Download or read book Seasonal Variability in Absorption and Fluorescence Properties of Chromophoric Dissolved Organic Matter in the Barataria Basin Louisiana USA written by Shatrughan Singh and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photobiogeochemistry of Organic Matter written by Khan M.G. Mostofa and published by Springer Science & Business Media. This book was released on 2012-12-15 with total page 919 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photoinduced processes, caused by natural sunlight, are key functions for sustaining all living organisms through production and transformation of organic matter (OM) in the biosphere. Production of hydrogen peroxide (H2O2) from OM is a primary step of photoinduced processes, because H2O2 acts as strong reductant and oxidant. It is potentially important in many aquatic reactions, also in association with photosynthesis. Allochthonous and autochthonous dissolved organic matter (DOM) can be involved into several photoinduced or biological processes. DOM subsequently undergoes several physical, chemical, photoinduced and biological processes, which can be affected by global warming. This book is uniquely structured to overview some vital issues, such as: DOM; H2O2 and ROOH; HO•; Degradation of DOM; CDOM, FDOM; Photosynthesis; Chlorophyll; Metal complexation, and Global warming, as well as their mutual interrelationships, based on updated scientific results.
Download or read book Issues in Environmental Research and Application 2012 Edition written by and published by ScholarlyEditions. This book was released on 2013-01-10 with total page 1286 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues in Environmental Research and Application: 2012 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Environmental Research. The editors have built Issues in Environmental Research and Application: 2012 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Environmental Research in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Environmental Research and Application: 2012 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.
Download or read book Optical absorption and fluorescence properties of chromophoric dissolved organic matter in natural waters written by S.A. GREEN and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Extreme Weather Events on Coastal Carbon and Nutrient Cycling written by Christopher Osburn and published by Frontiers Media SA. This book was released on 2022-11-10 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessing Chromophoric Dissolved Organic Matter CDOM Distribution Stocks and Fluxes in Apalachicola Bay Using Combined Field VIIRS Ocean Color and Model Observations written by and published by . This book was released on 2017 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the role of estuarine-carbon fluxes is essential to improve estimates of the global carbon budget. Dissolved organic matter (DOM) plays an important role in aquatic carbon cycling. Here, the chromophoric fraction of DOM (CDOM) can be readily detected via in situ and remotely-sensed optical measurements. DOM properties, including CDOM absorption coefficient at 412 nm (ag412) and dissolved organic carbon (DOC) concentrations were examined in Apalachicola Bay, a national estuarine research reserve located in the northeast Gulf of Mexico, using in situ and satellite observations during the spring and fall of 2015. Synoptic and accurate representation of estuarine-scale processes using satellite ocean color imagery necessitates the removal of atmospheric contribu- tion (~90%) to signals received by satellite sensors to successfully link to in situ observations. Three atmospheric correction schemes (e.g., Standard NIR correction, Iterative NIR correction, and SWIR correction) were tested first to find a suitable correction scheme for the VIIRS imagery in low to moderately turbid Apalachicola Bay. The iterative NIR correction performed well, and validation showed high correlation (R2 = 0.95, N = 25) against in situ light measurements. A VIIRS-based CDOM algorithm was developed (R2 = 0.87, N = 9) and validated (R2 = 0.76, N = 20, RMSE = 0.29 m-1) against in situ observations. Subsequently, ag412 was used as a proxy of DOC in March (DOC = 1.08 + 0.94 × ag412,R2 =0.88, N = 13)and in November (DOC= 1.61 + 1.33 × ag412, R2 = 0.83, N = 24) to derive DOC maps that provided synoptic views of DOC distribution, sources, and their transport to the coastal waters during the wet and dry seasons. The estimated DOC stocks were ~3.71 × 106 kg C in March and ~4.07 × 106 kg C in November over an area of ~560 km2. Volume flux (out of the bay) almost doubled for March 24 (735 m3 s-1) relative to November 4 (378 m3 s-1). However, estimates of DOC fluxes exported out of the bay from model-derived currents and satellite-derived DOC were only marginally greater in March (0.163 × 106 kg C d-1) than in November (0.124 × 106 kg C d-1) and reflected greater DOC stocks in the fall. Finally, the combination of satellite-, field-, and model-based observations revealed the strong linkage between the Apalachicola River plume, a major source of DOM, and the overall hydrodynamic forcing that controlled distributions of CDOM abundance, DOC concentration, stocks, and fluxes in the bay.
