scholarly journals Bulk Atmospheric Deposition of Major Ions and Dissolved Organic Nitrogen in the Lower Course of a Tropical River Basin, Southern Bahia, Brazil

2015 ◽  
Author(s):  
Taiana G. Araujo ◽  
Marcelo F. L. Souza ◽  
William Z. de Mello ◽  
Daniela M. L. da Silva
Keyword(s):  
Atmospheric Deposition ◽  
River Basin ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Major Ions ◽  
Tropical River ◽  
Southern Bahia ◽  
Bulk Atmospheric Deposition

scholarly journals Sources and fluxes of organic nitrogen in precipitation over the southern East Sea/Sea of Japan

2015 ◽  
Vol 15 (5) ◽  
pp. 2761-2774 ◽  
Author(s):  
G. Yan ◽  
G. Kim
Keyword(s):  
Atmospheric Deposition ◽  
Sea Of Japan ◽  
Organic Nitrogen ◽  
Major Ions ◽  
Inorganic Nitrogen ◽  
East Sea ◽  
Reactive Nitrogen ◽  
Back Trajectory ◽  
Northwestern Pacific ◽  
Organic Fraction

Abstract. We measured total dissolved reactive nitrogen in precipitation samples collected at Uljin, a Korean coastal site upwind of the southern East Sea/Sea of Japan (EJS), selected as a representative study site of atmospheric deposition over the northwestern Pacific margin. NO3- was found to be the most abundant nitrogen species, followed by NH4+ and dissolved organic nitrogen (DON). Air-mass back-trajectory (AMBT) analysis revealed that a significant fraction of the inorganic nitrogen (NO3- and NH4+) originated from mainland Asia, whereas the DON was primarily derived from Korea. Using varimax-rotated factor analysis in combination with major ions as tracers, agricultural activities in Korea were identified as the primary sources of DON in these samples. In addition, a positive correlation was found at Uljin between the size of organic fraction in total reactive nitrogen and nitrogen to carbon atomic ratio in organic matter. This correlation has also been observed at other locations worldwide, implying the utilization potential of atmospheric organic nitrogen might increase with its proportion in total nitrogen. Combining wet deposition measurements in this study with literature values for dry deposition observed at a remote island in the EJS, the total atmospheric depositional flux of reactive nitrogen was estimated to be 115 mmol N m−2 yr−1 over the southern EJS. Our study sheds new light on the potentially significant contribution to primary productivity of the northwestern Pacific Ocean by atmospheric deposition of nitrogen, especially the organic fraction.

scholarly journals Capturing temporal and spatial variability in the chemistry of shallow permafrost ponds

2017 ◽  
Vol 14 (23) ◽  
pp. 5471-5485 ◽  
Author(s):  
Matthew Q. Morison ◽  
Merrin L. Macrae ◽  
Richard M. Petrone ◽  
LeeAnn Fishback
Keyword(s):  
Spatial Variability ◽  
Temporal Variability ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Multiple Scales ◽  
Major Ions ◽  
Inorganic Nitrogen ◽  
Storm Event ◽  
Rain Event ◽  
Event Scale

Abstract. Across the circumpolar north, the fate of small freshwater ponds and lakes (< 1 km2) has been the subject of scientific interest due to their ubiquity in the landscape, capacity to exchange carbon and energy with the atmosphere, and their potential to inform researchers about past climates through sediment records. A changing climate has implications for the capacity of ponds and lakes to support organisms and store carbon, which in turn has important feedbacks to climate change. Thus, an improved understanding of pond biogeochemistry is needed. To characterize spatial and temporal patterns in water column chemistry, a suite of tundra ponds were examined to answer the following research questions: (1) does temporal variability exceed spatial variability? (2) If temporal variability exists, do all ponds (or groups of ponds) behave in a similar temporal pattern, linked to seasonal hydrologic drivers or precipitation events? Six shallow ponds located in the Hudson Bay Lowlands region were monitored between May and October 2015 (inclusive, spanning the entire open-water period). The ponds span a range of biophysical conditions including pond area, perimeter, depth, and shoreline development. Water samples were collected regularly, both bimonthly over the ice-free season and intensively during and following a large summer storm event. Samples were analysed for nitrogen speciation (NO3−, NH4+, dissolved organic nitrogen) and major ions (Cl−, SO42−, K+, Ca2+, Mg2+, Na+). Across all ponds, temporal variability (across the season and within a single rain event) exceeded spatial variability (variation among ponds) in concentrations of several major species (Cl−, SO42−, K+, Ca2+, Na+). Evapoconcentration and dilution of pond water with precipitation and runoff inputs were the dominant processes influencing a set of chemical species which are hydrologically driven (Cl−, Na+, K+, Mg2+, dissolved organic nitrogen), whereas the dissolved inorganic nitrogen species were likely mediated by processes within ponds. This work demonstrates the importance of understanding hydrologically driven chemodynamics in permafrost ponds on multiple scales (seasonal and event scale).

