriodicalId":435850,"journal":{"name":"2014 IEEE/OES Baltic International Symposium (BALTIC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128751600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-27DOI: 10.1109/BALTIC.2014.6887891
O. Vladimirova, V. A. Tsarev
Spreading of a bottom saline water over the Arcona Basin caused by periodic inflow and outflow through the Strait of Zund is simulated. The model includes a system of hydrostatic equations of motion, the continuity equation, the transport equation and the equation of state. Simulation was run with and without taking into account a baroclinic factors. Calculations have shown that during inflow there is a rapid spreading of bottom salt water at significant part of the basin. In period of outflow the bottom salt water moves to the strait out of the Basin, but at the end of the outflow a significant part of salt water remains in the basin. The same calculations repeted without taking into account baroclinic factors shown that in that case at the end of outflow the bottom salt water leaves the basin almost entirely. Thus the calculations made it possible to estimate a role of baroclinic currents in formation of bottom salt water in the Arcona Basin.
{"title":"Role of baroclinic currents in bottom salty water formation in the Arkona basin","authors":"O. Vladimirova, V. A. Tsarev","doi":"10.1109/BALTIC.2014.6887891","DOIUrl":"https://doi.org/10.1109/BALTIC.2014.6887891","url":null,"abstract":"Spreading of a bottom saline water over the Arcona Basin caused by periodic inflow and outflow through the Strait of Zund is simulated. The model includes a system of hydrostatic equations of motion, the continuity equation, the transport equation and the equation of state. Simulation was run with and without taking into account a baroclinic factors. Calculations have shown that during inflow there is a rapid spreading of bottom salt water at significant part of the basin. In period of outflow the bottom salt water moves to the strait out of the Basin, but at the end of the outflow a significant part of salt water remains in the basin. The same calculations repeted without taking into account baroclinic factors shown that in that case at the end of outflow the bottom salt water leaves the basin almost entirely. Thus the calculations made it possible to estimate a role of baroclinic currents in formation of bottom salt water in the Arcona Basin.","PeriodicalId":435850,"journal":{"name":"2014 IEEE/OES Baltic International Symposium (BALTIC)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121379994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-27DOI: 10.1109/BALTIC.2014.6887837
R. Mateescu, A. Spînu, L. Buga, D. Niculescu, E. Mihailov, E. Vlasceanu
The marine and coastal spatial data & information management actions within the Romanian research & development institutions, formed towards the implementation of Coastal ecosystem based management standards include RS data validation, QC-QD procedure and Web-GIS services. The RS & GIS complementary actions, among other areas, are developed in order to provide a modern scientific and technical instrument toward the extension of an operational informational system. The paper presents certain national consortium actions that are developed as implementing activities of the international/European RS applications to coastal complex waters studies development, including the calibration and validation of RS algorithm extensions, Web-GIS systems/services as support tools for the ICZM implementation process in the Romanian Black Sea area. The results presented in this work are related to the development of a Marine & Coastal GIS able to accommodate the data exchange and integration, from several sources, which, associated in databases, can constitute the engine of a dynamic and efficient decision system for a specific area of the Romanian Coastal Zone based on its case study.
{"title":"Remote sensing applications for the ecosystem-based management process implementation in the Romanian Black Sea Coastal Zone","authors":"R. Mateescu, A. Spînu, L. Buga, D. Niculescu, E. Mihailov, E. Vlasceanu","doi":"10.1109/BALTIC.2014.6887837","DOIUrl":"https://doi.org/10.1109/BALTIC.2014.6887837","url":null,"abstract":"The marine and coastal spatial data & information management actions within the Romanian research & development institutions, formed towards the implementation of Coastal ecosystem based management standards include RS data validation, QC-QD procedure and Web-GIS services. The RS & GIS complementary actions, among other areas, are developed in order to provide a modern scientific and technical instrument toward the extension of an operational informational system. The paper presents certain national consortium actions that are developed as implementing activities of the international/European RS applications to coastal complex waters studies development, including the calibration and validation of RS algorithm extensions, Web-GIS systems/services as support tools for the ICZM implementation process in the Romanian Black Sea area. The results presented in this work are related to the development of a Marine & Coastal GIS able to accommodate the data exchange and integration, from several sources, which, associated in databases, can constitute the engine of a dynamic and efficient decision system for a specific area of the Romanian Coastal Zone based on its case study.","PeriodicalId":435850,"journal":{"name":"2014 IEEE/OES Baltic International Symposium (BALTIC)","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132881976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-27DOI: 10.1109/BALTIC.2014.6887855
L. Tuomi, J-V Bjorkqvist
The Archipelago Sea, located between the Baltic Proper and the Gulf of Bothnia, has countless small islands. The southern edge of the Archipelago Sea is also characterized with shoals that cause wave refraction and depth-induced wave breaking. To assist safe and efficient shipping in this area wave forecasts, with resolution high enough to solve the islands and small scale features in the bathymetry, are needed. Wave modelling in the Archipelago Sea was studied with two high-resolution, 0.1 nmi and 0.5 nmi grids using wave model WAM. To evaluate the accuracy of the wave forecast in this area and to estimate the properties of wave field inside the archipelago, a-posteriori forecasts were made for summer 2013 using wind forcing from the HIRLAM model. Comparison of modeled significant wave height against wave measurements made at Finnish Meteorological Institute's wave buoy close to Utö islands showed that waves propagating from the Northern Baltic Proper towards the Archipelago Sea were modelled with relatively good accuracy, being slightly underestimated. When the wave field was propagating from the north to the Utö station the modelled significant wave height was overestimated. Preliminary analysis indicated that the overestimation resulted from slight overestimation of the forcing wind speed from northerly direction and from the overestimation of the growth of wave energy at short fetch by the WAM model. Further studies and more measurements are needed in order to improve the accuracy of wave forecasts in this area.
{"title":"Wave forecasting in coastal archipelagos","authors":"L. Tuomi, J-V Bjorkqvist","doi":"10.1109/BALTIC.2014.6887855","DOIUrl":"https://doi.org/10.1109/BALTIC.2014.6887855","url":null,"abstract":"The Archipelago Sea, located between the Baltic Proper and the Gulf of Bothnia, has countless small islands. The southern edge of the Archipelago Sea is also characterized with shoals that cause wave refraction and depth-induced wave breaking. To assist safe and efficient shipping in this area wave forecasts, with resolution high enough to solve the islands and small scale features in the bathymetry, are needed. Wave modelling in the Archipelago Sea was studied with two high-resolution, 0.1 nmi and 0.5 nmi grids using wave model WAM. To evaluate the accuracy of the wave forecast in this area and to estimate the properties of wave field inside the archipelago, a-posteriori forecasts were made for summer 2013 using wind forcing from the HIRLAM model. Comparison of modeled significant wave height against wave measurements made at Finnish Meteorological Institute's wave buoy close to Utö islands showed that waves propagating from the Northern Baltic Proper towards the Archipelago Sea were modelled with relatively good accuracy, being slightly underestimated. When the wave field was propagating from the north to the Utö station the modelled significant wave height was overestimated. Preliminary analysis indicated that the overestimation resulted from slight overestimation of the forcing wind speed from northerly direction and from the overestimation of the growth of wave energy at short fetch by the WAM model. Further studies and more measurements are needed in order to improve the accuracy of wave forecasts in this area.","PeriodicalId":435850,"journal":{"name":"2014 IEEE/OES Baltic International Symposium (BALTIC)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133836139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-27DOI: 10.1109/BALTIC.2014.6887835
P. Philipson, K. Eriksso, K. Stelzer
According to the Water Framework Directive (WFD), all lakes larger than 50 ha (0,5 km2) should be monitored on a regular basis. In Sweden, chlorophyll a is one of the parameters used to classify the phytoplankton status of a lake. The possibility to use satellite based information (ENVISAT - MERIS) to measure and monitor the water quality status of Lake Bolmen and surrounding smaller lakes (>2 km2) has been investigated. The work was focused on chlorophyll a and data from 83 lakes in the investigated region has been analysed. In general, chlorophyll a (chl a) levels between 0-10 ug/l prevail in these lakes, but also more extreme levels of chla around 50 ug/l exist. Data from 5 years (2007-2011) has been analysed together with existing field data from approximately 20 lakes. The results indicate that good chl a estimates could be generated for lakes larger than 2-3 km2. This means that not all lakes required by the WFD are possible to monitor using MERIS, and future Sentinel-3-OLCI data, but that a significant contribution to the present and future monitoring program should be possible by adding earth observation data.
