Sediment-Water Chemical Exchange in the Coastal Zone Traced by in situ Radon-222 Flux Measurements

Science ◽  
1980 ◽  
Vol 208 (4441) ◽  
pp. 285-288 ◽  
Author(s):  
C. S. MARTENS ◽  
G. W. KIPPHUT ◽  
J. V. KLUMP
Keyword(s):  
Coastal Zone ◽  
Chemical Exchange ◽  
Flux Measurements

scholarly journals Reliability of Extreme Significant Wave Height Estimation from Satellite Altimetry and In Situ Measurements in the Coastal Zone

2020 ◽  
Vol 8 (12) ◽  
pp. 1039
Author(s):  
Ben Timmermans ◽  
Andrew G. P. Shaw ◽  
Christine Gommenginger
Keyword(s):  
Coastal Zone ◽  
Wave Height ◽  
Satellite Data ◽  
Significant Wave Height ◽  
Wave Climate ◽  
In Situ Measurements ◽  
Altimeter Data ◽  
Sea State ◽  
Significant Wave

Measurements of significant wave height from satellite altimeter missions are finding increasing application in investigations of wave climate, sea state variability and trends, in particular as the means to mitigate the general sparsity of in situ measurements. However, many questions remain over the suitability of altimeter data for the representation of extreme sea states and applications in the coastal zone. In this paper, the limitations of altimeter data to estimate coastal Hs extremes (<10 km from shore) are investigated using the European Space Agency Sea State Climate Change Initiative L2P altimeter data v1.1 product recently released. This Sea State CCI product provides near complete global coverage and a continuous record of 28 years. It is used here together with in situ data from moored wave buoys at six sites around the coast of the United States. The limitations of estimating extreme values based on satellite data are quantified and linked to several factors including the impact of data corruption nearshore, the influence of coastline morphology and local wave climate dynamics, and the spatio-temporal sampling achieved by altimeters. The factors combine to lead to considerable underestimation of estimated Hs 10-yr return levels. Sensitivity to these factors is evaluated at specific sites, leading to recommendations about the use of satellite data to estimate extremes and their temporal evolution in coastal environments.

scholarly journals Bridging the Gap Between Single-Strain and Community-Level Plant-Microbe Chemical Interactions

2020 ◽  
Vol 33 (2) ◽  
pp. 124-134 ◽  
Author(s):  
Bridget S. O’Banion ◽  
Lindsey O’Neal ◽  
Gladys Alexandre ◽  
Sarah L. Lebeis
Keyword(s):  
Chemical Exchange ◽  
Chemical Signals ◽  
Individual Plant ◽  
Single Strain ◽  
Plant Hosts ◽  
Culture Independent ◽  
Microbe Interactions ◽  
Tools And Techniques ◽  
Insight Into

Although the influence of microbiomes on the health of plant hosts is evident, specific mechanisms shaping the structure and dynamics of microbial communities in the phyllosphere and rhizosphere are only beginning to become clear. Traditionally, plant–microbe interactions have been studied using cultured microbial isolates and plant hosts but the rising use of ‘omics tools provides novel snapshots of the total complex community in situ. Here, we discuss the recent advances in tools and techniques used to monitor plant–microbe interactions and the chemical signals that influence these relationships in above- and belowground tissues. Particularly, we highlight advances in integrated microscopy that allow observation of the chemical exchange between individual plant and microbial cells, as well as high-throughput, culture-independent approaches to investigate the total genetic and metabolic contribution of the community. The chemicals discussed have been identified as relevant signals across experimental spectrums. However, mechanistic insight into the specific interactions mediated by many of these chemicals requires further testing. Experimental designs that attempt to bridge the gap in biotic complexity between single strains and whole communities will advance our understanding of the chemical signals governing plant–microbe associations in the rhizosphere and phyllosphere.

