scholarly journals Photochemistry of glyoxylate embedded in sodium chloride clusters, a laboratory model for tropospheric sea-salt aerosols

2018 ◽  
Vol 20 (12) ◽  
pp. 8143-8151 ◽  
Author(s):  
Nina K. Bersenkowitsch ◽  
Milan Ončák ◽  
Christian van der Linde ◽  
Andreas Herburger ◽  
Martin K. Beyer

Although marine aerosols undergo extensive photochemical processing in the troposphere, a molecular level understanding of the elementary steps involved in these complex reaction sequences is still missing.

Author(s):  
Yeny A. Tobon ◽  
Danielle El Hajj ◽  
Samantha Seng ◽  
Ferdaous Bengrad ◽  
Myriam Moreau ◽  
...  

Sodium chloride (NaCl) is the main constituent of sea-salt aerosols. During atmospheric transport, sea-salt aerosols can interact with gases and other particles including secondary aerosols containing ammonium sulfate ((NH4)2SO4). This...


2010 ◽  
Vol 10 (4) ◽  
pp. 1473-1490 ◽  
Author(s):  
A. Dörnbrack ◽  
I. S. Stachlewska ◽  
C. Ritter ◽  
R. Neuber

Abstract. This paper reports on backscatter and depolarization measurements by an airborne lidar in the Arctic during the ASTAR 2004 campaign. A unique weather situation facilitated the observation of the aerosol concentration under strongly forced atmospheric conditions. The vigorous easterly winds distorted the flow past Svalbard in such a way that mesoscale features were visible in the remote-sensing observations: The formation of a well-mixed aerosol layer inside the Adventdalen and the subsequent thinning of the aerosol plume were observed over the Isfjorden. Additionally, mobilization of sea salt aerosols due to a coastal low-level jet at the northern tip of Svalbard resulted in a sloped boundary layer toward north. Mesoscale numerical modelling was applied to identify the sources of the aerosol particles and to explain the observed patterns.


2006 ◽  
Vol 6 (6) ◽  
pp. 11621-11651 ◽  
Author(s):  
P. Glantz ◽  
D. E. Nilsson ◽  
W. von Hoyningen-Huene

Abstract. Retrieved aerosol optical thickness (AOT) based on data obtained by the Sea viewing Wide Field Sensor (SeaWiFS) is combined with surface wind speed, obtained at the European Centre for Medium-Range Weather Forecasts (ECMWFs), over the North Pacific for September 2001. In this study a cloud screening approach is introduced in an attempt to exclude pixels partly or fully covered by clouds. The relatively broad swath width for which the nadir looking SeaWiFS instrument scanned over the North Pacific means that the AOT can be estimated according to relatively large range of wind speeds for each of the scenes analyzed. The sensitivity in AOT due to sea salt and hygroscopic growth of the marine aerosols has also been investigated. The validation of the results is based on previous parameterization in combination with the environmental quantities wind speed, RH and boundary layer height (BLH), estimated at the ECMWF. In this study a factor of 2 higher mean AOT is obtained for a wind speed up to about 13 m s−1 for September 2001 over remote ocean areas. Furthermore, a factor of 2 higher AOT is more or less supported by the validation of the results. Approximately, 50% of the enhancement seems to be due to hygroscopic growth of the marine aerosols and the remaining part due to increase in the sea salt particle mass concentrations, caused by a wind driven water vapor and sea salt flux, respectively. Reasonable agreement occurs also between satellites retrieved aerosol optical thickness and AOT observed at several AERONET (Aerosol Robotic NETwork) ground-based remote sensing stations. Finally, possible reasons why relatively large standard deviations occur around the mean values of AOT estimated for a single scene are discussed.


2007 ◽  
Vol 41 (2) ◽  
pp. 136-159 ◽  
Author(s):  
Cameron S. McNaughton ◽  
Antony D. Clarke ◽  
Steven G. Howell ◽  
Mitchell Pinkerton ◽  
Bruce Anderson ◽  
...  

2020 ◽  
Vol 15 (3) ◽  
pp. 034047
Author(s):  
Yi-Chun Chen ◽  
Jui-Lin F Li ◽  
Wei-Liang Lee ◽  
David J Diner ◽  
Michael J Garay ◽  
...  

2007 ◽  
Vol 7 (21) ◽  
pp. 5555-5567 ◽  
Author(s):  
L. Smoydzin ◽  
R. von Glasow

Abstract. Organic material from the ocean's surface can be incorporated into sea salt aerosol particles often producing a surface film on the aerosol. Such an organic coating can reduce the mass transfer between the gas phase and the aerosol phase influencing sea salt chemistry in the marine atmosphere. To investigate these effects and their importance for the marine boundary layer (MBL) we used the one-dimensional numerical model MISTRA. We considered the uncertainties regarding the magnitude of uptake reduction, the concentrations of organic compounds in sea salt aerosols and the oxidation rate of the organics to analyse the possible influence of organic surfactants on gas and liquid phase chemistry with a special focus on halogen chemistry. By assuming destruction rates for the organic coating based on laboratory measurements we get a rapid destruction of the organic monolayer within the first meters of the MBL. Larger organic initial concentrations lead to a longer lifetime of the coating but lead also to an unrealistically strong decrease of O3 concentrations as the organic film is destroyed by reaction with O3. The lifetime of the film is increased by assuming smaller reactive uptake coefficients for O3 or by assuming that a part of the organic surfactants react with OH. With regard to tropospheric chemistry we found that gas phase concentrations for chlorine and bromine species decreased due to the decreased mass transfer between gas phase and aerosol phase. Aqueous phase chlorine concentrations also decreased but aqueous phase bromine concentrations increased. Differences for gas phase concentrations are in general smaller than for liquid phase concentrations. The effect on gas phase NO2 or NO is very small (reduction less than 5%) whereas liquid phase NO2 concentrations increased in some cases by nearly 100%. We list suggestions for further laboratory studies which are needed for improved model studies.


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