Temporal Variations of Nutrients, -Chlorophyll a and Particulate Matter in Three Coastal Lagoons of Amvrakikos Gulf (Ionian Sea, Greece)

2001 ◽  
Vol 22 (3) ◽  
pp. 201-213 ◽  
Author(s):  
Konstantinos A. Kormas ◽  
Artemis Nicolaidou ◽  
Sofia Reizopoulou
Keyword(s):  
Particulate Matter ◽  
Chlorophyll A ◽  
Coastal Lagoons ◽  
Temporal Variations ◽  
Ionian Sea

scholarly journals Downward fluxes of sinking particulate matter in the deep Ionian Sea (NESTOR site), Eastern Mediterranean: seasonal and interranual variability

2013 ◽  
Vol 10 (1) ◽  
pp. 591-641 ◽  
Author(s):  
S. Stavrakakis ◽  
A. Gogou ◽  
E. Krasakopoulou ◽  
A. P. Karageorgis ◽  
H. Kontoyiannis ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Organic Carbon ◽  
Mass Flux ◽  
Eastern Mediterranean ◽  
Sediment Traps ◽  
Temporal Variations ◽  
Late Winter ◽  
Ionian Sea ◽  
Nutrient Inputs ◽  
Overlying Water

Abstract. In order to assess seasonal and interranual variability in the export of particulate matter and its main constituents, sediment traps were deployed at five successive depths from February 2006 to March 2010 in the deepest basin of the Mediterranean (SE Ionian Sea, NESTOR site). The average total mass fluxes were 66, 58, 54, 34, and 52 mg m−2 d−1, at 700, 1200, 2000, 3200, and 4300 m, respectively. The interranual variability generally witnesses a gradual increase of fluxes during the experiment. The temporal variations of the mass flux showed similar seasonal signal at all sampling depths with higher values in spring–summer and lower in autumn–winter. Changes in the main constituents of the mass flux (organic carbon, carbonates, opal, and lithogenic matter) largely followed the same temporal variability with mass flux, revealing mechanisms of rapid vertical (top-down) transport from 700 m down to 4300 m-depth. Lateral inputs at the deepest trap are probably of importance, attributed to the influence of the deep Adriatic water, characterized by relatively higher turbidity than overlying water masses. The Ionian Sea displays high seasonal variability with maximum productivity rates observed during the late winter/spring convective mixing period. Our flux study proposes two additional processes, potentially of high importance for fuelling surface waters with nutrients at the NESTOR site: (1) the upwelling of intermediate waters in late spring-early summer, causing nutrient inputs in the surface layer which may lead to episodes of increased productivity, as witnessed by the organic carbon, carbonate, and opal fluxes in the mesopelagic and bathypelagic layers and (2) the influence of episodic dust input events, leading to enhanced fluxes of lithogenic matter.

Biogeochemical and ecological features of sinking particulate matter in the deep Ionian Sea (E. Mediterranean) during a 10-year time series study: impacts of atmospheric and oceanographic variabilities on carbon production and sequestration

2021 ◽  
Author(s):  
Alexandra Gogou ◽  
Constantine Parinos ◽  
Spyros Stavrakakis ◽  
Emmanouil Proestakis ◽  
Maria Kanakidou ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Organic Carbon ◽  
Carbon Cycle ◽  
Atmospheric Deposition ◽  
Water Column ◽  
Particulate Organic Carbon ◽  
Nutrient Dynamics ◽  
Ionian Sea ◽  
Ecological Features ◽  
The Impact