Combining current velocity data from different sources as input to coastal zone management

2021 ◽  
Author(s):  
Jenny Ullgren ◽  
Anne Stene
Keyword(s):  
Organic Carbon ◽  
Coastal Zone ◽  
Current Velocity ◽  
Coastal Zone Management ◽  
Marine Ecology ◽  
Management Tool ◽  
Thematic Maps ◽  
In Situ Data ◽  
Zone Management

&lt;p&gt;Sustainable development of the aquaculture industry depends on wise coastal zone management.&amp;#160; Aquaculture in Norway is typically found in small, rural municipalities that may lack expertise in marine ecology. In the project &amp;#8220;Precise coastal zone planning with focus on aquaculture&amp;#8221; we combine marine maps with in situ data and model results to produce a management tool for easier and more efficent aquaculture planning.&lt;/p&gt;&lt;p&gt;Our study area comprises five municipalities in Western Norway and includes both fjords and open coast. High resolution marine maps exist for the area. We also have access to environmental assessments from aquaculture sites, sediment samples for Total Organic Carbon (TOC), and current velocity time series from oceanographic moorings. We will compare the in situ data with output from two current models (Sinmod and NorKyst-800). The data will be used to produce thematic maps of key characteristics, mainly current and organic carbon content, to help administrators identify areas suitable for different types of aquaculture.&lt;/p&gt;&lt;p&gt;Here, we present results from in situ measurements that will provide the current velocity input to the thematic maps. Data from seven oceanographic moorings placed in the fjord system show the current variability on time scales from hours to years. In addition we have done four 1-month deployments of a current profiler on sites selected to improve the geographical data coverage. We show preliminary results and discuss the challenges in simplifying variable current fields in an area with complex geography into an overall map.&lt;/p&gt;

Expanded application of the Passive Flux Meter: in-situ measurements of 1,4-dioxane, sulfate, Cr(VI), and RDX

2018 ◽  
Author(s):  
Alexander Haluska ◽  
Meghan Thiemann ◽  
Patrick Evans ◽  
Jaehyun Cho ◽  
Mike Annable
Keyword(s):  
Inorganic Ions ◽  
Contaminated Sites ◽  
Chromium Vi ◽  
Reducing Conditions ◽  
Uptake Rates ◽  
Consumption Rates ◽  
Flux Measurements ◽  
Passive Flux Meter ◽  
Ion Species

Passive flux meters (PFMs) have become invaluable tools for site characterization and evaluation of remediation performance at groundwater contaminated sites. To date, PFMs technology has been demonstrated in the field to measure low - to midrange hydrophobic contaminants (e.g., chlorinated ethenes, fuel hydrocarbons, perchlorate) and inorganic ions (e.g., uranium and nitrate). However, flux measurements of a low partitioning contaminant (e.g., 1,4-dioxane, hexahydro-1,3,5-trinitro-s-triazine (RDX)) and reactive ions-species (e.g., sulfate (SO42-), Chromium(VI) (Cr(VI)) are still challenging because of their low retardation during transport and quick transformation under highly reducing conditions, respectively. This study comprises the first application of PFMs for the in-situ mass flux measurements of 1,4-Dioxane, RDX, Cr(VI) and SO42- reduction rates. Laboratory experiments were performed to model kinetic uptake rates and extraction efficiency for sorbent selections. Silver impregnated granular activated carbon (GAC) was selected for capture of 1,4-Dioxane and RDX, whereas Purolite 300A was selected for chromium and SO42-. PFM field demonstrations measured 1,4-Dioxane fluxes ranging from 13.3 to 55.9 mg/m2/day, an RDX flux of 4.9 mg/m2/day, Cr(VI) fluxes ranging from 2.3 to 2.8 mg/m2/day, and SO42- consumption rates ranging from 20 to 100 mg/L/day. These data suggest other low-partitioning contaminates and reactive ion-species could be monitored using the PFM.

