Pub Date : 2014-05-27DOI: 10.1109/BALTIC.2014.6887880
S. Lebedev, Y. Troitskaya, G. Rybushkina, M. Dobrovolsky
Variability of the water level of largest lakes in the Baltic Basin is characterized by alternating periods of rise and drop according to the altimeteric measurements of TOPEX/Poseidon and Jason-1/2 satellites. Water level was calculated with the use of an algorithm of regional adaptive retracking for the Lakes Ilmen, Ladoga. Onega and Peipus. Applications of this algorithm considerably increase the amount of actual data records and significantly improve the accuracy of water level evaluation. According to the results, temporal variability of the Lake Ilmen, the Lake Ladoga and the Lake Piepus level is characterized by a wave with a period of 4-5 years and the Lake Onega level we found a wave with a period of 15 years. During the period from 1993 to 2011 lakes level was rising at a rate of 1.17±0.95 cm/yr for the Lakes Il`men', 0.24±0.10 cm/yr - for the Lake Ladoga, 1.39±0.18 cm/yr - for the Lake Piepus and 0.18±0.09 cm/yr - for the Lake Onega.
{"title":"Satellite altimetry of large lakes of the Baltic Basin","authors":"S. Lebedev, Y. Troitskaya, G. Rybushkina, M. Dobrovolsky","doi":"10.1109/BALTIC.2014.6887880","DOIUrl":"https://doi.org/10.1109/BALTIC.2014.6887880","url":null,"abstract":"Variability of the water level of largest lakes in the Baltic Basin is characterized by alternating periods of rise and drop according to the altimeteric measurements of TOPEX/Poseidon and Jason-1/2 satellites. Water level was calculated with the use of an algorithm of regional adaptive retracking for the Lakes Ilmen, Ladoga. Onega and Peipus. Applications of this algorithm considerably increase the amount of actual data records and significantly improve the accuracy of water level evaluation. According to the results, temporal variability of the Lake Ilmen, the Lake Ladoga and the Lake Piepus level is characterized by a wave with a period of 4-5 years and the Lake Onega level we found a wave with a period of 15 years. During the period from 1993 to 2011 lakes level was rising at a rate of 1.17±0.95 cm/yr for the Lakes Il`men', 0.24±0.10 cm/yr - for the Lake Ladoga, 1.39±0.18 cm/yr - for the Lake Piepus and 0.18±0.09 cm/yr - for the Lake Onega.","PeriodicalId":435850,"journal":{"name":"2014 IEEE/OES Baltic International Symposium (BALTIC)","volume":" 32","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113953367","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.2014.6887847
A. Liibusk, S. Talvik, A. Ellmann, T. Oja
Sea surface topography (SST) - the difference between the geoid and sea surface height (SSH), is requested for many marine applications, e.g. for analyzing currents and variation of salinity. Globally, SST can be roughly determined by using satellite altimetry and oceanographic data. However, in coastal areas, the accuracy and spatial resolution of these methods are rather low. Accordingly, issues related to enhancing SST resolution and accuracy with GNSS (Global Navigation Satellite Systems) measurements are explored in this study. A practical case study that was carried out on the ice surface over a part of the Baltic Sea tackles profile- and point-wise GNSS measurements for determining SST. Profile-wise GNSS measurements were proceeded on official ice roads (altogether 50 km) between the mainland and the two major islands (Saaremaa and Hiiumaa). The GNSS profiles were complemented with GNSS point-wise measurements scattered (1 point per 25 km2) all over the study area. The GNSS-derived SSH, which is the difference between the ellipsoid and the sea surface, was corrected with ice freeboard and corrections due to offsets of instantaneous sea level height values from the mean sea level. For calculating SST from the GNSS-derived and corrected SSH, a recent high-resolution (1' × 2') gravimetric geoid model GRAV-GEOID2011 was used. The estimated SST was compared to the global SST model DTU10MDT and with an earlier regional SST model.
