Methanesulfonate (MSA) and non- sea salt sulfate (nss-sulfate)

Biosulfur_timeseies2021.JPG (Photo: Alfred-Wegener-Institut)

Time series of monthly mean atmospheric methane sulfonic acid (MSA, red line) and non-sea salt sulfate (nss-SO42-, blue line) concentrations. Aerosol formation from biogenic precursor gases such as algae-derived dimethyl sulfide (DMS) plays an important and crucial role in determining the Earths albedo by direct and indirect effects. This is especially true for the Southern Hemisphere, where the emission of man-made aero­sol is still much less dominant than in the Northern Hemi­sphere. Considering the naturally derived aerosol load of the Southern Hemisphere, the atmospheric photooxidation of DMS leading to the final reaction products methane sulfonic acid (MSA) and sulfuric acid is believed to be the most im­portant process. In contrast to sulfate, which comprises a composite signal of marine biogenic, sea salt, ter­restrial, and volcanic sources, MSA is known to be virtually exclusively formed by photooxidation of DMS. The non-sea salt sulfate and MSA records from Neumayer re­veal the strong seasonality of the signal with maximum con­centrations in January. In addition the close correlation of nss-sulfate and MSA indicate that most of the sulfate amount in Neumayer aerosol is of marine biogenic origin and thus DMS dominates the overall sulfur budget at this site. The extraor­dinarily pronounced seasonality of atmospheric MSA and nss-sulfate concentrations is characteristic for coastal Antarc­tica and is linked with the seasonality of the sea ice coverage and insolation. Details regarding the sampling method can be found here...

References:

Minikin, A., M. Legrand, J. Hall, D. Wagenbach, C. Kleefeld, E. Wolff, E.C. Pasteur, and F. Ducroz, Sulfur-containing species (sulfate and MSA) in coastal Antarctic aerosol and surface snow, J. Geophys. Res., 103, 10975-10990, 1998.

Legrand, M. and F. Ducroz, MSA to non sea-salt sulfate ratio in coastal Antarctic aerosol and surface snow, J. Geophys. Res., 103, 10991-11106, 198.

Weller, R., D. Wagenbach, M. Legrand, C. Elsässer, X. Tian-Kunze, G. König-Langlo, Continuous 25-years aerosol records at coastal Antarctica: 1. Inter-annual variability of ionic compounds and links to climate indices, Tellus, doi:10.1111/j.1600-0889.2011.00542.x, 2011.

Sodium (a tracer for sea salt aerosol)

Na_timeseries2021.JPG (Photo: Alfred-Wegener-Institut)

Time series of atmospheric sodium concentrations measured with the high volume sampling system showing a broad seasonal maximum during austral winter. Sea salt aerosol is produced by the action of wind on the ocean surface. Astonishingly, the maximum of sea salt concentration can be measured during winter, when open water is more than 1000 km away from Neumayer due to sea ice formation. It is believed that the sea ice surface can also act as sea salt aerosol source, but the process itself is still not really clarified. Details regarding the sampling method can be found here...

References:

Wagenbach, D., Ducroz, R. Mulvaney, L. Keck, A. Minikin, M. Legrand, J.S. Hall, and E.W. Wolff, Sea salt aerosol in coastal Antarctic Regions. J. Geophys. Res., 103, 10961-10974, 1998.

Weller, R., D. Wagenbach, M. Legrand, C. Elsässer, X. Tian-Kunze, G. König-Langlo, Continuous 25-years aerosol records at coastal Antarctica: 1. Inter-annual variability of ionic compounds and links to climate indices, Tellus, doi:10.1111/j.1600-0889.2011.00542.x, 2011.

Nitrate

Nitrate_timeseries2021.JPG (Photo: Alfred-Wegener-Institut)

Time series of atmospheric nitrate concentrations (i.e. nitric acid plus aerosol bound nitrate) measured with the high volume sampling system. The signal exhibits again a striking seasonality with maximum nitrate concentrations in November of each year. A more detailled data analysis revealed that the main nitrate source for Neumayer is most probably the stratosphere. Details regarding the sampling method can be found here...

Reference:

Wagenbach, D., M. Legrand, H. Fischer, F. Pichlmayer, and E. Wolff, Atmospheric near surface nitrate at coastal Antarctic sites, J. Geophys. Res., 103, 11007-11020, 1998.

Weller, R., D. Wagenbach, M. Legrand, C. Elsässer, X. Tian-Kunze, G. König-Langlo, Continuous 25-years aerosol records at coastal Antarctica: 1. Inter-annual variability of ionic compounds and links to climate indices, Tellus, doi:10.1111/j.1600-0889.2011.00542.x, 2011.

Rare earth element Lanthanum (a tracer for mineral dust)

The figure above shows the monthly mean Lanthanum (La) concentrations derived from the high volume filter samples by ICP-MS (Inductively Coupled Plasma Mass Spectroscopy) element analysis. The rare earth element La is a typical tracer for mineral dust. By far the most important mineral dust source for Neumayer is South America.

Reference:

Weller, R., J. Wöltjen, C. Piel, R. Resenberg, D. Wagenbach, G. König-Langlo, M. Kriews, Seasonal varaibility of crustal and marine trace elements in the aerosol at Neumayer Station, Antarctica. TellusB, 60(5), doi: 10.1111/j.1600-0889.2008.00372.x, 742-752, 2008