<p>Biotic and abiotic processes that form, alter, transport, and remineralize particulate organic carbon, silicon, calcium carbonate, and other minor and trace chemical species in the water column are central to the ocean’s ecological and biogeochemical functioning and of fundamental importance to the ocean carbon cycle. Sinking particulate matter is the major vehicle for exporting carbon from the sea surface to the deep sea. During its transit towards the sea floor, most particulate organic carbon (POC) is returned to inorganic form and redistributed in the water column. This redistribution determines the surface concentration of dissolved CO<sub>2</sub>, and hence the rate at which the ocean can absorb CO<sub>2</sub> from the atmosphere. The ability to predict quantitatively the depth profile of remineralization is therefore critical to deciphering the response of the global carbon cycle to natural and human-induced changes.</p><p>Aiming to investigate the significant biogeochemical and ecological features and provide new insights on the sources and cycles of sinking particulate matter, a mooring line of five sediment traps was deployed from 2006 to 2015 (with some gap periods) at 5 successive water column depths (700, 1200, 2000, 3200 and 4300 m) in the SE Ionian Sea, northeastern Mediterranean (‘NESTOR’ site). We have examined the long-term records of downward fluxes for Corg, N<sub>tot</sub>, δ<sup>13</sup>Corg and δ<sup>15</sup>N<sub>tot</sub>, along with the associated ballast minerals (opal, lithogenics and CaCO<sub>3</sub>), lipid biomarkers, Chl-a and PP rates, phytoplankton composition, nutrient dynamics and atmospheric deposition.  </p><p>The satellite-derived seasonal and interannual variability of phytoplankton metrics (biomass and phenology) and atmospheric deposition (meteorology and air masses origin) was examined for the period of the sediment trap experiment. Regarding the atmospheric deposition, synergistic opportunities using Earth Observation satellite lidar and radiometer systems are proposed (e.g. Cloud‐Aerosol Lidar with Orthogonal Polarization - CALIOP, Moderate Resolution Imaging Spectroradiometer - MODIS), aiming towards a four‐dimensional exploitation of atmospheric aerosol loading (e.g. Dust Optical Depth) in the study area.</p><p>Our main goals are to: i) develop a comprehensive knowledge of carbon fluxes and associated mineral ballast fluxes from the epipelagic to the mesopelagic and bathypelagic layers, ii) elucidate the mechanisms governing marine productivity and carbon export and sequestration to depth and iii) shed light on the impact of atmospheric forcing and deposition in respect to regional and large scale circulation patterns and climate variability and the prevailing oceanographic processes (internal variability).</p><p>Acknowledgments</p><p>We acknowledge support of this work by the Action ‘National Network on Climate Change and its Impacts – <strong>CLIMPACT</strong>’, funded by the Public Investment Program of Greece (GSRT, Ministry of Development and Investments).</p>

scholarly journals Temporal Variation of Chlorophyll-a Concentrations in Highly Dynamic Waters from Unattended Sensors and Remote Sensing Observations

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2699 ◽  
Author(s):  
Jian Li ◽  
Liqiao Tian ◽  
Qingjun Song ◽  
Zhaohua Sun ◽  
Hongjing Yu ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Water Quality ◽  
Chlorophyll Fluorescence ◽  
Chlorophyll A ◽  
Temporal Variations ◽  
Lake Area ◽  
Short Term ◽  
Chl A ◽  
Spatio Temporal

Monitoring of water quality changes in highly dynamic inland lakes is frequently impeded by insufficient spatial and temporal coverage, for both field surveys and remote sensing methods. To track short-term variations of chlorophyll fluorescence and chlorophyll-a concentrations in Poyang Lake, the largest freshwater lake in China, high-frequency, in-situ, measurements were collected from two fixed stations. The K-mean clustering method was also applied to identify clusters with similar spatio-temporal variations, using remote sensing Chl-a data products from the MERIS satellite, taken from 2003 to 2012. Four lake area classes were obtained with distinct spatio-temporal patterns, two of which were selected for in situ measurement. Distinct daily periodic variations were observed, with peaks at approximately 3:00 PM and troughs at night or early morning. Short-term variations of chlorophyll fluorescence and Chl-a levels were revealed, with a maximum intra-diurnal ratio of 5.1 and inter-diurnal ratio of 7.4, respectively. Using geostatistical analysis, the temporal range of chlorophyll fluorescence and corresponding Chl-a variations was determined to be 9.6 h, which indicates that there is a temporal discrepancy between Chl-a variations and the sampling frequency of current satellite missions. An analysis of the optimal sampling strategies demonstrated that the influence of the sampling time on the mean Chl-a concentrations observed was higher than 25%, and the uncertainty of any single Terra/MODIS or Aqua/MODIS observation was approximately 15%. Therefore, sampling twice a day is essential to resolve Chl-a variations with a bias level of 10% or less. The results highlight short-term variations of critical water quality parameters in freshwater, and they help identify specific design requirements for geostationary earth observation missions, so that they can better address the challenges of monitoring complex coastal and inland environments around the world.