{"title":"Determining regional sea surface topography by GNSS surveys on ice","authors":"A. Liibusk, S. Talvik, A. Ellmann, T. Oja","doi":"10.1109/BALTIC.2014.6887847","DOIUrl":"https://doi.org/10.1109/BALTIC.2014.6887847","url":null,"abstract":"Sea surface topography (SST) - the difference between the geoid and sea surface height (SSH), is requested for many marine applications, e.g. for analyzing currents and variation of salinity. Globally, SST can be roughly determined by using satellite altimetry and oceanographic data. However, in coastal areas, the accuracy and spatial resolution of these methods are rather low. Accordingly, issues related to enhancing SST resolution and accuracy with GNSS (Global Navigation Satellite Systems) measurements are explored in this study. A practical case study that was carried out on the ice surface over a part of the Baltic Sea tackles profile- and point-wise GNSS measurements for determining SST. Profile-wise GNSS measurements were proceeded on official ice roads (altogether 50 km) between the mainland and the two major islands (Saaremaa and Hiiumaa). The GNSS profiles were complemented with GNSS point-wise measurements scattered (1 point per 25 km2) all over the study area. The GNSS-derived SSH, which is the difference between the ellipsoid and the sea surface, was corrected with ice freeboard and corrections due to offsets of instantaneous sea level height values from the mean sea level. For calculating SST from the GNSS-derived and corrected SSH, a recent high-resolution (1' × 2') gravimetric geoid model GRAV-GEOID2011 was used. The estimated SST was compared to the global SST model DTU10MDT and with an earlier regional SST model.","PeriodicalId":435850,"journal":{"name":"2014 IEEE/OES Baltic International Symposium (BALTIC)","volume":"17 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":"116878180","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.2014.6887833
A. Banks, F. Mélin
One of the most important steps in utilizing ocean colour remote sensing data is subtracting the contribution of the atmosphere from the signal at the satellite to obtain marine water leaving radiance. To be done accurately this requires clear sky conditions, i.e. all clouds need to be excluded or masked from the data prior to atmospheric correction. The standard cloud mask used routinely in the processing of NASA's global ocean colour data is based on a simple threshold applied to the Rayleigh-corrected top-of-atmosphere radiance. The threshold is kept purposefully low to ensure high quality processing at a global scale. As a consequence, the standard scheme can sometimes inadvertently mask extreme optical events such as intense blue-green algal (cyanobacteria) blooms in the Baltic Sea. These blooms have important ecological and environmental impacts on the basin and require appropriate monitoring. Therefore, an assessment of 5 existing cloud masking schemes that could provide valuable alternatives for the Baltic Sea was carried out by systematically testing their application to time series of SeaWiFS, MODIS and MERIS data. By applying them to a number of years of satellite data, temporal and spatial implications were analyzed and a new hybrid cloud mask was developed and similarly tested. The results indicate that, by replacing the standard cloud mask, an increase of an average of 22% in ocean coverage over the course of a seasonal cycle in the Baltic Sea may be possible. Major occurrences of intense blooms can be recovered whilst at the same time not introducing any significant extra cloud into the processing. The full inclusion of the cyanobacteria blooms, even their most intense manifestations, into Baltic data series allows a more comprehensive analysis of their spectral characteristics with powerful implications for their detection, monitoring, and interannual evolution.
{"title":"Cloud masking schemes for satellite ocean colour data in the Baltic sea and applications to cyanobacteria bloom analysis","authors":"A. Banks, F. Mélin","doi":"10.1109/BALTIC.2014.6887833","DOIUrl":"https://doi.org/10.1109/BALTIC.2014.6887833","url":null,"abstract":"One of the most important steps in utilizing ocean colour remote sensing data is subtracting the contribution of the atmosphere from the signal at the satellite to obtain marine water leaving radiance. To be done accurately this requires clear sky conditions, i.e. all clouds need to be excluded or masked from the data prior to atmospheric correction. The standard cloud mask used routinely in the processing of NASA's global ocean colour data is based on a simple threshold applied to the Rayleigh-corrected top-of-atmosphere radiance. The threshold is kept purposefully low to ensure high quality processing at a global scale. As a consequence, the standard scheme can sometimes inadvertently mask extreme optical events such as intense blue-green algal (cyanobacteria) blooms in the Baltic Sea. These blooms have important ecological and environmental impacts on the basin and require appropriate monitoring. Therefore, an assessment of 5 existing cloud masking schemes that could provide valuable alternatives for the Baltic Sea was carried out by systematically testing their application to time series of SeaWiFS, MODIS and MERIS data. By applying them to a number of years of satellite data, temporal and spatial implications were analyzed and a new hybrid cloud mask was developed and similarly tested. The results indicate that, by replacing the standard cloud mask, an increase of an average of 22% in ocean coverage over the course of a seasonal cycle in the Baltic Sea may be possible. Major occurrences of intense blooms can be recovered whilst at the same time not introducing any significant extra cloud into the processing. The full inclusion of the cyanobacteria blooms, even their most intense manifestations, into Baltic data series allows a more comprehensive analysis of their spectral characteristics with powerful implications for their detection, monitoring, and interannual evolution.","PeriodicalId":435850,"journal":{"name":"2014 IEEE/OES Baltic International Symposium (BALTIC)","volume":"42 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":"128069337","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.2014.7028145
A. Giudicia, I. Nikolkina, T. Soomere
The presence of crossing seas in the nearshore may lead to a drastic amplification of local wave heights or to a substantial change in the orientation of the highest parts of the wave crest owing to nonlinear interactions of waves in shallow water. The location and strength of the related effects can be roughly forecast based on the properties of crossing wave systems in the framework of the Kadomtsev-Petviashvili equation. We introduce a method of the identification of crossing seas and singling out the properties of interacting wave systems from numerically simulated two-dimensional wave energy spectra of selected locations in the Baltic Sea obtained within a multi-decadal (1956-1997) wave hindcast using the WAM model. Each spectrum spans across 24 evenly spaced directions and 40 frequencies starting from 0.042 Hz (23.8 s) to about 1.718 Hz (0.58 s). The numerically replicated spectra usually contain a certain level of noise, which may lead to the detection of false maxima and is filtered out using a Gaussian-type convolution filter. We then test each sample of the resulting anti-aliased distribution with a pyramid shaped stencil in order to find the spectral density, frequency and direction of all relative maxima. Their frequency and direction is then mapped back onto the initial spectra to evaluate the heights of the single wave systems. The average reduction of maxima detection from unfiltered to filtered data is 9.2%.
{"title":"Automated detection of crossing seas from simulated wave spectra","authors":"A. Giudicia, I. Nikolkina, T. Soomere","doi":"10.1109/BALTIC.2014.7028145","DOIUrl":"https://doi.org/10.1109/BALTIC.2014.7028145","url":null,"abstract":"The presence of crossing seas in the nearshore may lead to a drastic amplification of local wave heights or to a substantial change in the orientation of the highest parts of the wave crest owing to nonlinear interactions of waves in shallow water. The location and strength of the related effects can be roughly forecast based on the properties of crossing wave systems in the framework of the Kadomtsev-Petviashvili equation. We introduce a method of the identification of crossing seas and singling out the properties of interacting wave systems from numerically simulated two-dimensional wave energy spectra of selected locations in the Baltic Sea obtained within a multi-decadal (1956-1997) wave hindcast using the WAM model. Each spectrum spans across 24 evenly spaced directions and 40 frequencies starting from 0.042 Hz (23.8 s) to about 1.718 Hz (0.58 s). The numerically replicated spectra usually contain a certain level of noise, which may lead to the detection of false maxima and is filtered out using a Gaussian-type convolution filter. We then test each sample of the resulting anti-aliased distribution with a pyramid shaped stencil in order to find the spectral density, frequency and direction of all relative maxima. Their frequency and direction is then mapped back onto the initial spectra to evaluate the heights of the single wave systems. The average reduction of maxima detection from unfiltered to filtered data is 9.2%.","PeriodicalId":435850,"journal":{"name":"2014 IEEE/OES Baltic International Symposium (BALTIC)","volume":"32 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":"126746925","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.2014.6887887
V. Rukšėnienė, K. Dučinskas, I. Dailidienė
The subjects of this research are the surface layer hydrophysical parameters and their spatial-temporal statistical models in the south-eastern Baltic Sea. Here we analyze sea surface water temperature (SST), water salinity and ice phenomena data collected in the period 2009-2012. The Center of Marine Research in Klaipėda (Lithuania) provides us with the data. The purpose of this research is to construct optimal parametric spatial trend and spatial variation (semivariogram) models at different time layers. To use constructed models for ice formation statistical dependence on water salinity and temperature research, also to interpolate and to predict using different linear prediction models (kriging).
{"title":"Spatial-temporal analysis of hydrophysical data by using multiple linear models","authors":"V. Rukšėnienė, K. Dučinskas, I. Dailidienė","doi":"10.1109/BALTIC.2014.6887887","DOIUrl":"https://doi.org/10.1109/BALTIC.2014.6887887","url":null,"abstract":"The subjects of this research are the surface layer hydrophysical parameters and their spatial-temporal statistical models in the south-eastern Baltic Sea. Here we analyze sea surface water temperature (SST), water salinity and ice phenomena data collected in the period 2009-2012. The Center of Marine Research in Klaipėda (Lithuania) provides us with the data. The purpose of this research is to construct optimal parametric spatial trend and spatial variation (semivariogram) models at different time layers. To use constructed models for ice formation statistical dependence on water salinity and temperature research, also to interpolate and to predict using different linear prediction models (kriging).","PeriodicalId":435850,"journal":{"name":"2014 IEEE/OES Baltic International Symposium (BALTIC)","volume":"22 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":"133469328","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.2014.6887868
P. Alenius, K. Tikka, C. Barrera
The Baltic Sea consists of several sub-basins. They all have their own physical characteristics and motion scales. General circulation and meso-scale eddies in the basins are in continuous interaction. Traditional monitoring by research ships, gives a general impression on the conditions, but that impression is not detailed unless towed instruments are used. Gliders have extensively been used for ocean research and monitoring in last decade. In Europe, a pan-European glider infrastructure is being planned in a EU funded project, Gliders for Research, Ocean Observation and Management (GROOM). Finnish Meteorological Institute (FMI) and Plataforma Oceánica de Canarias (PLOCAN) organized a joint experiment to Bothnian Sea and Archipelago Sea, two sub-basins of the northern Baltic Sea, to study the use and potentials of gliders in these shallow, low-salinity environments. The horizontal length scale of the glider observations in 100 m deep waters is about 200 m. It is well below the local internal Rossby-radius of deformation. Thus gliders give good possibilities to study multi-scale interactions and exchange processes between coastal and open-sea waters in detail. We used the glider in section mode in an open sea area and as a virtual mooring in a semi-enclosed small basin within an archipelago. These experiments proved the usefulness of gliders in the Baltic Sea research.
波罗的海由几个子盆地组成。它们都有自己的身体特征和运动尺度。一般环流和中尺度涡旋在盆地中持续相互作用。传统的科考船监测对条件有一个大致的印象，但除非使用拖曳仪器，否则这种印象是不详细的。近十年来，滑翔机被广泛用于海洋研究和监测。在欧洲，一个由欧盟资助的项目——滑翔机研究、海洋观测和管理(新郎)——正在规划一个泛欧滑翔机基础设施。芬兰气象研究所(FMI)和Oceánica de Canarias平台(PLOCAN)组织了一项联合实验，在波罗的海北部的两个子盆地——波斯尼亚海和群岛海，研究滑翔机在这些浅水、低盐度环境中的使用和潜力。100 m深水滑翔机观测的水平长度尺度约为200 m。它远远低于局部内部变形的罗斯比半径。因此，滑翔机为详细研究沿海和公海之间的多尺度相互作用和交换过程提供了很好的可能性。我们将滑翔机以截面模式应用于开阔海域，并将其作为群岛内半封闭小盆地的虚拟系泊。这些实验证明了滑翔机在波罗的海研究中的实用性。
{"title":"Gliders for studies of multi-scale variability in the Baltic Sea","authors":"P. Alenius, K. Tikka, C. Barrera","doi":"10.1109/BALTIC.2014.6887868","DOIUrl":"https://doi.org/10.1109/BALTIC.2014.6887868","url":null,"abstract":"The Baltic Sea consists of several sub-basins. They all have their own physical characteristics and motion scales. General circulation and meso-scale eddies in the basins are in continuous interaction. Traditional monitoring by research ships, gives a general impression on the conditions, but that impression is not detailed unless towed instruments are used. Gliders have extensively been used for ocean research and monitoring in last decade. In Europe, a pan-European glider infrastructure is being planned in a EU funded project, Gliders for Research, Ocean Observation and Management (GROOM). Finnish Meteorological Institute (FMI) and Plataforma Oceánica de Canarias (PLOCAN) organized a joint experiment to Bothnian Sea and Archipelago Sea, two sub-basins of the northern Baltic Sea, to study the use and potentials of gliders in these shallow, low-salinity environments. The horizontal length scale of the glider observations in 100 m deep waters is about 200 m. It is well below the local internal Rossby-radius of deformation. Thus gliders give good possibilities to study multi-scale interactions and exchange processes between coastal and open-sea waters in detail. We used the glider in section mode in an open sea area and as a virtual mooring in a semi-enclosed small basin within an archipelago. These experiments proved the usefulness of gliders in the Baltic Sea research.","PeriodicalId":435850,"journal":{"name":"2014 IEEE/OES Baltic International Symposium (BALTIC)","volume":"139 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114057998","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.2014.6887827
