scholarly journals Characteristics of Short-Period Internal Waves in the Avacha Bay Based on the In Situ and Satellite Observations in August-September, 2018

2020 ◽  
Vol 27 (3) ◽  
Author(s):  
E. I. Svergun ◽  
◽  
A. V. Zimin ◽  
◽  
◽  
...  
Keyword(s):  
Internal Waves ◽  
Satellite Images ◽  
Remote Sensing Data ◽  
Water Area ◽  
Satellite Observations ◽  
Maximum Height ◽  
Shallow Water Area ◽  
Short Period ◽  
Avacha Bay

Purpose. The paper is aimed at evaluating the characteristics of short-period internal waves in different regions of the Avacha Bay in the Рacific Ocean concerning their hydrological and morphometric conditions. Methods and Results. The characteristics of internal waves are assessed through synthesizing the results of the in situ studies in the Avacha Bay in August-September, 2018, the high-resolution remote sensing data and the results of tidal modeling. The data of the in situ and satellite observations of internal waves were also directly compared. The results show that in the shallow part of the Avacha Bay, the waves, whose heights are from 10 to 15 m were observed. They constitute 10 % of the total number of cases. In the deep-water part of the bay, the internal waves are also often observed, but their maximum height does not exceed 10 m. The satellite images show 72 manifestations of short-period internal waves. Some of them spread to the coast with a tidal frequency from the generation source located around the 500 m isobath where the bottom abruptly slows down. Conclusions. The results of the investigation revealed a pronounced relationship between the wave trains recorded in the shallow-water area and the semidiurnal tidal dynamics. Analysis of the hydrological situation and the satellite images permitted to assume that the internal waves could be generated as a result of not only a barotropic tide collapse, but also due to the inertial oscillations of the frontal zone formed by the Kamchatka current meanders in the presence of a shallow sharpened pycnocline. Having been analyzed, the synchronous satellite and in situ observations made it possible to find out that the internal waves of the 5–8 m height were distinctly manifested on the sea surface in case the pycnocline depth was 10–20 m.

Dispersal and Recruitment of Zebra Mussel (Dreissena polymorpha) in a Nearshore Area in West-central Lake Erie: The Significance of Postmetamorphic Drifting

1993 ◽  
Vol 50 (1) ◽  
pp. 3-12 ◽  
Author(s):  
André Martel
Keyword(s):  
Water Column ◽  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Lake Erie ◽  
Water Area ◽  
In Situ Growth ◽  
Growth Experiment ◽  
Quantitative Evidence ◽  
Shallow Water Area

Quantitative evidence that early postmetamorphic stages of zebra mussel (Dreissena polymorpha) can disperse in the water column and colonize substrates has been obtained using off-bottom scouring pad collectors and plankton sampling in a nearshore, shallow-water area (2–7 m) near Wheatley, Lake Erie, during August 1991. Collectors were deployed for 24–72 h, thus minimizing growth of recruits during deployments. Size criteria determined through an in situ growth experiment were used to discriminate between individuals arriving at a collector as (1) settling larvae or (2) postmetamorphic stages. During certain periods, 20–80% of individuals settling on collectors were postmetamorphic stages. Plankton samples taken near collectors also confirmed the presence of postmetamorphic stages in the water column. Most drifting juveniles ranged from about 300 μm shell length to 800 μm (some up to 1–2 mm). Although settlement by postmetamorphic stages occurred during various periods, they drifted and settled on collectors in much higher numbers during periods of strong wave action generated during storms. Colonization of natural and man-made substrates by postmetamorphic stages may be significant in exposed or turbulent areas and may impact on population dynamics. Whether postmetamorphic drifting is adaptive and which mechanisms are involved are unknown.

Internal waves in the Black Sea: satellite observations and in-situ measurements

2014 ◽  
Author(s):  
Olga Yu. Lavrova ◽  
Marina I. Mityagina ◽  
Andrey N. Serebryany ◽  
Konstantin D. Sabinin ◽  
Nina A. Kalashnikova ◽  
...  
Keyword(s):  
Internal Waves ◽  
Black Sea ◽  
In Situ Measurements ◽  
Satellite Observations ◽  
The Black Sea

scholarly journals Calibrating satellite-derived carbon fluxes for retrospective and near real-time assimilation systems

2020 ◽  
Author(s):  
Brad Weir ◽  
Lesley E. Ott ◽  
George J. Collatz ◽  
Stephan R. Kawa ◽  
Benjamin Poulter ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Growth Rates ◽  
Marine Boundary Layer ◽  
Remote Sensing Data ◽  
Surface Fluxes ◽  
Short Latency ◽  
Satellite Observations ◽  
Seasonal Forecasts ◽  
Spatial Coverage