{"title":"MERIS data for monitoring of small and medium sized humic Swedish lakes","authors":"P. Philipson, K. Eriksso, K. Stelzer","doi":"10.1109/BALTIC.2014.6887835","DOIUrl":"https://doi.org/10.1109/BALTIC.2014.6887835","url":null,"abstract":"According to the Water Framework Directive (WFD), all lakes larger than 50 ha (0,5 km2) should be monitored on a regular basis. In Sweden, chlorophyll a is one of the parameters used to classify the phytoplankton status of a lake. The possibility to use satellite based information (ENVISAT - MERIS) to measure and monitor the water quality status of Lake Bolmen and surrounding smaller lakes (>2 km2) has been investigated. The work was focused on chlorophyll a and data from 83 lakes in the investigated region has been analysed. In general, chlorophyll a (chl a) levels between 0-10 ug/l prevail in these lakes, but also more extreme levels of chla around 50 ug/l exist. Data from 5 years (2007-2011) has been analysed together with existing field data from approximately 20 lakes. The results indicate that good chl a estimates could be generated for lakes larger than 2-3 km2. This means that not all lakes required by the WFD are possible to monitor using MERIS, and future Sentinel-3-OLCI data, but that a significant contribution to the present and future monitoring program should be possible by adding earth observation data.","PeriodicalId":435850,"journal":{"name":"2014 IEEE/OES Baltic International Symposium (BALTIC)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114997912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-05-27DOI: 10.1109/BALTIC.2014.6887830
I. Maljutenko, U. Raudsepp
The hydrodynamic model GETM was used to simulate the hydrographic conditions in the Baltic Sea for the hindcast period from 1966 to 2005. Time series of surface and bottom salinity and bottom temperature at four monitoring stations belonging to the Bornholm Basin, Gotland Basin, the Gulf of Finland and the Gulf of Riga were used for model validation. The model has reproduced realistic conditions through the simulation period that was characterized by stagnation period in the 80s and numerous Major Baltic Inflow events. The simulated salinity and temperature at different depths were in good agreement with measurements. Also, the sea level and maximum ice extent were compared with observations.
{"title":"Validation of GETM model simulated long-term salinity fields in the pathway of saltwater transport in response to the Major Baltic Inflows in the Baltic Sea","authors":"I. Maljutenko, U. Raudsepp","doi":"10.1109/BALTIC.2014.6887830","DOIUrl":"https://doi.org/10.1109/BALTIC.2014.6887830","url":null,"abstract":"The hydrodynamic model GETM was used to simulate the hydrographic conditions in the Baltic Sea for the hindcast period from 1966 to 2005. Time series of surface and bottom salinity and bottom temperature at four monitoring stations belonging to the Bornholm Basin, Gotland Basin, the Gulf of Finland and the Gulf of Riga were used for model validation. The model has reproduced realistic conditions through the simulation period that was characterized by stagnation period in the 80s and numerous Major Baltic Inflow events. The simulated salinity and temperature at different depths were in good agreement with measurements. Also, the sea level and maximum ice extent were compared with observations.","PeriodicalId":435850,"journal":{"name":"2014 IEEE/OES Baltic International Symposium (BALTIC)","volume":"337 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123229647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：