A. Stips, Diego Macías, E. García‐Górriz, C. Coughlan
We use singular spectrum analysis techniques to discriminate the underlying signals within the HadCRUT4 global surface temperature record. Our analysis identifies a multidecadal oscillation (related to natural oscillations) and a secular trend (assumed to be representative of anthropogenic-induced warming) as the two main signals within the temperature record. Most current generation global circulation models (CMIP5) do not reproduce the multidecadal oscillation and fail to capture the present observed temperature hiatus in their simulations. Therefore, it is unlikely that these models can correctly forecast the temperature evolution during the coming decades. Statistical forecasts based on the analyzed secular trend and the multidecadal oscillations are indeed capable of reproducing the observed hiatus and generally result, in comparison to CMIP5 forecasts, in much lower temperature increases for 2100 of only about +0.39°C [-0.47-2.46] assuming a “business as usual” scenario. Either the global energy budget uncertainty is still too large or the increased radiative forcing does rather lead to accelerated warming of other parts of the climate system as the ocean or the cryosphere.
{"title":"Forecasting global temperatures: Missing the point? The consequences of the hiatus","authors":"A. Stips, Diego Macías, E. García‐Górriz, C. Coughlan","doi":"10.1109/BALTIC.2014.6887827","DOIUrl":"https://doi.org/10.1109/BALTIC.2014.6887827","url":null,"abstract":"We use singular spectrum analysis techniques to discriminate the underlying signals within the HadCRUT4 global surface temperature record. Our analysis identifies a multidecadal oscillation (related to natural oscillations) and a secular trend (assumed to be representative of anthropogenic-induced warming) as the two main signals within the temperature record. Most current generation global circulation models (CMIP5) do not reproduce the multidecadal oscillation and fail to capture the present observed temperature hiatus in their simulations. Therefore, it is unlikely that these models can correctly forecast the temperature evolution during the coming decades. Statistical forecasts based on the analyzed secular trend and the multidecadal oscillations are indeed capable of reproducing the observed hiatus and generally result, in comparison to CMIP5 forecasts, in much lower temperature increases for 2100 of only about +0.39°C [-0.47-2.46] assuming a “business as usual” scenario. Either the global energy budget uncertainty is still too large or the increased radiative forcing does rather lead to accelerated warming of other parts of the climate system as the ocean or the cryosphere.","PeriodicalId":435850,"journal":{"name":"2014 IEEE/OES Baltic International Symposium (BALTIC)","volume":"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":"128657027","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.2014.6887850
I. Kozlov, Toma Mingėlaitė, I. Dailidienė
In this work we present a basic statistics of coastal upwelling parameters inferred from satellite infrared (IR) Terra/Aqua MODIS sea surface temperature (SST) maps acquired over the South-Eastern (SE) Baltic Sea between 2000 and 2013. The maximum observed SST gradients across the front were up to 1.6 °C/km, temperature drop up to 14°C with total upwelling-affected area up to 16000 km2. The observed horizontal scale of the upwelling is about 100-400 km along the coast, and 10-20 km (max 70-80 km) cross-shore. The duration of the upwelling in this part of the sea is from several days up to several weeks. It is found that intensive coastal upwelling in the SE Baltic may lead up to 40-km long intrusion of relatively cold and saline sea water into the Curonian Lagoon forming very pronounced property gradients there and affecting nearly a half of the Lithuanian part of the lagoon.