Observing Sea Level Changes Using Satellite Altimetry and In Situ Data

2020 ◽  
Author(s):  
Nikos Flokos ◽  
Maria Tsakiri
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Coastal Zone ◽  
Satellite Altimetry ◽  
Tide Gauge ◽  
Altimeter Data ◽  
Atmospheric Effects ◽  
Data Sets ◽  
Altimetry Data

&lt;p&gt;corresponding author: N.Flokos&lt;/p&gt;&lt;p&gt;[email protected]&lt;/p&gt;&lt;p&gt;ABSTRACT&lt;/p&gt;&lt;p&gt;Sea level change is one of the key indicators of climate change with numerous effects such as flooding, erosion of beaches, salt intrusion.&amp;#160; The detailed global picture of sea level and the monitoring of its spatial-temporal changes is performed by Satellite Altimetry (SA). Nowadays, SA data compare well with measurements from the global tide gauge network, but the aim of 0.3 mm/year accuracy in the altimeter derived rate of global mean sea level rise is still not fully met.&amp;#160;&lt;/p&gt;&lt;p&gt;Whilst the precise determination of global and regional sea level rise from SA data is promising, there is however an observational gap in our knowledge regarding the coastal zone. While Tide Gauges (TG) are usually located at the coast, therefore providing coastal sea level measurements, altimeters have difficulties there. Filling this gap becomes important when considering that the impact of sea level rise can be devastating on the coast with effects on society and ecosystems. This makes it even more significant knowing that there are many stretches of the world&amp;#8217;s coast that still do not possess in situ level measuring devices.&amp;#160;&amp;#160;&lt;/p&gt;&lt;p&gt;This work aims to discuss the available data and methods that link the SA measurements of sea level rise with TG measurements. Whilst there is rich literature on relevant applications, it is important to have a clear and concise methodology on this.&lt;/p&gt;&lt;p&gt;Tide gauge data&lt;/p&gt;&lt;p&gt;Several post processing steps need to be applied to the raw TG data to enrich the raw Sea Surface Heights (SSH) values and make them comparable with SA data. There are several geophysical corrections, such as pressure and wind effects, which can be applied to TG data in order to deduce&amp;#160; Sea Level (SL) and be consistent with altimeter data. High frequency atmospheric effects on TG data are corrected using the Dynamic Atmospheric Correction (DAC) provided by AVISO. One other large uncertainty is the vertical stability of the TG benchmark over time. TG data must be corrected for the Vertical Land Motion (VLM) to enable the comparison of two sea level measurements (TG and SA) and their later integration within the surfaces of the absolute sea heights. The main VLM dataset can be obtained from SONEL database (SONEL 2016) which provides crustal velocities from the continuous GNSS measurements at sites collocated to the TG.&lt;/p&gt;&lt;p&gt;Satellite altimetry data&lt;/p&gt;&lt;p&gt;Whilst Satellite Altimetry over the open ocean is a mature discipline, global altimetry data collected over the coastal ocean remain still largely unexploited. This is because of intrinsic difficulties in the corrections and issues of land contamination in the footprint that have so far resulted in systematic flagging and rejection of these data. In this work, the relevant methodology to overcome these problems and extend the capabilities of current and future altimeters to the coastal zone (coastal altimetry) will be discussed and a number of coastal altimetry data sets will be used (eg SARvatore, X-TRACK, RADS etc). Finally, a practical example using real data sets over the Aegean Sea will be presented.&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

Estimating Vertical Land Motion in Northern Adriatic Sea with Coastal Altimetry and In Situ Observations

2020 ◽  
Author(s):  
Francesco De Biasio ◽  
Stefano Vignudelli ◽  
Giorgio Baldin
Keyword(s):  
Climate Change ◽  
Sea Level Rise ◽  
Mediterranean Sea ◽  
Sea Level ◽  
Coastal Zone ◽  
Satellite Altimetry ◽  
Data Sets ◽  
Tide Gauges ◽  
The Mediterranean