A first record of bulk atmospheric deposition patterns of major ions in southern South America

2019 ◽  
Vol 144 (3) ◽  
pp. 261-271
Author(s):  
D. A. Carnelos ◽  
S. I. Portela ◽  
E. G. Jobbágy ◽  
R. B. Jackson ◽  
C. M. Di Bella ◽  
...  
Keyword(s):  
South America ◽  
Atmospheric Deposition ◽  
Major Ions ◽  
First Record ◽  
Southern South America ◽  
Deposition Patterns ◽  
Bulk Atmospheric Deposition

scholarly journals Extreme dissolved organic nitrogen fluxes in the human impacted Pamba River, Kerala, India

2013 ◽  
Vol 10 (10) ◽  
pp. 16137-16171 ◽  
Author(s):  
S. Elizabeth David ◽  
T. C. Jennerjahn
Keyword(s):  
Land Use ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Aquatic Systems ◽  
Global Maximum ◽  
Livestock Farming ◽  
Tropical River ◽  
Human Interventions ◽  
Anthropogenic Nitrogen ◽  
River Catchments

Abstract. Cultural eutrophication of coastal aquatic systems is a major undesired phenomenon of today, which is mainly ascribed to the application of inorganic fertilizers in agriculture. Consequently, dissolved inorganic nitrogen (DIN) is considered the major problem and widely studied. However, human interventions also strongly influence the riverine dissolved organic nitrogen (DON) concentrations and fluxes. Studies of nutrient inputs from tropical river catchments are biased towards DIN, even though they account for only a portion of the total dissolved nitrogen (TDN) pool, whereas the rest is comprised of DON and has been largely ignored. The tropical Pamba River was studied because of its manifold human activities in the catchment and was sampled during the south west monsoon (SWM), north east monsoon (NEM) and the pre monsoon (PM) months during 2010 to 2013. The largest pilgrim center on earth, the Sabarimala temple, located in the upstream forest is a unique feature of the catchment. Fertilizer application, livestock farming and inadequate sewage treatment are the prevailing land use practices. The goals of this study were to (i) define cause-effect relationships by assessing the effect of various human interventions such as the pilgrims, agriculture and sewage disposal in combination with the seasonal variations in hydrology on the DON concentrations and fluxes and to (ii) quantify the inputs from respective land use segments. The global maximum DON concentration (29 302 μM) was measured for the Pamba River. Pilgrim activities, high population density, agricultural and livestock farming as well as the lack of infrastructure for sanitation facilities were the cause for extremely high DON concentrations and fluxes in the plantation and settlement with mixed tree crop (SMT) segments. A DON yield of 745 kg ha−1 yr−1 was calculated for the Pamba catchment. The total DON inputs from all quantifiable sources amounted to 514 kg ha−1 yr−1 comprising of 69% of the total Pamba DON yield. In the Pamba River, sewage is the major source of DON and the unique Sabarimala pilgrim event accounts for most of it. Nevertheless, sewage input from the rest of the densely-populated catchment is high, which is a common feature of developing countries that lack adequate sanitation and water technology, i.e. in South and Southeast Asia and tropical Africa. Our study shows that DON makes up a significant portion of anthropogenic nitrogen in rivers, in particular in those regions, which are, however, scarce in respective data. It underscores the need for more quantitative studies from densely-populated tropical river catchments in order to improve global nitrogen budgets and the assessment of the consequences of anthropogenic nitrogen inputs into coastal aquatic systems.

scholarly journals Sources and fluxes of organic nitrogen in precipitation over the southern East/Japan Sea: potential impacts on marine productivity

2014 ◽  
Vol 14 (23) ◽  
pp. 31987-32025
Author(s):  
G. Yan ◽  
G. Kim
Keyword(s):  
Atmospheric Deposition ◽  
Organic Nitrogen ◽  
Major Ions ◽  
Inorganic Nitrogen ◽  
Japan Sea ◽  
Atomic Ratio ◽  
Reactive Nitrogen ◽  
Back Trajectory ◽  
Northwestern Pacific ◽  
Organic Fraction