Turbidity Effect on the Fluorescence Determination of Chlorophyll-a in Water

2014 ◽  
Vol 522-524 ◽  
pp. 60-63 ◽  
Author(s):  
Jian Sheng Cui ◽  
Peng Yi Lv
Keyword(s):  
Particulate Matter ◽  
Chlorophyll A ◽  
Fluorimetric Determination ◽  
Water Turbidity ◽  
Fluorescence Determination ◽  
Suspended Particulate ◽  
On Line ◽  
Line Detector ◽  
Strong Scattering

The effect of turbidity on the determination of chlorophyll a by laboratory fluorometry-RF5301-Spectrofluorophotometer and online fluorescence instrumentthe On-line Detector for Seawater' chlorophyll were investigated.Using the RF5301-Spectrofluorophotometer determined the fluorescence intensity value of chlorophyll a with different turbidity,using the On-line Detector for Seawater' chlorophyll determined the chlorophyll a concentration with the different turbidity Microcystis aeruginosa samples and water samples.Analyzed the turbidity effect on fluorimetric determination results of chlorophyll a.Researches showed that when the water turbidity was large, due to the strong scattering effect of suspended particulate matter the chlorophyll a determined by fluorometry were on the high side.

scholarly journals Analysis of air pollution caused by particle matter emission from the copper smelter complex Bor (Serbia)

2010 ◽  
Vol 16 (3) ◽  
pp. 219-228 ◽  
Author(s):  
Visa Tasic ◽  
Novica Milosevic ◽  
Renata Kovacevic ◽  
Nevenka Petrovic
Keyword(s):  
Particulate Matter ◽  
Wind Speed ◽  
Ultrafine Particles ◽  
Fine Particles ◽  
Copper Smelter ◽  
Temporal Variations ◽  
Copper Production ◽  
Copper Smelting ◽  
Particulate Emissions ◽  
Limit Values

The main aim of this paper is to present analyses of temporal variations of particulate matter in Bor (Serbia) influenced by copper production at the Copper Smelter Complex Bor. Particulate emissions are of concern because the presence of fine particles (PM2.5 - particles with diametar less than 2.5 ?m) and ultrafine particles (PM0.1 - particles with diametar less than 0.1 ?m) assume higher risk for human health. Such particles can penetrate deeper into respiratory organs and, at the same time, a probability for such penetration and deposition in the respiratory system is greater. The analysis is based on comparison of SO2 and PM measurements at several locations in the area of Bor town in the close vicinity of Copper Smelter. PM concentrations were highly correlated with sulfur dioxide and inversely correlated with local wind speed during pollution episodes. Presented results indicate that the dominant source of coarse and fine particles in Bor town is the Copper Smelting Complex Bor. The most significant factors for particulate matter distribution are meteorological parameters of wind speed and direction. It was found that exceeding of daily limit values of concentrations of PM10 (50 ?g/m3) usually occurs due to very high concentrations in a period of several hours during the day.

scholarly journals Spatio-Temporal Variation of Particulate Matter(PM2.5) Concentrations and Its Health Impacts in a Mega City, Delhi in India

2018 ◽  
Vol 12 ◽  
pp. 117863021879286 ◽  
Author(s):  
Amit Kumar Gorai ◽  
Paul B Tchounwou ◽  
SS Biswal ◽  
Francis Tuluri
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Environmental Protection Agency ◽  
Quality Index ◽  
Temporal Variations ◽  
Air Quality Index ◽  
Capital City ◽  
Health Impacts ◽  
Quality Level ◽  
Spatio Temporal

Rising concentration of air pollution and its associated health effects is rapidly increasing in India, and Delhi, being the capital city, has drawn our attention in recent years. This study was designed to analyze the spatial and temporal variations of particulate matter (PM2.5) concentrations in a mega city, Delhi. The daily PM2.5 concentrations monitored by the Central Pollution Control Board (CPCB), New Delhi during November 2016 to October 2017 in different locations distributed in the region of the study were used for the analysis. The descriptive statistics indicate that the spatial mean of monthly average PM2.5 concentrations ranged from 45.92 μg m−3 to 278.77 μg m−3. The maximum and minimum spatial variance observed in the months of March and September, respectively. The study also analyzed the PM2.5 air quality index (PM2.5—Air Quality Index (AQI)) for assessing the health impacts in the study area. The AQI value was determined according to the U.S. Environmental Protection Agency (EPA) system. The result suggests that most of the area had the moderate to very unhealthy category of PM2.5-AQI and that leads to severe breathing discomfort for people residing in the area. It was observed that the air quality level was worst during winter months (October to January).

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