{"title":"Space-derived parameters of coastal upwelling in the SE Baltic Sea","authors":"I. Kozlov, Toma Mingėlaitė, I. Dailidienė","doi":"10.1109/BALTIC.2014.6887850","DOIUrl":"https://doi.org/10.1109/BALTIC.2014.6887850","url":null,"abstract":"In this work we present a basic statistics of coastal upwelling parameters inferred from satellite infrared (IR) Terra/Aqua MODIS sea surface temperature (SST) maps acquired over the South-Eastern (SE) Baltic Sea between 2000 and 2013. The maximum observed SST gradients across the front were up to 1.6 °C/km, temperature drop up to 14°C with total upwelling-affected area up to 16000 km2. The observed horizontal scale of the upwelling is about 100-400 km along the coast, and 10-20 km (max 70-80 km) cross-shore. The duration of the upwelling in this part of the sea is from several days up to several weeks. It is found that intensive coastal upwelling in the SE Baltic may lead up to 40-km long intrusion of relatively cold and saline sea water into the Curonian Lagoon forming very pronounced property gradients there and affecting nearly a half of the Lithuanian part of the lagoon.","PeriodicalId":435850,"journal":{"name":"2014 IEEE/OES Baltic International Symposium (BALTIC)","volume":"99 6 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":"133992601","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.2014.6887843
V. N. Sukhachev, E. Zakharchuk, N. Tikhonova
In the last decades in eastern part of Gulf of Finland has considerably increased frequency of dangerous sea levels rises. The results presented in Fig. 1 indicate that over the past 30 years the number of floods in the Neva estuary increased by 1.6 times. Despite the startup in 2010 of the complex structures protecting St. Petersburg from flooding (CPS), dangerous sea level rises continue to cause damage to coastal areas located to the west of the dam. Increasing number of floods, existing gaps in our knowledge about their nature, force of researchers to continue explore this dangerous natural phenomena in order to develop it more accurate prediction.
{"title":"On the mechanisms of dangerous sea level rise in the eastern part gulf of Finland and possible reasons for the increase in their frequency in the second half of XX and the beginning of the XXI century","authors":"V. N. Sukhachev, E. Zakharchuk, N. Tikhonova","doi":"10.1109/BALTIC.2014.6887843","DOIUrl":"https://doi.org/10.1109/BALTIC.2014.6887843","url":null,"abstract":"In the last decades in eastern part of Gulf of Finland has considerably increased frequency of dangerous sea levels rises. The results presented in Fig. 1 indicate that over the past 30 years the number of floods in the Neva estuary increased by 1.6 times. Despite the startup in 2010 of the complex structures protecting St. Petersburg from flooding (CPS), dangerous sea level rises continue to cause damage to coastal areas located to the west of the dam. Increasing number of floods, existing gaps in our knowledge about their nature, force of researchers to continue explore this dangerous natural phenomena in order to develop it more accurate prediction.","PeriodicalId":435850,"journal":{"name":"2014 IEEE/OES Baltic International Symposium (BALTIC)","volume":"27 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":"124926721","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.2014.6887879
O. Kurkina, A. Kurkin, T. Soomere, A. Rybin, D. Tyugin
Significant changes in the vertical structure of the Baltic Sea water masses within the latter decades may substantially influence the dynamics of this water body through changing the properties of single internal waves, their propagation pathways, regions of breaking and associated areas of intense mixing and resuspension of bottom sediments. We evaluate the average nonlinear parameters that govern the field of long high-frequency weakly nonlinear internal waves in the framework of Gardner's equation. The calculations are performed using hydrographic data calculated by the Rossby Centre Ocean circulation model (RCO) for the entire Baltic Sea for 1961-2005 with a horizontal resolution of 2 nautical miles. The focus is on changes in the nonlinear wave regimes such as wave polarities and limiting amplitudes of solitary internal waves. The extension of the changes is demonstrated by comparison of the parameters in question in the 1960s (characterizing the situation when strong salt-water inflows were frequent) and 1990s (when inflows were weak and rare). The spatial and seasonal distributions of the listed parameters differ considerably for these years. The largest change is a shift in the possible nonlinear wave regime (e.g., (dis)appearance of probable breather generation, polarity change and/or transition from one family of soliton solutions to another) over the sea areas between Gotland and the Swedish mainland. The typical areas where the internal waves alter their appearance (through adjustment, transformation or breaking) and areas of intense breaking have also been shifted over the three decades. The overall geographical distribution of the listed parameters of internal waves is still quite stable despite the notable changes of pycnocline depth both in summer and in winter.
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