Abstract. We measured total dissolved reactive nitrogen in precipitation samples collected at Uljin, a Korean coastal site upwind of the southern East/Japan Sea (EJS), selected as a representative study site of atmospheric deposition over the northwestern Pacific margin. NO3− was found to be the most abundant nitrogen species, followed by NH4+ and dissolved organic nitrogen (DON). Air mass back trajectory analysis revealed that a significant fraction of the inorganic nitrogen (NO3− and NH4+) originated from mainland Asia, whereas the DON was primarily derived from Korea. Using varimax-rotated factor analysis in combination with major ions as tracers, agricultural activities in Korea were identified as the primary sources of DON in these samples. In addition, a positive correlation was found at Uljin between the size of organic fraction in total reactive nitrogen and nitrogen to carbon atomic ratio in organic matter. This correlation has also been observed at other locations worldwide, implying the utilization potential of atmospheric organic nitrogen might increase with its proportion in total nitrogen. Combining wet deposition measurements in this study with literature values for dry deposition observed at a remote island in the EJS, the total atmospheric depositional flux of reactive nitrogen was estimated to be 115 mmol N m−2 yr−1 over the southern EJS. Our study sheds new light on the potentially significant contribution to primary productivity of the northwestern Pacific Ocean by atmospheric deposition of nitrogen, especially the organic fraction.

Organochlorine Contaminants in Headwater Peatlands, and Selected Estuary Sites of the Moose River

1986 ◽  
Vol 21 (2) ◽  
pp. 251-256 ◽  
Author(s):  
Robert C. McCrea ◽  
Greg M. Wickware
Keyword(s):  
Atmospheric Deposition ◽  
Organochlorine Pesticides ◽  
River Basin ◽  
Vascular Plants ◽  
Typha Latifolia ◽  
Coastal Marshes ◽  
Surficial Sediments ◽  
Organochlorine Contaminants ◽  
Hexachlorocyclohexane Isomers ◽  
Moose River

Abstract Peatland waters of the Moose River basin, as well as surficial sediments and vascular plants of the estuary were sampled in 1982. Elevated levels of PCBs were found at all five peatland sites; concentrations ranged from 28 to 65 ng/L. Of the seventeen organochlorine pesticides investigated, the hexachlorocyclohexane isomers (a-and y-BHC) were the most prominent with total BHC concentrations ranging from 1.5 to 13.7 ng/L. The presence of these contaminants in ombrotrophic bogs indicated that there was atmospheric deposition of organochlorine contaminants in the basin. Analyses of surficial sediments, collected from tidal flats and coastal marshes, showed that PCBs and organochlorine pesticides were not present. Samples of Triglochin maritima L. seed heads and Typha latifolia L. roots were also free of PCBs.

Lake Superior Atmospheric Wet Deposition 1980-1983

1987 ◽  
Vol 22 (3) ◽  
pp. 365-376
Author(s):  
C. H. Chan ◽  
L. H. Perkins
Keyword(s):  
Atmospheric Deposition ◽  
Wet Deposition ◽  
Major Ions ◽  
Lake Superior ◽  
Relative Accuracy ◽  
Lake Chemistry ◽  
Total Load ◽  
Wet Precipitation ◽  
Percentage Basis ◽  
Nitrogen Loadings

Abstract Wet deposition estimates were computed from monthly wet precipitation samples collected in the Lake Superior Basin. Sulphate and nitrogen loadings from wet precipitation corresponded to 142 and 40 thousand tonnes per year. On a percentage basis, wet deposition of sulphate and nitrogen accounted for 21% and 54%, respectively, of the total load. Atmospheric sources for other major ions ranged from 1 to 10%. Atmospheric deposition at the eastern end of Lake Superior was higher than the western end of the Basin. The relative accuracy of these estimates were examined in relation to the changes in lake chemistry in Lake Superior from 1973 to 1983.

Sources and transport of phosphorus in the Vltava river basin (Czech Republic)

1996 ◽  
Vol 33 (4-5) ◽  
pp. 137-144 ◽  
Author(s):  
Josef Hejzlar ◽  
Vojtech Vyhnálek ◽  
Jirí Kopácek ◽  
Jirí Duras
Keyword(s):  
Czech Republic ◽  
Population Density ◽  
Atmospheric Deposition ◽  
River Basin ◽  
Point Sources ◽  
Diffuse Sources ◽  
River Elbe ◽  
Municipal Wastewaters ◽  
Total P

Export and sources of P in the Vltava basin (subbasin of upper Elbe: total area – 28,093 km2; population density – 115 km−2; forests – 35%, farmland – 51%) were evaluated during 1972–1993. Annual export rates of total P from the basin to the river Elbe ranged between 38 and 68 kg km−2 a−1. Reservoirs with hydraulic retention times longer than 15 days were efficient traps for phosphorus retaining 20 to 30% of total P loading into the watercourses. Point sources (municipal wastewaters) were most important throughout the period and their share varied from approximately 60% in wet years to more than 90% in dry years. Export from diffuse sources (dominated by output from farmland) was highly dependent on discharge and fluctuaded between 5 and 40 kg km−2 a−1 in dry and wet years, respectively. Only about 2% of the P input into the basin from the fertilisation of farmland and from the atmospheric deposition was exported to the watercourses.

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