2014 IEEE/OES Baltic International Symposium (BALTIC)最新文献_第3页

Satellite altimetry of large lakes of the Baltic Basin 波罗的海盆地大型湖泊的卫星测高图

2014 IEEE/OES Baltic International Symposium (BALTIC) Pub Date : 2014-05-27 DOI: 10.1109/BALTIC.2014.6887880

S. Lebedev, Y. Troitskaya, G. Rybushkina, M. Dobrovolsky

引用次数: 2

Determining regional sea surface topography by GNSS surveys on ice 通过冰面上的GNSS调查确定区域海面地形

2014 IEEE/OES Baltic International Symposium (BALTIC) Pub Date : 2014-05-27 DOI: 10.1109/BALTIC.2014.6887847

A. Liibusk, S. Talvik, A. Ellmann, T. Oja

{"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}

引用次数: 2

Cloud masking schemes for satellite ocean colour data in the Baltic sea and applications to cyanobacteria bloom analysis 波罗的海卫星海洋颜色数据的云掩蔽方案及其在蓝藻华分析中的应用

2014 IEEE/OES Baltic International Symposium (BALTIC) Pub Date : 2014-05-27 DOI: 10.1109/BALTIC.2014.6887833

A. Banks, F. Mélin

{"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}

引用次数: 0

Automated detection of crossing seas from simulated wave spectra 利用模拟波浪谱自动探测跨海

2014 IEEE/OES Baltic International Symposium (BALTIC) Pub Date : 2014-05-27 DOI: 10.1109/BALTIC.2014.7028145

A. Giudicia, I. Nikolkina, T. Soomere

{"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}

引用次数: 0

Spatial-temporal analysis of hydrophysical data by using multiple linear models 基于多元线性模型的水物理数据时空分析

2014 IEEE/OES Baltic International Symposium (BALTIC) Pub Date : 2014-05-27 DOI: 10.1109/BALTIC.2014.6887887

V. Rukšėnienė, K. Dučinskas, I. Dailidienė

引用次数: 0

Gliders for studies of multi-scale variability in the Baltic Sea 用于波罗的海多尺度变率研究的滑翔机

2014 IEEE/OES Baltic International Symposium (BALTIC) Pub Date : 2014-05-27 DOI: 10.1109/BALTIC.2014.6887868

P. Alenius, K. Tikka, C. Barrera

{"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}

引用次数: 5

Forecasting global temperatures: Missing the point? The consequences of the hiatus 预测全球气温:错过重点?中断的后果

2014 IEEE/OES Baltic International Symposium (BALTIC) Pub Date : 2014-05-27 DOI: 10.1109/BALTIC.2014.6887827

A. Stips, Diego Macías, E. García‐Górriz, C. Coughlan

{"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}

引用次数: 0

Space-derived parameters of coastal upwelling in the SE Baltic Sea 波罗的海东南部沿海上升流的空间参数

2014 IEEE/OES Baltic International Symposium (BALTIC) Pub Date : 2014-05-27 DOI: 10.1109/BALTIC.2014.6887850

I. Kozlov, Toma Mingėlaitė, I. Dailidienė

引用次数: 2

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 芬兰湾东部海平面危险上升的机制及其在20世纪下半叶和21世纪初频率增加的可能原因

2014 IEEE/OES Baltic International Symposium (BALTIC) Pub Date : 2014-05-27 DOI: 10.1109/BALTIC.2014.6887843

V. N. Sukhachev, E. Zakharchuk, N. Tikhonova

引用次数: 0

Pycnocline variations in the Baltic Sea affect background conditions for internal waves 波罗的海斜斜的变化影响内波的背景条件

2014 IEEE/OES Baltic International Symposium (BALTIC) Pub Date : 2014-05-27 DOI: 10.1109/BALTIC.2014.6887879

O. Kurkina, A. Kurkin, T. Soomere, A. Rybin, D. Tyugin

{"title":"Pycnocline variations in the Baltic Sea affect background conditions for internal waves","authors":"O. Kurkina, A. Kurkin, T. Soomere, A. Rybin, D. Tyugin","doi":"10.1109/BALTIC.2014.6887879","DOIUrl":"https://doi.org/10.1109/BALTIC.2014.6887879","url":null,"abstract":"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.","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":"127656835","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}

引用次数: 4