scholarly journals Size distributions of organic nitrogen and carbon in remote marine aerosols: Evidence of marine biological origin based on their isotopic ratios

2010 ◽  
Vol 37 (6) ◽  
pp. n/a-n/a ◽  
Author(s):  
Yuzo Miyazaki ◽  
Kimitaka Kawamura ◽  
Maki Sawano
2011 ◽  
Vol 11 (7) ◽  
pp. 3037-3049 ◽  
Author(s):  
Y. Miyazaki ◽  
K. Kawamura ◽  
J. Jung ◽  
H. Furutani ◽  
M. Uematsu

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.


2010 ◽  
Vol 10 (11) ◽  
pp. 28721-28753 ◽  
Author(s):  
Y. Miyazaki ◽  
K. Kawamura ◽  
J. Jung ◽  
H. Furutani ◽  
M. Uematsu

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 increased 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 showed positive correlations with local wind speeds, suggesting that sea-to-air emissions of ON via sea spray significantly contributes to marine organic aerosols over the study region.


2014 ◽  
Vol 11 (7) ◽  
pp. 11361-11389 ◽  
Author(s):  
K. Violaki ◽  
J. Sciare ◽  
J. Williams ◽  
A. R. Baker ◽  
M. Martino ◽  
...  

Abstract. To obtain a comprehensive picture on the spatial distribution of water soluble organic nitrogen (WSON) in marine aerosols, samples were collected during research cruises in the tropical and south Atlantic Ocean and during a one year period (2005) over the southern Indian Ocean (Amsterdam island). Samples have been analyzed for both organic and inorganic forms of nitrogen and the factors controlling their levels have been examined. Fine mode WSON was found to play a significant role in the remote marine atmosphere with enhanced biogenic activity, with concentrations of WSON (11.3 ± 3.3 nmol N m–3) accounting for about 84% of the total dissolved nitrogen (TDN). Such levels are similar to those observed in the polluted marine atmosphere of the eastern Mediterranean (11.6 ± 14.0 nmol N m–3). Anthropogenic activities were found to be an important source of atmospheric WSON as evidenced by the ten times higher levels in the Northern Hemisphere (NH) than in the remote Southern Hemisphere (SH). Furthermore, the higher contribution of WSON to TDN (40%) in the SH, compared to the NH (20%), underlines the important role of organic nitrogen in remote marine areas. Finally, Sahara dust was also identified as a significant source of WSON in the coarse mode aerosols of the NH.


2009 ◽  
Vol 9 (3) ◽  
pp. 13859-13888
Author(s):  
G. Wang ◽  
K. Kawamura ◽  
M. Xie ◽  
S. Hu ◽  
S. Gao ◽  
...  

Abstract. Size-segregated (9 stages) n-alkanes, polycyclic aromatic hydrocarbons (PAHs) and hopanes in the urban (Baoji city in inland China), mountain (Mt. Tai in east coastal China) and marine (Okinawa Island, Japan) atmospheres over East Asia were studied using a GC/MS technique. Concentrations of n-alkanes (1698±568 ng m−3 in winter and 487±145 ng m−3 in spring), PAHs (536±80 and 161±39 ng m−3), and hopanes (65±24 and 20±2.4 ng m−3) in the urban air are 1–2 orders of magnitude higher than those in the mountain aerosols and 2–3 orders of magnitude higher than those in the marine samples. Mass ratios of n-alkanes, PAHs and hopanes clearly demonstrate coal-burning emissions as the major source of the determined organic aerosols. Size distributions of fossil fuel derived n-alkane, PAHs and hopanes were found as a unimodal in most cases, peaking at 0.7–1.1 μm size. In contrast, plant wax derived n-alkanes present a bimodal distribution with two peaks at the sizes of 0.7–1.1 μm and >4.7 μm in the summer mountain and spring marine samples. Among the three types of samples, geometric mean diameter (GMD) of the determined organics in fine mode (<2.1 μm) was the smallest (av. 0.63 μm in spring) in the urban samples and the largest (1.01 μm) in the marine samples, whereas the GMD in coarse mode (≥2.1 μm) was smallest (3.48 μm) in the marine aerosols and largest (4.04 μm) in the urban aerosols. The fine mode of GMDs in the urban and mountain samples were larger in winter than in spring and summer. Moreover, GMDs of 3- and 4-ring PAHs were larger than 5- and 6-ring PAHs in the three types of atmospheres. Such differences in GMDs may be interpreted by coagulation and repartitioning of organic compound during a long range transport from the inland continent to the marine site, suggesting that the size changes arising from these physical processes must be included in climate models in relevant to organic aerosols.