Abstract. The ability to monitor and understand natural and anthropogenic variability in atmospheric carbon dioxide (CO2) is a growing need of many stakeholders across the world. Systems that assimilate satellite observations, given their short latency and dense spatial coverage, into high-resolution global models are valuable, if not essential, tools for addressing this need. A notable drawback of modern assimilation systems is the long latency of many vital input datasets, e.g., inventories, in situ measurements, and reprocessed remote-sensing data can trail the current date by months to years. This paper describes techniques for calibrating surface fluxes derived from satellite observations of the Earth's surface to be consistent with constraints from inventories and in situ CO2 datasets. The techniques are applicable in both short-term forecasts and retrospective simulations, thus taking advantage of the coverage and short latency of satellite data while reproducing the major features of long-term inventory and in situ records. Our approach begins with a standard collection of diagnostic fluxes which incorporate a variety of remote-sensing driver data, viz. vegetation indices, fire radiative power, and nighttime lights. We then apply an empirical sink to calibrate the diagnostic fluxes to match given atmospheric and oceanic growth rates for each year. This step removes coherent, systematic flux errors that produce biases in CO2 which mask the signals an assimilation system hopes to capture. Depending on the simulation mode, the empirical sink uses different choices of atmospheric growth rates: estimates based on observations in retrospective mode and projections based on seasonal forecasts of sea surface temperature in forecasting mode. The retrospective fluxes, when used in simulations with NASA's Goddard Earth Observing System (GEOS), reproduce marine boundary layer measurements with comparable skill to those using fluxes from a modern inversion system. The forecasted fluxes show promising accuracy in their application to the analysis of changes in the carbon cycle as they occur.

scholarly journals Remote sensing data driven bathing water quality assessment using sentinel-3

2021 ◽  
Vol 21 (3) ◽  
pp. 1634
Author(s):  
Antonia Senta ◽  
Ljiljana Šerić
Keyword(s):  
Remote Sensing ◽  
Water Quality ◽  
Quality Assessment ◽  
Satellite Images ◽  
Remote Sensing Data ◽  
Water Quality Assessment ◽  
Data Driven ◽  
Bathing Water ◽  
Bathing Water Quality

<span>In this paper we are investigating the possibility of usage of remote sensing satellite data, more precisely sentinel-3 OLCI and SLSTR data, for assessment of bathing water quality. In this research we used data driven approach and analysis of data in order to pinpoint aspects of remote sensing data that can be useful for bathing water quality assessment. For this purpose we collected satellite images for period from start of June till end of September of 2019 and results of in-situ measurement for the same period. Results of in-situ measurement were correlated with satellite images bands and analyzed. We propose a simple method for rapid assessment of possible deterioration of bathing water quality to be used by public health authorities for better planning of in situ measurements. Results of implementation of predictive models based on k-nearest neighbour (KNN) and decision tree (DT) are described.</span>

scholarly journals Potential and Limitations of Satellite Altimetry Constellations for Monitoring Surface Water Storage Changes—A Case Study in the Mississippi Basin

2020 ◽  
Vol 12 (20) ◽  
pp. 3320
Author(s):  
Denise Dettmering ◽  
Laura Ellenbeck ◽  
Daniel Scherer ◽  
Christian Schwatke ◽  
Christoph Niemann
Keyword(s):  
Surface Water ◽  
Mississippi River ◽  
Satellite Altimetry ◽  
Remote Sensing Data ◽  
Water Area ◽  
Water Levels ◽  
In Situ Data ◽  
Ocean Topography

Remote sensing data are essential for monitoring the Earth’s surface waters, especially since the amount of publicly available in-situ data is declining. Satellite altimetry provides valuable information on the water levels and variations of lakes, reservoirs and rivers. In combination with satellite imagery, the derived time series allow the monitoring of lake storage changes and river discharge. However, satellite altimetry is limited in terms of its spatial resolution due to its measurement geometry, only providing information in the nadir direction beneath the satellite’s orbit. In a case study in the Mississippi River Basin (MRB), this study investigates the potential and limitations of past and current satellite missions for the monitoring of basin-wide storage changes. For that purpose, an automated target detection is developed and the extracted lake surfaces are merged with the satellites’ tracks. This reveals that the current altimeter configuration misses about 80% of all lakes larger than 0.1 km2 in the MRB and 20% of lakes larger than 10 km2, corresponding to 30% and 7% of the total water area, respectively. Past altimetry configurations perform even more poorly. From the larger water bodies represented by a global hydrology model, at least 91% of targets and 98% of storage changes are captured by the current altimeter configuration. This will improve significantly with the launch of the planned Surface Water and Ocean Topography (SWOT) mission.

scholarly journals Development of the Statistical Model for Monitoring Salinization in the Mekong Delta of Vietnam Using Remote Sensing Data and In-Situ Measurements

Proceedings ◽  
2018 ◽  
Vol 2 (10) ◽  
pp. 565
Author(s):  
Nguyen Nguyen Vu ◽  
Le Van Trung ◽  
Tran Thi Van
Keyword(s):  
Statistical Model ◽  
Mekong Delta ◽  
Remote Sensing Data ◽  
Principal Component ◽  
Measured Data ◽  
In Situ Measurements ◽  
Landsat 8 ◽  
Spectral Bands ◽  
Component Band

This article presents the methodology for developing a statistical model for monitoring salinity intrusion in the Mekong Delta based on the integration of satellite imagery and in-situ measurements. We used Landsat-8 Operational Land Imager and Thermal Infrared Sensor (Landsat- 8 OLI and TIRS) satellite data to establish the relationship between the planetary reflectance and the ground measured data in the dry season during 2014. The three spectral bands (blue, green, red) and the principal component band were used to obtain the most suitable models. The selected model showed a good correlation with the exponential function of the principal component band and the ground measured data (R2 > 0.8). Simulation of the salinity distribution along the river shows the intrusion of a 4 g/L salt boundary from the estuary to the inner field of more than 50 km. The developed model will be an active contribution, providing managers with adaptation and response solutions suitable for intrusion in the estuary as well as the inner field of the Mekong Delta.

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