The relation between dissolved organic carbon and apparent oxygen utilization in the Western North Pacific

1970 ◽  
Vol 17 (2) ◽  
pp. 221-231 ◽  
Author(s):  
Norio Ogura
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
North Pacific ◽  
Western North Pacific ◽  
Oxygen Utilization ◽  
Apparent Oxygen Utilization

scholarly journals Dissolved organic carbon and apparent oxygen utilization in the Atlantic Ocean

2014 ◽  
Vol 85 ◽  
pp. 80-87 ◽  
Author(s):  
Xi Pan ◽  
Eric P. Achterberg ◽  
Richard Sanders ◽  
Alex J. Poulton ◽  
Kevin I.C. Oliver ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Atlantic Ocean ◽  
Dissolved Organic Carbon ◽  
Oxygen Utilization ◽  
Apparent Oxygen Utilization

scholarly journals Effect of biomass burning over the western North Pacific Rim: wintertime maxima of anhydrosugars in ambient aerosols from Okinawa

2015 ◽  
Vol 15 (4) ◽  
pp. 1959-1973 ◽  
Author(s):  
C. Zhu ◽  
K. Kawamura ◽  
B. Kunwar
Keyword(s):  
Organic Carbon ◽  
Biomass Burning ◽  
Atmospheric Aerosols ◽  
North Pacific ◽  
Western North Pacific ◽  
Agricultural Waste ◽  
Northern China ◽  
Water Soluble ◽  
Pacific Rim ◽  
Okinawa Island

Abstract. Biomass burning (BB) largely modifies the chemical composition of atmospheric aerosols on the globe. We collected aerosol samples (TSP) at Cape Hedo, on subtropical Okinawa Island, from October 2009 to February 2012 to study anhydrosugars as BB tracers. Levoglucosan was detected as the dominant anhydrosugar followed by its isomers, mannosan and galactosan. We found a clear seasonal trend of levoglucosan and mannosan with winter maxima and summer minima. Positive correlation was found between levoglucosan and nss-K+ (r = 0.38, p < 0.001); the latter is another BB tracer. The analyses of air mass trajectories and fire spots demonstrated that the seasonal variations of anhydrosugars are caused by long-range transport of BB emissions from the Asian continent. We found winter maxima of anhydrosugars, which may be associated with open burning and domestic heating and cooking in northern and northeastern China, Mongolia and Russia and with the enhanced westerly winds. The monthly averaged levoglucosan / mannosan ratios were lower (2.1–4.8) in May–June and higher (13.3–13.9) in November–December. The lower values may be associated with softwood burning in northern China, Korea and southwestern Japan whereas the higher values are probably caused by agricultural waste burning of maize straw in the North China Plain. Anhydrosugars comprised 0.22% of water-soluble organic carbon (WSOC) and 0.13% of organic carbon (OC). The highest values to WSOC (0.37%) and OC (0.25%) were found in winter, again indicating an important BB contribution to Okinawa aerosols in winter. This study provides useful information to better understand the effect of East Asian biomass burning on the air quality in the western North Pacific Rim.

scholarly journals Influence of hydrodynamic mixing on the distribution of dissolved organic carbon in the East China Sea and the northwest Pacific

2018 ◽  
Author(s):  
Ling Ding ◽  
Tiantian Ge ◽  
Xuchen Wang
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
East China Sea ◽  
Kuroshio Extension ◽  
Water Masses ◽  
East China ◽  
Northwest Pacific ◽  
Western Boundary ◽  
Oxygen Utilization ◽  
China Sea

Abstract. Oceanic dissolved organic carbon (DOC) is one of the largest carbon reservoirs on Earth, and its distribution and behavior play important roles in carbon cycling and biogeochemical processes in the ocean. Here, we report distribution and concentrations of DOC for water samples collected from the shelf-edge and slope regions in East China Sea (ECS) and the Kuroshio Extension (KE) in the northwestern North Pacific (NP) during two cruises in 2014–2015. Concentrations of DOC were 45–88 µM in the ECS and 35–65 µM in the KE. In addition to biological processes, the distribution of DOC is largely controlled by hydrodynamic mixing of different water masses. The intrusion of Kuroshio Current could dilute DOC concentrations at stations in the outer shelf and slope ranges of the ECS. The inverse correlation of DOC with apparent oxygen utilization (AOU) suggests that DOC oxidation only contributes 18 % of the oxygen consumption in the ECS slope waters. In contrast, concentrations of DOC in the KE were significantly lower in surface waters, and a relatively low and stable DOC level (~ 40 µM) was found in deep waters. The observed spatial variations of DOC in the upper 700 m among the stations in the KE were largely influenced by the mixing of the two water masses carried by the two major western boundary currents: Kuroshio and Oyashio that mix and form the KE. The hydrodynamic processes play important roles not only in the distribution of DOC but nutrients as well, thus could have major impact to primary production and ecosystems in the KE region.

scholarly journals Effect of biomass burning over the western North Pacific Rim: wintertime maxima of anhydrosugars in ambient aerosols from Okinawa

2014 ◽  
Vol 14 (18) ◽  
pp. 25581-25616 ◽  
Author(s):  
C. Zhu ◽  
K. Kawamura
Keyword(s):  
Organic Carbon ◽  
Biomass Burning ◽  
Atmospheric Aerosols ◽  
North Pacific ◽  
Western North Pacific ◽  
North China ◽  
Water Soluble ◽  
Pacific Rim ◽  
Chemical Compositions ◽  
Okinawa Island

Abstract. Biomass burning (BB) largely modifies the chemical compositions of atmospheric aerosols on the globe. We collected aerosol samples (TSP) at Cape Hedo, subtropical Okinawa Island from October 2009 to February 2012 to study anhydrosugars as BB tracers. Levoglucosan was detected as the dominant anhydrosugar followed by its isomers, mannosan and galactosan. We found a clear seasonal trend of levoglucosan and mannosan with winter maxima and summer minima. Positive correlation was found between levoglucosan and nss-K+ (r = 0.38, p < 0.001); the latter is another BB tracer. The analyses of air mass trajectories and fire spots demonstrated that the seasonal variations of anhydrsosugsars are caused by a long-range transport of BB emissions from the Asian continent. We found winter maxima of anhydrosugars, which may be associated with open burning and domestic heating and cooking in north and northeast China, Mongolia and Russia and with the enhanced westerly. The monthly averaged levoglucosan/mannosan ratios were lower (2.1–4.8) in May–June and higher (13.3–13.9) in November–December. The lower values may be associated with softwood burning in north China, Korea and southwest Japan whereas the higher values are probably caused by agriculture waste burning of maize straw in the North China Plain. Anhydrosugars comprised 0.22% of water-soluble organic carbon (WSOC) and 0.13% of organic carbon (OC). The highest values to WSOC (0.37%) and OC (0.25%) were found in winter, again indicating an important BB contribution to Okinawa aerosols in winter. This study provides useful information to better understand the effect of East Asian biomass burning on the air quality in the western North Pacific Rim.

scholarly journals Latitudinal distributions of organic nitrogen and organic carbon in marine aerosols over the western North Pacific

2011 ◽  
Vol 11 (7) ◽  
pp. 3037-3049 ◽  
Author(s):  
Y. Miyazaki ◽  
K. Kawamura ◽  
J. Jung ◽  
H. Furutani ◽  
M. Uematsu
Keyword(s):  
Organic Carbon ◽  
North Pacific ◽  
Western North Pacific ◽  
Organic Nitrogen ◽  
Biological Activities ◽  
Organic Aerosols ◽  
Total Carbon ◽  
Isotopic Ratios ◽  
Study Region ◽  
Marine Biological

Abstract. Marine aerosol samples were collected over the western North Pacific along the latitudinal transect from 44° N to 10° N in late summer 2008 for measurements of organic nitrogen (ON) and organic carbon (OC) as well as isotopic ratios of total nitrogen (TN) and total carbon (TC). Increased concentrations of methanesulfonic acid (MSA) and diethylammonium (DEA+) at 40–44° N and subtropical regions (10–20° N) together with averaged satellite chlorophyll-a data and 5-day back trajectories suggest a significant influence of marine biological activities on aerosols in these regions. ON exhibited increased concentrations up to 260 ngN m−3 in these marine biologically influenced aerosols. Water-insoluble organic nitrogen (WION) was found to be the most abundant nitrogen in the aerosols, accounting for 55 ± 16% of total aerosol nitrogen. In particular, the average WION/ON ratio was as high as 0.93 ± 0.07 at 40–44° N. These results suggest that marine biological sources significantly contributed to ON, a majority of which is composed of water-insoluble fractions in the study region. Analysis of the stable carbon isotopic ratios (δ13C) indicated that, on average, marine-derived carbon accounted for ~88 ± 12% of total carbon in the aerosols. In addition, the δ13C showed higher values (from −22 to −20‰) when ON/OC ratios increased from 0.15 to 0.35 in marine biologically influenced aerosols. These results clearly show that organic nitrogen is enriched in organic aerosols originated from an oceanic region with high biological productivity, indicating a preferential transfer of nitrogen-containing organic compounds from the sea surface to the marine atmosphere. Both WION concentrations and WION/water-insoluble organic carbon (WIOC) ratios tended to increase with increasing local wind speeds, indicating that sea-to-air emissions of ON via sea spray contribute significantly to the marine organic aerosols over the study region.

scholarly journals Long-term (2001–2012) trends of carbonaceous aerosols from a remote island in the western North Pacific: an outflow region of Asian pollutants

2018 ◽  
Vol 18 (2) ◽  
pp. 1291-1306 ◽  
Author(s):  
Suresh K. R. Boreddy ◽  
M. Mozammel Haque ◽  
Kimitaka Kawamura
Keyword(s):  
Organic Carbon ◽  
Long Range ◽  
North Pacific ◽  
Western North Pacific ◽  
Atmospheric Transport ◽  
Carbonaceous Aerosols ◽  
Central Pacific ◽  
Air Masses ◽  
Photochemical Formation

Abstract. The present study reports on long-term trends of carbonaceous aerosols in total suspended particulate (TSP) samples collected at Chichijima in the western North Pacific during 2001–2012. Seasonal variations of elemental carbon (EC), organic carbon (OC), and water-soluble organic carbon (WSOC) concentrations showed maxima in winter to spring and minima in summer. These seasonal differences in the concentrations of carbonaceous aerosols were associated with the outflows of polluted air masses from East Asia, which are clearly distinguishable from pristine air masses from the central Pacific. The higher concentrations of carbonaceous aerosols during winter to spring are associated with long-range atmospheric transport of East Asian continental polluted air masses, whereas lower concentrations may be due to pristine air masses from the central Pacific in summer. The annual trends of OC ∕ EC (+0.46 % yr−1), WSOC (+0.18 % yr−1) and WSOC ∕ OC (+0.08 % yr−1) showed significant (p  <  0.05) increases during the period of 2001–2012, suggesting that photochemical formation of WSOC and its contributions to secondary organic aerosols (SOAs) have increased over the western North Pacific via long-range atmospheric transport. We found a significant increase (+0.33 % yr−1) in nss-K+ ∕ EC ratios, demonstrating that concentrations of biomass-burning-derived carbonaceous aerosols have increased, while those of primary fossil-fuel-derived aerosols have decreased over the western North Pacific. Further, secondary biogenic emissions are also important over the western North Pacific as inferred from a significant increase (+0.14 % yr−1) in the concentrations of methanesulfonate (MSA−, a tracer for biogenic sources). This point was further supported by a moderate correlation (r = 0.40) between WSOC and MSA−. We also found a significant increase in OC ∕ TC (total carbon) and WSOC ∕ TC ratios, further suggesting that photochemical formation of WSOC and its contributions to SOAs have increased over the western North Pacific during 2001–2012 via long-range atmospheric transport from East Asia.

scholarly journals Concentration and UV reactivity of total organic carbon in the upper layer in the oligotrophic subtropical western North Pacific

2010 ◽  
Vol 115 (C11) ◽  
Author(s):  
Sangkyun Lee ◽  
Takeo Hama ◽  
Masao Ishii ◽  
Shu Saito ◽  
Yuko Omori ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
North Pacific ◽  
Western North Pacific

Temporal Trends in Apparent Oxygen Utilization in the Upper Pycnocline of the North Pacific: 1980–2000

2004 ◽  
Vol 60 (1) ◽  
pp. 139-147 ◽  
Author(s):  
Steven Emerson ◽  
Yutaka W. Watanabe ◽  
Tsuneo Ono ◽  
Sabine Mecking
Keyword(s):  
North Pacific ◽  
Temporal Trends ◽  
Oxygen Utilization ◽  
The North ◽  
The North Pacific ◽  
Apparent Oxygen Utilization
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