&lt;p align=&quot;justify&quot;&gt;&lt;span&gt;The European Space Agency, in the framework of the Sea Level Climate Change Initiative (SL_CCI), is developing consistent and long-term satellite-based data-sets to study climate-scale variations of sea level globally and in the coastal zone. Two altimetry data-sets were recently produced. The first product is generated over a grid of 0.25x0.25 degrees, merging and homogenizing the various satellite altimetry missions. The second product that is still experimental is along track over a grid of 0.35 km. An operational production of climate-oriented altimeter sea level products has just started in the framework of the European Copernicus Climate Change Service (C3S) and a daily-mean product is now available over a grid of 0.125x0.125 degrees covering the global ocean since 1993 to present.&lt;/span&gt;&lt;/p&gt;&lt;p align=&quot;justify&quot;&gt;&lt;span&gt;We made a comparison of the SL_CCI satellite altimetry dataset with sea level time series at selected tide gauges in the Mediterranean Sea, focusing on Venice and Trieste. There, the coast is densely covered by civil settlements and industrial areas with a strongly rooted seaside tourism, and tides and storm-related surges reach higher levels than in most of the Mediterranean Sea, causing damages and casualties as in the recent storm of November 12th, 2019: the second higher water registered in Venice since 1872. Moreover, in the Venice area the ground displacements exhibit clear negative trends which deepen the effects of the absolute sea level rise.&lt;/span&gt;&lt;/p&gt;&lt;p align=&quot;justify&quot;&gt;&lt;span&gt;Several authors have pointed out the synergy between satellite altimetry and tide gauges to corroborate evidences of ground displacements. Our contribution aims at understanding the role played by subsidence, estimated by the diffence between coastal altimetry and in situ measurements, on the local sea level rise. A partial validation of these estimates has been made against GPS-derived values, in order to distinguish the contributions of subsidence and eustatism. This work will contribute to identify problems and challenges to extend the sea level climate record to the coastal zone with quality comparable to the open ocean, and also to assess the suitability of altimeter-derived absolute sea levels as a tool to estimate subsidence from tide gauge measurement in places where permanent GPS receivers are not available.&lt;/span&gt;&lt;/p&gt;

scholarly journals Expanded Application of the Passive Flux Meter: In-Situ Measurements of 1,4-Dioxane, Sulfate, Cr(VI) and RDX

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1335 ◽  
Author(s):  
Alexander Haluska ◽  
Meghan Thiemann ◽  
Patrick Evans ◽  
Jaehyun Cho ◽  
Michael Annable
Keyword(s):  
Inorganic Ions ◽  
Contaminated Sites ◽  
Chromium Vi ◽  
Reducing Conditions ◽  
Uptake Rates ◽  
Consumption Rates ◽  
Flux Measurements ◽  
Passive Flux Meter ◽  
Ion Species

Passive flux meters (PFMs) have become invaluable tools for site characterization and evaluation of remediation performance at groundwater contaminated sites. To date, PFMs technology has been demonstrated in the field to measure midrange hydrophobic contaminants (e.g., chlorinated ethenes, fuel hydrocarbons, perchlorate) and inorganic ions (e.g., uranium and nitrate). However, flux measurements of low partitioning contaminants (e.g., 1,4-dioxane, hexahydro-1,3,5-trinitro-s-triazine (RDX)) and reactive ions-species (e.g., sulfate (SO42−), Chromium(VI) (Cr(VI)) are still challenging because of their low retardation during transport and quick transformation under highly reducing conditions, respectively. This study is the first application of PFMs for in-situ mass flux measurements of 1,4-dioxane, RDX, Cr(VI) and SO42− reduction rates. Laboratory experiments were performed to model kinetic uptake rates and extraction efficiency for sorbent selections. Silver impregnated granular activated carbon (GAC) was selected for the capture of 1,4-dioxane and RDX, whereas Purolite 300A (Bala Cynwyd, PA, USA) was selected for Cr(VI) and SO42−. PFM field demonstrations measured 1,4-dioxane fluxes ranging from 13.3 to 55.9 mg/m2/day, an RDX flux of 4.9 mg/m2/day, Cr(VI) fluxes ranging from 2.3 to 2.8 mg/m2/day and SO42− consumption rates ranging from 20 to 100 mg/L/day. This data suggests other low-partitioning contaminates and reactive ion-species could be monitored using the PFM.

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