2009 ◽  
Vol 9 (22) ◽  
pp. 8869-8882 ◽  
Author(s):  
G. Wang ◽  
K. Kawamura ◽  
M. Xie ◽  
S. Hu ◽  
S. Gao ◽  
...  

Abstract. Size-segregated (9 stages) n-alkanes, polycyclic aromatic hydrocarbons (PAHs) and hopanes in the urban (Baoji city in inland China), mountain (Mt. Tai in east coastal China) and marine (Okinawa Island, Japan) atmospheres over East Asia were studied using a GC/MS technique. Ambient concentrations of n-alkanes (1698±568 ng m−3 in winter and 487±145 ng m−3 in spring), PAHs (536±80 and 161±39 ng m−3), and hopanes (65±24 and 20±2.4 ng m−3) in the urban air are 1–2 orders of magnitude higher than those in the mountain aerosols and 2–3 orders of magnitude higher than those in the marine samples. Mass ratios of n-alkanes, PAHs and hopanes clearly demonstrate coal-burning emissions as their major source. Size distributions of fossil fuel derived n-alkane, PAHs and hopanes were found to be unimodal in most cases, peaking at 0.7–1.1 μm size. In contrast, plant wax derived n-alkanes presented a bimodal distribution with two peaks at the sizes of 0.7–1.1 μm and >4.7 μm in the summer mountain and spring marine samples. Among the three types of samples, geometric mean diameter (GMD) of the organics in fine mode (<2.1 μm) was found to be smallest (av. 0.63 μm in spring) for the urban samples and largest (1.01 μm) for the marine samples, whereas the GMD in coarse mode (≥2.1 μm) was found to be smallest (3.48 μm) for the marine aerosols and largest (4.04 μm) for the urban aerosols. The fine mode GMDs of the urban and mountain samples were larger in winter than in spring and summer. Moreover, GMDs of 3- and 4-ring PAHs were larger than those of 5- and 6-ring PAHs in the three types of atmospheres. Such differences in GMDs can be interpreted by the repartitioning of organic compounds and the coagulation and hygroscopic growth of particles during a long-range transport from the inland continent to the marine area, as well as the difference in their sources among the three regions.


2021 ◽  
Author(s):  
Goutam Choudhury ◽  
Matthias Tesche

Abstract. We present a novel methodology to estimate cloud condensation nuclei (CCN) concentrations from spaceborne CALIPSO lidar measurements. The algorithm utilizes (i) the CALIPSO-derived backscatter and extinction coefficient, depolarization ratio, and aerosol subtype information, (ii) the normalized volume size distributions and refractive indices from the CALIPSO aerosol model, and (iii) the MOPSMAP optical modelling package. For each CALIPSO height bin, we first select the aerosol-type specific size distribution and then adjust it to reproduce the extinction coefficient derived from the CALIPSO retrieval. The scaled size distribution is integrated to estimate the aerosol number concentration which is then used in the CCN parameterizations to calculate CCN concentrations at different supersaturations. To account for the hygroscopicity of continental and marine aerosols, we use the kappa parameterization and correct the size distributions before the scaling step. We have studied the sensitivity of the thus derived CCN concentration to the effect of variations of the initial size distributions. It is found that the uncertainty associated with the algorithm can range between a factor of 2 and 3. We have also compared our results with the POLIPHON and found comparable results for extinction coefficients larger than 0.05 km−1. An initial application to a case with coincident airborne in-situ measurements for independent validation shows promising results and illustrates the potential of CALIPSO for constructing a global height-resolved CCN climatology.


Sign in / Sign up

Export Citation Format

Share Document