Download or read book Inherent optical properties of the ocean written by F.E. HOGE and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seasonal Dynamics of Chromophoric Dissolved Organic Matter in Lake Kinneret written by Jonathan Liberzon and published by . This book was released on 2011 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seasonal Variability of Dissolved Organic Matter in the Columbia River written by Urban Wünsch and published by . This book was released on 2014 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Direct and Indirect Photoreactions of Chromophoric Dissolved Organic Matter written by Jared Verrill Goldstone and published by . This book was released on 2002 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photochemical transformations of chromophoric dissolved organic matter (CDOM) are one of the principal processes controlling its fate in coastal waters. The photochemical decomposition of CDOM leads to the formation of a variety of biologically available carbon substrates. Photomineralization of CDOM to dissolved inorganic carbon may constitute a significant flux in the global carbon cycle. Photoreactions ultimately lead to the destruction of the chromophores and hence to the loss of absorption and fluorescence (bleaching), thus acting as a sink for CDOM. Photodecomposition may proceed both via direct photochemical reactions, following absorption of photons by CDOM, or via indirect processes, involving DOM reactions with photochemically generated intermediates such as reactive oxygen species (ROS). The reactions of CDOM with two important ROS, superoxide (02- ) and hydroxyl radical (OH), have different consequences. Superoxide reactions with CDOM did not appear to degrade the CDOM. Instead, CDOM catalysed the dismutation of 02- to 02 and HOOH. This reactivity has the effect of limiting the steady-state concentration of 02- in most coastal waters. In contrast, reactions of CDOM with radiolytically produced OH formed CO2 and several low molecular weight carboxylic acids, as well as bleached both the absorption and fluorescence at slow rates. These reactions did not increase the bioavailability of this material to a microbial consortium. Both direct and indirect photochemical processes are expected to be accelerated by the presence of iron.
Download or read book Seasonal Variations in Colloidal Chromophoric Dissolved Organic Matter CDOM in the Damariscotta River Estuary Maine written by Sheri Ann Floge and published by . This book was released on 2005 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Temporal and Spatial Patterns in Optical Properties of Colored Dissolved Organic Matter on Florida s Gulf Coast written by Robyn Nicole Conmy and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Characterization of Colored Dissolved Organic Matter (CDOM) in surface and ground waters in South Florida was conducted using fluorescence and absorption spectroscopy. Waters of the West Florida Shelf are heavily influenced by many river systems on Florida's Gulf Coast that, to the first order control CDOM distributions on the shelf. Seasonal surveys revealed that changes in the underwater light field as a result of major hurricanes and resuspension events are linked closely with a number of factors prior to a storm's passing such as the presence of persistant blooms, rainfall and discharge. Additionally, storm track and wind direction were found to play a significant role in CDOM signatures. A study of ten riversheds located between the Mississippi / Atchafalya River system and the Shark River in the Everglades revealed a wide range in CDOM seasonality. A regional dependence of CDOM was also found, where highest aromaticity and concentration of organic material was found for the southernmost watersheds. Basin characteristics, vegetation differences, land use and climatic patterns are implicated in the cause for regional differences. In addition to surface flow, organic material in groundwater was measured in deep and shallow aquifers surrounding the Tampa Bay Estuary. As a result of strong hydrologic links between shallow aquifers and the overlying surface waters, CDOM in both reservoirs were found to be quite similar. Deep aquifers (> 150 ft) however are less concentrated and have CDOM signatures more similar to marine waters. This suggests similar biogeochemical pathways of the material, including the influence of the aquatic microbial community. Furthermore, multi-spectral CDOM fluorescence measurements were shown to be a potential indicator of groundwater presence in Tampa Bay during times of low surficial discharge to the bay, and when some rivers are almost entirely spring-fed. Investigating CDOM distribution and signatures is vital to carbon budget and cycling questions. The amount and quality of organic material has significant implications for ecosystems, thereby affecting organisms that use CDOM as a food source, light availability for photosynthesis, UV shading provided to biota, satellite estimates of chlorophyll a, metal binding, materials transport and overall water quality.
Download or read book Biogeochemical and Photochemical Dynamics of Oceanic Chromophoric Dissolved Organic Matter written by Chantal Melanie Swan and published by . This book was released on 2009 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Absorption by open-ocean chromophoric dissolved organic matter (CDOM), the optically-active fraction of the marine DOM pool (
Download or read book Absorbance and Fluorescence Characteristics of Dissolved Organic Matter in North America Pacific and Arctic Oceans cby Paul G Dainard written by Paul G. Dainard and published by . This book was released on 2015 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Relation of Chromophoric Dissolved Organic Matter CDOM Spectral Absorption Coefficients to Salinity Values in the Mississippi Sound and Statistical Comparison of CDOM Filtrate Methodology written by Christopher L. Martin and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photochemically Induced Changes in the Optical Properties of Chromophoric Dissolved Organic Matter CDOM in Rainwater electronic Resource written by Mary Beth Adams and published by . This book was released on 2010 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Fluorescence of Dissolved Organic Matter in the Marine Environment written by Robert Francis Chen and published by . This book was released on 1992 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:
